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Value-Based Pricing for Emerging Gene Therapies: The Economic Case for a Higher Cost-Effectiveness Threshold.Publié le 21 02 2019

While one-time gene replacement therapies may offer transformative innovation for the management of ultrarare, health-catastrophic diseases, they also pose challenges to the current U.S. health care system. Historically, the United States and other countries have demonstrated a willingness to support higher prices for health gains in rare diseases. However, payers may be ill-prepared to address reimbursement based on single administrations associated with gene therapies. As yet, there is no consensus on how to appropriately reward gene therapy innovation. The purpose of this article is to characterize challenges for traditional approaches to assessing the value of one-time gene replacement therapies and to provide a health economic rationale for a higher value-based cost-effectiveness threshold (CET). There is a general recognition that ultrarare, health-catastrophic conditions should be judged against a higher CET. The Institute for Clinical and Economic Review in the United States has discussed a range of up to $500K per quality-adjusted life-year (QALY) gained for ultrarare diseases, and the National Institute for Health and Care Excellence in the United Kingdom has described a variable threshold up to £300,000 per QALY depending on the magnitude of the health gains. In practice, health technology assessment decision makers often make comparisons to "benchmarks" to justify both standard and extraordinary CETs. We briefly review and present a list of relevant benchmarks. We also sketch out how a broader concept of value could provide the basis for higher CETs for some ultrarare diseases. This approach is outlined by the recent International Society for Pharmacoeconomics and Outcomes Research Special Task Force on Value Assessment Frameworks. In addition to the QALY gains, other elements of value related to uncertainty may also be important. They include insurance value, severity of disease, real option value, value of hope, and equity. A gene therapy currently in development for the treatment of spinal muscular atrophy (SMA) provides an exemplar for discussing the issues that accompany one-time gene replacement therapies. It is imperative that we find a consensus on how to appropriately reward value created by these gene therapies to incentivize appropriate risk taking and investments by their developers-a higher CET would, by economic logic, support a higher value-based price. If consensus on appropriate rewards cannot be found for safe and effective gene therapies for diseases such as SMA with clear criticality and unmet need, it will be even more difficult to do so for diseases where the value provided is less apparent. DISCLOSURES: Funding for the writing of this article was provided by AveXis Pharmaceuticals, which reviewed the manuscript and contributed feedback during manuscript development. The authors had final editorial control. Jackson and Paul are employees of MME, a biopharmaceutical consulting firm that received funding from AveXis for work on this project. Jackson and Paul report consulting fees from AveXis and numerous other biopharmaceutical companies outside of this project. Garrison reports consulting fees from AveXis for work on this project and advisory/consultancy fees from BioMarin, Roche, Novartis, and Pfizer unrelated to this project. Kenston is a former employee of AveXis and reports consulting fees from AveXis for this project and for other projects outside of this work.

Population genomic screening of all young adults in a health-care system: a cost-effectiveness analysis.Publié le 19 02 2019

PURPOSE: To consider the impact and cost-effectiveness of offering preventive population genomic screening to all young adults in a single-payer health-care system.
METHODS: We modeled screening of 2,688,192 individuals, all adults aged 18-25 years in Australia, for pathogenic variants in BRCA1/BRCA2/MLH1/MSH2 genes, and carrier screening for cystic fibrosis (CF), spinal muscular atrophy (SMA), and fragile X syndrome (FXS), at 71% testing uptake using per-test costs ranging from AUD$200 to $1200 (~USD$140 to $850). Investment costs included genetic counseling, surveillance, and interventions (reimbursed only) for at-risk individuals/couples. Cost-effectiveness was defined below AUD$50,000/DALY (disability-adjusted life year) prevented, using an incremental cost-effectiveness ratio (ICER), compared with current targeted testing. Outcomes were cancer incidence/mortality, disease cases, and treatment costs reduced.
RESULTS: Population screening would reduce variant-attributable cancers by 28.8%, cancer deaths by 31.2%, and CF/SMA/FXS cases by 24.8%, compared with targeted testing. Assuming AUD$400 per test, investment required would be between 4 and 5 times higher than current expenditure. However, screening would lead to substantial savings in medical costs and DALYs prevented, at a highly cost-effective ICER of AUD$4038/DALY. At AUD$200 per test, screening would approach cost-saving for the health system (ICER?=?AUD$22/DALY).
CONCLUSION: Preventive genomic screening in early adulthood would be highly cost-effective in a single-payer health-care system, but ethical issues must be considered.

Characteristics and advantages of adeno-associated virus vector-mediated gene therapy for neurodegenerative diseases.Publié le 15 02 2019

Common neurodegenerative diseases of the central nervous system are characterized by progressive damage to the function of neurons, even leading to the permanent loss of function. Gene therapy via gene replacement or gene correction provides the potential for transformative therapies to delay or possibly stop further progression of the neurodegenerative disease in affected patients. Adeno-associated virus has been the vector of choice in recent clinical trials of therapies for neurodegenerative diseases due to its safety and efficiency in mediating gene transfer to the central nervous system. This review aims to discuss and summarize the progress and clinical applications of adeno-associated virus in neurodegenerative disease in central nervous system. Results from some clinical trials and successful cases of central neurodegenerative diseases deserve further study and exploration.

Making sense of antisense oligonucleotides: A narrative review.Publié le 13 02 2019

Synthetic nucleic acid sequences that bind to ribonucleic acid (RNA) through Watson-Crick base pairing are known as antisense oligonucleotides (ASOs) because they are complementary to "sense strand" nucleic acids. ASOs bind to selected sequences of RNA and regulate the expression of genes by several mechanisms depending on their chemical properties and targets. They can be used to restore deficient protein expression, reduce the expression of a toxic protein, modify functional effects of proteins, or reduce toxicity of mutant proteins. Two ASOs were approved by the U.S. Food and Drug Administration in 2016: eteplirsen for Duchenne muscular dystrophy and nusinersen for spinal muscular atrophy. Clinical trials in amyotrophic lateral sclerosis and familial amyloid polyneuropathy are ongoing. We review the chemistry, pharmacology, and mechanisms of action of ASOs, preclinical data, and clinical trials in neuromuscular diseases and discuss some ethical, regulatory, and policy considerations in the clinical development and use of ASOs. Muscle Nerve 57: 356-370, 2018.

Intraperitoneal delivery of a novel drug-like compound improves disease severity in severe and intermediate mouse models of Spinal Muscular Atrophy.Publié le 09 02 2019

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder that causes progressive muscle weakness and is the leading genetic cause of infant mortality worldwide. SMA is caused by the loss of survival motor neuron 1 (SMN1). In humans, a nearly identical copy gene is present, called SMN2. Although SMN2 maintains the same coding sequence, this gene cannot compensate for the loss of SMN1 because of a single silent nucleotide difference in SMN2 exon 7. SMN2 primarily produces an alternatively spliced isoform lacking exon 7, which is critical for protein function. SMN2 is an important disease modifier that makes for an excellent target for therapeutic intervention because all SMA patients retain SMN2. Therefore, compounds and small molecules that can increase SMN2 exon 7 inclusion, transcription and SMN protein stability have great potential for SMA therapeutics. Previously, we performed a high throughput screen and established a class of compounds that increase SMN protein in various cellular contexts. In this study, a novel compound was identified that increased SMN protein levels in vivo and ameliorated the disease phenotype in severe and intermediate mouse models of SMA.

Technological advances and changing indications for lumbar puncture in neurological disorders.Publié le 09 02 2019

Technological advances have changed the indications for and the way in which lumbar puncture is done. Suspected CNS infection remains the most common indication for lumbar puncture, but new molecular techniques have broadened CSF analysis indications, such as the determination of neuronal autoantibodies in autoimmune encephalitis. New screening techniques have increased sensitvity for pathogen detection and can be used to identify pathogens that were previously unknown to cause CNS infections. Evidence suggests that potential treatments for neurodegenerative diseases, such as Alzheimer's disease, will rely on early detection of the disease with the use of CSF biomarkers. In addition to being used as a diagnostic tool, lumbar puncture can also be used to administer intrathecal treatments as shown by studies of antisense oligonucleotides in patients with spinal muscular atrophy. Lumbar puncture is generally a safe procedure but complications can occur, ranging from minor (eg, back pain) to potentially devastating (eg, cerebral herniation). Evidence that an atraumatic needle tip design reduces complications of lumbar puncture is compelling, and reinforces the need to change clinical practice.

[Respiratory care in spinal muscular atrophy in the new therapeutic era].Publié le 07 02 2019

Spinal muscular atrophy (SMA) is the first inherited cause of mortality in infants, with four subtypes: SMA0 prenatal onset, SMA1 babies less than 3 months non sitters, SMA2 sitters and SMA3 walkers. Pneumonia and respiratory insufficiency are the most severe complications. Informed parental de cisions are relevant. Respiratory management includes cough assistance, prevention of lung under development due to chest deformity, prompt treatment of respiratory infections, hypoventilation, swallow problems, gastro esophageal reflux and malnutrition. In view of the FDA and EMA approval of the nonsense oligonucleotides nusinersen, the first specific treatment for SMA and the future with gene therapy and others under development, we need to optimize preventive respiratory manage ment with the new standard of care.

Transspinal delivery of drugs by transdermal patch back-of-neck for Alzheimer's disease: a new route of administration.Publié le 06 02 2019

NSAIDs may prevent Alzheimer's disease (AD) but have failed as a treatment, possibly because only 1-2% of an oral NSAID dose reaches the brain. This minuscule dose is enough to have a preventative effect on Alzheimer's disease but not to treat it. We propose a new route of administration for drugs to treat AD: transspinal delivery by transdermal patch over the back-of-neck/cervical spine. The drug would diffuse from the patch through the intervertebral spaces, penetrate the dura, enter the CSF, and reach the brain. For example, diclofenac from a transdermal patch over the back of neck should readily penetrate the dura mater to reach the CSF and brain; since the analgesic ziconotide, and antisense molecules for treating spinal muscular atrophy in children and Huntington's disease, are delivered intrathecally and readily enter the brain. In addition to NSAIDs, an anticancer drug, paclitaxel, has considerable potential as an AD treatment. Paclitaxel is administered IV. But the blood-brain penetration of paclitaxel is poor and paclitaxel has systemic side effects such as anemia, leukopenia, peripheral neuropathy, etc. A high dose of paclitaxel might be administered to the brain by transdermal patch over the back of the neck/cervical spine while avoiding the systemic side effects. A transdermal patch over the cervical spine could revolutionize the drug therapy of AD, and probably other neurodegenerative/neuropsychiatric diseases as well.

Cost Effectiveness of Nusinersen in the Treatment of Patients with Infantile-Onset and Later-Onset Spinal Muscular Atrophy in Sweden.Publié le 05 02 2019

BACKGROUND: Spinal muscular atrophy is a rare neuromuscular disorder with a spectrum of severity related to age at onset and the number of SMN2 gene copies. Infantile-onset (? 6 months of age) is the most severe spinal muscular atrophy and is the leading monogenetic cause of infant mortality; patients with later-onset (> 6 months of age) spinal muscular atrophy can survive into adulthood. Nusinersen is a new treatment for spinal muscular atrophy.
OBJECTIVE: The objective of this study was to evaluate the cost effectiveness of nusinersen for the treatment of patients with infantile-onset spinal muscular atrophy and later-onset spinal muscular atrophy in Sweden.
METHODS: One Markov cohort health-state transition model was developed for each population. The infantile-onset and later-onset models were based on the efficacy results from the ENDEAR phase III trial and the CHERISH phase III trial, respectively. The cost effectiveness of nusinersen in both models was compared with standard of care in Sweden.
RESULTS: For a time horizon of 40 years in the infantile-onset model and 80 years in the later-onset model, treatment with nusinersen resulted in 3.86 and 9.54 patient incremental quality-adjusted life-years and 0.02 and 2.39 caregiver incremental quality-adjusted life-years and an incremental cost of 21.9 and 38.0 million SEK (Swedish krona), respectively. These results translated into incremental cost-effectiveness ratios (including caregiver quality-adjusted life-years) of 5.64 million SEK (€551,300) and 3.19 million SEK (€311,800) per quality-adjusted life-year gained in the infantile-onset model and later-onset model, respectively.
CONCLUSIONS: Treatment with nusinersen resulted in overall survival and quality-adjusted life-year benefits but with incremental costs above 21 million SEK (€2 million) [mainly associated with maintenance treatment with nusinersen over a patient's lifespan]. Nusinersen was not cost effective when using a willingness-to-pay threshold of 2 million SEK (€195,600), which has been considered in a recent discussion by the Dental and Pharmaceutical Benefits Agency as a reasonable threshold for rare disease. Nonetheless, nusinersen gained reimbursement in Sweden in 2017 for paediatric patients (below 18 years old) with spinal muscular atrophy type I-IIIa.

Psychological well-being in adults with spinal muscular atrophy: the contribution of participation and psychological needs.Publié le 01 02 2019

PURPOSE: Patients with spinal muscular atrophy (SMA) suffer from slowly progressive weakness of axial, respiratory and proximal muscles, leading to restrictions in activity and participation. This study aims to investigate patients' level of psychological well-being, using the International Classification of Functioning model and self-determination theory as theoretical frameworks.
MATERIALS AND METHODS: In this cross-sectional study, adults with SMA were invited to complete a questionnaire. Instruments to assess psychological well-being included the Satisfaction with Life Scale, the Rosenberg Self-Esteem Scale and the Positive and Negative Affect Scale. Hierarchical lineal regression analyses were performed to investigate the contribution of participation (International Classification of Functioning model) and satisfaction of the need for autonomy, competence and relatedness (self-determination theory) to well-being.
RESULTS: Ninety-two respondents (67%) returned the questionnaire. Levels of psychological well-being were comparable to that of healthy reference samples. Well-being was unrelated to sociodemographic variables or illness characteristics. By contrast, well-being was closely related to respondents' satisfaction with participation, and their sense of autonomy, competence and relatedness.
CONCLUSIONS: This study illustrates the relevance of psychological needs for understanding well-being of individuals with SMA. Supporting patients in meeting their psychological needs should become an objective of person-centred care for this population. Implications for rehabilitation Spinal muscular atrophy is a rare inherited disease, characterized by slowly progressive muscle weakness. Psychological well-being, including satisfaction with life, self-esteem and emotional functioning of adults with spinal muscular atrophy appears very comparable with that of healthy reference samples. In line with the International Classification of Functioning framework, well-being in adults with spinal muscular atrophy may be improved by increasing their (satisfaction with) participation. Moreover, clinical assessment and management should focus on optimizing patients' satisfaction with their basic psychological needs (autonomy, competence, relatedness), as this is strongly related to indices of psychological well-being.

Long-term treatment with leuprorelin for spinal and bulbar muscular atrophy.Publié le 30 01 2019

PMID: 28794153 [PubMed - indexed for MEDLINE]

Rebuttal From Dr Panitch.Publié le 29 01 2019

PMID: 27989615 [PubMed - indexed for MEDLINE]

Rebuttal From Dr Bach.Publié le 29 01 2019

PMID: 27989613 [PubMed - indexed for MEDLINE]

Revised Upper Limb Module for Spinal Muscular Atrophy: 12 month changes.Publié le 25 01 2019

INTRODUCTION: The aim of the study was to assess 12 month changes in upper limb function in patients affected by spinal muscular atrophy type 2 and 3.
METHODS: Longitudinal 12 month data was collected in 114 patients, 60 type 2 and 54 type 3, using the Revised Upper Limb Module.
RESULTS: The 12 month changes ranged between -7 and 9 (mean: -0.41; SD: 2.93). The mean changes were not significantly different between the three spinal muscular atrophy groups (-0.45 in type 2, -0.23 in non-ambulant type 3 and -0.34 in ambulant type 3, p=0.96) and the relationship between 12 month change and age classes was not significantly different among the three types of SMA patients.
DISCUSSION: Our results confirm that the Module explores a wide range of functional abilities and can be used in ambulant and non-ambulant patients of different ages in conjunction with other functional scales. This article is protected by copyright. All rights reserved.

SMArtCARE - A platform to collect real-life outcome data of patients with spinal muscular atrophy.Publié le 23 01 2019

BACKGROUND: Survival and quality of life for patients affected by spinal muscular atrophy (SMA) are thought to have improved over the last decade due to changes in care. In addition, targeted treatments for SMA have been developed based on a better understanding of the molecular pathology. In 2016 and 2017, nusinersen was the first drug to be approved for treatment of all types of SMA in the United States and in Europe based on well-controlled clinical trials in a small subgroup of pediatric SMA patients. Systems are required to monitor treated and untreated SMA patients in a real-life environment to optimize treatment and care, and to provide outcome data to regulators, payers, and the SMA community.
METHODS: Within SMArtCARE, we conduct a prospective, multicenter non-randomized registration and outcome study. SMArtCARE collects longitudinal data on all available SMA patients independent of their actual treatment regime as disease-specific SMA registry. For this purpose, we provide an online platform for SMA patients seen by health-care providers in Germany, Austria and Switzerland. All data are collected during routine patient visits. Items for data collection are aligned with the international consensus for SMA registries. Data analysis is carried out independent of commercial partners.
CONCLUSION: A prospective monitoring of all SMA patients will lead to a better understanding of the natural history of SMA and the influence of drug treatment. This is crucial to improve the care of SMA patients. Further, we will establish a network for neuromuscular centers to share experience with SMA patients and to promote research projects on SMA.
TRIAL REGISTRATION: German Clinical Trials Register ("Deutsches Register klinischer Studien") DRKS00012699. Registered 09 August 2018. https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00012699 .

Novel challenges in spinal muscular atrophy - How to screen and whom to treat?Publié le 19 01 2019

In recent years, disease-modifying and life-prolonging therapies for spinal muscular atrophy (SMA) have been developed. However, patients are currently diagnosed with significant delay and therapies are often administered in advanced stages of motor neuron degeneration, showing limited effects. Methods to identify children in presymptomatic stages are currently evaluated in newborn screening programs. Yet, not all children develop symptoms shortly after birth raising the question whom to treat and when to initiate therapy. Finally, monitoring disease progression becomes essential to individualize management. Here, we review the literature on screening approaches, strategies to predict disease severity, and biomarkers to monitor therapy.

Parents' Experiences of Information and Decision Making in the Care of Their Child With Severe Spinal Muscular Atrophy: A Population Survey.Publié le 16 01 2019

OBJECTIVE:: This study aims to assess the experiences and wishes of parents of children with severe spinal muscular atrophy regarding information and decision-making throughout the course of the illness.
STUDY DESIGN:: A full population survey, conducted in 2015, among parents of children with severe spinal muscular atrophy who were born in Denmark between January 1, 2003, and December 31, 2013. We used a study-specific questionnaire with items about experiences and wishes concerning the provision of information about diagnosis, treatment, and end-of-life care.
RESULTS:: Among the 47 parents that were identified, 34 parents of 21 children participated. Eleven of them were nonbereaved and 23 were bereaved parents. All parents stated that health care staff did not take any decisions without informing them. A proportion of parents indicated that they were not informed about what spinal muscular atrophy entails (32%), possible treatment options (18%), or the fact that their child would have a short life (26%) or that death was imminent (57%). Most of the bereaved parents who had wishes concerning how and where their child would pass away had their wishes fulfilled.
CONCLUSIONS:: The study showed that health care staff did not take treatment decisions without parents being informed. However, there is room for improvement concerning information about what spinal muscular atrophy entails, treatment options, and prognosis. Possibilities of palliative care and advance care planning should be investigated for these parents, their child, and health care staff.

[S2 Alar-Iliac Screws in Fixation and Correction of Combined Neuromuscular Spinal and Pelvic Deformities].Publié le 15 01 2019

PURPOSE OF THE STUDY Neuromuscular deformities of the spine represent surgically uneasy to solve problems as well as serious handicaps causing sitting instability, pressure ulcers as well as pain. The aim of our study is to conduct a retrospective clinical analysis of the results of surgical correction of these deformities. This paper presents the use of a recent technique of sacral-alar-iliac (S2AI) screws and its comparison with other techniques of pelvic stabilisation. MATERIAL AND METHODS The group of 41 patients treated surgically with S2AI screws technique and transpedicular or hybrid instrumentation of the spine consisted of patients with the primary diagnosis of muscular dysthrophy, spinal muscular atrophy, cerebral palsy and some other neuromuscular diseases. The results of pelvic obliquity correction and scoliotic correction in combined neuromuscular deformities of the spine and pelvis were analysed. The technique of S2AI screws implantation and the possibility of their free-hand technique implementation were presented. RESULTS In the followed-up group of patients an average correction of pelvic obliquity by 81% (from 29.1 degrees before the operation to 5.6 degrees after the operation) was reported. On average, 74% correction of scoliotic spine deformity was achieved (from 83.3 degrees before the operation to 22.5 degrees after the operation). In both the cases neither a significant loss of correction at the minimum one-year follow-up nor any serious complications associated with grappling of pelvic fixation were observed. DISCUSSION The S2AI screws offer at least the same stability and ability of correction as iliac screws and at the same time they provide significantly better results compared with the older methods of pelvic fixation such as the Galvestone technique. With a good knowledge of the surgical technique and anatomical aspects this technique can be applied in the form of a free-hand technique. Navigation as well as robotic techniques can help with the accurate positioning of the S2AI screw. Transfixation of sacroiliacal syndesmosis in patients with a neuromuscular handicap does not lead to deterioration of their mobility. CONCLUSIONS Simultaneous stabilisation of spine and pelvis makes it possible to achieve a good quality correction of the deformity and good clinical results over a long period of time. It allows for stability of the sitting position of the patients and improves the quality of their lives. Nowadays, the S2AI screws are considered to be biomechanically the best quality pelvic fixation, eliminating subcutaneous prominence of the instrumentation and reducing the risk of skin decubitus. Key words:neuromuscular deformity, sacral-alar-iliac screw, pelvic obliquity, stabilization, scoliosis.

Treating Disease at the RNA Level with Oligonucleotides.Publié le 12 01 2019

PMID: 30601736 [PubMed - indexed for MEDLINE]

Self-oligomerization regulates stability of survival motor neuron protein isoforms by sequestering an SCFSlmb degron.Publié le 10 01 2019

Spinal muscular atrophy (SMA) is caused by homozygous mutations in human SMN1 Expression of a duplicate gene (SMN2) primarily results in skipping of exon 7 and production of an unstable protein isoform, SMN?7. Although SMN2 exon skipping is the principal contributor to SMA severity, mechanisms governing stability of survival motor neuron (SMN) isoforms are poorly understood. We used a Drosophila model system and label-free proteomics to identify the SCFSlmb ubiquitin E3 ligase complex as a novel SMN binding partner. SCFSlmb interacts with a phosphor degron embedded within the human and fruitfly SMN YG-box oligomerization domains. Substitution of a conserved serine (S270A) interferes with SCFSlmb binding and stabilizes SMN?7. SMA-causing missense mutations that block multimerization of full-length SMN are also stabilized in the degron mutant background. Overexpression of SMN?7S270A, but not wild-type (WT) SMN?7, provides a protective effect in SMA model mice and human motor neuron cell culture systems. Our findings support a model wherein the degron is exposed when SMN is monomeric and sequestered when SMN forms higher-order multimers.

[Spinal muscular atrophy treated with nusinersen].Publié le 09 01 2019

Spinal muscular atrophy (SMA) is an autosomal recessive disorder, which causes degeneration of peripheral nerves and muscles. It usually presents in childhood due to an insufficient level of survival motor neuron protein. This is a case series of three children, who had SMA type 1 or 2 and were treated with nusinersen from the age of five months, 16 months, and five years, respectively. At one-year follow-up, all children had improved motor function, but the child, who was treated from the age of five months, had more pronounced motor improvements than the other children. In conclusion, nusinersen seems to improve motor development in SMA, and an early treatment start is crucial.

[Treatment evaluation in patients with 5q-associated spinal muscular atrophy : Real-world experience].Publié le 09 01 2019

Spinal muscular atrophy (SMA) is a progressive autosomal recessive neurodegenerative disease with an incidence of 1:10,000 live births. With a deeper understanding of the molecular basis of SMA in the past two decades, a major focus of therapeutic development has been on increasing the proportion of functionally capable SMN protein by increasing the inclusion of exon 7 in SMN2 transcripts, enhancing SMN2 gene expression, stabilizing the SMN protein or replacing the SMN1 gene. Since June 2017, the antisense oligonucleotide nusinersen/Spinraza® (Biogen GmbH, Ismaning, Germany) has been approved for 5qSMA treatment. Nusinersen modifies premessenger RNA splicing of exon 7, leading to stable SMN protein expression and for the first time an effective disease-modifying treatment is available. In several controlled trials nusinersen showed a favorable benefit-risk profile along with clinically relevant improvements in motor function. The efficacy was most pronounced in presymptomatic patients, which underlines the necessity for a newborn screening program and is the key to start efficient treatment prior to motor neuron death. The repeated intrathecal administration of nusinersen is associated with practical challenges, in particular for patients with severe scoliosis or after spinal straightening surgery. As the vast majority of SMA patients were outside previous study populations regarding age and disease duration, experts complained about a lack of data on efficacy and safety beyond childhood. To fill these gaps a systematic data collection has been initiated by the SMArtCARE initiative, aiming at collecting comprehensive data in the clinical routine, regardless of the patients' individual treatment regimen.

[Non-invasive positive pressure ventilation during the management of severe spinal muscular atrophy type I].Publié le 03 01 2019

Patients with spinal muscular atrophy type ? (SMA ?) with the onset before the age of 3 months are considered as severe form of SMA ? (severe SMA ?) and have poor prognosis. Here, we report the efficacy of non-invasive positive pressure ventilation (NPPV) in a patient with severe SMA ?. She was born with generalized hypotonia and feeding difficulties, and had SMN1 gene mutations (the deletion of exons 7 and 8). At 1 month of age, she was intubated because of respiratory failure due to a respiratory tract infection, and extubation proved difficult. Her parents decided that NPPV and a mechanical in-exsufflator (MI-E) should be used for respiratory management rather than a tracheotomy. The NPPV improved her peripheral coldness, cold sweats, chest wall movement, and heart rate and enabled her to sleep well. At 1 year and 2 months, chest computed tomography revealed mild pneumonia and did not show any atelectasis. The NPPV facilitated discharge, and the patient had a good quality of life (QOL) from the point of view of voice production, the ability to move easily, the simplicity of bathing, and the low level of discomfort she experienced. However, she suffered repeated episodes of aspiration pneumonia and airway obstruction (by sputum) after 11 months of age. Thereafter, she required continuous NPPV and high-span inspiratory positive airway pressure (21 cmH2O). At 1 year and 4 months, she died of respiratory failure at home. As her bulbar weakness worsened, respiratory management with NPPV became difficult. However, the long-term use of NPPV together with high-span positive inspiratory pressure plus positive end-expiratory pressure, and a high-pressure MI-E at an early age might improve respiratory management outcomes and patient prognosis. In our case, NPPV was effective at improving ventilation and preventing atelectasis and helped to provide the patient with a good QOL.

Perspectives on Spinraza (Nusinersen) Treatment Study: Views of Individuals and Parents of Children Diagnosed with Spinal Muscular Atrophy.Publié le 31 12 2018

BACKGROUND: Spinal muscular atrophy (SMA) is a genetic disorder characterized by muscle loss. In December 2016 the FDA approved the first and only treatment drug for SMA: Spinraza (nusinersen). Despite excitement and optimism, there are no published data on the perceptions of individuals with SMA and their families about the benefits, risks, and challenges associated with treatment.
OBJECTIVE: This qualitative interview study sought to characterize the perspectives of patients/families with SMA who did not want, or were unsure about, receiving this new innovative treatment for a previously untreatable and often fatal condition.
METHODS: Individuals and families were recruited via advertisements on Facebook groups related to SMA and through the Stanford Neuromuscular Contact Registry. Participants completed a demographic questionnaire and participated in a semi-structured interview via voice conferencing. Interview questions focused on: 1) experiences with SMA, 2) opinions about Spinraza treatment, and 3) factors considered in decisions regarding treatment.
RESULTS: Thirteen people were interviewed: ten adults with SMA (ages 27- 48, nine with Type II) and three parents of minor children with SMA (one each of Types I, II and III). Qualitative content analysis identified a range of opinions about Spinraza treatment: five were uninterested (2 adults, 3 parents), four adults were still deciding whether to pursue treatment, three adults were interested or in the process of pursuing treatment, and one adult was currently receiving the drug after overcoming significant reluctance. Participants described several key factors influencing their treatment decisions, including: concerns about risk factors and side effects, high cost, insurance coverage, time involvement, and lack of data about efficacy. Participants reported learning about most of these factors through parent/patient testimonials on SMA-specific social media groups.
CONCLUSIONS: Participants reported basing decisions about pursuing Spinraza on a variety of practical and value-based considerations. They described carefully weighing the perceived potential benefits and risks of treatment through the lens of their current quality of life and prognosis. These findings suggest that providers should be aware that some patients and parents, especially those with Types II-IV, may approach treatment decisions differently than parents of children with SMA I. Informed treatment decisions can be supported through: 1) the collection and dissemination of better data on Spinraza treatment in these populations; 2) clear communication about risks, side effects and eligibility; 3) improved access to payment and treatment facilities; and 4) facilitation of discussions between providers and patients/families about identity and disability in the context of goals of care and other life and support challenges.

Longitudinal evaluation of SMN levels as biomarker for spinal muscular atrophy: results of a phase IIb double-blind study of salbutamol.Publié le 30 12 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder, due to the loss of function of the survival motor neuron (SMN1) gene. The first treatment for the condition, recently approved, is based on the reduction of exon 7 skipping in mRNAs produced by a highly homologous gene (SMN2). The primary objective of the present study was to evaluate the applicability of the dosage of SMN gene produts in blood, as biomarker for SMA, and the safety of oral salbutamol, a beta2-adrenergic agonist modulating SMN2 levels.
METHODS: We have performed a 1-year multicentre, double-blind, placebo-controlled study with salbutamol in 45 adult patients with SMA. Patients assumed 4?mg of salbutamol or placebo/three times a day. Molecular tests were SMN2 copy number, SMN transcript and protein levels. We have also explored the clinical effect, by the outcome measures available at the time of study design.
RESULTS: Thirty-six patients completed the study. Salbutamol was safe and well tolerated. We observed a significant and progressive increase in SMN2 full-length levels in peripheral blood of the salbutamol-treated patients (p<0.00001). The exploratory analysis of motor function showed an improvement in most patients.
CONCLUSIONS: Our data demonstrate safety and molecular efficacy of salbutamol. We provide the first longitudinal evaluation of SMN levels (both transcripts and protein) in placebo and in response to a compound modulating the gene expression: SMN transcript dosage in peripheral blood is reliable and may be used as pharmacodynamic marker in clinical trials with systemic compounds modifying SMN2levels.
TRIAL REGISTRATION NUMBER: EudraCT no. 2007-001088-32.

Gene Therapy for Spinal Muscular Atrophy: An Emerging Treatment Option for a Devastating Disease.Publié le 25 12 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease that, in most cases, involves homozygous deletion of the SMN1 gene. This causes a deficiency in survival motor neuron (SMN) protein, which plays a critical role in motor neuron development. SMA has a range of phenotype expression resulting in variable age of symptom onset, maximum motor strength achieved, and survival. Without intervention, infants with a more severe form of the disease (type 1 SMA) die before 2 years of age. Although it is rare, SMA is the most common fatal inherited disease of infancy, and until recently, treatment was primarily supportive. In 2016, a new agent, nusinersen, was approved by the FDA. Other treatments are in development, including a gene therapy, AVXS-101. These treatments are not only improving the lives of patients with SMA and their families, they are changing the disease phenotype. They have the greatest benefit when given early in the disease course.
OBJECTIVES: To discuss current knowledge about SMA, provide clinical evidence for available and emerging treatment options, and present approaches for adding new therapies to hospital/health system formularies to ensure timely access to newly approved therapies for SMA.
SUMMARY: Advances in clinical care have significantly extended the lives of individuals with SMA, and research into the genetic mechanisms leading to disease have revealed strategies for intervention that target the underlying cause of SMA. Nusinersen is now on the market, and other treatment options, such as AVXS-101, may soon be approved. This article provides an overview of SMA and the genetic mechanisms leading to SMN deficiency, then describes how new and emerging treatments work to overcome this deficiency and prevent associated nerve damage and disability. In addition, we discuss steps for incorporating AVXS-101 into hospital/health system formularies, along with barriers and concerns that may delay access, based in part on lessons learned with nusinersen.

Perceived Fatigue in Spinal Muscular Atrophy: A Pilot Study.Publié le 20 12 2018

BACKGROUND: Fatigue is a common complaint in spinal muscular atrophy (SMA). Fatigability is well described in ambulatory SMA but the relationship to perceived fatigue has not been evaluated. Understanding this relationship has proven challenging for most disorders.
OBJECTIVE: To assess the relationship of perceived fatigue to fatigability, function, and quality of life in SMA.
METHODS: Thirty-two participants with SMA (21.9% type 2, 78.1% type 3) were recruited. Perceived fatigue and fatigability, function, and quality of life were assessed using standardized questionnaires and assessments. Associations were analyzed using Pearson correlation coefficients (p?=?0.05). Also, the effects of age, type, and ambulatory status were determined on perceived fatigue.
RESULTS: All SMA participants reported fatigue. Perceived fatigue was not associated with function, quality of life, or fatigability in ambulatory SMA patients. Neither age, type, nor ambulatory status influenced perceived fatigue.
CONCLUSIONS: Perceived fatigue can be quantified in SMA. Interestingly, perceived fatigue did not correlate with fatigability or function, suggesting that cognitive, homeostatic, or psychologic factors may be more relevant as co-morbid factors. Clinical trials targeting perceived fatigue in SMA should focus on these patient-reported assessments. A multilevel approach is required to separate the various mechanisms involved in perceived fatigue.

Health outcomes in spinal muscular atrophy type 1 following AVXS-101 gene replacement therapy.Publié le 15 12 2018

BACKGROUND: Spinal Muscular Atrophy type 1 (SMA1) is a rare genetic neuromuscular disease where 75% of SMA1 patients die/require permanent-ventilation by 13.6 months. This study assessed the health outcomes of SMA1 infants treated with AVXS-101 gene replacement therapy.
METHODS: Twelve genetically confirmed SMA1 infants with homozygous deletions of the SMN1 gene and two SMN2 gene copies received a one-time intravenous proposed therapeutic dose of AVXS-101 in an open label study conducted between December 2014 and 2017. Patients were followed for 2-years post-treatment for outcomes including (1) pulmonary interventions; (2) nutritional interventions; (3) swallow function; (4) hospitalization rates; and (5) motor function.
RESULTS: All 12 patients completed the study. Seven infants did not require noninvasive ventilation (NIV) by study completion. Eleven patients had stable or improved swallow function, demonstrated by the ability to feed orally; 11 patients were able to speak. The mean proportion of time hospitalized was 4.4%; the mean unadjusted annualized hospitalization rate was 2.1 (range?=?0, 7.6), with a mean length of stay/hospitalization of 6.7 (range?=?3, 12.1) days. Eleven patients achieved full head control and sitting unassisted and two patients were walking independently.
CONCLUSIONS: AVXS-101 treatment in SMA1 was associated with reduced pulmonary and nutritional support requirements, improved motor function, and decreased hospitalization rate over the follow-up period. This contrasts with the natural history of progressive respiratory failure and reduced survival. The reduced healthcare utilization could potentially alleviate patient and caregiver burden, suggesting an overall improved quality of life following gene replacement therapy.
TRIAL REGISTRATION: ClinicalTrials.gov number, NCT02122952.

Overexpression of SMN2 Gene in Motoneuron-Like Cells Differentiated from Adipose-Derived Mesenchymal Stem Cells by Ponasterone A.Publié le 12 12 2018

Cell therapy and stem cell transplantation strategies have provided potential therapeutic approaches for the treatment of neurological disorders. Adipose-derived mesenchymal stem cells (ADMSCs) are abundant adult stem cells with low immunogenicity, which can be used for allogeneic cell replacement therapies. Differentiation of ADMSCs into acetylcholine-secreting motoneurons (MNs) is a promising treatment for MN diseases, such as spinal muscular atrophy (SMA), which is associated with the level of SMN1 gene expression. The SMN2 gene plays an important role in MN disorders, as it can somewhat compensate for the lack of SMN1 expression in SMA patients. Although the differentiation potential of ADMSCs into MNs has been previously established, overexpression of SMN2 gene in a shorter period with a longer survival has yet to be elucidated. Ponasterone A (PNA), an ecdysteroid hormone activating the PI3K/Akt pathway, was studied as a new steroid to promote SMN2 overexpression in MNs differentiated from ADMSCs. After induction with retinoic acid, sonic hedgehog, forskolin, and PNA, MN phenotypes were differentiated from ADMSCs, and immunochemical staining, specific for ?-tubulin, neuron-specific enolase, and choline acetyltransferase, was performed. Also, the results of real-time PCR assay indicated nestin, Pax6, Nkx2.2, Hb9, Olig2, and SMN2 expression in the differentiated cells. After 2 weeks of treatment, cultures supplemented with PNA showed a longer survival and a 1.2-fold increase in the expression of SMN2 (an overall 5.6-fold increase; *P???0.05), as confirmed by the Western blot analysis. The PNA treatment increased the levels of ChAT, Isl1, Hb9, and Nkx2 expression in MN-like cells. Our findings highlight the role of PNA in the upregulation of SMN2 genes from MSC-derived MN-like cells, which may serve as a potential candidate in cellular therapy for SMA patients.

Motor Unit Number Index (MUNIX) of hand muscles is a disease biomarker for adult spinal muscular atrophy.Publié le 12 12 2018

OBJECTIVE: There is still insufficient knowledge about natural history in adult spinal muscular atrophy, thus valid markers for treatment and disease monitoring are urgently needed.
METHODS: We studied hand muscle innervation pattern of 38 adult genetically confirmed 5q spinal muscular atrophy (SMA) patients by the motor unit number index (MUNIX) method. Data were compared to healthy controls and amyotrophic lateral sclerosis (ALS) patients and systematically correlated to typical disease-relevant scores and other clinical as well as demographic characteristics.
RESULTS: Denervation of hand muscles in adult SMA was not evenly distributed. By calculation of the MUNIX ratios, we identified a specific hand muscle wasting pattern for SMA which is different to the split hand in ALS. Furthermore, MUNIX parameters strongly correlated with established disease course parameters independent of disease stages.
CONCLUSION: We found a pathophysiological remarkable denervation pattern of hand muscles, a 'reversed split hand'. MUNIX of single hand muscles correlated well with disease severity and thus represents an easily available biomarker for adult SMA.
SIGNIFICANCE: Our data show the power of the MUNIX method as a biomarker for upcoming questions in adult SMA.

Targeting RNA structure in SMN2 reverses spinal muscular atrophy molecular phenotypes.Publié le 12 12 2018

Modification of SMN2 exon 7 (E7) splicing is a validated therapeutic strategy against spinal muscular atrophy (SMA). However, a target-based approach to identify small-molecule E7 splicing modifiers has not been attempted, which could reveal novel therapies with improved mechanistic insight. Here, we chose as a target the stem-loop RNA structure TSL2, which overlaps with the 5' splicing site of E7. A small-molecule TSL2-binding compound, homocarbonyltopsentin (PK4C9), was identified that increases E7 splicing to therapeutic levels and rescues downstream molecular alterations in SMA cells. High-resolution NMR combined with molecular modelling revealed that PK4C9 binds to pentaloop conformations of TSL2 and promotes a shift to triloop conformations that display enhanced E7 splicing. Collectively, our study validates TSL2 as a target for small-molecule drug discovery in SMA, identifies a novel mechanism of action for an E7 splicing modifier, and sets a precedent for other splicing-mediated diseases where RNA structure could be similarly targeted.

Risdiplam distributes and increases SMN protein in both the central nervous system and peripheral organs.Publié le 08 12 2018

Spinal muscular atrophy (SMA) is a rare, inherited neuromuscular disease caused by deletion and/or mutation of the Survival of Motor Neuron 1 (SMN1) gene. A second gene, SMN2, produces low levels of functional SMN protein that are insufficient to fully compensate for the lack of SMN1. Risdiplam (RG7916; RO7034067) is an orally administered, small-molecule SMN2 pre-mRNA splicing modifier that distributes into the central nervous system (CNS) and peripheral tissues. To further explore risdiplam distribution, we assessed in vitro characteristics and in vivo drug levels and effect of risdiplam on SMN protein expression in different tissues in animal models. Total drug levels were similar in plasma, muscle, and brain of mice (n = 90), rats (n = 148), and monkeys (n = 24). As expected mechanistically based on its high passive permeability and not being a human multidrug resistance protein 1 substrate, risdiplam CSF levels reflected free compound concentration in plasma in monkeys. Tissue distribution remained unchanged when monkeys received risdiplam once daily for 39 weeks. A parallel dose-dependent increase in SMN protein levels was seen in CNS and peripheral tissues in two SMA mouse models dosed with risdiplam. These in vitro and in vivo preclinical data strongly suggest that functional SMN protein increases seen in patients' blood following risdiplam treatment should reflect similar increases in functional SMN protein in the CNS, muscle, and other peripheral tissues.

Camptocormia Induced by a Dopaminergic Agonist.Publié le 28 11 2018

Camptocormia, a condition that involves the abnormal flexion of the trunk and results in a forward-bending posture, is relatively common during the course of Parkinson disease (PD). Despite this, there is ongoing controversy concerning its mechanisms and no consensus regarding the underlying etiology. This report demonstrates a case in which a dopaminergic agonist (DA) was implicated in the onset of camptocormia episodes in a non-PD patient who developed camptocormia after the start of DA treatment. Over a course of 8 years, the patient experienced intermittent camptocormia, which resulted in multiple falls. After cessation of the DA, the patient showed decreased camptocormia symptoms. This case report suggests that clinicians should consider the possibility of DA-induced camptocormia in patients with PD and non-PD patients receiving DA treatments, and serves to caution clinicians regarding the administration of DAs.

Pharmacoeconomic Review Report: Nusinersen (Spinraza): (Biogen Canada Inc.): Indication: Treatment of patients with 5q SMAPublié le 28 11 2018

Spinal muscular atrophy (SMA) is a severe neuromuscular disease and is the leading genetic cause of infant death. It is characterized by the degeneration of alpha motor neurons in the anterior horn of the spinal cord, leading to progressive muscle weakness. The most common form of SMA, 5q SMA, makes up over 95% of all cases and is an autosomal recessive disorder caused by homozygous deletion or deletion and mutation of the alleles of the survival motor neuron 1 (SMN1) gene. SMA is a rare disease and estimates of its incidence and prevalence vary between studies. The incidence of SMA is often cited as being approximately 10 in 100,000 live births. Four clinical subtypes of SMA are described; SMA type I makes about 60% of SMA diagnoses where patients show symptoms before 6 months of age, never achieve the motor milestone of sitting unsupported, and generally do not survive past two years of age due to respiratory failure; SMA type II achieve the milestone of sitting unsupported, but never walk independently. Symptoms generally appear between 6 to 18 months after birth and most patients will survive past the age of 25, with life expectancy improved by aggressive supportive care; SMA type III makes up about 10% to 20% of SMA cases3 and presents between 18 months of age and adulthood. These patients are able to walk independently at some point in their life and typically have a normal life expectancy; SMA type IV constitutes very small proportion of SMA cases, has an adult onset SMA, and is the mildest form of the disease. Although muscle weakness is present, these patients retain the ability to walk, have a normal life expectancy, and do not suffer from respiratory or nutritional issues. Nusinersen (Spinraza) is a solution for intrathecal injection, indicated for the treatment of 5q spinal muscular atrophy (SMA). It is available as a single use solution in a 5mL vial size (12 mg) administered intrathecal by lumbar puncture. The recommended dose is: initial treatment with 4 loading doses, with the first 3 loading doses administered at 14-day intervals (day 0, day 14, and day 28), and a final loading dose approximately 30 days after the third loading dose (day 63); maintenance treatment is 12 mg every 4 months. The marketed price of $118,000 per 5mL vial, the annual cost of treatment with nusinersen ranges from $354,000 for maintenance treatment (3 doses) to $708,000 in the 1st year (6 doses). The manufacturer’s listing request is as per the Health Canada indication. The manufacturer submitted three cost-utility analyses for SMA type I, II and II. Each analysis was based on a Markov state-transition model comparing nusinersen with current standard of care (or real world care [RWC] which includes supportive symptomatic treatment of respiratory, nutritional, and orthopedic function decline) - for patients with q5 SMA.

Specific inhibition of myostatin activation is beneficial in mouse models of SMA therapy.Publié le 28 11 2018

Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by loss of ?-motor neurons, leading to profound skeletal muscle atrophy. Patients also suffer from decreased bone mineral density and increased fracture risk. The majority of treatments for SMA, approved or in clinic trials, focus on addressing the underlying cause of disease, insufficient production of full-length SMN protein. While restoration of SMN has resulted in improvements in functional measures, significant deficits remain in both mice and SMA patients following treatment. Motor function in SMA patients may be additionally improved by targeting skeletal muscle to reduce atrophy and improve muscle strength. Inhibition of myostatin, a negative regulator of muscle mass, offers a promising approach to increase muscle function in SMA patients. Here we demonstrate that muSRK-015P, a monoclonal antibody which specifically inhibits myostatin activation, effectively increases muscle mass and function in two variants of the pharmacological mouse model of SMA in which pharmacologic restoration of SMN has taken place either 1 or 24 days after birth to reflect early or later therapeutic intervention. Additionally, muSRK-015P treatment improves the cortical and trabecular bone phenotypes in these mice. These data indicate that preventing myostatin activation has therapeutic potential in addressing muscle and bone deficiencies in SMA patients. An optimized variant of SRK-015P, SRK-015, is currently in clinical development for treatment of SMA.

Clinical Review Report: Nusinersen (Spinraza): (Biogen Canada Inc.): Indication: Treatment of patients with 5q SMAPublié le 27 11 2018

Spinal muscular atrophy (SMA) is a severe neuromuscular disease and is the leading genetic cause of infant death. It is characterized by the degeneration of alpha motor neurons in the anterior horn of the spinal cord, leading to progressive muscle weakness. Neurological studies indicate that the disease causes a rapid and irreversible degeneration of motor neurons. The rate of motor neuron degeneration has been reported to plateau with time. The most common form of SMA, 5q SMA, makes up more than 95% of all cases and is an autosomal recessive disorder caused by homozygous deletion or deletion and mutation of the alleles of the survival motor neuron 1 (SMN1) gene. While deletion or mutation of the SMN1 gene results in survival motor neuron (SMN) protein deficiency (which is essential for the development of motor neurons), the survival motor neuron 2 (SMN2) gene produces a relatively small amount of functional SMN protein and SMN2 copy number modulates the severity of the disease. SMA is a rare disease and estimates of its incidence and prevalence vary between studies. The incidence of SMA is often cited as being approximately 10 in 100,000 live births. Incidence and prevalence estimates in Canada are not well described in the literature. However, the manufacturer of nusinersen provided Canadian figures of an annualized estimate of new cases of SMA in Canada at 37.2 new cases per year. Four clinical subtypes of SMA are described. SMA type I makes up about 60% of SMA diagnoses where patients show symptoms before 6 months of age, never achieve the motor milestone of sitting unsupported, and generally do not survive past two years of age due to respiratory failure. Patients with SMA type II achieve the milestone of sitting unsupported, but never walk independently. Symptoms generally appear between 6 to 18 months after birth. Most patients will survive past the age of 25, with life expectancy improved by aggressive supportive care. SMA type III makes up about 10% to 20% of SMA cases and presents between 18 months of age and early adulthood. These patients are able to walk independently at some point in their life and typically have a normal life expectancy. SMA type IV constitutes a very small proportion of SMA cases, has an adult onset, and is the mildest form of the disease. Although muscle weakness is present, these patients retain the ability to walk, have a normal life expectancy, and do not suffer from respiratory or nutritional issues.

Intrathecal administration of nusinersen in adolescent and adult SMA type 2 and 3 patients.Publié le 22 11 2018

Spinal muscular atrophy is a genetic motor neuron disease that leads to progressive muscular atrophy and muscle weakness. In December 2016, the Food and Drug Administration, and in June 2017, the European Medicines Agency approved the antisense oligonucleotide nusinersen for treatment of spinal muscular atrophy. Nusinersen has to be repeatedly administered intrathecally. Due to the clinical features of SMA, the application of the ASO by lumbar puncture can be challenging in symptomatic patients considering the frequently observed scoliosis, previous spine fusion surgeries, joint contractures, and respiratory insufficiency. To evaluate safety and feasibility of the intrathecal treatment in adolescent and adult SMA type 2 and 3 patients, we analyzed 93 lumbar punctures, monitored number of lumbar puncture attempts, duration of the procedure, injection site, and needle length. Oxygen saturation during the intervention, medication for sedation and local anesthesia, adverse events related to lumbar punctures, and macroscopic analysis of CSF were recorded. Moreover, we analyzed the use of CT-scans for performing lumbar punctures and its associated radiation exposure. Performing lumbar puncture for the intrathecal administration of nusinersen in adolescent and adult patients with later-onset SMA is feasible and safe, even in patients with complex spinal anatomies and respiratory insufficiency. To guarantee the quality of the procedure, we recommend establishing an experienced interdisciplinary team consisting of neurologists and/or neuropediatricians, anesthesiologists, orthopedic surgeons, and/or neuroradiologists.

10th Young Faculty Meeting, 6th June 2017.Publié le 18 11 2018

PMID: 30188297 [PubMed - indexed for MEDLINE]

Onabotulinum Toxin A Injections Into the Salivary Glands for Spinal Muscle Atrophy Type I: A Prospective Case Series of 4 Patients.Publié le 16 11 2018

OBJECTIVE: The aim of the study was to investigate the safety and efficacy of onabotulinum toxin A injection to the salivary glands under ultrasound guidance for the treatment of sialorrhea in patients with spinal muscular atrophy type I.
DESIGN: Prospective case series with four patients with spinal muscular atrophy type I who received onabotulinum toxin A injection to parotid and submandibular glands for sialorrhea as part of clinical care. All four patients received validated surveys for measuring drooling, including objective measures of number of bib changes, and number of mouth wipes before injection and 4-6 wks after injection. Research was limited to survey completion. Scales included the Drooling Severity and Frequency Scale and the Drooling Impact Scale as well as a new scale used in our clinic, the Posterior Drooling Scales looking at coughing/choking and number of aspiration pneumonias.
RESULTS: There were no adverse events. All four patients showed clinically significant improvements. The improvement in drooling using the Drooling Impact Scale was statistically significant (paired t test, t = 3.243, P = 0.048). All patients improved with number of mouth wipes.
CONCLUSION: Ultrasound-guided onabotulinum toxin A injections to the salivary glands may be a safe and effective method of decreasing drooling in patients with spinal muscular atrophy type I.

Intrathecal nusinersen treatment for SMA in a dedicated neuromuscular clinic: an example of multidisciplinary and integrated care.Publié le 16 11 2018

Nusinsersen is now available in Italy for all SMA types. We describe the experience with intrathecal treatment with nusinersen in 50 patients with SMA at the NEMO Center (NEuroMuscular Omniservice Clinical Center) in Milan, a neuromuscular patient-centered clinic hosted within Niguarda Hospital, a National Public General Hospital. Our results indicate that the pathway of care described outweighs the burden due to the repeated intrathecal injections. Irrespective of age and severity, the treatment is feasible, accessible, and replicable provided that there is a multidisciplinary team having experience and training in SMA.

Changing respiratory expectations with the new disease trajectory of nusinersen treated spinal muscular atrophy [SMA] type 1.Publié le 12 11 2018

Spinal muscular atrophy [SMA] is the most common genetic cause of childhood mortality, primarily from the most severe form SMA type 1. It is a severe, progressive motor neurone disease, affecting the lower brainstem nuclei and the spinal cord. There is a graded level of severity with SMA children from a practical viewpoint described as "Non-sitters", "Sitters" and less commonly, "Ambulant" correlating with SMA Type 0/Type 1, Type 2 and Type 3 respectively. Children with SMA Type 0 have a severe neonatal form whilst those with SMA Type 1 develop hypoventilation, pulmonary aspiration, recurrent lower respiratory tract infections, dysphagia and failure to thrive before usually succumbing to respiratory failure and death before the age of 2?years. The recent introduction of the antisense oligonucleotide nusinersen into clinical practice in certain countries, following limited trials of less than two years duration, has altered the treatment landscape and improved the outlook considerably for SMN1 related SMA. Approximately 70% of infants appear to have a clinically significant response to nusinersen with improved motor function. It appears the earlier the treatment is initiated the better the response. There are other rarer genetic forms of SMA that are not treated with nusinersen. Clinical expectations will change although it is unclear as yet what the extent of response will mean in terms of screening initiatives [e.g., newborn screening], "preventative strategies" to maintain respiratory wellbeing, timing of introduction of respiratory supports, and prolonged life expectancy for the subcategory of children with treated SMA type 1. This article provides a review of the strategies available for supporting children with respiratory complications of SMA, with a particular emphasis on SMA Type 1.

Upper camptocormia in Parkinson's disease reversed by bilateral subthalamic deep brain stimulation.Publié le 10 11 2018

PMID: 28233683 [PubMed - indexed for MEDLINE]

Discovery of small molecule splicing modulators of survival motor neuron-2 (SMN2) for the treatment of Spinal Muscular Atrophy (SMA).Publié le 09 11 2018

Spinal muscular atrophy (SMA), a rare neuromuscular disorder, is the leading genetic cause of death in infants and toddlers. SMA is caused by the deletion or a loss of function mutation of the survival motor neuron 1 (SMN1) gene. In humans, a second closely related gene SMN2 exists, however it codes for a less stable SMN protein. In recent years, significant progress has been made toward disease modifying treatments for SMA by modulating SMN2 pre-mRNA splicing. Herein, we describe the discovery of LMI070 / branaplam, a small molecule that stabilizes the interaction between the spliceosome and SMN2 pre-mRNA. Branaplam (1) originated from a high-throughput phenotypic screening hit, pyridazine 2, and evolved via multi-parameter lead optimization. In a severe mouse SMA model, branaplam treatment increased full-length SMN RNA and protein levels, and extended survival. Currently, branaplam is in clinical studies for SMA.

The role of sleep diagnostics and non-invasive ventilation in children with spinal muscular atrophy.Publié le 07 11 2018

Spinal muscular atrophy (SMA) is a degenerative motor neurone disorder causing progressive muscular weakness. Without assisted ventilation or novel therapies, most children with SMA type 1 die before the second year of life due to respiratory failure as the respiratory muscles and bulbar function are severely affected. Active respiratory treatment (mechanically assisted cough, invasive or non-invasive ventilation) has improved survival significantly in recent decades, but often at the cost of becoming ventilator dependent. The advent of a new oligonucleotide based therapy (Nusinersen) has created new optimism for improving motor function. However, the long-term effect on respiratory function is unclear and non-invasive respiratory support will remain an important part of medical management in patients with SMA. This review summarises the existing knowledge about sleep-disordered breathing and respiratory failure in patients with SMA, especially type 1, as well as the evidence of improved outcome and survival in patients treated with non-invasive or invasive ventilation. Practical considerations and ethical concerns are delineated with discussion on how these may be affected by the advent of new therapies such as Nusinersen.

Long-term non-invasive ventilation therapies in children: A scoping review.Publié le 06 11 2018

Long-term non-invasive ventilation (NIV) is a common modality of breathing support used for a range of sleep and respiratory disorders. The aim of this scoping review was to provide a summary of the literature relevant to long-term NIV use in children. We used systematic methodology to identify 11,581 studies with final inclusion of 289. We identified 76 terms referring to NIV; the most common term was NIV (22%). Study design characteristics were most often single center (84%), observational (63%), and retrospective (54%). NIV use was reported for 73 medical conditions with obstructive sleep apnea and spinal muscular atrophy as the most common conditions. Descriptive data, including NIV incidence (61%) and patient characteristics (51%), were most commonly reported. Outcomes from sleep studies were reported in 27% of studies followed by outcomes on reduction in respiratory morbidity in 19%. Adverse events and adherence were reported in 20% and 26% of articles respectively. Authors reported positive conclusions for 73% of articles. Long-term use of NIV has been documented in a large variety of pediatric patient groups with studies of lower methodological quality. While there are considerable data for the most common conditions, there are fewer data to support NIV use for many additional conditions.

Nusinersen (Spinraza) for spinal muscular atrophy.Publié le 06 11 2018

PMID: 28323809 [PubMed - indexed for MEDLINE]

New Frontiers in the Treatment of Spinal Muscular Atrophy.Publié le 31 10 2018

PMID: 30376223 [PubMed - in process]

Kan man patentere solen?Publié le 31 10 2018

PMID: 29663751 [PubMed - indexed for MEDLINE]

Postural Disorders and Antiparkinsonian Treatments in Parkinson Disease: An Exploratory Case-Control Study.Publié le 30 10 2018

OBJECTIVE: The aim of this study was to evaluate the relationship between antiparkinsonian treatments, especially dopamine agonist (DAs) and the development of postural disorders in patients with Parkinson's disease (PD).
METHODS: We performed an exploratory case-control study. Cases were PD patients with camptocormia, Pisa syndrome, or anterocollis. Control subjects were PD patients without postural disorders matched by sex and age. Demographic and clinical data including pharmacologic treatments history were collected retrospectively. Characteristics of cases and control subjects were compared using parametric and nonparametric tests accordingly, and logistic regression models were used to analyze correlations.
RESULTS: We included 63 patients with PD and postural disorders and 63 control subjects. Cases were more exposed to DAs (74.60% vs 58.73%, P = 0.05) and amantadine (30.16% vs 7.94%, P < 0.05) than control subjects. Cases showed longer disease duration (7.63 ± 7.83 vs 4.27 ± 3.87 years, P < 0.05), higher Hoehn and Yahr stage (2.83 ± 0.80 vs 2.15 ± 0.73, P < 0.05), higher Movement Disorder Society Unified Parkinson's Disease Rating Scale part III score (29.61 ± 1.39 vs 20.76 ± 10.94, P = 0.05), and more dyslipidemia (28.57% vs 12.70%, P < 0.05) than control subjects, as well as lower prevalence of depression (46.03% vs 28.57%, P < 0.05). We found no clinical predictors for the development of postural disorders after multivariable adjusted regression.
CONCLUSIONS: Our results suggest a possible association between the use of DAs and amantadine and the development of postural disorders in PD and suggest potential risk factors including advanced disease and more severe motor symptoms. These results support the need of a cautious use of these medications in patients with advanced disease due to the possibility of increasing the risk-benefit ratio.

Human Cardiac Gene Therapy.Publié le 27 10 2018

In the past 10 years, there has been tremendous progress made in the field of gene therapy. Effective treatments of Leber congenital amaurosis, hemophilia, and spinal muscular atrophy have been largely based on the efficiency and safety of adeno-associated vectors. Myocardial gene therapy has been tested in patients with heart failure using adeno-associated vectors with no safety concerns but lacking clinical improvements. Cardiac gene therapy is adapting to the new developments in vectors, delivery systems, targets, and clinical end points and is poised for success in the near future.

Physiological Roles of Metallothioneins in Central Nervous System Diseases.Publié le 27 10 2018

Metallothioneins (MTs) are small-molecular weight metal-binding proteins involved in the maintenance of tissue structure, efficient metal metabolism, and metal detoxification and have an antioxidative effect. Moreover, MTs are expressed as four isoforms, and there are no known patterns in their localization with various effects. According to recent studies, MTs affect central nervous system (CNS) diseases, and many reports suggest that each isoform of MT has a protective effect against disease. Notably, MTs are involved in regions of diseases related to unmet medical needs, and MTs affect intractable neurological diseases, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). This review specifically focuses on MT-related ocular diseases, cerebral ischemia, psychological disorders, ALS, and SMA. Each of these diseases has a separate cause, but the conditions are related to MTs. To understand the physiological roles of MTs in CNS diseases, we reviewed the current literature on the complex interactions between each MT, pathological conditions, and perspectives. We also discuss current evidence on the expression and function of MTs for diagnosis and new therapeutic strategies.

Five-Year Follow-Up and Outcomes of Noninvasive Ventilation in Subjects With Neuromuscular Diseases.Publié le 24 10 2018

INTRODUCTION: The purpose of this study was to investigate the 5-year outcomes of noninvasive ventilation (NIV) application in different neuromuscular disease (NMD) groups.
METHODS: We categorized 180 subjects who had initiated NIV between March 2001 and August 2009 into 4 groups and followed them for > 5 y. The NIV maintenance rate and average duration, applying time, and forced vital capacity (FVC) were investigated at the time NIV was initiated and 5 y after NIV initiation in each group.
RESULTS: In subjects with amyotrophic lateral sclerosis (ALS), Duchenne muscular dystrophy (DMD), and spinal muscular atrophy (SMA)-congenital myopathy, the 5-year subjects who continued to use NIV over time were 22.5%, 89.4%, and 91.3%, respectively, and the average NIV maintenance durations were 21.53 ± 19.26 months, 55.22 ± 11.47 months, and 57.48 ± 8.34 months, respectively (P < .001). Median daily applying time changed from 8.0 h to 24.0 h (P < .001), from 8.0 h to 12.0 h (P < .001), and from 8.0 h to 9.0 h (P = .11) in subjects with ALS, DMD, and SMA-congenital myopathy, respectively. FVC decreased significantly after 5 y except in the group with combined SMA-congenital myopathy.
CONCLUSIONS: NIV was tolerated long-term without significant increases in daily application time for most subjects with NMD. However, in individuals with ALS, development of severe bulbar symptoms can risk maintaining NIV.

Successful use of extracorporeal membrane oxygenation in a child with obstructive shock due to massive bilateral pulmonary embolism.Publié le 24 10 2018

BACKGROUND: Acute massive pulmonary embolism (PE) is a very rare condition in children. We report the successful use of veno-arterial extracorporeal membrane oxygenation (VA ECMO) as a lifesaving modality in a child with acute massive PE.
CASE PRESENTATION: A nine-year-old female with spinal muscular atrophy type 1, chronic respiratory failure with tracheostomy and ventilator dependence presented with tachypnea and hypoxia. She had recent coiling of her pulmonary arterio-venous malformation. A chest computerized tomography scan showed massive bilateral PE. Urgent catheter-directed thrombolysis failed. She was placed on VA-ECMO with stabilization of hemodynamics. She underwent surgical thrombo-embolectomy followed by weaning of ECMO support.
DISCUSSION: The use of VA ECMO supported the cardio-respiratory status and perfusion to facilitate surgical embolectomy.

Calpain Inhibition Increases SMN Protein in Spinal Cord Motoneurons and Ameliorates the Spinal Muscular Atrophy Phenotype in Mice.Publié le 18 10 2018

Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is caused by the loss of survival motor neuron 1 (SMN1) gene. SMA is characterized by the degeneration and loss of spinal cord motoneurons (MNs), muscular atrophy, and weakness. SMN2 is the centromeric duplication of the SMN gene, whose numbers of copies determine the intracellular levels of SMN protein and define the disease onset and severity. It has been demonstrated that elevating SMN levels can be an important strategy in treating SMA and can be achieved by several mechanisms, including promotion of protein stability. SMN protein is a direct target of the calcium-dependent protease calpain and induces its proteolytic cleavage in muscle cells. In this study, we examined the involvement of calpain in SMN regulation on MNs. In vitro experiments showed that calpain activation induces SMN cleavage in CD1 and SMA mouse spinal cord MNs. Additionally, calpain 1 knockdown or inhibition increased SMN level and prevent neurite degeneration in these cells. We examined the effects of calpain inhibition on the phenotype of two severe SMA mouse models. Treatment with the calpain inhibitor, calpeptin, significantly improved the lifespan and motor function of these mice. Our observations show that calpain regulates SMN level in MNs and calpeptin administration improves SMA phenotype demonstrating the potential utility of calpain inhibitors in SMA therapy.

Therapeutic advances in 5q-linked spinal muscular atrophy.Publié le 18 10 2018

Spinal muscular atrophy (SMA) is a severe and clinically-heterogeneous motor neuron disease caused, in most cases, by a homozygous mutation in the SMN1 gene. Regarding the age of onset and motor involvement, at least four distinct clinical phenotypes have been recognized. This clinical variability is, in part, related to the SMN2 copy number. By now, only supportive therapies have been available. However, promising specific therapies are currently being developed based on different mechanisms to increase the level of SMN protein; in particular, intrathecal antisense oligonucleotides that prevent the skipping of exon 7 during SMN2 transcription, and intravenous SMN1 insertion using viral vector. These therapeutic perspectives open a new era in the natural history of the disease. In this review, we intend to discuss the most recent and promising therapeutic strategies, with special consideration to the pathogenesis of the disease and the mechanisms of action of such therapies.

Camptocormia as an onset symptom of myasthenia gravis.Publié le 16 10 2018

PMID: 27812759 [PubMed - indexed for MEDLINE]

Evidence in focus: Nusinersen use in spinal muscular atrophy: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology.Publié le 15 10 2018

OBJECTIVE: To identify the level of evidence for use of nusinersen to treat spinal muscular atrophy (SMA) and review clinical considerations regarding use.
METHODS: The author panel systematically reviewed nusinersen clinical trials for patients with SMA and assigned level of evidence statements based on the American Academy of Neurology's 2017 therapeutic classification of evidence scheme. Safety information, regulatory decisions, and clinical context were also reviewed.
RESULTS: Four published clinical trials were identified, 3 of which were rated above Class IV. There is Class III evidence that in infants with homozygous deletions or mutations of SMN1, nusinersen improves the probability of permanent ventilation-free survival at 24 months vs a well-defined historical cohort. There is Class I evidence that in term infants with SMA and 2 copies of SMN2, treatment with nusinersen started in individuals younger than 7 months results in a better motor milestone response and higher rates of event-free survival than sham control. There is Class I evidence that in children aged 2-12 years with SMA symptom onset after 6 months of age, nusinersen results in greater improvement in motor function at 15 months than sham control. Nusinersen was safe and well-tolerated.
CLINICAL CONTEXT: Evidence of efficacy is currently highest for treatment of infantile- and childhood-onset SMA in the early and middle symptomatic phases. While approved indications for nusinersen use in North America and Europe are broad, payer coverage for populations outside those in clinical trials remain variable. Evidence, availability, cost, and patient preferences all influence decision-making regarding nusinersen use.

Cell-Penetrating Peptide Conjugates of Steric Blocking Oligonucleotides as Therapeutics for Neuromuscular Diseases from a Historical Perspective to Current Prospects of Treatment.Publié le 12 10 2018

The review starts with a historical perspective of the achievements of the Gait group in synthesis of oligonucleotides (ONs) and their peptide conjugates toward the award of the 2017 Oligonucleotide Therapeutic Society Lifetime Achievement Award. This acts as a prelude to the rewarding collaborative studies in the Gait and Wood research groups aimed toward the enhanced delivery of charge neutral ON drugs and the development of a series of Arg-rich cell-penetrating peptides called Pip (peptide nucleic acid/phosphorodiamidate morpholino oligonucleotide [PNA/PMO] internalization peptides) as conjugates of such ONs. In this review we concentrate on these developments toward the treatment of the neuromuscular diseases Duchenne muscular dystrophy and spinal muscular atrophy toward a platform technology for the enhancement of cellular and in vivo delivery suitable for widespread use as neuromuscular and neurodegenerative ON drugs.

Feasibility and safety of intrathecal treatment with nusinersen in adult patients with spinal muscular atrophy.Publié le 12 10 2018

Background: Nusinersen is an intrathecally administered antisense oligonucleotide (ASO) and the first approved drug for the treatment of spinal muscular atrophy (SMA). However, progressive neuromyopathic scoliosis and the presence of spondylodesis can impede lumbar punctures in SMA patients. Our aim was to assess the feasibility and safety of the treatment in adults with SMA.
Methods: For the intrathecal administration of nusinersen, we performed conventional, fluoroscopy-assisted and computer tomography (CT)-guided lumbar punctures in adult patients with type 2 and type 3 SMA. We documented any reported adverse events and performed blood tests.
Results: We treated a total of 28 adult SMA patients (9 patients with SMA type 2 and 19 patients with SMA type 3) aged between 18-61?years with nusinersen. The mean Revised Upper Limb Module (RULM) score at baseline in SMA type 2 and SMA type 3 patients was 9.9 ± 4.6 and 29.5 ± 8.5, respectively. The mean Hammersmith Functional Motor Scale Expanded (HFMSE) score at baseline was 3.1 ± 2.5 and 31.2 ± 18.1, respectively. Half of the SMA type 3 patients were ambulatory at treatment onset. In total, we performed 122 lumbar punctures with 120 successful intrathecal administrations of nusinersen. Lumbar punctures were well tolerated, and no serious adverse events occurred.
Conclusions: Our data demonstrate the feasibility and tolerability of intrathecal treatment with nusinersen in adults with SMA type 2 and type 3. However, treatment can be medically and logistically challenging, particularly in patients with SMA type 2 and in patients with spondylodesis.

Spinal muscular atrophy 5Q - Treatment with nusinersen.Publié le 12 10 2018

The Guidelines Project, an initiative of the Brazilian Medical Association, aims to combine information from the medical field in order to standardize producers to assist the reasoning and decision-making of doctors. The information provided through this project must be assessed and criticized by the physician responsible for the conduct that will be adopted, depending on the conditions and the clinical status of each patient.

A Phase 1 healthy male volunteer single escalating dose study of the pharmacokinetics and pharmacodynamics of risdiplam (RG7916, RO7034067), a SMN2 splicing modifier.Publié le 12 10 2018

AIMS: Risdiplam (RG7916, RO7034067) is an orally administered, centrally and peripherally distributed, survival of motor neuron 2 (SMN2) mRNA splicing modifier for the treatment of spinal muscular atrophy (SMA). The objectives of this entry-into-human study were to assess the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics of risdiplam, and the effect of the strong CYP3A inhibitor itraconazole on the PK of risdiplam in healthy male volunteers.
METHODS: Part 1 had a randomized, double-blind, adaptive design with 25 subjects receiving single ascending oral doses of risdiplam (ranging from 0.6-18.0 mg, n = 18) or placebo (n = 7). A Bayesian framework was applied to estimate risdiplam's effect on SMN2 mRNA. The effect of multiple doses of itraconazole on the PK of risdiplam was also assessed using a two-period cross-over design (n = 8).
RESULTS: Risdiplam in the fasted or fed state was well tolerated. Risdiplam exhibited linear PK over the dose range with a multi-phasic decline with a mean terminal half-life of 40-69 hours. Food had no relevant effect, and itraconazole had only a minor effect on plasma PK indicating a low fraction of risdiplam metabolized by CYP3A. The highest tested dose of 18.0 mg risdiplam led to approximately 41% (95% confidence interval 27-55%) of the estimated maximum increase in SMN2 mRNA.
CONCLUSIONS: Risdiplam was well tolerated and proof of mechanism was demonstrated by the intended shift in SMN2 splicing towards full-length SMN2 mRNA. Based on these data, Phase 2/3 studies of risdiplam in patients with SMA are now ongoing.

The Swedish motor neuron disease quality registry.Publié le 10 10 2018

OBJECTIVE: We set up the Swedish Motor Neuron Disease (MND) Quality Registry to assure early diagnosis and high-quality health care for all MND patients (mainly amyotrophic lateral sclerosis, ALS), and to create a research base by prospectively following the entire MND population in Sweden.
METHODS: Since 2015, the MND Quality Registry continuously collects information about a wide range of clinical measures, biological samples, and quality of life outcomes from all MND patients recruited at the time of MND diagnosis in Sweden and followed at each clinic visit approximately every 12 weeks. The Registry includes an Internet based patient own reporting portal that involves patients in the registration of their current symptoms and health status.
RESULTS: As of 20th January 2017, the MND Quality Registry included 99% of the MND patients of the Stockholm area (N?=?194), consisting mostly of ALS patients (N?=?153, 78.9%), followed by patients labeled as MND due to a neurophysiology finding but not fulfilling the criteria for ALS (N?=?20, 10.3%), primary lateral sclerosis (N?=?13, 6.7%), and progressive spinal muscular atrophy patients (N?=?8, 4.1%). A higher proportion of these patients were women (N?=?100, 52%), and women and men had a similar age at symptoms onset (59 years).
CONCLUSIONS: Main strengths of the MND Quality Registry are its clinical, quantitative, qualitative, and prospective nature, providing the researchers potential means of identifying appropriate candidates for clinical trials and other research projects, as well as assuring to the patients an effective and adequate time spent on-site with the healthcare professionals.

A retrospective cohort study of children with spinal muscular atrophy type 2 receiving anesthesia for intrathecal administration of nusinersen.Publié le 05 10 2018

INTRODUCTION: Spinal muscular atrophy is characterized by loss of motor neurons in the anterior horn of the spinal cord with resultant proximal muscle weakness. Intrathecal nusinersen has revolutionized the treatment of spinal muscular atrophy. We reviewed the perioperative care of 61 anesthetics performed on eight patients with spinal muscular atrophy type 2 who received nusinersen over 30 months in conjunction with nusinersen's phase 3 clinical trials.
METHODS: Anesthesia was induced in all patients with sevoflurane, nitrous oxide, and oxygen (30%) via facemask. A peripheral intravenous line was placed after the loss of consciousness in all but three procedures. General anesthesia was maintained in 58 anesthetics with a propofol infusion at 250-300 ?g/kg/min, while the remainder was maintained with inhalational anesthetics. The airway was managed via facemask or nasal cannula in all but two procedures, in whom a laryngeal mask airway was placed. We analyzed patient demographics, duration of anesthesia and of postanesthesia care unit stay, discharge destination, preprocedure oxygen saturation (SaO2 ), postanesthesia care unit discharge oxygen saturation, and occurrence of unanticipated admission or postdischarge hospitalization.
RESULTS: Eight American Society of Anesthesiologists physical status three patients (3 male: 5 female) with a median age of 4.1 (2.1-7.8) years and median weight of 13.2 (10-24.7) kg, underwent 61 anesthetics for nusinersen administration or sham procedure. There were no intraoperative anesthetic complications of unanticipated cardiovascular instability, major neurologic events, respiratory failure, or death. Anesthesiologists performed 83% of the procedures.
CONCLUSION: Nusinersen has revolutionized the care of patients with spinal muscular atrophy type 2 and anesthesiologists will be involved in its administration. We found that routine anesthetic care was safe and effective.

Precision Medicine through Antisense Oligonucleotide-Mediated Exon Skipping.Publié le 05 10 2018

Clinical implementation of two recently approved antisense RNA therapeutics - Exondys51® to treat Duchenne muscular dystrophy (Duchenne MD) and Spinraza® as a treatment for spinal muscular atrophy (SMA) - highlights the therapeutic potential of antisense oligonucleotides (ASOs). As shown in the Duchenne and Becker cases, the identification and specific removal of 'dispensable' exons by exon-skipping ASOs could potentially bypass lethal mutations in other genes and bring clinical benefits to affected individuals carrying amenable mutations. In this review, we discuss the potential of therapeutic alternative splicing, with a particular focus on targeted exon skipping using Duchenne MD as an example, and speculate on new applications for other inherited rare diseases where redundant or dispensable exons may be amenable to exon-skipping ASO intervention as precision medicine.

Motor neurone disease-associated neck pain misdiagnosed as cervical spondylosis: A case report and literature review.Publié le 28 09 2018

BACKGROUND: Motor neurone disease (MND) is a chronic, progressive and currently incurable neurodegenerative disorder. Although pain as a symptom appears in many patients with MND, it is often misdiagnosed as other diseases when occurs before the onset of weakness. Patients are often assigned to non-neurological departments due to the atypical symptoms, which can lead to diagnostic delay and inappropriate treatment.
OBJECTIVE: To analyze the causes of misdiagnosis and improve the clinician's understanding of neck pain in patients with MND.
METHODS: We reviewed relevant literature and retrospectively reported a misdiagnosis case of MND-associated neck pain.
RESULTS: A case of MND presenting prominently as neck pain was suspected of suffering from cervical spondylosis and wrongly assigned to orthopedic clinic. When eventually being diagnosed as MND, his neck pain was found to be caused by intracranial hypertension (ICH) resulting from hypoxia via insidious respiratory failure through ventilator insufficiency.
CONCLUSION: Careful evaluation of the clinical progression of the symptoms, extensive EMG and nerve conduction study, as well as the establishment of better clinical approach to the diagnosis and higher public awareness allow a reduction of misdiagnosis.

[Spinal muscular atrophy - clinical spectrum and therapy].Publié le 26 09 2018

Spinal muscular atrophy (SMA) is a progressive autosomal recessive motor neuron disease with an incidence of 1:10,000 live births, caused by loss of the survival motor neuron 1 gene (SMN1), and represents the most frequent neurodegenerative disorder in children. With greater understanding of the molecular basis of SMA in the past two decades, a major focus of therapeutic developments has been on increasing the fulllength SMN protein by increasing the inclusion of exon 7 in SMN2 transcripts, enhancing SMN2 gene expression, stabilizing the SMN protein or replacing the SMN1 gene. Although the SMA research field is rapidly expanding with new therapeutic opportunities, there are still several issues that remain unsolved. The timing of an optimal intervention is not clear, in particular the point at which there is irreversible pathology precluding any meaningful therapeutic response. Early diagnosis will be crucial for therapeutic success; presumably, the clinical outcome will be much better if treatment already starts presymptomatically. Therefore, presymptomatic diagnosis of SMA via a nationwide genetic newborn screening will be key for an efficient therapy prior to motor neuron death.

Putting our best foot forward: Clinical, treatment-based and ethical considerations of nusinersen therapy in Canada for spinal muscular atrophy.Publié le 26 09 2018

Spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality. SMA is a spectral disorder and is categorised based on symptom onset and severity. The median life expectancy for infants with SMA presenting before 6 months of age is less than 2 years without respiratory support. To date, there is no cure for SMA. In June 2017, nusinersen was approved in Canada as the first disease-modifying drug for SMA because of its demonstrated benefits on motor function and survival in clinical trials. However, with a price tag of almost 1 million dollars for the first year of therapy, careful clinical, treatment-based and ethical consideration of the principles of (i) best interests; (ii) universality; (iii) portability; (iv) public administration; (v) accessibility; and (vi) comprehensiveness are important guideposts to ensure transparent and equitable allocation of health-care resources for nusinersen and all other future orphan drugs.

Pharmacological c-Jun NH2-Terminal Kinase (JNK) Pathway Inhibition Reduces Severity of Spinal Muscular Atrophy Disease in Mice.Publié le 21 09 2018

Spinal muscular atrophy (SMA) is a severe neurodegenerative disorder that occurs in early childhood. The disease is caused by the deletion/mutation of the survival motor neuron 1 (SMN1) gene resulting in progressive skeletal muscle atrophy and paralysis, due to the degeneration of spinal motor neurons (MNs). Currently, the cellular and molecular mechanisms underlying MN death are only partly known, although recently it has been shown that the c-Jun NH2-terminal kinase (JNK)-signaling pathway might be involved in the SMA pathogenesis. After confirming the activation of JNK in our SMA mouse model (SMN2+/+; SMN?7+/+; Smn-/-), we tested a specific JNK-inhibitor peptide (D-JNKI1) on these mice, by chronic administration from postnatal day 1 to 10, and histologically analyzed the spinal cord and quadriceps muscle at age P12. We observed that D-JNKI1 administration delayed MN death and decreased inflammation in spinal cord. Moreover, the inhibition of JNK pathway improved the trophism of SMA muscular fibers and the size of the neuromuscular junctions (NMJs), leading to an ameliorated innervation of the muscles that resulted in improved motor performances and hind-limb muscular tone. Finally, D-JNKI1 treatment slightly, but significantly increased lifespan in SMA mice. Thus, our results identify JNK as a promising target to reduce MN cell death and progressive skeletal muscle atrophy, providing insight into the role of JNK-pathway for developing alternative pharmacological strategies for the treatment of SMA.

Pre-emptive awake airway management under dexmedetomidine sedation in a parturient with spinal muscular atrophy type-2.Publié le 21 09 2018

Historically, pregnancy in females with spinal muscular atrophy was contraindicated due to the great risk to the parturient, but with improved management and increased survival more patients are becoming pregnant. We describe the management of a pregnant patient with spinal muscular atrophy type-2, who had severe restrictive lung disease, extensive spinal fusion that precluded neuraxial anesthesia, and chronic respiratory failure on nocturnal Bilevel Positive Airway Pressure. Airway management was further complicated by limited mouth opening and cervical spine ankylosis.

Magnetically Controlled Devices Parallel to the Spine in Children with Spinal Muscular Atrophy.Publié le 20 09 2018

Background: Children with severe spinal deformity frequently are managed with growth-friendly implants. After initial surgery, externally controlled magnetic rods allow spinal deformity correction during growth without further surgical intervention. The ability to lengthen the spine without additional surgical procedures is especially beneficial in high-risk children, such as those with spinal muscular atrophy (SMA). The purpose of the present study was to assess the level of control of spinal deformity in a homogeneous group of patients with SMA who were managed with magnetically controlled implants for 2 years.
Methods: This prospective, nonrandomized study included 21 non-ambulatory children with type-II SMA and progressive scoliosis who were managed bilaterally with a magnetically controlled implant that was inserted parallel to the spine with use of rib-to-pelvis hook fixation. Radiographic measurements of scoliotic curves, kyphosis, lordosis, pelvic obliquity, and spinal length were performed before and after implantation of the magnetically controlled device and during external lengthening. The mean duration of follow-up was 2 years.
Results: The mean main curve of patients without prior vertical expandable prosthetic titanium rib (VEPTR) treatment decreased from 70° before implantation of the magnetically controlled device to 30° after implantation of the device. Correction was maintained during the follow-up period, with a mean curve of 31° at the time of the latest follow-up at 2.2 years. Pelvic obliquity was surgically corrected by 76% (from 17° to 4°) and remained stable during follow-up. Thoracic kyphosis could not be corrected within the follow-up period. Spinal length of children without prior spinal surgery increased by >50 mm immediately after device implantation and steadily increased at a rate of 13.5 mm/yr over the course of treatment. During treatment, 4 general complications occurred and 6 lengthening procedures failed, with 3 patients requiring surgical revision.
Conclusions: Bilateral implantation of an externally controlled magnetic rod with rib-to-pelvis fixation represents a safe and efficient method to control spinal deformity in children with SMA, achieving sufficient and stable curve correction as well as increased spinal length. The complication rate was lower than those that have been described for VEPTR and other growing rod instrumentation strategies.
Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Motor Function Test Reliability During the NeuroNEXT Spinal Muscular Atrophy Infant Biomarker Study.Publié le 19 09 2018

BackgroundThe NeuroNEXT SMA Infant Biomarker Study, a two year, longitudinal, multi-center study of infants with SMA type 1 and healthy infants, presented a unique opportunity to assess multi-site rater reliability on three infant motor function tests (MFTs) commonly used to assess infants with SMA type 1.ObjectiveTo determine the effect of prospective MFT rater training and the effect of rater experience on inter-rater and intra-rater reliability for the Test of Infant Motor Performance Screening Items (TIMPSI), the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) and the Alberta Infant Motor Scale (AIMS).MethodsTraining was conducted utilizing a novel set of motor function test (MFT) videos to optimize accurate MFT administration and reliability for the study duration. Inter- and intra-rater reliability of scoring for the TIMPSI and inter-rater reliability of scoring for the CHOP INTEND and the AIMS was assessed using intraclass correlation coefficients (ICC). Effect of rater experience on reliability was examined using ICC. Agreement with 'expert' consensus scores was examined using Pearson's correlation coefficients.ResultsInter-rater reliability on all MFTs was good to excellent. Intra-rater reliability for the primary MFT, the TIMPSI, was excellent for the study duration. Agreement with 'expert' consensus was within predetermined limits (?85%) after training. Evaluator experience with SMA and MFTs did not affect reliability.ConclusionsReliability of scores across evaluators was demonstrated for all three study MFTs and scores were reproducible on repeated administration. Evaluator experience had no effect on reliability.

Nusinersen treatment of spinal muscular atrophy: current knowledge and existing gaps.Publié le 18 09 2018

Spinal muscular atrophy (SMA) is a recessive disorder caused by a mutation in the survival motor neuron 1 gene (SMN1); it affects 1 in 11 000 newborn infants. The most severe and most common form, type 1 SMA, is associated with early mortality in most cases and severe disability in survivors. Nusinersen, an antisense oligonucleotide, promotes production of full-length protein from the pseudogene SMN2. Nusinersen treatment prolongs survival of patients with type 1 SMA and allows motor milestone acquisition. Patients with type 2 SMA also show progress on different motor scales after nusinersen treatment. Nusinersen was recently approved by the European Medicines Agency and the US Food and Drug Administration; it is now reimbursed in several European countries and in the USA. In Australia, the transition from expanded access programme to commercial availability is coming soon. In New Zealand, an expanded access programme is opened, and in Canada price negotiation for the treatment is in progress. In this review we exemplify the clinical benefit of nusinersen in subgroups of patients with SMA. Nusinersen represents the first efficacious marked approved drug in type 1 and type 2 SMA. Different knowledge gaps, such as results in older patients, in patients with permanent ventilation, in patients with neonatal forms, or in patients after spinal fusion, still need to be addressed.
WHAT THIS PAPER ADDS: Identifies gaps in knowledge about the efficacy of nusinersen in broader populations of patients with spinal muscular atrophy. Identifies open questions in populations of patients where proof of efficacy is available.

Prenatal aspects in spinal muscular atrophy: From early detection to early presymptomatic intervention.Publié le 18 09 2018

With the recent advances in spinal muscular atrophy therapies, the complete scenario of standard of care and following up is changing not only in the clinical field with new phenotypes emerging but also with new expectations for patients, caregivers and health providers. The actual evidence indicates that early intervention and treatment is crucial for better response and prognosis. Knowledge of the prenatal and pre-symptomatic postnatal stages of the disease are becoming essential to consider the opportunities of timely diagnosis and to decide the earliest therapeutic intervention.

Rescue of four pediatric patients with severe influenza A (H3N2) in Weifang, China.Publié le 16 09 2018

In this report, we summarize our experience of rescuing four children with severe type A H3N2 influenza from January to February 2017 in Weifang People's Hospital, Shandong Province, China for reference in clinical treatment. Two boys and two girls, ranging in age from 3 months to 6 years, with fever, cough, and asthma, were admitted to the pediatric intensive care unit. All children had severe pulmonary infection with respiratory distress. Three children had myocardial damage, two had liver damage, and one had encephalitis. One child had a history of bronchial asthma and one had severe spinal muscular atrophy. After all four children were admitted to the pediatric intensive care unit, they were provided active and effective organ function support and ventilator-assisted respiration. They were treated with gamma globulin, methylprednisolone, and antibiotics. Three children were treated with anti-influenza drugs and recovered from influenza; one child died even before antiviral treatment intervention on the first day. Definite diagnosis of the cases was through clinical manifestations, supplemented by laboratory tests, such as influenza virus H3N2 rapid antigen detection and nucleic acid detection. Early antiviral therapy, high-dose glucocorticoids and immunoglobulins, and systemic comprehensive rescue might be important for rescuing children with severe influenza A (H3N2).

A Direct Comparison of IV and ICV Delivery Methods for Gene Replacement Therapy in a Mouse Model of SMARD1.Publié le 13 09 2018

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an infantile autosomal recessive disease caused by the loss of the ubiquitously expressed IGHMBP2 gene. SMARD1 causes degeneration of alpha-motor neurons, resulting in distal muscle weakness, diaphragm paralysis, and respiratory malfunction. We have reported that delivery of a low dose of AAV9-IGHMBP2 to the CNS results in a significant rescue of the SMARD1 mouse model (nmd). To examine how a delivery route can impact efficacy, a direct comparison of intravenous (IV) and intracerebroventricular (ICV) delivery of AAV9-IGHMBP2 was performed. Using a low-dose, both IV and ICV delivery routes led to a significant extension in survival and increased body weight. Conversely, only ICV-treated animals demonstrated improvements in the hindlimb muscle, neuromuscular junction, and motor function. The hindlimb phenotype of IV-treated mice resembled the untreated nmd mice. We investigated whether the increased survival of IV-treated nmd mice was the result of a positive impact on the cardiac function. Our results revealed that cardiac function and pathology were similarly improved in IV- and ICV-treated mice. We concluded that while IV delivery of a low dose does not improve the hindlimb phenotype and motor function, partial restoration of cardiac performance is sufficient to significantly extend survival.

New Directions for SMA Therapy.Publié le 13 09 2018

Spinal muscular atrophy (SMA) is a severe disorder of motor neurons and the most frequent genetic cause of mortality in childhood, due to respiratory complications. The disease occurs due to mutations in the survival motor neuron 1 (SMN1) gene that leads to a reduction in the SMN protein, causing degeneration of lower motor neurons, muscle weakness and atrophy. Recently, the Food and Drug Administration (FDA) and the European Medical Agency (EMA) approved the antisense oligonucleotide nusinersen, the first disease-modifying treatment for SMA. Encouraging results from SMN1 gene therapy studies have raised hope for other therapeutic approaches that might arise in the coming years. However, nusinersen licensing has created ethical, medical, and financial implications that will need to be addressed. In this review, the history and challenges of the new SMA therapeutic strategies are highlighted.

Use of pediatric Tracheal Stoma Retainer® in a 24-year-old spinal muscular atrophy patient.Publié le 11 09 2018

PMID: 29508482 [PubMed - indexed for MEDLINE]

Innovation for rare diseases and bioethical concerns: A thin thread between medical progress and suffering.Publié le 08 09 2018

With the development of precision medicines based on small molecules, antibodies, RNAs and gene therapy, technological innovation is providing some exciting possibilities to treat the most severe genetic diseases. However, these treatments do not always lead to a cure for the disease, and there are several factors that may hinder their overall success. Patients living during a period of great medical change and innovation may benefit from these technological advances but may also just face failures, both in terms of frustrated hopes as well as suffering. In this article, we are telling the stories of three children with rare and severe disorders, who live in an age of significant medical changes, bearing the burden of difficult scientific and ethical choices. The first two cases that are suffering respectively from severe immunodeficiency and beta thalassemia have already been described in scientific journals, as well as in popular magazines. Although similar when considering the medical challenges, the two cases had opposite outcomes, which resulted in distinct ethical implications. The third case is a baby with spinal muscular atrophy, living at a time of continued innovation in the treatment of the disease. With these cases, we discuss the challenges of providing correct information and proper counseling to families and patients that are making the bumpy journey on the road of medical innovation.

Evaluation of potential effects of Plastin 3 overexpression and low-dose SMN-antisense oligonucleotides on putative biomarkers in spinal muscular atrophy mice.Publié le 08 09 2018

OBJECTIVES: Spinal muscular atrophy (SMA) is a devastating motor neuron disorder caused by homozygous loss of the survival motor neuron 1 (SMN1) gene and insufficient functional SMN protein produced by the SMN2 copy gene. Additional genetic protective modifiers such as Plastin 3 (PLS3) can counteract SMA pathology despite insufficient SMN protein. Recently, Spinraza, an SMN antisense oligonucleotide (ASO) that restores full-length SMN2 transcripts, has been FDA- and EMA-approved for SMA therapy. Hence, the availability of biomarkers allowing a reliable monitoring of disease and therapy progression would be of great importance. Our objectives were (i) to analyse the feasibility of SMN and of six SMA biomarkers identified by the BforSMA study in the Taiwanese SMA mouse model, (ii) to analyse the effect of PLS3 overexpression on these biomarkers, and (iii) to assess the impact of low-dose SMN-ASO therapy on the level of SMN and the six biomarkers.
METHODS: At P10 and P21, the level of SMN and six putative biomarkers were compared among SMA, heterozygous and wild type mice, with or without PLS3 overexpression, and with or without presymptomatic low-dose SMN-ASO subcutaneous injection. SMN levels were measured in whole blood by ECL immunoassay and of six SMA putative biomarkers, namely Cartilage Oligomeric Matrix Protein (COMP), Dipeptidyl Peptidase 4 (DPP4), Tetranectin (C-type Lectin Family 3 Member B, CLEC3B), Osteopontin (Secreted Phosphoprotein 1, SPP1), Vitronectin (VTN) and Fetuin A (Alpha 2-HS Glycoprotein, AHSG) in plasma.
RESULTS: SMN levels were significantly discernible between SMA, heterozygous and wild type mice. However, no significant differences were measured upon low-dose SMN-ASO treatment compared to untreated animals. Of the six biomarkers, only COMP and DPP4 showed high and SPP1 moderate correlation with the SMA phenotype. PLS3 overexpression neither influenced the SMN level nor the six biomarkers, supporting the hypothesis that PLS3 acts as an independent protective modifier.

[Pharmacological and clinical profile of spinal muscular atrophy (SMA) therapeutic drug nusinersen (Spinraza®)].Publié le 08 09 2018

Nusinersen (Spinraza®) was approved as Japan's first antisense oligonucleotide (ASO) drug for treatment of SMA (spinal muscular atrophy) patients with a deletion or mutation of the survival motor neuron (SMN) 1 gene and ?1 copy of the SMN2 gene. Nuseinersen is a fully modified 2'-O-(2-methoxyethyl) (2'-MOE) ASO designed to bind the SMN2 pre-mRNA and alter splicing, such that a mature mRNA is produced and is translated as full-length SMN protein. In 4 types of mouse SMA disease models, treatment with nusinersen improved the form of the neuromuscular junction, increased myofiber size, improved righting reflex and grip, and prolonged survival. The efficacy of nusinersen was verified in 2 multinational, randomized, double-blind, sham-controlled clinical studies in SMA patients with differing ages of onset and ages (ENDEAR study and CHERISH study), and improvement and maintenance of motor function by nusinersen were demonstrated regardless of the type of SMA. Moreover, both studies showed that greater efficacy may be obtained with early initiation of nusinersen treatment. Therefore, treatment with nusinersen should be started as early as possible to delay or halt progression of the disease and maximize therapeutic effect. As nusinersen is the only ASO currently available for SMA, it will be widely used, therefore we will expect that nusinersen will contribute to improve patients' QOL and reduce the burden of caregivers and the healthcare system by improving motor function of patients with SMA.

Systemic and ICV Injections of Antisense Oligos into SMA Mice and Evaluation.Publié le 02 09 2018

Spinal muscular atrophy (SMA) is the most common genetic cause of infantile death caused by mutations in the SMN1 gene. Nusinersen (Spinraza), an antisense therapy-based drug with the 2'-methoxyethoxy (2'MOE) chemistry approved by the FDA in 2016, brought antisense drugs into the spotlight. Antisense-mediated exon inclusion targeting SMN2 leads to SMN protein expression. Although effective, 2'MOE has weaknesses such as the inability to cross the blood-brain barrier and the high cost of treatment. To investigate new chemistries of antisense oligonucleotides (ASOs), SMA mouse models can serve as an important source. Here we describe methods to test the efficacy of ASOs, such as phosphorodiamidate morpholino oligomers (PMOs), in a severe SMA mouse model.

In Vitro Evaluation of Antisense-Mediated Exon Inclusion for Spinal Muscular Atrophy.Publié le 02 09 2018

Spinal muscular atrophy (SMA), the most common gentic cause of infantile death caused by mutations in the SMN1 gene, presents a unique case in the field of splice modulation therapy, where a gene (or lack of) is responsible for causing the disease phenotype but treatment is not focused around it. Antisense therapy targeting SMN2 which leads to SMN protein expression has been at the forefront of research when it comes to developing a feasible therapy for treating SMA. Recent FDA approval of an antisense-based drug with the 2'-methoxyethoxy (2'MOE) chemistry, called nusinersen (Spinraza), brought antisense drugs into the spotlight. The 2'MOE, although effective, has weaknesses such as the inability to cross the blood-brain barrier and the high cost of treatment. This propelled the research community to investigate new chemistries of antisense oligonucleotides (ASOs) that may be better in both treatment and cost efficiency. Here we describe two types of ASOs, phosphorodiamidate morpholino oligomers (PMOs) and locked nucleic acids (LNA)-DNA mixmers, being investigated as potential treatments for SMA, and methods used to test their efficacy, including quantitative RT-PCR, Western blotting, and immunofluorescence staining to detect SMN in nuclear gems/Cajal bodies, in type I SMA patient fibroblast cell lines.

Tips to Design Effective Splice-Switching Antisense Oligonucleotides for Exon Skipping and Exon Inclusion.Publié le 02 09 2018

Antisense-mediated exon skipping and exon inclusion have proven to be powerful tools for treating neuromuscular diseases. The approval of Exondys 51 (eteplirsen) and Spinraza (nusinersen) for the treatment of patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) was the most noteworthy accomplishment in 2016. Exon skipping uses short DNA-like molecules called antisense oligonucleotides (AONs) to correct the disrupted reading frame, allowing the production of functional quasi-dystrophin proteins, and ameliorate the progression of the disease. Exon inclusion for SMA employs an AON targeting an intronic splice silencer site to include an exon which is otherwise spliced out. Recently, these strategies have also been explored in many other genetic disorders, including dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy; MM, limb-girdle muscular dystrophy type 2B; LGMD2B, and distal myopathy with anterior tibial onset; DMAT), laminin ?2 chain (merosin)-deficient congenital muscular dystrophy (MDC1A), sarcoglycanopathy (e.g., limb-girdle muscular dystrophy type 2C; LGMD2C), and Fukuyama congenital muscular dystrophy (FCMD). A major challenge in exon skipping and exon inclusion is the difficulty in designing effective AONs. The mechanism of mRNA splicing is highly complex, and the efficacy of AONs is often unpredictable. We will discuss the design of effective AONs for exon skipping and exon inclusion in this chapter.

Nusinersen in the Treatment of Spinal Muscular Atrophy.Publié le 02 09 2018

Spinal muscular atrophy (SMA) is one of the most common genetic causes of infantile death arising due to mutations in the SMN1 gene and the subsequent loss of motor neurons. With the discovery of the intronic splicing silencer N1 (ISS-N1) as a potential target for antisense therapy, several antisense oligonucleotides (ASOs) are being developed to include exon 7 in the final mRNA transcript of the SMN2 gene and thereby increasing the production of spinal motor neuron (SMN) proteins. Nusinersen (spinraza), a modified 2'-O-methoxyethyl (MOE) antisense oligonucleotide is the first drug to be approved by Food and Drug Agency (FDA) in December of 2016. Here we briefly review the pharmacological relevance of the drug, clinical trials, toxicity, and future directions following the approval of nusinersen.

Recent Advances and Clinical Applications of Exon Inclusion for Spinal Muscular Atrophy.Publié le 02 09 2018

Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by a mutation in SMN1 that stops production of SMN (survival of motor neuron) protein. Insufficient levels of SMN results in the loss of motor neurons, which causes muscle weakness, respiratory distress, and paralysis. A nearly identical gene (SMN2) contains a C-to-T transition which excludes exon 7 from 90% of the mature mRNA transcripts, leading to unstable proteins which are targeted for degradation. Although SMN2 cannot fully compensate for a loss of SMN1 due to only 10% functional mRNA produced, the discovery of the intronic splicing silencer (ISS-N1) opened a doorway for therapy. By blocking its function with antisense oligonucleotides manipulated for high specificity and efficiency, exon 7 can be included to produce full-length mRNA, which then compensates for the loss of SMN1. Nusinersen (Spinraza), the first FDA-approved antisense oligonucleotide drug targeting SMA, was designed based on this concept and clinical studies have demonstrated a dramatic improvement in patients. Novel chemistries including phosphorodiamidate morpholino oligomers (PMOs) and locked nucleic acids (LNAs), as well as peptide conjugates such as Pip that facilitate accurate targeting to the central nervous system, are explored to increase the efficiency of exon 7 inclusion in the appropriate tissues to ameliorate the SMA phenotype. Due to the rapid advancement of treatments for SMA following the discovery of ISS-N1, the future of SMA treatment is highly promising.

Invention and Early History of Exon Skipping and Splice Modulation.Publié le 02 09 2018

Since its discovery in 1977, much has been known about RNA splicing and how it plays a central role in human development, function, and, notably, disease. Defects in RNA splicing account for at least 10% of all genetic disorders, with the number expected to increase as more information is uncovered on the contribution of noncoding genomic regions to disease. Splice modulation through the use of antisense oligonucleotides (AOs) has emerged as a promising avenue for the treatment of these disorders. In fact, two splice-switching AOs have recently obtained approval from the US Food and Drug Administration: eteplirsen (Exondys 51) for Duchenne muscular dystrophy, and nusinersen (Spinraza) for spinal muscular atrophy. These work by exon skipping and exon inclusion, respectively. In this chapter, we discuss the early development of AO-based splice modulation therapy-its invention, first applications, and its evolution into the approach we are now familiar with. We give a more extensive history of exon skipping in particular, as it is the splice modulation approach given the most focus in this book.

[Innovative therapeutic approaches for hereditary neuromuscular diseases].Publié le 02 09 2018

Advances in the understanding of the genetic mechanisms and pathophysiology of neuromuscular diseases have recently led to the development of new, innovative and often mutation-specific therapeutic approaches. Methods used include splicing modification by antisense oligonucleotides, read-through of premature stopcodons, use of viral vectors to introduce genetic information, or optimizing the effectiveness of enzyme replacement therapies. The first drugs have already been approved for the treatment of Duchenne muscular dystrophy and spinal muscular atrophy. For other diseases, such as myotubular myopathy, myotonic dystrophy, facioscapulohumeral muscular dystrophy and Pompe disease, new promising approaches are in preclinical or clinical development. As these are rare diseases with a broad spectrum of clinical severity, drug approval is often based on a limited amount of evidence. Therefore, systematic follow-up in the postmarketing period is particularly important to assess the safety and efficacy of these new and often high-priced orphan drugs.

Ultrasound-guided cervical puncture for nusinersen administration in adolescents.Publié le 02 09 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal-recessive disease affecting motor neurons and is the most common genetic cause of death in infants. Intrathecal nusinersen is the only therapy approved by the U.S. Food and Drug Administration for SMA. Deformities and spinal instrumentation from orthopedic surgeries are common in children with SMA, complicating traditional intrathecal access for nusinersen delivery. Cervical punctures are routinely performed in adults for cervical myelograms and should be considered for children with SMA as a viable form of intrathecal access.
OBJECTIVE: This retrospective study assessed technical feasibility and complications of ultrasound-guided cervical puncture for nusinersen administration.
MATERIALS AND METHODS: We reviewed 14 consecutive ultrasound-guided cervical punctures for nusinersen administration with local anesthesia. We reviewed technical success and complications.
RESULTS: All procedures were technically successful. There were no major complications. Two minor complications included headaches that resolved by observation within 24 h after the procedure.
CONCLUSION: Our series describes a successful novel method of ultrasound-guided cervical spine access for intrathecal administration of nusinersen, adding to the armamentarium of procedures for delivering nusinersen to adolescents with challenging lumbar spine access caused by scoliosis and spinal instrumentation. This technique has the advantages of real-time ultrasound guidance and potential avoidance of general anesthesia in children.

A potential biomarker strategy to monitor treatment response in spinal muscular atrophy.Publié le 31 08 2018

PMID: 30158561 [PubMed - as supplied by publisher]

Nusinersen in spinal muscular atrophy type 1 patients older than 7 months: A cohort study.Publié le 31 08 2018

OBJECTIVE: To evaluate the safety and clinical efficacy of nusinersen in patients with spinal muscular atrophy type 1 (SMA1) older than 7 months.
METHODS: Patients with SMA1 were treated with nusinersen by intrathecal injections as a part of the Expanded Access Program (EAP; NCT02865109). We evaluated patients before treatment initiation (M0) and at 2 months (M2) and 6 months (M6) after treatment initiation. Survival, respiratory, and nutritional data were collected. Motor function was assessed with the modified Hammersmith Infant Neurologic Examination Part 2 (HINE-2) and physiotherapist scales adjusted to patient age (Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders and the Motor Function Measure 20 or 32).
RESULTS: We treated 33 children ranging in age from 8.3 to 113.1 months between December 2016 and May 2017. All patients were alive and were continuing treatment at M6. Median progress on the modified HINE-2 score was 1.5 points after 6 months of treatment (p < 0.001). The need for respiratory support significantly increased over time. There were no statistically significant differences between patients presenting with 2 and those presenting with 3 copies of the survival motor neuron 2 (SMN2) gene.
CONCLUSIONS: Our results are in line with the phase 3 study for nusinersen in patients with SMA1 treated before 7 months of age and indicate that patients benefit from nusinersen even at a later stage of the disease.
CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that for patients with SMA1 who are older than 7 months, nusinersen is beneficial.

Essay On Being A Doctor: Mirrors.Publié le 28 08 2018

Through the generosity of Charles R. Millikan, D. Min., vice president for Spiritual Care and Values Integration, an annual award competition was established at Houston Methodist Hospital among the resident staff. To enter the writing competition, residents must submit a poem or essay of 1,000 words or less on the topic, "On Being a Doctor." A committee of seven was selected from Houston Methodist Hospital Education Institute to establish the judging criteria and select the winning entries. The following is the second-place winning entry for 2017; the third-place entry will be published in the next issue of this journal.

A blended psychosocial support program for partners of patients with amyotrophic lateral sclerosis and progressive muscular atrophy: protocol of a randomized controlled trial.Publié le 28 08 2018

BACKGROUND: Informal caregivers of patients with Amyotrophic Lateral Sclerosis (ALS) or Progressive Muscular Atrophy (PMA) face stressful demands due to severe impairments and prospect of early death of the patients they care for. Caregivers often experience feelings of psychological distress and caregiver burden, but supportive interventions are lacking. The objective of this study is to investigate the effectiveness of a psychosocial support program aimed at enhancing feelings of control over caregiving tasks and reducing psychological distress. This support program is based on an existing program for adult partners of people with cancer and is adapted to meet the needs of ALS caregivers.
METHODS: This study is a randomized controlled trial using a wait-list control design. One hundred and forty caregiver-patient dyads, recruited from a nationwide database and through the website of the Dutch ALS Center, will be either randomized to a support program or a wait-list control group. The blended intervention is based on Acceptance and Commitment Therapy and consists of 1 face-to-face contact, 6 online guided modules and 1 telephone contact. The intervention can be worked through in 8 weeks. The effectiveness and the participants' satisfaction with the intervention will be evaluated using a mixed method design. Caregivers and patients will be asked to fill in questionnaires on 4 occasions during the study: baseline, 3 months, 6 months and 9 months. The main study outcome is the psychological distress of the caregiver assessed with the Hospital Anxiety and Depression Scale. Secondary outcomes are caregiver burden, caregiver quality of life, quality of life of the patient and psychological distress of the patient. Group differences in primary and secondary outcomes at 6 months will be compared with linear mixed model analysis. In a subgroup of caregivers we will explore experiences with the support program through semi-structured interviews. Usage of the online modules will be logged.
DISCUSSION: The study will provide insights into the effectiveness of a blended psychosocial support program on psychological distress of caregivers of patients with ALS or PMA, as well as into indirect relations with patients' wellbeing.
TRIAL REGISTRATION: Netherlands Trial Registry NTR5734 , registered 28 March 2016.

Inhibition of autophagy delays motoneuron degeneration and extends lifespan in a mouse model of spinal muscular atrophy.Publié le 28 08 2018

Spinal muscular atrophy (SMA) is a recessive autosomal neuromuscular disease, due to homozygous mutations or deletions in the telomeric survival motoneuron gene 1 (SMN1). SMA is characterized by motor impairment, muscle atrophy, and premature death following motor neuron (MN) degeneration. Emerging evidence suggests that dysregulation of autophagy contributes to MN degeneration. We here investigated the role of autophagy in the SMNdelta7 mouse model of SMA II (intermediate form of the disease) which leads to motor impairment by postnatal day 5 (P5) and to death by P13. We first showed by immunoblots that Beclin 1 and LC3-II expression levels increased in the lumbar spinal cord of the SMA pups. Electron microscopy and immunofluorescence studies confirmed that autophagic markers were enhanced in the ventral horn of SMA pups. To clarify the role of autophagy, we administered intracerebroventricularly (at P3) either an autophagy inhibitor (3-methyladenine, 3-MA), or an autophagy inducer (rapamycin) in SMA pups. Motor behavior was assessed daily with different tests: tail suspension, righting reflex, and hindlimb suspension tests. 3-MA significantly improved motor performance, extended the lifespan, and delayed MN death in lumbar spinal cord (10372.36?±?2716 MNs) compared to control-group (5148.38?±?94 MNs). Inhibition of autophagy by 3-MA suppressed autophagosome formation, reduced the apoptotic activation (cleaved caspase-3 and Bcl2) and the appearance of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive neurons, underlining that apoptosis and autophagy pathways are intricately intertwined. Therefore, autophagy is likely involved in MN death in SMA II, suggesting that it might represent a promising target for delaying the progression of SMA in humans as well.

Preliminary Safety and Tolerability of a Novel Subcutaneous Intrathecal Catheter System for Repeated Outpatient Dosing of Nusinersen to Children and Adults With Spinal Muscular Atrophy.Publié le 23 08 2018

BACKGROUND: Many patients with spinal muscular atrophy (SMA) who might benefit from intrathecal antisense oligonucleotide (nusinersen) therapy have scoliosis or spinal fusion that precludes safe drug delivery. To circumvent spinal pathology, we designed a novel subcutaneous intrathecal catheter (SIC) system by connecting an intrathecal catheter to an implantable infusion port.
METHODS: Device safety and tolerability were tested in 10 SMA patients (age, 5.4 to 30.5?y; 80% with 3 copies of SMN2); each received 3 sequential doses of nusinersen (n=30 doses). Pretreatment disease burden was evaluated using the Revised Hammersmith Scale, dynamometry, National Institutes of Health pegboard, pulmonary function testing, electromyography, and 2 health-related quality of life tools.
RESULTS: Device implantation took ?2 hours and was well tolerated. All outpatient nusinersen doses were successfully administered via SIC within 20 minutes on the first attempt, and required no regional or systemic analgesia, cognitive distraction, ultrasound guidance, respiratory precautions, or sedation. Cerebrospinal fluid withdrawn from the SIC had normal levels of glucose and protein; cerebrospinal fluid white blood cells were slightly elevated in 2 (22%) of 9 specimens (median, 1?cell/µL; range, 0 to 12?cells/µL) and red blood cells were detected in 7 (78%) specimens (median, 4; range, 0 to 2930?cells/µL).
DISCUSSION: Preliminary observations reveal the SIC to be relatively safe and well tolerated in SMA patients with advanced disease and spinal fusion. The SIC warrants further study and, if proven effective in larger trials of longer duration, could double the number of patients able to receive nusinersen worldwide while reducing administration costs 5- to 10-fold.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.

Subthalamic deep brain stimulation and trunk posture in Parkinson's disease.Publié le 23 08 2018

OBJECTIVES: We sought to assess the efficacy of subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson's disease (PD)-associated trunk posture abnormalities retrospectively analyzing data from 101 patients reporting mild-to-severe trunk posture abnormalities of a cohort of 216 PD patients treated with STN-DBS at our center.
METHODS: Abnormal trunk posture was rated on a scale of 0 (normal) to 4 (marked flexion with an extreme abnormality of posture) as per the grading score reported in the Unified Parkinson's Disease Rating Scale. The independent effect of STN-DBS on trunk posture was assessed comparing Medication-Off (presurgery) vs Stimulation-On/Medication-Off (post-surgery). The combined effect of STN-DBS plus levodopa was evaluated comparing Medication-On (presurgery) vs Stimulation-On/Medication-On (post-surgery). Analyses were conducted considering both the entire cohort of patients and the subgroup with camptocormia (CMC) and Pisa syndrome (PS).
RESULTS: The independent effect of STN-DBS resulted in a 41.4% improvement in abnormal trunk posture severity (P < .001), with 78.2% of patients (n = 79) reporting an improvement of at least 1 point. The combined effect of STN-DBS and levodopa resulted in a 30.9% improvement (P = .061), with 54.5% of patients (n = 55) reporting an improvement of at least 1 point. The subanalysis of patients with CMC (n = 23) and PS (n = 5) showed a 42.7% improvement in abnormal posture severity when considering the independent effect of STN-DBS (P < .001) and 30.5% when considering the combined effect of STN-DBS and levodopa (P < .001).
CONCLUSIONS: STN-DBS may have the potential for improving posture in patients with advanced PD.

Future avenues for therapy development for spinal muscular atrophy.Publié le 21 08 2018

PMID: 30124076 [PubMed - as supplied by publisher]

Novel BICD2 mutation in a Japanese family with autosomal dominant lower extremity-predominant spinal muscular atrophy-2.Publié le 21 08 2018

INTRODUCTION: The most common form of spinal muscular atrophy (SMA) is a recessive disorder caused by SMN1 mutations in 5q13, whereas the genetic etiologies of non-5q SMA are very heterogenous and largely remain to be elucidated. We present a father and son with atrophy and weakness of the lower leg muscles since infancy. Genetic studies in this family revealed a novel BICD2 mutation causing autosomal dominant lower extremity-predominant SMA type 2.
PATIENTS: The proband was the father, aged 30, and the son was aged 3. Both of them were born uneventfully to nonconsanguineous parents. While the father first walked at the age of 19?months, the son was unable to walk at age 3?years. In both, knee and ankle reflexes were absent and sensation was intact. Serum creatine kinase levels were normal. The son showed congenital arthrogryposis and underwent orthopedic corrections for talipes calcaneovalgus. Investigation of the father at the age of 5?years revealed normal results on nerve conduction studies and sural nerve biopsy. Electromyography showed chronic neurogenic change, and muscle biopsy showed features suggestive of denervation. The father was diagnosed clinically with a sporadic distal SMA. Follow-up studies showed very slow progression.
INVESTIGATIONS AND RESULTS: Next-generation and Sanger sequencing revealed a deleterious mutation in BICD2: c.1667A>G, p.Tyr556Cys, in this family.
DISCUSSION: BICD2 is a cytoplasmic conserved motor-adaptor protein involved in anterograde and retrograde transport along the microtubules. Next-generation sequencing will further clarify the genetic basis of non-5q SMA.

Preconditioning and Cellular Engineering to Increase the Survival of Transplanted Neural Stem Cells for Motor Neuron Disease Therapy.Publié le 19 08 2018

Despite the extensive research effort that has been made in the field, motor neuron diseases, namely, amyotrophic lateral sclerosis and spinal muscular atrophies, still represent an overwhelming cause of morbidity and mortality worldwide. Exogenous neural stem cell-based transplantation approaches have been investigated as multifaceted strategies to both protect and repair upper and lower motor neurons from degeneration and inflammation. Transplanted neural stem cells (NSCs) exert their beneficial effects not only through the replacement of damaged cells but also via bystander immunomodulatory and neurotrophic actions. Notwithstanding these promising findings, the clinical translatability of such techniques is jeopardized by the limited engraftment success and survival of transplanted cells within the hostile disease microenvironment. To overcome this obstacle, different methods to enhance graft survival, stability, and therapeutic potential have been developed, including environmental stress preconditioning, biopolymers scaffolds, and genetic engineering. In this review, we discuss current engineering techniques aimed at the exploitation of the migratory, proliferative, and secretive capacity of NSCs and their relevance for the therapeutic arsenal against motor neuron disorders and other neurological disorders.

Surgical treatment of spinal disorders in Parkinson's disease.Publié le 19 08 2018

PURPOSE: Most patients suffering from Parkinson's disease (PD) exhibit alterations in the posture, which can in several cases give rise to spine deformities, both in the sagittal and the coronal plane. In addition, degenerative disorders of the spine frequently associated to PD, such as spinal stenosis and sagittal instability, can further impact the quality of life of the patient. In recent years, spine surgery has been increasingly performed, with mixed results. The aim of this narrative review is to analyze the spinal disorders associated to PD, and the current evidence about their surgical treatment.
METHODS: Narrative review.
RESULTS: Camptocormia, i.e., a pronounced flexible forward bending of the trunk with 7% prevalence, is the most reported sagittal disorder of the spine. Pisa syndrome and scoliosis are both common and frequently associated. Disorders to the spinopelvic alignment were not widely investigated, but a tendency toward a lower ability of PD patients to compensate the sagittal malalignment with respect to non-PD elderly subjects with imbalance seems to emerge. Spine surgery in PD patients showed high rates of complications and re-operations.
CONCLUSIONS: Disorders of the posture and spinal alignment, both in the sagittal and in the coronal planes, are common in PD patients, and have a major impact on the quality of life. Outcomes of spine surgery are generally not satisfactory, likely mostly due to muscle dystonia and poor bone quality. Knowledge in this field needs to be consolidated by further clinical and basic science studies. These slides can be retrieved under Electronic Supplementary Material.

Do Perineuronal Net Elements Contribute to Pathophysiology of Spinal Muscular Atrophy? In Vitro and Transcriptomics Insights.Publié le 16 08 2018

Spinal muscular atrophy (SMA) is one of the most common childhood onset neurodegenerative disorders in global health whereby novel biomarkers and therapeutic targets are sorely needed. SMA is an autosomal recessive genetic disorder resulting in degeneration of ?-motor neurons in the brain stem and spinal cord that leads to mortality in infants worldwide. In majority of the patients, SMA is caused by homozygous deletion of the SMN1 gene. The clinical spectrum of the SMA displays, however, large person-to-person variations where the underlying mechanisms are poorly understood. We report in this study transcriptomics insights gleaned from patients with the severe type I (GM03813 and GM09677) and the mild type III. Pathway enrichment and functional analysis showed that especially extracellular matrix (ECM), synapse organization, and ECM receptor interaction pathways were affected. Among the neural ECM components, hyaluronan and proteoglycan link protein (HAPLN1), which is a key triggering molecule of the perineuronal net (PNN), was significantly downregulated in type I fibroblasts compared to type III. PNN is a specialized form of neural ECM around the neuronal cell bodies and dendrites in the central nervous system. In addition, we evaluated the PNN expression in vitro in a model established by SMN silencing in the PC12 rat pheochromocytoma cell line which can be differentiated into neurons with nerve growth factor treatment. In this neuronal in vitro model, we found that HAPLN1 showed a significant 50% decrease. Our results describe the association between PNN elements, especially HAPLN1, and SMA pathophysiology for the first time. These observations collectively inform future translational research on SMA for discovery of novel molecular targets for diagnostics and precision medicine innovation.

Evaluation of the role of an antioxidant gene in NSC-34 motor neuron-like cells as a model of a motor neuron disease.Publié le 16 08 2018

BACKGROUND: Spinal muscular atrophy is a rare genetic disease, which primarily affects motor neurons and predominantly occurs in children. To date, alternatives for the treatment of the disease have been controversial. Spinal muscular atrophy has a multi-factorial etiology, with mitochondrial oxidative stress considered as the crucial pathogenic mechanism. To determine the mechanisms underlying the loss of motor neurons, NSC-34 motor neuron-like cells are often used as an in vitro model of spinal muscular atrophy. As Plastin 3 (PLS3) has been demonstrated as a modifier of spinal muscular atrophy, the aim of the current study was to evaluate the neuroprotective effect of plastin 3 in NSC-34 cells.
MATERIALS AND METHODS: Plastin 3 was overexpressed in human embryonic kidney 293T cells and NSC-34 cells via lentiviral transduction. NSC-34 cells transduced with a lentiviral vector carrying the gene for LacZ ?-galactosidase served as a control. Oxidative stress was then induced by depriving cells of serum, and the protective effect of plastin 3 was assessed using a cellular reactive oxygen species detection assay.
RESULTS: While plastin 3 was successfully overexpressed in human embryonic kidney 293T cells and NSC-34 cells, upregulation of this protein did not significantly decrease oxidative stress in serum-deprived NSC-34 cells relative to controls.
CONCLUSIONS: Plastin 3 overexpression in NSC-34 cells did not elicit an antioxidative effect following serum deprivation.

Spinraza-a rare disease success story.Publié le 14 08 2018

PMID: 28963567 [PubMed - indexed for MEDLINE]

Gene Therapy, more than ever-a new vision for the journal.Publié le 14 08 2018

PMID: 28963565 [PubMed - indexed for MEDLINE]

Spinraza-the patient perspective.Publié le 14 08 2018

PMID: 28880018 [PubMed - indexed for MEDLINE]

Gene therapy for neurological disorders: progress and prospects.Publié le 13 08 2018

Adeno-associated viral (AAV) vectors are a rapidly emerging gene therapy platform for the treatment of neurological diseases. In preclinical studies, transgenes encoding therapeutic proteins, microRNAs, antibodies or gene-editing machinery have been successfully delivered to the central nervous system with natural or engineered viral capsids via various routes of administration. Importantly, initial clinical studies have demonstrated encouraging safety and efficacy in diseases such as Parkinson disease and spinal muscular atrophy, as well as durability of transgene expression. Here, we discuss key considerations and challenges in the future design and development of therapeutic AAV vectors, highlighting the most promising targets and recent clinical advances.

Incidence of infantile spinal muscular atrophy on Shikoku Island of Japan.Publié le 13 08 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by homozygous mutations in the SMN1 gene. SMA has long been known to be the most common genetic cause of infant mortality. However, there have been no reports on the epidemiology of infantile SMA (types 1 and 2) based on genetic testing in Japan. In this study, we estimated the incidence of infantile SMA on Shikoku Island, which is a main island of Japan and consists of four prefectures: Ehime, Kagawa, Tokushima and Kochi.
METHODS: A questionnaire was sent to 91 hospitals on Shikoku Island to investigate the number of SMA infants born from 2011 to 2015. A second questionnaire was then sent to confirm the diagnoses of SMA based on clinical and genetic features.
RESULTS: Responses were received from all of the hospitals, and four patients were diagnosed with infantile SMA among 147,950 live births. We estimated the incidence of infantile SMA patients as 2.7 per 100,000 live births (95% confidence interval, 0.1-5.4). A comparison of the four prefectures indicated that the incidence of infantile SMA was significantly higher in Ehime Prefecture than in the other three prefectures; 5.6 per 100,000 live births (95% confidence interval, -0.7 to 11.9) in Ehime Prefecture and 1.1 per 100,000 live births (95% confidence interval, -1.0 to 3.1) in the other prefectures.
CONCLUSION: We estimated the incidence of infantile SMA in an isolated area of Japan. For more precise determination of the incidence of infantile SMA, further studies that include neonatal screening will be needed.

Gene therapy rescues newborns with spinal muscular atrophy.Publié le 07 08 2018

PMID: 30080825 [PubMed - in process]

Protocol for a phase II, monocentre, double-blind, placebo-controlled, cross-over trial to assess efficacy of pyridostigmine in patients with spinal muscular atrophy types 2-4 (SPACE trial).Publié le 01 08 2018

INTRODUCTION: Hereditary proximal spinal muscular atrophy (SMA) is caused by homozygous loss of function of the survival motor neuron 1 gene. The main characteristic of SMA is degeneration of alpha motor neurons in the anterior horn of the spinal cord, but recent studies in animal models and patients have shown additional anatomical abnormalities and dysfunction of the neuromuscular junction (NMJ). NMJ dysfunction could contribute to symptoms of weakness and fatigability in patients with SMA. We hypothesise that pyridostigmine, an acetylcholinesterase inhibitor that improves neuromuscular transmission, could improve NMJ function and thereby muscle strength and fatigability in patients with SMA.
METHODS AND ANALYSIS: We designed a monocentre, placebo-controlled, double-blind cross-over trial with pyridostigmine and placebo to investigate the effect and efficacy of pyridostigmine on muscle strength and fatigability in patients with genetically confirmed SMA. We aim to include 45 patients with SMA types 2-4, aged 12 years and older in the Netherlands. Participants receive 8 weeks of treatment with pyridostigmine and 8 weeks of treatment with placebo in a random order separated by a washout period of 1?week. Treatment allocation is double blinded. Treatment dose will gradually be increased from 2?mg/kg/day to the maximum dose of 6?mg/kg/day in four daily doses, in the first week of each treatment period. The primary outcome measures are a change in the Motor Function Measure and repeated nine-hole peg test before and after treatment. Secondary outcome measures are changes in recently developed endurance tests, that is, the endurance shuttle nine-hole peg test, the endurance shuttle box and block test and the endurance shuttle walk test, muscle strength, level of daily functioning, quality of and activity in life, perceived fatigue and fatigability, presence of decrement on repetitive nerve stimulation and adverse events.
ETHICS AND DISSEMINATION: The protocol is approved by the local medical ethical review committee at the University Medical Center Utrecht and by the national Central Committee on Research Involving Human Subjects. Findings will be shared with the academic and medical community, funding and patient organisations in order to contribute to optimisation of medical care and quality of life for patients with SMA.

Manual Feeding Device Experiences of People With a Neurodisability.Publié le 01 08 2018

OBJECTIVE: Neurological bilateral upper limb weakness can result in self-feeding difficulties and reliance on care providers. Mealtimes become time consuming and frustrating. In this exploratory inquiry, we examined the experiences of users of a feeding device.
METHOD: Semistructured interviews were either conducted by telephone or administered via email to explore quality of life, changes to independence, benefits and limitations, and psychological impact of the equipment.
RESULTS: Thematic analysis gave rise to five themes: independence and positivity, emotions, impact on family and social life, equipment functionality, and motivation.
CONCLUSION: This exploratory inquiry has contributed new qualitative evidence to the knowledge and understanding of users' experiences of a manual feeding device. Users reported that the need for assistance was reduced and that their quality of life, independence, and freedom improved. Time and resources savings for the family, care providers, and staff appeared to result in a more equal relationship between user and care provider.

Amyotrophic lateral sclerosis: the complex path to precision medicine.Publié le 30 07 2018

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease of the corticomotorneuronal network responsible for voluntary movement. There are well-established clinical, genetic and pathological overlaps between ALS and frontotemporal dementia (FTD), which together constitute the 'TDP-43 proteinopathies'. An ever-expanding list of genes in which mutation leads to typical ALS have implicated abnormalities in RNA processing, protein homoeostasis and axonal transport. How these apparently distinct pathways converge to cause the characteristic clinical syndrome of ALS remains unclear. Although there are major gaps in our understanding of the essential nature of ALS pathophysiology, the identification of genetic causes in up to 15% of ALS patients, coupled with advances in biotechnology and biomarker research provide a foundation for approaches to treatment based on 'precision medicine', and even prevention of the disease in pre-symptomatic mutation carriers in the future. Currently, multidisciplinary care remains the bedrock of management and this is increasingly being put onto an evidence-based footing.

Symptom management and psychological support for families are the cornerstones of end-of-life care for children with spinal muscular atrophy type 1.Publié le 28 07 2018

AIM: This study described end-of-life care for children affected by spinal muscular atrophy type 1 (SMA1), which is characterised by progressive muscle weakness and develops in the first six months of life.
METHODS: We retrospectively analysed 17 children (13 boys) who attended the University of Padua's paediatric palliative care centre in Italy from March 2000 to March 2015. All the children received supportive care without proactive respiratory intervention to prolong survival.
RESULTS: The median age at admission was 3.57 months, and the median age at death was 6.80 months. The most frequent symptoms were dyspnoea and pain. In the last 72 hours of life, 15/17 children required more intense doses of morphine and, or, benzodiazepines for intractable dyspnoea and pain, but deep palliative sedation was not needed. Airway suction to manage secretions and nasogastric tubes was required in all cases. The place of death was previously planned by the parents in all cases - home, hospital or hospice - and 15/17 deaths occurred in that place. We also interviewed 16 of the 17 parents after their child died.
CONCLUSION: Our study found that symptom management and psychological support for families were the cornerstones of end-of-life care for children with SMA1.

Prospective and longitudinal natural history study of patients with Type 2 and 3 spinal muscular atrophy: Baseline data NatHis-SMA study.Publié le 27 07 2018

Spinal muscular atrophy (SMA) is a monogenic disorder caused by loss of function mutations in the survival motor neuron 1 gene, which results in a broad range of disease severity, from neonatal to adult onset. There is currently a concerted effort to define the natural history of the disease and develop outcome measures that accurately capture its complexity. As several therapeutic strategies are currently under investigation and both the FDA and EMA have recently approved the first medical treatment for SMA, there is a critical need to identify the right association of responsive outcome measures and biomarkers for individual patient follow-up. As an approved treatment becomes available, untreated patients will soon become rare, further intensifying the need for a rapid, prospective and longitudinal study of the natural history of SMA Type 2 and 3. Here we present the baseline assessments of 81 patients aged 2 to 30 years of which 19 are non-sitter SMA Type 2, 34 are sitter SMA Type 2, 9 non-ambulant SMA Type 3 and 19 ambulant SMA Type 3. Collecting these data at nine sites in France, Germany and Belgium established the feasibility of gathering consistent data from numerous and demanding assessments in a multicenter SMA study. Most assessments discriminated between the four groups well. This included the Motor Function Measure (MFM), pulmonary function testing, strength, electroneuromyography, muscle imaging and workspace volume. Additionally, all of the assessments showed good correlation with the MFM score. As the untreated patient population decreases, having reliable and valid multi-site data will be imperative for recruitment in clinical trials. The pending two-year study results will evaluate the sensitivity of the studied outcomes and biomarkers to disease progression.
TRIAL REGISTRATION: ClinicalTrials.gov (NCT02391831).

A Semi-mechanistic Population Pharmacokinetic Model of Nusinersen: An Antisense Oligonucleotide for the Treatment of Spinal Muscular Atrophy.Publié le 26 07 2018

A pharmacokinetic (PK) model was developed for Nusinersen, an antisense oligonucleotide (ASO) that is the first approved treatment for Spinal Muscular Atrophy. The model was built with data from 92 non-human primates following intrathecal doses (0.3-7mg) and characterized the PK in cerebrospinal fluid (CSF), plasma, total spinal cord, brain and pons. The estimated volumes were 13.6, 937, 4.5, 53.8 and 2.11 mL, respectively. Global sensitivity analysis demonstrated that the CSF-to-plasma drug distribution rate (0.09 hr-1 ) is a major determinant of the maximum nusinersen concentration in central nervous system tissues. Physiological age- and body weight-based allometric scaling was then implemented with exponent values of -0.08 and 1 for the rate constants and the volume of distribution, respectively. Simulations of the scaled model were in agreement with clinical observations from 52 pediatric Phase I PK profiles. The developed model can be employed to guide the design of clinical trials with ASOs. This article is protected by copyright. All rights reserved.

Intrathecal administration of Nusinersen in type 1 SMA: successful psychological program in a single Italian center.Publié le 26 07 2018

Nusinersen is the first approved drug to treat spinal muscular atrophy (SMA). Its periodic intrathecal delivery may cause psychological burden in infants and in their parents. We report our experience during expanded access program (EAP) for type 1 SMA in a single Italian center. Because of the occurrence of stress emotional states, anxious reactions and fear before, during, and after lumbar puncture (LP), a specific psychological intervention was implemented based on regulation of emotions, anticipatory expectations, and post-event attributions. Activities included the use of fairy tales, distraction, music play through listening preferred cartoon themes in the youngest children, and contextual games and solution of fun riddle quizzes in the oldest ones. State anxiety greatly reduced in children and their parents. Treatment of psychological aspects should therefore become an integral part of health care in SMA infants and children during Nusinersen treatment.

Discovery of Risdiplam, a Selective Survival of Motor Neuron-2 ( SMN2) Gene Splicing Modifier for the Treatment of Spinal Muscular Atrophy (SMA).Publié le 26 07 2018

SMA is an inherited disease that leads to loss of motor function and ambulation and a reduced life expectancy. We have been working to develop orally administrated, systemically distributed small molecules to increase levels of functional SMN protein. Compound 2 was the first SMN2 splicing modifier tested in clinical trials in healthy volunteers and SMA patients. It was safe and well tolerated and increased SMN protein levels up to 2-fold in patients. Nevertheless, its development was stopped as a precautionary measure because retinal toxicity was observed in cynomolgus monkeys after chronic daily oral dosing (39 weeks) at exposures in excess of those investigated in patients. Herein, we describe the discovery of 1 (risdiplam, RG7916, RO7034067) that focused on thorough pharmacology, DMPK and safety characterization and optimization. This compound is undergoing pivotal clinical trials and is a promising medicine for the treatment of patients in all ages and stages with SMA.

Acid ceramidase deficiency: Farber disease and SMA-PME.Publié le 23 07 2018

Acid ceramidase (ACDase) deficiency is a spectrum of disorders that includes a rare lysosomal storage disorder called Farber disease (FD) and a rare epileptic disorder called spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). Both disorders are caused by mutations in the ASAH1 gene that encodes the lysosomal hydrolase that breaks down the bioactive lipid ceramide. To date, there have been fewer than 200 reported cases of FD and SMA-PME in the literature. Typical textbook manifestations of classical FD include the formation of subcutaneous nodules, accumulation of joint contractures, and development of a hoarse voice. In reality, however, the clinical presentation is much broader. Patients may develop severe pathologies leading to death in infancy or may develop attenuated forms of the disorder wherein they are often misdiagnosed or not diagnosed until adulthood. A clinical variability also exists for SMA-PME, in which patients develop progressive muscle weakness and seizures. Currently, there is no known cure for FD or for SMA-PME. The main treatment is symptom management. In rare cases, treatment may include surgery or hematopoietic stem cell transplantation. Research using disease models has provided insights into the pathology as well as the role of ACDase in the development of these conditions. Recent studies have highlighted possible biomarkers for an effective diagnosis of ACDase deficiency. Ongoing work is being conducted to evaluate the use of recombinant human ACDase (rhACDase) for the treatment of FD. Finally, gene therapy strategies for the treatment of ACDase deficiency are actively being pursued. This review highlights the broad clinical definition and outlines key studies that have improved our understanding of inherited ACDase deficiency-related conditions.

Emerging antisense oligonucleotide and viral therapies for amyotrophic lateral sclerosis.Publié le 23 07 2018

PURPOSE OF REVIEW: Amyotrophic lateral sclerosis (ALS) is a rapidly fatal disease for which there is currently no effective therapy. The present review describes the current progress of existing molecular therapies in the clinical trial pipeline and highlights promising future antisense oligonucleotide (ASO) and viral therapeutic strategies for treating ALS.
RECENT FINDINGS: The immense progress in the design of clinical trials and generation of ASO therapies directed towards superoxide dismutase-1 (SOD1) and chromosome 9 open reading frame 72 (C9orf72) repeat expansion related disease have been propelled by fundamental work to identify the genetic underpinnings of familial ALS and develop relevant disease models. Preclinical studies have also identified promising targets for sporadic ALS (sALS). Moreover, encouraging results in adeno-associated virus (AAV)-based therapies for spinal muscular atrophy (SMA) provide a roadmap for continued improvement in delivery and design of molecular therapies for ALS.
SUMMARY: Advances in preclinical and clinical studies of ASO and viral directed approaches to neuromuscular disease, particularly ALS, indicate that these approaches have high specificity and are relatively well tolerated.

Nusinersen: A Review in 5q Spinal Muscular Atrophy.Publié le 23 07 2018

Spinal muscular atrophy (SMA) is a rare autosomal recessive neuromuscular disorder most commonly caused by a deletion or mutation in the survival motor neuron 1 (SMN1) gene, which leads to insufficient levels of survival motor neuron (SMN) protein. In such patients, SMN protein production relies on the SMN2 gene. Nusinersen (Spinraza®) is a modified antisense oligonucleotide (ASO) approved in several countries worldwide, including the USA, Japan and those of the EU, for the treatment of 5q SMA. It binds to a specific site in the intron downstream of exon 7 on the SMN2 pre-messenger ribonucleic acid (pre-mRNA), modulating the splicing of SMN2 mRNA and thus increasing the production of SMN protein. In multinational phase III studies, nusinersen (administered intrathecally) provided significant improvements in motor function in patients with infantile- and later-onset 5q SMA compared with a sham procedure. It was also associated with significant improvements in event-free survival and overall survival in patients with infantile-onset 5q SMA, with preliminary data from an ongoing multinational phase II study suggesting a potential clinical benefit with early intervention (i.e. before symptom onset) with nusinersen. Preliminary subgroup data from a phase III extension study suggested continued improvements in motor function with longer-term therapy. Nusinersen demonstrated a favourable safety profile in clinical studies in symptomatic and presymptomatic patients, with no safety concerns due to nusinersen exposure. In conclusion, although studies in presymptomatic patients and over the long term in symptomatic patients are ongoing, current evidence indicates that nusinersen modifies 5q SMA and has a favourable safety profile and, thus, is a valuable treatment for this patient population.

A comprehensive institutional overview of intrathecal nusinersen injections for spinal muscular atrophy.Publié le 20 07 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal-recessive neuromuscular disorder resulting in progressive muscle weakness. In December 2016, the U.S. Food and Drug Administration approved the first treatment for SMA, a drug named nusinersen (Spinraza) that is administered intrathecally. However many children with SMA have neuromuscular scoliosis or spinal instrumentation resulting in challenging intrathecal access. Therefore alternative routes must be considered in these complex patients.
OBJECTIVE: To investigate routes of drug access, we reviewed our institutional experience of administering intrathecal nusinersen in all children with spinal muscular atrophy regardless of spinal anatomy or instrumentation.
MATERIALS AND METHODS: We reviewed children with SMA who were referred for intrathecal nusinersen injections from March to December 2017 at our institution. In select children with spinal hardware, spinal imaging was requested to facilitate pre-procedure planning. Standard equipment for intrathecal injections was utilized. All children were followed up by their referring neurologist.
RESULTS: A total of 104 intrathecal nusinersen injections were performed in 26 children with 100% technical success. Sixty procedures were performed without pre-procedural imaging and via standard interspinous technique. The remaining 44 procedures were performed in 11 complex (i.e. neuromuscular scoliosis or spinal instrumentation) patients requiring pre-procedural imaging for planning purposes. Nineteen of the 44 complex procedures were performed via standard interspinous technique from L2 to S1. Twenty-two of the 44 complex procedures were performed using a neural-foraminal approach from L3 to L5. Three of the 44 complex procedures were performed via cervical puncture technique. There were no immediate or long-term complications but there was one child with short-term complications of meningismus and back pain at the injection site.
CONCLUSION: Although we achieved 100% technical success in intrathecal nusinersen administration, our practices evolved during the course of this study. As a result of our early experience we developed an algorithm to assist in promoting safe and effective nusinersen administration in children with spinal muscular atrophy regardless of SMA type, abnormal spinal anatomy and complex spinal instrumentation.

Different profiles of upper limb function in four types of neuromuscular disorders.Publié le 20 07 2018

The aim of this research was to study impairments, activity limitations and participation restrictions due to upper limb involvement in people with four different types of neuromuscular disorders (NMD) - FacioScapuloHumeral Dystrophy (FSHD), Limb-Girdle Muscular Dystrophy (LGMD), Spinal Muscular Atrophy (SMA) and Duchenne Muscular Dystrophy (DMD) - and to investigate whether common or different profiles could be identified. Total of 267 respondents with NMD from the Netherlands answered a set of questionnaires covering upper limb impairments (pain and stiffness), activity limitations and participation restrictions. Pain was most often reported by persons with FSHD. Problems in the FSHD group were mainly characterized by relatively high scores for pain and stiffness and low scores for activity limitations. People with LGMD reported also low scores for activity limitations. Conversely, people with SMA and DMD experienced in general relatively low scores for pain and stiffness and high scores for activity limitations. Although people with FSHD and LGMD had relatively few activity limitations, all NMD groups experienced restrictions when participating in social activities. Our results indicate specific profiles of upper limb function in different types of NMD. While the profile observed in persons with FSHD seems to reflect overuse, the profile seen in persons with DMD and SMA is suspicious of disuse, each requiring a specific rehabilitation strategy.

Nusinersen: A Treatment for Spinal Muscular Atrophy.Publié le 17 07 2018

OBJECTIVE: To review the efficacy and safety of nusinersen (Spinraza) in the treatment of spinal muscular atrophy (SMA).
DATA SOURCES: An English-language literature search of PubMed and MEDLINE (1946 to June 2018) was performed using the terms nusinersen, ISIS-SMN (Rx), and spinal muscular atrophy. Manufacturer prescribing information, abstracts, article bibliographies, and clinicaltrials.gov data were incorporated for additional materials.
STUDY SELECTION/DATA EXTRACTION: All clinical trials of nusinersen were identified and analyzed in the review.
DATA SYNTHESIS: Nusinersen is the first drug therapy approved for the treatment of SMA. It is a novel modified antisense oligonucleotide designed to treat SMA caused by mutations in chromosome 5q that lead to survival motor neuron protein deficiency. Nusinersen has been studied for safety, pharmacokinetics, and efficacy in both open-label and randomized controlled trials. The studies show improvement in motor function across SMA of all types. The most common adverse effects were respiratory tract infections, headache, back pain, constipation, and post-lumbar puncture syndrome. Relevance to Patient Care and Clinical Practice: Based on phase III trial data, nusinersen produced positive changes in the clinical course of patients with SMA. The acquisition and administration of nusinersen present a number of challenges in clinical practice. Its intrathecal delivery and costly price tag must be recognized.
CONCLUSION: Nusinersen is safe and effective in patients with SMA. It was well tolerated across all studied age groups.

Cervical puncture to deliver nusinersen in patients with spinal muscular atrophy.Publié le 15 07 2018

OBJECTIVE: To report our experience delivering intrathecal nusinersen through cervical puncture in patients with spinal muscular atrophy (SMA) with no lumbar access.
BACKGROUND: SMA is a neuromuscular disorder characterized by profound muscle weakness, atrophy, and paralysis due to degeneration of the anterior horn cells. Nusinersen, the first Food and Drug Administration-approved treatment for SMA, is administered intrathecally via lumbar puncture; however, many patients with SMA have scoliosis or solid spinal fusion with hardware that makes lumbar access impossible. Studies in primates have demonstrated better spinal cord tissue concentration with intrathecal injections than with intracerebral ventricular injections. Therefore we have used C1/C2 puncture as an alternative to administer nusinersen.
METHOD: Retrospective chart review.
RESULTS: Intrathecal nusinersen via cervical puncture was given to 3 patients who had thoracic and lumbosacral spinal fusion: a 12-year-old girl with type 1 SMA and 2 17-year-old girls with type 2 SMA. Cervical puncture was performed without deep sedation under fluoroscopic guidance using a 25-G or a 24-G Whitacre needle in the posterior aspect of C1-C2 interspace and full dose of nusinersen (12 mg/5 mL) was injected after visualizing free CSF flow. Patients completed their 4 loading doses and first maintenance dose of nusinersen, and 15 procedures were successful and well-tolerated.
CONCLUSION: Cervical puncture is a feasible alternative delivery route to administer intrathecal nusinersen in patients with longstanding SMA and spine anatomy precluding lumbar access when done by providers with expertise in this procedure.

Two breakthrough gene-targeted treatments for spinal muscular atrophy: challenges remain.Publié le 11 07 2018

The motor neuron disease spinal muscular atrophy (SMA) is caused by recessive, loss-of-function mutations of the survival motor neuron 1 gene (SMN1). Alone, such mutations are embryonically lethal, but SMA patients retain a paralog gene, SMN2, that undergoes alternative pre-mRNA splicing, producing low levels of SMN protein. By mechanisms that are not well understood, reduced expression of the ubiquitously expressed SMN protein causes an early-onset motor neuron disease that often results in infantile or childhood mortality. Recently, striking clinical improvements have resulted from two novel treatment strategies to increase SMN protein by (a) modulating the splicing of existing SMN2 pre-mRNAs using antisense oligonucleotides, and (b) transducing motor neurons with self-complementary adeno-associated virus 9 (scAAV9) expressing exogenous SMN1 cDNA. We review the recently published clinical trial results and discuss the differing administration, tissue targeting, and potential toxicities of these two therapies. We also focus on the challenges that remain, emphasizing the many clinical and biologic questions that remain open. Answers to these questions will enable further optimization of these remarkable SMA treatments as well as provide insights that may well be useful in application of these therapeutic platforms to other diseases.

Insights into the Pharmaceuticals and Mechanisms of Neurological Orphan Diseases: Current Status and Future Expectations.Publié le 08 07 2018

Several rare or orphan diseases have been characterized that singly affect low numbers of people, but cumulatively reach ?6% - 10% of the population in Europe and in the United States. Human genetics has shown to be broadly effective when evaluating subjacent genetic defects such as orphan genetic diseases, but on the other hand, a modest progress has been achieved toward comprehending the molecular pathologies and designing new therapies. Chemical genetics, placed at the interface of chemistry and genetics, could be employed to understand the molecular mechanisms of subjacent illnesses and for the discovery of new remediation processes. This review debates current progress in chemical genetics, and how a variety of compounds and reaction mechanisms can be used to study and ultimately treat rare genetic diseases. We focus here on a study involving Amyotrophic lateral sclerosis (ALS), Duchenne Muscular Dystrophy (DMD), Spinal muscular atrophy (SMA) and Familial Amyloid Polyneuropathy (FAP), approaching different treatment methods and the reaction mechanisms of several compounds, trying to elucidate new routes capable of assisting in the treatment profile.

CHP1 reduction ameliorates spinal muscular atrophy pathology by restoring calcineurin activity and endocytosis.Publié le 04 07 2018

Autosomal recessive spinal muscular atrophy (SMA), the leading genetic cause of infant lethality, is caused by homozygous loss of the survival motor neuron 1 (SMN1) gene. SMA disease severity inversely correlates with the number of SMN2 copies, which in contrast to SMN1, mainly produce aberrantly spliced transcripts. Recently, the first SMA therapy based on antisense oligonucleotides correcting SMN2 splicing, namely SPINRAZATM, has been approved. Nevertheless, in type I SMA-affected individuals-representing 60% of SMA patients-the elevated SMN level may still be insufficient to restore motor neuron function lifelong. Plastin 3 (PLS3) and neurocalcin delta (NCALD) are two SMN-independent protective modifiers identified in humans and proved to be effective across various SMA animal models. Both PLS3 overexpression and NCALD downregulation protect against SMA by restoring impaired endocytosis; however, the exact mechanism of this protection is largely unknown. Here, we identified calcineurin-like EF-hand protein 1 (CHP1) as a novel PLS3 interacting protein using a yeast-two-hybrid screen. Co-immunoprecipitation and pull-down assays confirmed a direct interaction between CHP1 and PLS3. Although CHP1 is ubiquitously present, it is particularly abundant in the central nervous system and at SMA-relevant sites including motor neuron growth cones and neuromuscular junctions. Strikingly, we found elevated CHP1 levels in SMA mice. Congruently, CHP1 downregulation restored impaired axonal growth in Smn-depleted NSC34 motor neuron-like cells, SMA zebrafish and primary murine SMA motor neurons. Most importantly, subcutaneous injection of low-dose SMN antisense oligonucleotide in pre-symptomatic mice doubled the survival rate of severely-affected SMA mice, while additional CHP1 reduction by genetic modification prolonged survival further by 1.6-fold. Moreover, CHP1 reduction further ameliorated SMA disease hallmarks including electrophysiological defects, smaller neuromuscular junction size, impaired maturity of neuromuscular junctions and smaller muscle fibre size compared to low-dose SMN antisense oligonucleotide alone. In NSC34 cells, Chp1 knockdown tripled macropinocytosis whereas clathrin-mediated endocytosis remained unaffected. Importantly, Chp1 knockdown restored macropinocytosis in Smn-depleted cells by elevating calcineurin phosphatase activity. CHP1 is an inhibitor of calcineurin, which collectively dephosphorylates proteins involved in endocytosis, and is therefore crucial in synaptic vesicle endocytosis. Indeed, we found marked hyperphosphorylation of dynamin 1 in SMA motor neurons, which was restored to control level by the heterozygous Chp1 mutant allele. Taken together, we show that CHP1 is a novel SMA modifier that directly interacts with PLS3, and that CHP1 reduction ameliorates SMA pathology by counteracting impaired endocytosis. Most importantly, we demonstrate that CHP1 reduction is a promising SMN-independent therapeutic target for a combinatorial SMA therapy.

[Clinical diagnosis and management of cervical spondylotic amyotrophy].Publié le 04 07 2018

Objective: To investigate the clinical characteristics and surgical treatment of cervical spondylotic amyotrophy. Methods: Thirteen patients(13 man) with proximal (10) and distal(3) cervical spondylotic amyotrophy between November 2014 and September 2016 were included in this study. The average age of the patients was 55 (range, 47-66) years. The sex, age, clinical course, type of amyotrophy, lesion segment and postdecompression improvement in muscle power were reviewed. Results: Of 13 cervical spondylotic amyotrophy patients, 9 were performed on with cervical disectomy, 2 were performed on with cervical posterior operation, 2 remainding patients received nonoperative treatment. Cervical spondylotic amyotrophy patients were followed up 6-22 (average 10.6) months, muscle power of 4 patients (all proximal-type)were improved completely (the average recovery time were 4.4 months), muscle power of 6 patients were improved uncompletely, 1 patients failed to improve, the 2 remainding patients received nonoperative treatment had no change. Conclusion: Cervical spondylotic amyotrophy as a rare type of cervical spondylotic disorder, It should distinguish cervical spondylotic amyotrophy from amyotrophic lateral sclerosis, especially in the early stage of amyotrophic lateral sclerosis. A surgical treatment is recommended as the first line of proximal-type CSA, especially those with serious compression. It is important that clinicians should be aware that distal-type CSA had a poor results, resulting in a lower lower satisfaction, especially those with no, or insignificant, sensory disturbance.

[A survivor of Hodgkin lymphoma manifesting dropped head syndrome as a late-onset complication of radiotherapy: a case report].Publié le 29 06 2018

We report the case of a 50-year-old female survivor of Hodgkin lymphoma (HL), who developed dropped head syndrome (DHS). The patient was diagnosed with HL at 20 years of age, and underwent chemo-radiotherapy, which led to complete remission. Undergoing supplemental therapy for post-radiation hypothyroidism, she had twin babies. She noticed white stains on her neck at the age of 30, and the decolored area gradually expanded. Sixteen years after the radiotherapy (RT), her posterior neck muscle strength began to decline. She had to make considerable efforts to keep her neck straight, and came to experience a severe pain in the neck and shoulders. The patient visited our department due to DHS at the age of 50. She had leukoderma, muscle weakness, and muscle atrophy in the neck and para-spinal region, which were consistent with the area of RT. The strength was preserved in the other parts of the muscle, including the proximal upper limbs. Sensory nerve disorder was not detected. The serum creatine kinase level was slightly elevated. Cervical spine or cervical cord disease that can cause DHS was not detected by MRI examination. The MRI and CT images revealed marked atrophy in the posterior neck and para-spinal muscles. The electromyogram revealed myopathic changes, and the cause of her DHS was diagnosed as radiation-induced myopathy. DHS is a well-known late-onset radiation injury, and Japanese cases have been reported in elderly persons with laryngeal or lung cancer. However, there have been no Japanese case reports of radiation-induced DHS due to RT against HL in younger persons. The patient had visited several clinics and hospitals before she came to our hospital, but RT-induced DHS had been overlooked. Greater recognition and consideration is required for DHS as one of the various issues arising after long passage of HL survivors.

Ambulatory function in spinal muscular atrophy: Age-related patterns of progression.Publié le 28 06 2018

Individuals with spinal muscular atrophy (SMA) type 3 are able to walk but they have weakness, gait impairments and fatigue. Our primary study objective was to examine longitudinal changes in the six-minute walk test (6MWT) and to evaluate whether age and SMA type 3 subtype are associated with decline in ambulatory function. Data from three prospective natural history studies were used. Seventy-three participants who performed the 6MWT more than once, at least 6 months apart, were included; follow-up ranged from 0.5-9 years. Only data from patients who completed the 6MWT were included. The mean age of the participants was 13.5 years (range 2.6-49.1), with 52 having disease onset before age 3 years (type 3A). At baseline, type 3A participants walked a shorter distance on average (257.1 m) than type 3B participants (390.2 m) (difference = 133.1 m, 95% confidence interval [CI] 71.8-194.3, p < 0.001). Distance walked was weakly associated with age (r = 0.25, p = 0.04). Linear mixed effects models were used to estimate the mean annual rate of change. The overall mean rate of change was -7.8 m/year (95% CI -13.6 --2.0, p = 0.009) and this did not differ by subtype (type 3A: -8.5 m/year, type 3B: -6.6 m/year, p = 0.78), but it did differ by age group (< 6: 9.8 m/year; 6-10: -7.9 m/year; 11-19: -20.8 m/year; ? 20: -9.7 m/year; p = 0.005). Our results showed an overall decline on the 6MWT over time, but different trajectories were observed depending on age. Young ambulant SMA patients gain function but in adolescence, patients lose function. Future clinical trials in ambulant SMA patients should consider in their design the different trajectories of ambulatory function over time, based on age.

Targeting TGF? Signaling to Address Fibrosis Using Antisense Oligonucleotides.Publié le 28 06 2018

Fibrosis results from the excessive accumulation of extracellular matrix in chronically injured tissue. The fibrotic process is governed by crosstalk between many signaling pathways. The search for an effective treatment is further complicated by the fact that there is a degree of tissue-specificity in the pathways involved, although the process is not completely understood for all tissues. A plethora of drugs have shown promise in pre-clinical models, which is not always borne out translationally in clinical trial. With the recent approvals of two antisense oligonucleotides for the treatment of the genetic diseases Duchenne muscular dystrophy and spinal muscular atrophy, we explore here the potential of antisense oligonucleotides to knockdown the expression of pro-fibrotic proteins. We give an overview of the generalized fibrotic process, concentrating on key players and highlight where antisense oligonucleotides have been used effectively in cellular and animal models of different fibrotic conditions. Consideration is given to the advantages antisense oligonucleotides would have as an anti-fibrotic therapy alongside factors that would need to be addressed to improve efficacy. A prospective outlook for the development of antisense oligonucleotides to target fibrosis is outlined.

Mathematical Disease Progression Modeling in Type 2/3 Spinal Muscular Atrophy.Publié le 28 06 2018

Introduction We propose a mathematical model to empirically describe spinal muscular atrophy (SMA) progression assessed by the three domains of the motor function measure (MFM) scale. The model implements development and deterioration of muscle function. Methods Nonlinear mixed-effects modeling was applied to data from two observational and one prospective clinical efficacy study comprising in total 190 healthy subjects and 277 Type 2/3 SMA patients. Results The model evidenced correlations between parameters for different MFM domains. Slower development in MFM domain D1 was associated with faster deterioration for MFM domains D2 and D3. Discussion The model describes all individual data well, although sparseness and variability of observational data prevented numerically stable estimation of parameters. Treatment duration in clinical studies was too limited to determine a proper drug effect model that could differentiate between symptomatic and disease modifying effect. This article is protected by copyright. All rights reserved.

Being Yourself and Thinking About the Future in People With Motor Neuron Disease: A Grounded Theory of Self-care Processes.Publié le 28 06 2018

INTRODUCTION: Self-care is a crucial aspect in the management of people with motor neuron disease (MND). Nurses and healthcare professionals must know the processes used by patients in performing self-care to identify problems and help them. Decision-making processes, self-understanding, and political and social support influence the self-care process in chronic diseases. Little is known about the self-care process in MND.
OBJECTIVE: The aim of this study was to gain insight on the self-care processes in people with MND.
METHOD: A grounded theory method was chosen for this study. Data from interviews were gathered, and a simultaneous comparative analysis was conducted to identify categories and codes.
RESULTS: Twenty-one people with spinal muscular atrophy and amyotrophic lateral sclerosis participated in the study. Five categories were identified as grounded in the data. The process starts from "being yourself in the care," and it develops thanks to "growing and changing" and with a "thinking about the future" approach. "Family role" and "you and who helps you" categories affect the process itself.
CONCLUSION: The self-care process in people with MND is not seen in a daily perspective but changes with the evolution of the disease. For the growing patients with MND, changing, accepting and controlling the disease while deciding autonomously are the foundations of the process.

Molecular Therapies for Muscular Dystrophies.Publié le 23 06 2018

PURPOSE OF REVIEW: To construct a framework to understand the different molecular interventions for muscular dystrophy.
RECENT FINDINGS: The recent approval of antisense oligonucleotides treatment for Duchenne muscular dystrophy and spinal muscular atrophy and current clinical trials using recombinant adeno-associated virus for the treatment of those diseases suggests that we are at a tipping point where we are able to treat and potentially cure muscular dystrophies. Understanding the basic molecular pathogenesis of muscular dystrophies and the molecular biology of the treatment allows for critical evaluation of the proposed therapies.

Quantitative Evaluation of Lower Extremity Joint Contractures in Spinal Muscular Atrophy: Implications for Motor Function.Publié le 22 06 2018

PURPOSE: To quantitatively describe passive lower extremity range of motion in participants with spinal muscular atrophy (SMA) types 2 and 3, and to establish preliminary thresholds to identify individuals at risk for performing poorly on disease-specific motor function outcome measures.
METHODS: Eighty participants with SMA types 2 and 3, enrolled in an international multicenter natural history study, were evaluated with lower extremity range of motion testing and the Hammersmith Functional Motor Scale-Expanded.
RESULTS: A hip extension joint angle of -7.5° or less for SMA type 2 and 0° or less for SMA type 3 identified diminished motor ability with good sensitivity. For knee extension, a joint angle of -9.0° or less for SMA type 2 or 0° or less for SMA type 3 was similarly sensitive.
CONCLUSIONS: Minimal hip and knee joint contractures were associated with diminished motor ability. Clinical trial designs should consider the effect of contractures on motor function.

Onabotulinumtoxin-A injections into the salivary glands for spinal muscle atrophy type I: A prospective case series of four patients.Publié le 20 06 2018

OBJECTIVE: To investigate the safety and efficacy of Onabotulinum Toxin-A (BTX-A) injection to the salivary glands under ultrasound guidance for the treatment of sialorrhea in patients with spinal muscular atrophy type I (SMA I).
DESIGN: Prospective case series with four patients with SMA I who received BTX-A injection to parotid and submandibular glands for sialorrhea as part of clinical care. All four patients received validated surveys for measuring drooling, including objective measures of number of bib changes, and number of mouth wipes before injection and 4-6 weeks after injection. Research was limited to survey completion. Scales included the Drooling Severity and Frequency Scale and the Drooling Impact Scale as well as a new scale used in our clinic, the Posterior Drooling Scales looking at coughing/choking and number of aspiration pneumonias.
RESULTS: There were no adverse events. All four patients showed clinically significant improvements. The improvement in drooling using the DIS was statistically significant (Paired-t test, t=3.243, P=0.048). All patients improved with number of mouth wipes.
CONCLUSION: Ultrasound guided BTX-A injections to the salivary glands may be a safe and effective method of decreasing drooling in patients with SMA I.

Carbon nanofiber-based multiplexed immunosensor for the detection of survival motor neuron 1, cystic fibrosis transmembrane conductance regulator and Duchenne Muscular Dystrophy proteins.Publié le 12 06 2018

Simultaneous and point-of-care detection of multiple protein biomarkers has significant impact on patient care. Spinal Muscular Atrophy (SMA), Cystic Fibrosis (CF) and Duchenne Muscular Dystrophy (DMD) are well known progressive hereditary disorders associated with increased morbidity as well as mortality. Therefore, rapid detection of biomarkers specific for these three disorders in newborns offers new opportunities for early diagnosis, delaying symptoms and effective treatment. Here, we report the development of a disposable carbon nanofiber (CNF)-based electrochemical immunosensor for simultaneous detection of survival motor neuron 1 (SMN1), cystic fibrosis transmembrane conductance regulator (CFTR) and DMD proteins. The CNF-modified array electrodes were first functionalized by electroreduction of carboxyphenyl diazonium salt. Then, the immunosensor was fabricated by the covalent immobilization of the three antibodies on the working electrodes of the array sensor via carbodiimide (EDC/NHS) chemistry. Simultaneous detection of CFTR, DMD and SMN1 was achieved with high sensitivity and detection limits of 0.9?pg/ml, 0.7?pg/ml and 0.74?pg/ml, respectively. The multiplexed immunosensor has also shown strong selectivity against non-specific proteins. Moreover, high recovery percentage was obtained when the immunosensor was applied in spiked whole blood samples. This voltammetric immunosensor offers cost effective, easy to use, rapid and high throughput potential screening method for these three hereditary disorders using only few drops of blood.

[Nusinersen in the treatment of spinal muscular atrophy].Publié le 12 06 2018

Until recently, the diagnosis of spinal muscular atrophy (SMA) has been associated with severe life-long motor disability in adults and with early death in infants. The new experimental therapeutic approaches of the last few years have become more and more promising, while nusinersen was approved for the treatment of SMA in December 2016 in the USA, and in May 2017 in Hungary. Our paper presents mechanisms and clinical benefits of this new medication, and highlights some of the other therapeutic strategies still in experimental stages.

Weight-Loss Cognitive-Behavioural Treatment and Essential Amino Acid Supplementation in a Patient with Spinal Muscular Atrophy and Obesity.Publié le 12 06 2018

Spinal muscular atrophy is a genetic neuromuscular disease characterised by muscle atrophy, hypotonia, weakness, and progressive paralysis. Usually, these patients display increased fat mass deposition and reductions in fat-free mass and resting energy expenditure-an unfavourable condition that facilitates the development of obesity. However, weight management of these patients remains poorly described. Hence, the aim of this case report was to describe the clinical presentation and weight management of a 31-year-old male patient with spinal muscular atrophy type III, class I obesity, and metabolic syndrome treated for 1 year by means of a personalised multistep cognitive-behavioural treatment for obesity. The treatment produced a weight loss of 7.2?kg (7.1%), which was associated with a marked improvement in both the patient's self-reported general conditions and obesity-related cardiometabolic profile, and no adverse effects in terms of spinal muscular atrophy (i.e., reductions in fat-free mass or resting energy expenditure).

Evaluator Training and Reliability for SMA Global Nusinersen Trials1.Publié le 06 06 2018

BACKGROUND: Training methodology was established to optimize reliability of outcome measures in the nusinersen clinical trials. The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), Hammersmith Functional Motor Scale Expanded (HFMSE), and Revised Upper Limb (RULM) were primary or secondary outcomes.
METHODS: Video review, quarterly conference calls, and item scoring checks supported evaluator competence. Baseline and screening along with video review established intra and inter-rater reliability.
RESULTS: Inter and intra-rater reliability were both excellent. Intraclass correlation coefficients (ICC) ranged between 0.906-0.994 across initial training meetings and 0.824-0.996 across annual retraining meetings. This was similar for CHOP INTEND (ICC = 0.824-0.951), HFMSE (ICC = 0.981-0.996), and RULM (ICC = 0.966-0.990). Intra-rater reliability for the CHOP INTEND, HFMSE, and RULM were ICC = 0.895 (95% CI: 0.852-0.926; n = 116), ICC = 0.959 (95% CI: 0.942-0.971; n = 125), and ICC = 0.948 (95% CI: 0.927-0.963; n = 126) respectively.
CONCLUSIONS: Rigorous evaluator training ensures reliability of assessment of subjects with spinal muscular atrophy (SMA) in multicenter international trials.

Update on Standard Operating Procedures in Preclinical Research for DMD and SMA Report of TREAT-NMD Alliance Workshop, Schiphol Airport, 26 April 2015, The Netherlands.Publié le 06 06 2018

A workshop took place in 2015 to follow up TREAT-NMD activities dedicated to improving quality in the preclinical phase of drug development for neuromuscular diseases. In particular, this workshop adressed necessary future steps regarding common standard experimental protocols and the issue of improving the translatability of preclinical efficacy studies.

Designing Effective Antisense Oligonucleotides for Exon Skipping.Publié le 06 06 2018

During the past 10 years, antisense oligonucleotide-mediated exon skipping and splice modulation have proven to be powerful tools for correction of mRNA splicing in genetic diseases. In 2016, the US Food and Drug Administration (FDA)-approved Exondys 51 (eteplirsen) and Spinraza (nusinersen), the first exon skipping and exon inclusion drugs, to treat patients with Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), respectively. The exon skipping of DMD mRNA aims to restore the disrupted reading frame using antisense oligonucleotides (AONs), allowing the production of truncated but partly functional dystrophin proteins, and slow down the progression of the disease. This approach has also been explored in several other genetic disorders, including laminin ?2 chain-deficient congenital muscular dystrophy, dysferlin-deficient muscular dystrophy (e.g., Miyoshi myopathy and limb-girdle muscular dystrophy type 2B), sarcoglycanopathy (limb-girdle muscular dystrophy type 2C), and Fukuyama congenital muscular dystrophy. Antisense-mediated exon skipping is also a powerful tool to examine the function of genes and exons. A significant challenge in exon skipping is how to design effective AONs. The mechanism of mRNA splicing is highly complex with many factors involved. The selection of target sites, the length of AONs, the AON chemistry, and the melting temperature versus the RNA strand play important roles. A cocktail of AONs can be employed to skip multiples exons. In this chapter, we discuss the design of effective AONs for exon skipping.

A Camptocormia Case Treated With Electroconvulsive Therapy.Publié le 05 06 2018

PMID: 27668941 [PubMed - indexed for MEDLINE]

Antisense Oligonucleotide-Mediated Terminal Intron Retention of the SMN2 Transcript.Publié le 03 06 2018

The severe childhood disease spinal muscular atrophy (SMA) arises from the homozygous loss of the survival motor neuron 1 gene (SMN1). A homologous gene potentially encoding an identical protein, SMN2 can partially compensate for the loss of SMN1; however, the exclusion of a critical exon in the coding region during mRNA maturation results in insufficient levels of functional protein. The rate of transcription is known to influence the alternative splicing of gene transcripts, with a fast transcription rate correlating to an increase in alternative splicing. Conversely, a slower transcription rate is more likely to result in the inclusion of all exons in the transcript. Targeting SMN2 with antisense oligonucleotides to influence the processing of terminal exon 8 could be a way to slow transcription and induce the inclusion of exon 7. Interestingly, following oligomer treatment of SMA patient fibroblasts, we observed the inclusion of exon 7, as well as intron 7, in the transcript. Because the normal termination codon is located in exon 7, this exon/intron 7-SMN2 transcript should encode the normal protein and only carry a longer 3' UTR. Further studies showed the extra 3' UTR length contained a number of regulatory motifs that modify transcript and protein regulation, leading to translational repression of SMN. Although unlikely to provide therapeutic benefit for SMA patients, this novel technique for gene regulation could provide another avenue for the repression of undesirable gene expression in a variety of other diseases.

Edaravone is a candidate agent for spinal muscular atrophy: In vitro analysis using a human induced pluripotent stem cells-derived disease model.Publié le 02 06 2018

Spinal muscular atrophy (SMA) is an intractable disease characterized by a progressive loss of spinal motor neurons, which leads to skeletal muscle weakness and atrophy. Currently, there are no curative agents for SMA, although it is understood to be caused by reduced levels of survival motor neuron (SMN) protein. Additionally, why reduced SMN protein level results in selective apoptosis in spinal motor neurons is still not understood. Our purpose in this study was to evaluate the therapeutic potential of edaravone, a free radical scavenger, by using induced pluripotent stem cells from an SMA patient (SMA-iPSCs) and to address oxidative stress-induced apoptosis in spinal motor neurons. We first found that edaravone could improve impaired neural development of SMA-iPSCs-derived spinal motor neurons with limited effect on nuclear SMN protein expression. Furthermore, edaravone inhibited the generation of reactive oxygen species and mitochondrial reactive oxygen species upregulated in SMA-iPSCs-derived spinal motor neurons, and reversed oxidative-stress induced apoptosis. In this study, we suggest that oxidative stress might be partly the reason for selective apoptosis in spinal motor neurons in SMA pathology, and that oxidative stress-induced apoptosis might be the therapeutic target of SMA.

Antisense oligonucleotides in neurological disorders.Publié le 02 06 2018

The introduction of genetics revolutionized the field of neurodegenerative and neuromuscular diseases and has provided considerable insight into the underlying pathomechanisms. Nevertheless, effective treatment options have been limited. This changed recently when antisense oligonucleotides (ASOs) could be translated from in vitro and experimental animal studies into clinical practice. In 2016, two ASOs were approved by the United States US Food and Drug Administration (FDA) and demonstrated remarkable efficacy in Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA). ASOs are synthetic single-stranded strings of nucleic acids. They selectively bind to specific premessenger ribonucleic acid (pre-mRNA)/mRNA sequences and alter protein synthesis by several mechanisms of action. Thus, apart from gene replacement, ASOs may therefore provide the most direct therapeutic strategy for influencing gene expression. In this review, we shall discuss basic mechanisms of ASO action, the role of chemical modifications needed to improve the pharmacodynamic and pharmacokinetic properties of ASOs, and we shall then focus on several ASOs developed for the treatment of neurodegenerative and neuromuscular disorders, including SMA, DMD, myotonic dystrophies, Huntington's disease, amyotrophic lateral sclerosis and Alzheimer's disease.

A Half-Century History of Applications of Antisense Oligonucleotides in Medicine, Agriculture and Forestry: We Should Continue the Journey.Publié le 31 05 2018

Antisense oligonucleotides (ASO), short single-stranded polymers based on DNA or RNA chemistries and synthesized in vitro, regulate gene expression by binding in a sequence-specific manner to an RNA target. The functional activity and selectivity in the action of ASOs largely depends on the combination of nitrogenous bases in a target sequence. This simple and natural property of nucleic acids provides an attractive route by which scientists can create different ASO-based techniques. Over the last 50 years, planned and realized applications in the field of antisense and nucleic acid nanotechnologies have produced astonishing results and posed new challenges for further developments, exemplifying the essence of the post-genomic era. Today the majority of ASOs are chemically modified and/or incorporated within nanoparticles to enhance their stability and cellular uptake. This review critically analyzes some successful cases using the antisense approach in medicine to address severe diseases, such as Duchenne muscular dystrophy and spinal muscular atrophy, and suggests some prospective directions for future research. We also examine in detail the elaboration of unmodified insect-specific DNA insecticides and RNA preparations in the areas of agriculture and forestry, a relatively new branch of ASO that allows circumvention of the use of non-selective chemical insecticides. When considering the variety of successful ASO modifications with an efficient signal-to-noise ratio of action, coupled with the affordability of in vitro oligonucleotide synthesis and post-synthesis procedures, we predict that the next half-century will produce a fruitful yield of tools created from effective ASO-based end products.

Small-Molecule Screening for Genetic Diseases.Publié le 29 05 2018

The genetic determinants of many diseases, including monogenic diseases and cancers, have been identified; nevertheless, targeted therapy remains elusive for most. High-throughput screening (HTS) of small molecules, including high-content analysis (HCA), has been an important technology for the discovery of molecular tools and new therapeutics. HTS can be based on modulation of a known disease target (called reverse chemical genetics) or modulation of a disease-associated mechanism or phenotype (forward chemical genetics). Prominent target-based successes include modulators of transthyretin, used to treat transthyretin amyloidoses, and the BCR-ABL kinase inhibitor Gleevec, used to treat chronic myelogenous leukemia. Phenotypic screening successes include modulators of cystic fibrosis transmembrane conductance regulator, splicing correctors for spinal muscular atrophy, and histone deacetylase inhibitors for cancer. Synthetic lethal screening, in which chemotherapeutics are screened for efficacy against specific genetic backgrounds, is a promising approach that merges phenotype and target. In this article, we introduce HTS technology and highlight its contributions to the discovery of drugs and probes for monogenic diseases and cancer. Expected final online publication date for the Annual Review of Genomics and Human Genetics Volume 19 is August 31, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Temporal and tissue-specific variability of SMN protein levels in mouse models of spinal muscular atrophy.Publié le 28 05 2018

Spinal muscular atrophy (SMA) is a progressive motor neuron disease caused by deleterious variants in SMN1 that lead to a marked decrease in survival motor neuron (SMN) protein expression. Humans have a second SMN gene (SMN2) that is almost identical to SMN1. However, due to alternative splicing the majority of SMN2 mRNA is translated into a truncated, unstable protein that is quickly degraded. Because the presence of SMN2 provides a unique opportunity for therapy development in SMA patients, the mechanisms that regulate SMN2 splicing and mRNA expression have been elucidated in great detail. In contrast, how much SMN protein is produced at different developmental time points and in different tissues remains under-characterised. In this study, we addressed this issue by determining SMN protein expression levels at three developmental time points across six different mouse tissues and in two distinct mouse models of SMA ('severe' Taiwanese and 'intermediate' Smn2B/- mice). We found that, in healthy control mice, SMN protein expression was significantly influenced by both age and tissue type. When comparing mouse models of SMA, we found that, despite being transcribed from genetically different alleles, control SMN levels were relatively similar. In contrast, the degree of SMN depletion between tissues in SMA varied substantially over time and between the two models. These findings offer an explanation for the differential vulnerability of tissues and organs observed in SMA and further our understanding of the systemic and temporal requirements for SMN with direct relevance for developing effective therapies for SMA.

The progress of AAV-mediated gene therapy in neuromuscular disorders.Publié le 28 05 2018

INTRODUCTION: The well-defined genetic causes and monogenetic nature of many neuromuscular disorders, including Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA), present gene therapy as a prominent therapeutic approach. The novel variants of adeno-associated virus (AAV) can achieve satisfactory transduction efficiency of exogenous genes through the central nervous system and body-wide in skeletal muscle. Areas covered: In this review, we summarize the strategies of AAV gene therapy that are currently under preclinical and clinical evaluation for the treatment of degenerative neuromuscular disorders, with a focus on diseases such as DMD and SMA. In addition to gene replacement strategy, we provide an overview of other approaches such as AAV-mediated RNA therapy and gene editing in the treatment of muscular dystrophies. Expert opinion: AAV gene therapy has achieved striking therapeutic efficacy in clinical trials in infants with SMA. Promising results have also come from the preclinical studies in small and large animal models of DMD and several clinical trials are now on the way. This strategy shows great potential as a therapy for various neuromuscular disorders. Further studies are still required to confirm its long-term safety and improve the efficacy.

Glial Activation and Central Synapse Loss, but Not Motoneuron Degeneration, Are Prevented by the Sigma-1 Receptor Agonist PRE-084 in the Smn2B/- Mouse Model of Spinal Muscular Atrophy.Publié le 17 05 2018

Spinal muscular atrophy (SMA) is characterized by the loss of ?-motoneurons (MNs) with concomitant muscle denervation. MN excitability and vulnerability to disease are particularly regulated by cholinergic synaptic afferents (C-boutons), in which Sigma-1 receptor (Sig1R) is concentrated. Alterations in Sig1R have been associated with MN degeneration. Here, we investigated whether a chronic treatment with the Sig1R agonist PRE-084 was able to exert beneficial effects on SMA. We used a model of intermediate SMA, the Smn2B/- mouse, in which we performed a detailed characterization of the histopathological changes that occur throughout the disease. We report that Smn2B/- mice exhibited qualitative differences in major alterations found in mouse models of severe SMA: Smn2B/- animals showed more prominent MN degeneration, early motor axon alterations, marked changes in sensory neurons, and later MN deafferentation that correlated with conspicuous reactive gliosis and altered neuroinflammatory M1/M2 microglial balance. PRE-084 attenuated reactive gliosis, mitigated M1/M2 imbalance, and prevented MN deafferentation in Smn2B/- mice. These effects were also observed in a severe SMA model, the SMN?7 mouse. However, the prevention of gliosis and MN deafferentation promoted by PRE-084 were not accompanied by any improvements in clinical outcome or other major pathological changes found in SMA mice.

Interventions Targeting Glucocorticoid-Krüppel-like Factor 15-Branched-Chain Amino Acid Signaling Improve Disease Phenotypes in Spinal Muscular Atrophy Mice.Publié le 09 05 2018

The circadian glucocorticoid-Krüppel-like factor 15-branched-chain amino acid (GC-KLF15-BCAA) signaling pathway is a key regulatory axis in muscle, whose imbalance has wide-reaching effects on metabolic homeostasis. Spinal muscular atrophy (SMA) is a neuromuscular disorder also characterized by intrinsic muscle pathologies, metabolic abnormalities and disrupted sleep patterns, which can influence or be influenced by circadian regulatory networks that control behavioral and metabolic rhythms. We therefore set out to investigate the contribution of the GC-KLF15-BCAA pathway in SMA pathophysiology of Taiwanese Smn-/-;SMN2 and Smn2B/- mouse models. We thus uncover substantial dysregulation of GC-KLF15-BCAA diurnal rhythmicity in serum, skeletal muscle and metabolic tissues of SMA mice. Importantly, modulating the components of the GC-KLF15-BCAA pathway via pharmacological (prednisolone), genetic (muscle-specific Klf15 overexpression) and dietary (BCAA supplementation) interventions significantly improves disease phenotypes in SMA mice. Our study highlights the GC-KLF15-BCAA pathway as a contributor to SMA pathogenesis and provides several treatment avenues to alleviate peripheral manifestations of the disease. The therapeutic potential of targeting metabolic perturbations by diet and commercially available drugs could have a broader implementation across other neuromuscular and metabolic disorders characterized by altered GC-KLF15-BCAA signaling.

Recent Advances in Antisense Oligonucleotide Therapy in Genetic Neuromuscular Diseases.Publié le 04 05 2018

Genetic neuromuscular diseases are caused by defective expression of nuclear or mitochondrial genes. Mutant genes may reduce expression of wild-type proteins, and strategies to activate expression of the wild-type proteins might provide therapeutic benefits. Also, a toxic mutant protein may cause cell death, and strategies that reduce mutant gene expression may provide therapeutic benefit. Synthetic antisense oligonucleotide (ASO) can recognize cellular RNA and control gene expression. In recent years, advances in ASO chemistry, creation of designer ASO molecules to enhance their safety and target delivery, and scientific controlled clinical trials to ascertain their therapeutic safety and efficacy have led to an era of plausible application of ASO technology to treat currently incurable neuromuscular diseases. Over the past 1 year, for the first time, the United States Food and Drug Administration has approved two ASO therapies in genetic neuromuscular diseases. This overview summarizes the recent advances in ASO technology, evolution and use of synthetic ASOs as a therapeutic platform, and the mechanism of ASO action by exon-skipping in Duchenne muscular dystrophy and exon-inclusion in spinal muscular atrophy, with comments on their advantages and limitations.

Recent therapeutic developments in spinal muscular atrophyPublié le 02 05 2018

Proximal spinal muscular atrophy (SMA) is an inherited neurodegenerative disease with a heterogeneous clinical phenotype. Although there is no cure for SMA, several strategies are currently being developed. In this review, we summarize the ongoing clinical trials and molecular mechanisms of successful approaches to SMA treatment.

Mechanistic studies of a small-molecule modulator of SMN2 splicing.Publié le 02 05 2018

RG-7916 is a first-in-class drug candidate for the treatment of spinal muscular atrophy (SMA) that functions by modulating pre-mRNA splicing of the SMN2 gene, resulting in a 2.5-fold increase in survival of motor neuron (SMN) protein level, a key protein lacking in SMA patients. RG-7916 is currently in three interventional phase 2 clinical trials for various types of SMA. In this report, we show that SMN-C2 and -C3, close analogs of RG-7916, act as selective RNA-binding ligands that modulate pre-mRNA splicing. Chemical proteomic and genomic techniques reveal that SMN-C2 directly binds to the AGGAAG motif on exon 7 of the SMN2 pre-mRNA, and promotes a conformational change in two to three unpaired nucleotides at the junction of intron 6 and exon 7 in both in vitro and in-cell models. This change creates a new functional binding surface that increases binding of the splicing modulators, far upstream element binding protein 1 (FUBP1) and its homolog, KH-type splicing regulatory protein (KHSRP), to the SMN-C2/C3-SMN2 pre-mRNA complex and enhances SMN2 splicing. These findings underscore the potential of small-molecule drugs to selectively bind RNA and modulate pre-mRNA splicing as an approach to the treatment of human disease.

New and developing therapies in spinal muscular atrophy.Publié le 30 04 2018

Great progress has been made in the clinical translation of several therapeutic strategies for spinal muscular atrophy (SMA), including measures to selectively address Survival Motor Neuron (SMN) protein deficiency with SMN1 gene replacement or modulation of SMN2 encoded protein levels, as well as neuroprotective approaches and supporting muscle strength and function. This review highlights these novel therapies. This is particularly vital with the advent of the first disease modifying therapy, which has brought to the fore an array of questions surrounding who, how and when to treat, and stimulated challenges in resource limited healthcare systems to streamline access for those eligible for drug therapy. The overhaul of the landscape for all those involved in SMA extends to the design of further drug trials and the necessity of multidisciplinary supportive care to potentiate the effects of disease modifying medications. The impact of respiratory complications in SMA is central to management in the current era of emerging novel therapies. These fundamental changes in our knowledge and management approach to those with SMA are explored further in this review.

Comprehensive nutritional and metabolic assessment in patients with spinal muscular atrophy: Opportunity for an individualized approach.Publié le 28 04 2018

Optimal nutrition support is recommended for patients with spinal muscular atrophy (SMA). In a prospective study, we performed comprehensive nutritional assessments with the aim to guide best nutritional strategies for patients with SMA types II and III. We recorded a) anthropometry; b) macro- and micronutrient intakes; c) measured resting energy expenditure by indirect calorimetry; and d) body composition including dual X-ray absorptiometry. We enrolled a cohort of 21 patients aged 3 to 36 years of which 13 were female; 19 had SMA type II and 2 had SMA type III. The body mass index z-score ranged from -3 to 2.4. Forty-five percent of the cohort was either underfed or overfed, based on the difference between actual energy intake and measured resting energy expenditure. Vitamin D, E, K, folate and calcium intakes were low in a majority of the cohort. Forty-five percent of the cohort was either hypometabolic or hypermetabolic. Fat mass index (kg/m2) was significantly higher and lean body mass index (kg/m2) was significantly lower in the study cohort compared to population normalized values. Bone mineral density was low in 13 of 17 patients. In summary, we have described the prevalence of malnutrition, suboptimal feeding and alterations in body composition in children with SMA. A comprehensive nutritional assessment could guide individualized nutrition therapy in this vulnerable population.

Structural basis for the activation of acid ceramidase.Publié le 26 04 2018

Acid ceramidase (aCDase, ASAH1) hydrolyzes lysosomal membrane ceramide into sphingosine, the backbone of all sphingolipids, to regulate many cellular processes. Abnormal function of aCDase leads to Farber disease, spinal muscular atrophy with progressive myoclonic epilepsy, and is associated with Alzheimer's, diabetes, and cancer. Here, we present crystal structures of mammalian aCDases in both proenzyme and autocleaved forms. In the proenzyme, the catalytic center is buried and protected from solvent. Autocleavage triggers a conformational change exposing a hydrophobic channel leading to the active site. Substrate modeling suggests distinct catalytic mechanisms for substrate hydrolysis versus autocleavage. A hydrophobic surface surrounding the substrate binding channel appears to be a site of membrane attachment where the enzyme accepts substrates facilitated by the accessory protein, saposin-D. Structural mapping of disease mutations reveals that most would destabilize the protein fold. These results will inform the rational design of aCDase inhibitors and recombinant aCDase for disease therapeutics.

Evaluation of Children with SMA Type 1 Under Treatment with Nusinersen within the Expanded Access Program in Germany.Publié le 25 04 2018

BACKGROUND: Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by muscle weakness and muscle atrophy. Nusinersen acts as a splicing modifier and has recently been approved for intrathecal treatment of SMA.
OBJECTIVE: Prior to approval, nusinersen was provided to patients with SMA type 1 in Germany within an Expanded Access Program (EAP). In contrast to previous clinical trials, children of different age groups and different stages of the disease were treated with nusinersen.
METHODS: We conducted a prospective, longitudinal data collection of patients treated with nusinersen within the EAP in seven neuromuscular centers in Germany. Standardized assessments including CHOP-INTEND and HINE-2 motor milestones were performed at baseline and 60 and 180 days after start of treatment.
RESULTS: Data from 61 SMA type 1 patients (mean age 21.08 months, range 1-93) were available for analysis. After six months of treatment, 47 children (77.0%) improved by ?4 points in CHOP INTEND score. Mean change in CHOP INTEND score was 9.0±8.0 points. Nineteen patients (31.1%) improved by ?2 points in HINE-2 motor milestones. Regression analysis revealed age at onset of treatment as major determinant of change in CHOP INTEND from baseline.
CONCLUSION: When analyzing a broad spectrum of SMA type 1 patients, many children showed an improvement of motor function after six months of treatment with nusinersen, which is generally not expected within the natural course of the disease. Long-term observation and follow-up of patients with later onset types of SMA are crucial to understand the clinical impact of treatment with nusinersen.

Antisense oligonucleotides correct the familial dysautonomia splicing defect in IKBKAP transgenic mice.Publié le 21 04 2018

Familial dysautonomia (FD) is a rare inherited neurodegenerative disorder caused by a point mutation in the IKBKAP gene that results in defective splicing of its pre-mRNA. The mutation weakens the 5' splice site of exon 20, causing this exon to be skipped, thereby introducing a premature termination codon. Though detailed FD pathogenesis mechanisms are not yet clear, correcting the splicing defect in the relevant tissue(s), thus restoring normal expression levels of the full-length IKAP protein, could be therapeutic. Splice-switching antisense oligonucleotides (ASOs) can be effective targeted therapeutics for neurodegenerative diseases, such as nusinersen (Spinraza), an approved drug for spinal muscular atrophy. Using a two-step screen with ASOs targeting IKBKAP exon 20 or the adjoining intronic regions, we identified a lead ASO that fully restored exon 20 splicing in FD patient fibroblasts. We also characterized the corresponding cis-acting regulatory sequences that control exon 20 splicing. When administered into a transgenic FD mouse model, the lead ASO promoted expression of full-length human IKBKAP mRNA and IKAP protein levels in several tissues tested, including the central nervous system. These findings provide insights into the mechanisms of IKBKAP exon 20 recognition, and pre-clinical proof of concept for an ASO-based targeted therapy for FD.

Update on muscle disease.Publié le 21 04 2018

In this article, we highlight some of the most important developments from the last few years in the field of muscle diseases, including new additions to the congenital myasthenic syndromes (CMS) and limb-girdle muscular dystrophies (LGMD), advances in our understanding of the pathophysiology of certain muscle disorders and progress in diagnostics and therapeutics. Unsurprisingly, the most prominent developments have come from the field of genetics, with significant advances in diagnosis and gene therapy giving hope to those with hitherto untreatable conditions.

Effect of Salbutamol on Respiratory Muscle Strength in Spinal Muscular Atrophy.Publié le 14 04 2018

BACKGROUND: Oral salbutamol has shown clinical benefits in spinal muscular atrophy (SMA). We studied its effect on the respiratory muscle strength in children with different types of SMA.
METHODS: Lung and respiratory muscle functions were assessed in children receiving daily oral salbutamol for at least one year. The respiratory data of age-matched SMA II historical control subjects were compared with data of SMA II patients receiving salbutamol.
RESULTS: Seven children (6.4 ± 2.0 years old, range four to ten; one SMA I, five SMA II, and one SMA III) treated with salbutamol (duration 23 ± 8 months) were assessed. Maximal static inspiratory pressure, sniff nasal inspiratory pressure, and slow vital capacity were significantly better in the salbutamol-treated SMA II group compared with control subjects (P < 0.05).
CONCLUSIONS: Long-term oral salbutamol showed benefits in respiratory function in children with SMA and appeared to increase the strength of the inspiratory muscles in a small cohort of SMA II patients.

Modelling Motor Neuron Disease in Fruit Flies: Lessons from Spinal Muscular Atrophy.Publié le 13 04 2018

Motor neuron disease (MND) is characterised by muscle weakness and paralysis downstream of motor neuron degeneration. Genetic factors play a major role in disease pathogenesis and progression. This is best underscored by spinal muscular atrophy (SMA), the most common MND affecting children. Although SMA is caused by homozygous mutations in the survival motor neuron 1 (SMN1) gene, partial compensation by the paralogous SMN2 gene and/or genetic modifiers influence age of onset and disease severity. SMA is also the first MND that is treatable thanks to the recent development of a molecular-based therapy. This key milestone was possible following an intense research campaign in which animal models had a starring role. In this review, we specifically focus on the fruit fly Drosophila melanogaster and highlight its sterling contributions aimed at furthering our understanding of SMA pathogenesis. Methods of gene disruption utilised to generate SMA fly models are discussed and ways through which neuromuscular defects have been characterised are elaborated on. A phenotypic overlap with patients and mammalian models, allowed the use of SMA fly models to identify genetic modifiers, hence spurring investigators to discover pathways that are perturbed in disease. Targeting these can potentially lead to complimentary therapies for SMA. The same output is expected from the use of SMA fly models to identify therapeutic compounds that have an ameliorative effect. We believe that lessons gained from SMA will allow researchers to eagerly exploit Drosophila to confirm novel genes linked to MND, reveal disease mechanisms and ultimately identify therapeutics.

[Camptocormia: From diagnosis to treatment].Publié le 13 04 2018

Camptocormia or Bent Spine Syndrome (BSS) is a symptom, often unknown, affecting elderly patients. Camptocormia is a dynamic anteflexion of the trunk occurring during physical exercises or in standing position and reducible in decubitus. It is caused by an impairment of the extensor muscles of the spinal column, either idiopathic or secondary to a muscular or a neurological disease. Its diagnosis is primarily anamnestic and clinical. The use of imaging could highlight a paraver tebral muscular fatty infi l tration with preserved volume in the case of idiopathic disorder and allows exclusion of osteoarticular pathologies. The treatment must be proposed as early as possible, before advanced adipose muscle evolution and significant anteflexion of the trunck. Symptomatic measures apply to primary and secondary forms and include physiotherapy, technical assistances to the walk and equipment by lordosis supporting corsets.

Dose-Dependent Lowering of Mutant Huntingtin Using Antisense Oligonucleotides in Huntington Disease Patients.Publié le 06 04 2018

On December 11 of 2017, Ionis Pharmaceuticals published a press release announcing dose-dependent reductions of mutant huntingtin protein in their HTTRx Phase 1/2a study in Huntington disease (HD) patients. The results from this Ionis trial have gained much attention from the patient community and the oligonucleotide therapeutics field, since it is the first trial targeting the cause of HD, namely the mutant huntingtin protein, using antisense oligonucleotides (ASOs). The press release also states that the primary endpoints of the study (safety and tolerability) were met, but does not contain data. This news follows the approval of another therapeutic ASO nusinersen (trade name Spinraza) for a neurological disease, spinal muscular atrophy, by the U.S. Food and Drug Administration and European Medicines Agency, in 2016 and 2017, respectively. Combined, this offers hope for the development of the HTTRx therapy for HD patients.

RNA-Targeted Therapeutics.Publié le 05 04 2018

RNA-targeted therapies represent a platform for drug discovery involving chemically modified oligonucleotides, a wide range of cellular RNAs, and a novel target-binding motif, Watson-Crick base pairing. Numerous hurdles considered by many to be impassable have been overcome. Today, four RNA-targeted therapies are approved for commercial use for indications as diverse as Spinal Muscular Atrophy (SMA) and reduction of low-density lipoprotein cholesterol (LDL-C) and by routes of administration including subcutaneous, intravitreal, and intrathecal delivery. The technology is efficient and supports approaching "undruggable" targets. Three additional agents are progressing through registration, and more are in clinical development, representing several chemical and structural classes. Moreover, progress in understanding the molecular mechanisms by which these drugs work has led to steadily better clinical performance and a wide range of mechanisms that may be exploited for therapeutic purposes. Here we summarize the progress, future challenges, and opportunities for this drug discovery platform.

Treatment Algorithm for Infants Diagnosed with Spinal Muscular Atrophy through Newborn Screening.Publié le 05 04 2018

BACKGROUND: Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by the degeneration of alpha motor neurons in the spinal cord, leading to muscular atrophy. SMA is caused by deletions or mutations in the survival motor neuron 1 gene (SMN1). In humans, a nearly identical copy gene, SMN2, is present. Because SMN2 has been shown to decrease disease severity in a dose-dependent manner, SMN2 copy number is predictive of disease severity.
OBJECTIVE: To develop a treatment algorithm for SMA-positive infants identified through newborn screening based upon SMN2 copy number.
METHODS: A working group comprised of 15 SMA experts participated in a modified Delphi process, moderated by a neutral third-party expert, to develop treatment guidelines.
RESULTS: The overarching recommendation is that all infants with two or three copies of SMN2 should receive immediate treatment (n?=?13). For those infants in which immediate treatment is not recommended, guidelines were developed that outline the timing and appropriate screens and tests to be used to determine the timing of treatment initiation.
CONCLUSIONS: The identification SMA affected infants via newborn screening presents an unprecedented opportunity for achievement of maximal therapeutic benefit through the administration of treatment pre-symptomatically. The recommendations provided here are intended to help formulate treatment guidelines for infants who test positive during the newborn screening process.

Drugs that made headlines in 2016.Publié le 05 04 2018

PMID: 27923025 [PubMed - indexed for MEDLINE]

[Ethical attitudes of intensive care paediatricians as regards patients with spinal muscular atrophy type 1].Publié le 04 04 2018

INTRODUCTION: Spinal muscular atrophy type 1 (SMA-1) is a progressive and fatal disease that leads to ethical problems for Paediatric professionals. Our objective was to determine the ethical options of Paediatric Intensive Care Unit (PICU) paediatricians as regards a child with SMA-1 and respiratory failure.
MATERIAL AND METHODS: A cross-sectional descriptive study was conducted using an anonymous questionnaire sent to PICUs in Spain (which can be accessed through the Spanish Society of Paediatric Critical Care web page).
RESULTS: Of the 124 responses analysed, 70% were from women, 51% younger than 40 years, 54% from a PICU with more than 10 beds, 69% with prior experience in such cases, and 53% with religious beliefs. In the last patient cared for, most paediatricians opted for non-invasive mechanical ventilation (NIV) and limitation of therapeutic effort (LET) in case of NIV failure. Confronted with a future hypothetical case, half of paediatricians would opt for the same plan (NIV+LET), and 74% would support the family's decision, even in case of disagreement. Age, prior experience and sex were not related to the preferred options. Paediatricians with religious beliefs were less in favour of initial LET. Less than two-thirds (63%) scored the quality of life of a child with SMA-1 and invasive mechanical ventilation as very poor.
CONCLUSIONS: Faced with child with SMA-1 and respiratory failure, most paediatricians are in favour of initiating NIV and LET when such support is insufficient, but they would accept the family's decision, even in case of disagreement.

CIM Journal Club: Gene therapy for spinal muscular atrophy Comment on Mendell et al. N Engl J Med 2017;377:1713-22.Publié le 01 04 2018

In their landmark paper, Mendell et al. show that infants with spinal muscular atrophy (SMA) reached important motor milestones and survived longer when treated with AVXS-101 (AveXis), a viral vector containing DNA encoding the survival of motor neuron protein (SMN). Patients not only crawled, stood and walked independently, but learned to speak. These results are very encouraging for patients with SMA and offer hope for pediatric and adult patients with other types of motor neuron diseases.

GeneReviews®Publié le 30 03 2018

CLINICAL CHARACTERISTICS: The spectrum of ASAH1-related disorders ranges from Farber disease (FD) to spinal muscular atrophy with progressive myoclonic epilepsy (SMA-PME). Classic FD is characterized by onset in the first weeks of life of painful, progressive deformity of the major joints; palpable subcutaneous nodules of joints and mechanical pressure points; and a hoarse cry resulting from granulomas of the larynx and epiglottis. Life expectancy is usually less than two years. In the other less common types of FD, onset, severity, and primary manifestations vary. SMA-PME is characterized by early-childhood-onset progressive lower motor neuron disease manifest typically between ages three and seven years as proximal lower-extremity weakness, followed by progressive myoclonic and atonic seizures, tremulousness/tremor, and sensorineural hearing loss. Myoclonic epilepsy typically begins in late childhood after the onset of weakness and can include jerking of the upper limbs, action myoclonus, myoclonic status, and eyelid myoclonus. Other findings include generalized tremor, and cognitive decline. The time from disease onset to death from respiratory complications is usually five to 15 years.
DIAGNOSIS/TESTING: The diagnosis of an ASAH1-related disorder is established in a proband with suggestive clinical findings by identification of biallelic pathogenic variants in ASAH1 and/or decreased activity of the enzyme acid ceramidase in peripheral blood leukocytes or cultured skin fibroblasts.
MANAGEMENT: Treatment of manifestations is symptomatic and multidisciplinary. For FD: Management may include gastrostomy tube placement, surgical removal of oral and airway granulomas, and treatment of seizures as per standard practice. Hematopoietic stem cell transplantation may be an option in affected individuals who do not have significant neurologic involvement. For SMA-PME: Management may include standard treatment for hearing loss, scoliosis, seizures, and tremor. Weakness can be mitigated with the use of orthotics, wheelchairs, or other assistive devices. Surveillance: For FD: At each visit assess growth with emphasis on feeding and nutritional status; airway, joint mobility, and developmental milestones. For SMA-PME: At each visit monitor growth with emphasis on feeding and nutritional status, pulmonary function, back for evidence of scoliosis, strength, seizure control, functional capacity (e.g., mobility, communication); assess hearing annually.
GENETIC COUNSELING: ASAH1-related disorders are inherited in an autosomal recessive manner. At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Sibs with the same two pathogenic variants would be expected to have the same (or very similar) phenotype. Once the ASAH1 pathogenic variants have been identified in an affected family member, carrier testing for at-risk relatives, prenatal testing for a pregnancy at increased risk, and preimplantation genetic diagnosis are possible.

Intron-retained transcripts of the spinal muscular atrophy genes, SMN1 and SMN2.Publié le 29 03 2018

BACKGROUND: The SMN genes, SMN1 and SMN2, are highly homologous genes which are related to the development or clinical severity of spinal muscular atrophy. Some alternative splicing patterns of the SMN genes have been well documented. In 2007, an SMN1 transcript with a full sequence of intron 3 was reported as the first intron-retained SMN transcript.
METHODS: Intron-retained SMN transcripts in various cells and tissues were studied using reverse transcription (RT)-PCR. HeLa cells were used for subcellular localization of the transcripts and protein expression analysis with Western blotting.
RESULTS: Two intron-retained SMN transcripts were detected, which contain full sequences of intron 2b or intron 3. These transcripts were produced from SMN1 and SMN2, and ubiquitously expressed in human cells and tissues. Western blotting analysis showed no proteins derived from the intron-retained transcripts. Fractionation analysis showed that these intron-retained transcripts were localized mainly in the nucleus. Contrary to our expectation, the intron-retained transcript levels decreased during the treatment of cycloheximide, an inhibitor of nonsense-mediated decay (NMD), suggesting that they were not targets of NMD.
CONCLUSION: Intron 2b-retained SMN transcript and intron3-retained SMN transcript were ubiquitously expressed in human cells and tissues. The intron-retained transcripts were mainly localized in the nucleus and decreased through non-NMD pathway.

Gender-Specific Amelioration of SMA Phenotype upon Disruption of a Deep Intronic Structure by an Oligonucleotide.Publié le 27 03 2018

Spinal muscular atrophy (SMA), the leading genetic disease of children, is caused by low levels of survival motor neuron (SMN) protein. Here, we employ A15/283, an antisense oligonucleotide targeting a deep intronic sequence/structure, to examine the impact of restoration of SMN in a mild SMA mouse model. We show gender-specific amelioration of tail necrosis upon subcutaneous administrations of A15/283 into SMA mice at postnatal days 1 and 3. We also demonstrate that a modest increase in SMN due to early administrations of A15/283 dramatically improves testicular development and spermatogenesis. Our results reveal near total correction of expression of several genes in adult testis upon temporary increase in SMN during early postnatal development. This is the first demonstration of in vivo efficacy of an antisense oligonucleotide targeting a deep intronic sequence/structure. This is also the first report of gender-specific amelioration of SMA pathology upon a modest peripheral increase of SMN.

Nusinersen for spinal muscular atrophy.Publié le 24 03 2018

PMID: 29568328 [PubMed]

Transforaminal Lumbar Puncture: An Alternative Technique in Patients with Challenging Access.Publié le 24 03 2018

Interlaminar lumbar puncture and cervical puncture may not be ideal in all circumstances. Recently, we have used a transforaminal approach in selected situations. Between May 2016 and December 2017, twenty-six transforaminal lumbar punctures were performed in 9 patients (25 CT-guided, 1 fluoroscopy-guided). Seven had spinal muscular atrophy and were referred for intrathecal nusinersen administration. In 2, CT myelography was performed via transforaminal lumbar puncture. The lumbar posterior elements were completely fused in 8, and there was an overlying abscess in 1. The L1-2 level was used in 2; the L2-3 level, in 10; the L3-4 level, in 12; and the L4-5 level, in 2 procedures. Post-lumbar puncture headache was observed on 4 occasions, which resolved without blood patching. One patient felt heat and pain at the injection site that resolved spontaneously within hours. One patient had radicular pain that resolved with conservative treatment. Transforaminal lumbar puncture may become an effective alternative to classic interlaminar lumbar puncture or cervical puncture.

Gait dynamics in Pisa syndrome and Camptocormia: The role of stride length and hip kinematics.Publié le 22 03 2018

This is an observational cross-sectional study evaluating gait dynamics in patients with Parkinson's Disease (PD) and severe postural deformities, PD without axial deviations and healthy subjects. Ten PS individuals with Pisa syndrome (PS) and nine subjects with Camptocormia (CC) performed 3-D Gait Analysis and were evaluated with walking and balance scales. Correlations with clinical and functional scales were investigated. Spatio-temporal and kinematic data were compared to ten PD subjects without postural deformities (PP) and ten healthy matched individuals (CG). Data obtained showed decreased walking velocity, stride and step length in PP, PS and CC groups compared to controls. The correlation analysis showed that stride and step length were associated with reduced functional abilities and disease severity in PS and CC groups. Kinematic data revealed marked reduction in range of movements (ROMs) at all lower-extremity joints in PS group. While, in CC group the main differences were pronounced in hip and knee joints. PS and CC groups presented a more pronounced reduction in hip articular excursion compared to PP subjects, revealing an increased hip flexion pattern during gait cycle. Moreover, the increased hip and knee flexion pattern adversely affected functional performance during walking tests. Results obtained provide evidence that step length, along with stride length, can be proposed as simple and clear indicators of disease severity and reduced functional abilities. The reduction of ROMs at hip joint represented an important mechanism contributing to decreased walking velocity, balance impairment and reduced gait performance in PD patients with postural deformities.

Oligonucleotide therapeutics in neurodegenerative diseases.Publié le 22 03 2018

Therapeutics that directly target RNAs are promising for a broad spectrum of disorders, including the neurodegenerative diseases. This is exemplified by the FDA approval of Nusinersen, an antisense oligonucleotide (ASO) therapeutic for spinal muscular atrophy (SMA). RNA targeting therapeutics are currently under development for amyotrophic lateral sclerosis (ALS), Huntington's disease (HD), and spinocerebellar ataxias. We have used an ASO approach toward developing a treatment for spinocerebellar ataxia type 2 (SCA2), for targeting the causative gene ATXN2. We demonstrated that reduction of ATXN2 expression in SCA2 mice treated by intracerebroventicular injection (ICV) of ATXN2 ASO delayed motor phenotype onset, improved the expression of several genes demonstrated abnormally reduced by transcriptomic profiling of SCA2 mice, and restored abnormal Purkinje cell firing frequency in acute cerebellar sections. Here we discuss RNA abnormalities in disease and the prospects of targeting neurodegenerative diseases at the level of RNA control using ASOs and other RNA-targeted therapeutics.

Spinal muscular atrophy type I and the dual role of viruses: An interview with Professor Basil T. Darras, Professor of Neurology (Pediatrics) at Harvard Medical School.Publié le 22 03 2018

According to Professor Basil T. Darras, Professor of Neurology (Pediatrics) at Harvard Medical School and Director of the Spinal Muscular Atrophy (SMA) Program at Boston Children's Hospital in Boston (MA, USA), the diagnosis of SMA type I is clinical and is based on detailed general physical and neurological examinations. SMA type I remains the most common genetic disease resulting in death in infancy and is really devastating for the child, the parents, as well as the medical professionals with the privilege of caring for patients with SMA and their parents. The proposed management options include: i) no respiratory support; ii) non-invasive ventilation; and iii) tracheotomy with mechanical ventilation. Deciding, which option is the best, is indeed a very personal decision. The optimal clinical care should be extremely mindful of parents' wishes and management goals with regard to the quality of life. Since the end of 2016 in the USA, and recently in Europe, there exists the possibility of accessing a novel treatment drug for SMA, namely Nusinersen. This antisense oligonucleotide is administered intrathecally and increases the production of the fully functional SMN protein, thus improving motor function, the quality of life and survival. Among the ongoing clinical trials, oral treatment with RG7916, a small molecule SMN2 splicing modifier, appears to be really promising. Gene therapy using viral vectors is expected to offer an 'one and done' therapy and possibly a cure, if administered early in life, before any symptoms appear. It is really interesting that viruses, which at the moment are the cause of death of children with SMA, if genetically modified, may be used for their treatment.

Plastin 3 Promotes Motor Neuron Axonal Growth and Extends Survival in a Mouse Model of Spinal Muscular Atrophy.Publié le 20 03 2018

Spinal muscular atrophy (SMA) is a devastating childhood motor neuron disease. SMA is caused by mutations in the survival motor neuron gene (SMN1), leading to reduced levels of SMN protein in the CNS. The actin-binding protein plastin 3 (PLS3) has been reported as a modifier for SMA, making it a potential therapeutic target. Here, we show reduced levels of PLS3 protein in the brain and spinal cord of a mouse model of SMA. Our study also revealed that lentiviral-mediated PLS3 expression restored axonal length in cultured Smn-deficient motor neurons. Delivery of adeno-associated virus serotype 9 (AAV9) harboring Pls3 cDNA via cisterna magna in SMN?7 mice, a widely used animal model of SMA, led to high neuronal transduction efficiency. PLS3 treatment allowed a small but significant increase of lifespan by 42%. Although there was no improvement of phenotype, this study has demonstrated the potential use of Pls3 as a target for gene therapy, possibly in combination with other disease modifiers.

Nusinersen for SMA: expanded access programme.Publié le 20 03 2018

BACKGROUND: Spinal muscular atrophy (SMA) is a devastating motor neuron disorder causing progressive muscle weakness and respiratory insufficiency. We present the initial Australian experiences implementing the expanded access programme (EAP) to enable preapproval access to nusinersen, the first disease-modifying therapy, for SMA type 1.
METHODS: An Australian multicentre, open-label EAP for nusinersen enrolled patients with infantile-onset SMA type 1 from November 2016 to September 2017. Standard-of-care medical therapy and treatment with intrathecal nusinersen were provided to all patients. Clinical and diagnostic characteristics, molecular genetics, treatment administered, and functional motor outcomes were assessed.
RESULTS: A total of 20 patients with SMA type 1 met the inclusion criteria, of whom 16 consented and received nusinersen treatment. Median time to diagnosis from symptom onset was 5.0 months and was correlated with age of onset (r=0.54, P<0.05). Management shifts included proactive nutritional and pulmonary support in all newly diagnosed patients with increased complexity of decision making. Supplemental nutrition with or without nocturnal non-invasive ventilation was implemented during follow-up in new diagnoses with age of onset <3 months and 2 SMN2 copies.
CONCLUSIONS: The nusinersen EAP highlights difficulties in achieving early diagnosis and/or prevention, the evolution of optimal clinical care in a time of uncertain prognostication, resource implications and ethical issues in clinical practice for SMA type 1. These challenges are broadly relevant to the realisation of all novel therapeutics in neurological disorders.

Adult-onset spinal muscular atrophy: An update.Publié le 20 03 2018

Spinal muscular atrophy (SMA) refers to a group of disorders affecting lower motor neurons. The age of onset of these disorders is variable, ranging from the neonatal period to adulthood. Over the last few years, there has been enormous progress in the description of new genes and phenotypes that throw new light on the molecular pathways involved in motor neuron degeneration. Advances in our understanding of the pathophysiology of the most frequent forms, SMA linked to SMN1 gene mutations and Kennedy disease, has led to the development of therapeutic strategies currently being tested in clinical trials. This report provides a general overview of the clinical features and pathophysiological mechanisms in adult-onset genetic SMA disorders in which the causative gene has been identified (SMN1-related SMA, Kennedy disease, CHCHD10, TRPV4, DYNC1H1 and BICD2). Sporadic lower motor neuron disease, also known as progressive muscular atrophy (PMA), is also discussed. The finding of TDP-43 aggregates in immunohistochemical studies of PMA strongly supports the idea that it is a phenotypic variant of amyotrophic lateral sclerosis (ALS).

Benign focal amyotrophy.Publié le 20 03 2018

Within lower motor neuron diseases, benign focal amyotrophy is a rare syndrome characterized by insidious neurogenic asymmetric atrophy restricted to upper or lower limbs with a good prognosis over time. Described under several terms, the nosology is probably heterogeneous. In juvenile distal upper-limbs forms, specific MRI signs with in particular a compression of the spinal cord by forward displacement of dura, lead to evoke a mechanical process. In other forms, occurring later in the life, affecting proximal part of upper limbs or lower limbs, the physiopathology is still unknown and a focal spinal muscular atrophy is suspected. In this review, we will discuss the clinical, electrophysiological and radiological features of each presentation.

Stem cell derived phenotypic human neuromuscular junction model for dose response evaluation of therapeutics.Publié le 18 03 2018

There are currently no functional neuromuscular junction (hNMJ) systems composed of human cells that could be used for drug evaluations or toxicity testing in vitro. These systems are needed to evaluate NMJs for diseases such as amyotrophic lateral sclerosis, spinal muscular atrophy or other neurodegenerative diseases or injury states. There are certainly no model systems, animal or human, that allows for isolated treatment of motoneurons or muscle capable of generating dose response curves to evaluate pharmacological activity of these highly specialized functional units. A system was developed in which human myotubes and motoneurons derived from stem cells were cultured in a serum-free medium in a BioMEMS construct. The system is composed of two chambers linked by microtunnels to enable axonal outgrowth to the muscle chamber that allows separate stimulation of each component and physiological NMJ function and MN stimulated tetanus. The muscle's contractions, induced by motoneuron activation or direct electrical stimulation, were monitored by image subtraction video recording for both frequency and amplitude. Bungarotoxin, BOTOX® and curare dose response curves were generated to demonstrate pharmacological relevance of the phenotypic screening device. This quantifiable functional hNMJ system establishes a platform for generating patient-specific NMJ models by including patient-derived iPSCs.

Hirayama disease.Publié le 18 03 2018

PURPOSE: Hirayama disease is an initially progressive disease caused by cervical neck flexion compressing the anterior horns of the lower cervical spinal cord. It is primarily seen in young males of Indian or Asian descent. With increasing dispersion of these populations this condition is increasingly being encountered internationally. This grand round reviews this rare but increasingly recognized condition.
MATERIALS AND METHODS: We present a classic case of a young Indian male with progressive hand and forearm weakness. We discuss the typical clinical presentation, appropriate investigations and management of this condition.
RESULTS: Our patient presented with oblique amyotrophy and underwent a diagnostic flexion MRI scan which revealed anterior translation of the posterior dura with compression of the anterior horns of the lower cervical cord. He has been successfully treated in a cervical collar.
CONCLUSIONS: This case illustrates the typical presentation, diagnostic investigations and treatment of Hirayama syndrome. It is hoped that this review will alert clinicians of this condition and optimize the management of affected individuals.

Effectiveness of spinal cord stimulation for painful camptocormia with Pisa syndrome in Parkinson's disease: a case report.Publié le 14 03 2018

BACKGROUND: Spinal cord stimulation (SCS) has recently been reported to be effective for truncal postural abnormalities such as camptocormia and Pisa syndrome in Parkinson's disease. In this case report, we describe a case of a woman with Parkinson's disease in whom SCS was effective for painful camptocormia with Pisa syndrome.
CASE PRESENTATION: A 65-year-old woman was admitted to our hospital because of painful camptocormia. She had noticed resting tremor in the left upper limb and aprosody at 48 years of age. She was diagnosed as having Parkinson's disease (Hoehn & Yahr stage 1) at 53 years of age. Cabergoline was started during that same year, with subsequent addition of selegiline hydrochloride; the symptoms of parkinsonism disappeared. Wearing-off occurred when she was 57 years old, 3 years after starting carbidopa/levodopa, and truncal postural abnormalities-painful camptocormia with Pisa syndrome to the right-appeared at 58 years of age. These symptoms worsened despite adjustment of her oral medications, and deep brain stimulation (DBS) was performed when she was 60 years old. The truncal postural abnormalities improved after DBS, and she could travel abroad at 61 years of age. However, from 62 years of age, painful camptocormia with Pisa syndrome to the right reappeared. The pain was unsuccessfully treated with oral analgesics, radiofrequency coagulation of the dorsal and medial branches of the lumbar spinal nerve, and lumbar epidural block. Finally, SCS was performed for the pain relief. The pain disappeared immediately after SCS and her posture then gradually improved. Unified Parkinson's Disease Rating Scale score improved from 48 to 34 points and Timed Up and Go Test improved from 15 s to 7 s after SCS.
CONCLUSIONS: This case suggests that SCS may be effective for improving painful truncal postural abnormalities and motor complications of Parkinson's disease. Pain relief or a direct effect on the central nervous system by SCS was considered to explain the alleviation of these symptoms.

Noninvasive airway approaches for acute neuromuscular respiratory failure in emergency departments.Publié le 13 03 2018

Emerging evidence advocates for noninvasive ventilation (NIV) combined with mechanical in-exsufflation (MIE) as a first-line approach for acute respiratory failure (ARF) in patients with neuromuscular disorders (NMD). To date, most NIV studies of ARF in NMD patients have been performed in intensive care units or in hospital settings. However, the utility of using combined NIV/MIE in the emergency department (ED) settings is unclear. We report on the implementation of NIV/MIE in two children with type II spinal muscular atrophy who presented to the ED with ARF. This is the first report on the feasibility and efficacy of combining NIV/MIE in ED settings for pediatric NMD patients with ARF.

Augmenting the SMN Protein to Treat Infantile Spinal Muscular Atrophy.Publié le 09 03 2018

Spinal muscular atrophy (SMA) is a common and oft-fatal pediatric neuromuscular disorder caused by insufficient SMN protein. Now, two clinical trials (Mendell et al., 2017; Finkel et al., 2017) demonstrate that restoring the protein is therapeutic, offering new treatment options and renewed hope to SMA patients.

ASO Therapy: Hope for Genetic Neurological Diseases.Publié le 03 03 2018

PMID: 29383373 [PubMed - indexed for MEDLINE]

Prenatal transplantation of human amniotic fluid stem cells for spinal muscular atrophy.Publié le 02 03 2018

PURPOSE OF REVIEW: To review the current medical and stem-cell therapy for spinal muscular atrophy (SMA) and prenatal transplantation of amniotic fluid stem cells in the future.
RECENT FINDINGS: SMA is an autosomal recessive inheritance of neurodegenerative disease, which is caused of the mutation in survival motor neuron. The severe-type SMA patients usually die from the respiratory failure within 2 years after birth. Recently, researchers had found that 3-methyladenine could inhibit the autophagy and had the capacity to reduce death of the neurons. The first food and drug administration-approved drug to treat SMA, Nusinersen, is a modified antisense oligonucleotide to target intronic splicing silencer N1 just recently launched. Not only medical therapy, but also stem cells including neural stem cells, embryonic stem cells, mesenchymal stem cells, and induced pluripotent stem cells could show the potential to repair the injured tissue and differentiate into neuron cells to rescue the SMA animal models. Human amniotic fluid stem cells (HAFSCs) share the potential of mesenchymal stem cells and could differentiate into tri-lineage-relative cells, which are also having the ability to restore the injured neuro-muscular function. In this review, we further demonstrate the therapeutic effect of using HAFSCs to treat type III SMA prenatally. HAFSCs, similar to other stem cells, could also help the improvement of SMA with even longer survival.
SUMMARY: The concept of prenatal stem-cell therapy preserves the time window to treat disease in utero with much less cell number. Stem cell alone might not be enough to correct or cure the SMA but could be applied as the additional therapy combined with antisense oligonucleotide in the future.

Long-term Non-Invasive Ventilation in Infants: A Systematic Review and Meta-Analysis.Publié le 01 03 2018

Background: The use of long-term non-invasive ventilation (NIV) to treat sleep and breathing disorders in children has increased substantially in the last decade; however, less data exist about its use in infants. Given that infants have distinct sleep and breathing patterns when compared to older children, the outcomes of infants on long-term NIV may differ as well. The aim of this study is to systematically review the use and outcomes of long-term NIV in infants.
Methods: Ovid Medline, Ovid Embase, CINAHL (via EbscoHOST), PubMed, and Wiley Cochrane Library were systematically searched from January 1990 to July 2017. Studies on infants using long-term NIV outside of an acute care setting were included. Data were extracted on study design, population characteristics, and NIV outcomes.
Results: A total of 327 studies were full-text reviewed, with final inclusion of 60. Studies were distributed across airway (40%), neuromuscular (28%), central nervous system (10%), cardio-respiratory (2%), and multiple (20%) disease categories. Of the 18 airway studies reporting on NIV outcomes, 13 (72%) reported improvements in respiratory parameters. Of the 12 neuromuscular studies exclusively on spinal muscular atrophy type 1 (SMA1), six (50%) reported decreased hospitalizations and nine (75%) reported on mortality outcomes. Risk of bias was moderate to serious, and quality of the evidence was low to very low for all studies. Most studies had an observational design with no control group, limiting the potential for a meta-analysis.
Conclusion: The outcomes reported in studies differed by the disease category being studied. Studies on airway conditions showed improvements in respiratory parameters for infants using NIV. Studies on neuromuscular disorder, which were almost exclusively on SMA1, reported decreased hospitalizations and prolonged survival. Overall, it appears that NIV is an effective long-term therapy for infants. However, the high risk of bias and low quality of the available evidence limited strong conclusions.

The Canadian Neuromuscular Disease Registry: Connecting patients to national and international research opportunities.Publié le 01 03 2018

Introduction: Patient registries serve an important role in rare disease research, particularly for the recruitment and planning of clinical trials. The Canadian Neuromuscular Disease Registry was established with the primary objective of improving the future for neuromuscular (NM) patients through the enablement and support of research into potential treatments.
Methods: In this report, we discuss design and utilization of the Canadian Neuromuscular Disease Registry with special reference to the paediatric cohort currently enrolled in the registry.
Results: As of July 25, 2017, there are 658 paediatric participants enrolled in the registry, 249 are dystrophinopathies (229 are Duchenne muscular dystrophy), 57 are myotonic dystrophy participants, 98 spinal muscular atrophy participants and 65 are limb girdle muscular dystrophy. A total of 175 patients have another NM diagnosis. The registry has facilitated 20 clinical trial inquiries, 5 mail-out survey studies and 5 other studies in the paediatric population.
Discussion: The strengths of the registry are discussed. The registry has proven to be an invaluable tool to NM disease research and has increased Canada's visibility as a competitive location for the conduct of clinical trials for NM therapies.

Genome-wide CRISPR-Cas9 Screen Identifies Leukemia-Specific Dependence on a Pre-mRNA Metabolic Pathway Regulated by DCPS.Publié le 01 03 2018

To identify novel targets for acute myeloid leukemia (AML) therapy, we performed genome-wide CRISPR-Cas9 screening using AML cell lines, followed by a second screen in vivo. Here, we show that the mRNA decapping enzyme scavenger (DCPS) gene is essential for AML cell survival. The DCPS enzyme interacted with components of pre-mRNA metabolic pathways, including spliceosomes, as revealed by mass spectrometry. RG3039, a DCPS inhibitor originally developed to treat spinal muscular atrophy, exhibited anti-leukemic activity via inducing pre-mRNA mis-splicing. Humans harboring germline biallelic DCPS loss-of-function mutations do not exhibit aberrant hematologic phenotypes, indicating that DCPS is dispensable for human hematopoiesis. Our findings shed light on a pre-mRNA metabolic pathway and identify DCPS as a target for AML therapy.

Intracerebroventricular Delivery in Mice for Motor Neuron Diseases.Publié le 01 03 2018

The use of antisense oligonucleotides to target specific mRNA sequences represents a promising therapeutic strategy for neurological disorders. Recent advances in antisense technology enclose the development of phosphorodiamidate morpholino oligomers (MO), which is one of the best candidates for molecular therapies due to MO's excellent pharmacological profile.Nevertheless, the route of administration of antisense compounds represents a critical issue in the neurological field. Particularly, as regards motor neuron diseases, intracerebroventricular (ICV) injection is undoubtedly the most efficient procedure to directly deliver therapeutic molecules in the central nervous system (CNS). Indeed, we recently demonstrated the outstanding efficacy of the MO antisense approach by its direct administration to CNS of the transgenic mouse models of Spinal Muscular Atrophy (SMA) and Amyotrophic Lateral Sclerosis (ALS).Here, we describe methods to perform the ICV delivery of MO in neonatal SMA mice and in adult ALS mice.

Barriers and facilitators to clinical trial participation among parents of children with pediatric neuromuscular disorders.Publié le 26 02 2018

BACKGROUND/AIMS: Pediatric rare disease presents a challenging situation of high unmet need and a limited pool of potential clinical trial participants. Understanding perspectives of parents of children who have not participated in trials may facilitate approaches to optimize participation rates. The objective of this study was to explore factors associated with parental interest in enrolling children with pediatric neuromuscular disorders in clinical trials.
METHODS: Parents of individuals with Duchenne or Becker muscular dystrophy and spinal muscular atrophy were recruited through advocacy organizations, a registry, and clinics. These parents ( N?=?203) completed a questionnaire including assessments of barriers and facilitators to clinical trial participation, parents' interest in trial participation, and their perceptions of others' views about participation in a clinical trial.
RESULTS: Trial interest in participating parents was high (64% combined group). The most highly endorsed barrier to participation was the possibility of receiving placebo, followed by not having enough information on risks and trial procedures. Compared to parents of children with Duchenne or Becker muscular dystrophy, parents of children with spinal muscular atrophy endorsed significantly more information and knowledge barriers. The greatest facilitators of participation were (1) confidence in improving disease understanding and (2) guarantee to receive the treatment after a successful trial. A logistic regression model, ?2 (4, n?=?188)?=?80.64, p?<?.001, indicated that higher perceived barriers and more frequent trial communication by the provider were associated with lower interest, while positive trial perceptions by the child's providers and concordance in trial perceptions among those close to the decision-maker were associated with higher interest.
CONCLUSION: We found high parental interest in pediatric neuromuscular trials that was tempered by concerns about the potential for randomization to a placebo arm. Participants perceived that their trial participation would be facilitated by additional education and guidance from their clinicians. Yet, intentions were negatively associated with frequency of provider communication, perhaps reflecting waning parental interest with a greater understanding of limitations in trial access, increased sophistication in their understanding of trial design, and appreciation of potential burden. To support parents' informed decisions, it is important to educate them to evaluate the quality of research, as well as providing lay information explaining the use of placebo, trial processes, and potential barriers to long-term drug access. Our findings should inform the development of targeted educational content, clinician training, and decision support tools.

Respiratory complications, management and treatments for neuromuscular disease in children.Publié le 26 02 2018

PURPOSE OF REVIEW: To summarize current literature describing the respiratory complications of neuromuscular disease (NMD) and the effect of respiratory interventions and to explore new gene therapies for patients with NMD.
RECENT FINDINGS: Measurements of respiratory function focus on vital capacity and maximal inspiratory and expiratory pressure and show decline over time. Management of respiratory complications includes lung volume recruitment, mechanical insufflation-exsufflation, chest physiotherapy and assisted ventilation. Lung volume recruitment can slow the progression of lung restriction. New gene-specific therapies for Duchenne muscular dystrophy and spinal muscular atrophy have the potential to preserve respiratory function longitudinally. However, the long-term therapeutic benefit remains unknown.
SUMMARY: Although NMDs are heterogeneous, many lead to progressive muscle weakness that compromises the function of the respiratory system including upper airway tone, cough and secretion clearance and chest wall support. Respiratory therapies augment or support the normal function of these components of the respiratory system. From a respiratory perspective, the new mutation and gene-specific therapies for NMD are likely to confer long-term therapeutic benefit. More sensitive and standard tools to assess respiratory function longitudinally are needed to monitor respiratory complications in children with NMD, particularly the youngest patients.

Disease impact on general well-being and therapeutic expectations of European Type II and Type III spinal muscular atrophy patients.Publié le 23 02 2018

Spinal muscular atrophy (SMA) is a neurodegenerative disorder showing a broad clinical spectrum and no cure to date. To design and select evaluation criteria for the potential assessment of drugs currently being developed, the patient's perspective is critical. A survey, aiming to obtain a view on the current clinical state of European Type II and Type III SMA patients, the impact of this situation on their quality of life and their expectations regarding clinical development, was carried out by SMA-Europe member organizations in July 2015. A questionnaire was set up, translated into 8 European languages and sent out directly via electronic mailing to the targeted SMA patient population by the respective European patient organizations. We were able to collect 822 valid replies in less than two weeks. The questionnaire captured the current abilities of the respondents, their perception of the disease burden which appeared very similar across Europe despite some regional variations in care. According to the great majority of the respondents, stabilization of their current clinical state would represent a therapeutic progress for a compelling majority of the respondents to the questionnaire.

Antisense oligonucleotides and other genetic therapies made simple.Publié le 20 02 2018

Many genetic neurological diseases result from the dysfunction of single proteins. Genetic therapies aim to modify these disease-associated proteins by targeting the RNA and DNA precursors. This review provides a brief overview of the main types of genetic therapies, with a focus on antisense oligonucleotides (ASOs) and RNA interference (RNAi). We use examples of new genetic therapies for spinal muscular atrophy, Duchenne muscular dystrophy and familial amyloid polyneuropathy to highlight the different mechanisms of action of ASOs and RNAi.

FDA-Approved Oligonucleotide Therapies in 2017.Publié le 20 02 2018

Oligonucleotides (oligos) have been under clinical development for approximately the past 30 years, beginning with antisense oligonucleotides (ASOs) and apatmers and followed about 15 years ago by siRNAs. During that lengthy period of time, numerous clinical trials have been performed and thousands of trial participants accrued onto studies. Of all the molecules evaluated as of January 2017, the regulatory authorities assessed that six provided clear clinical benefit in rigorously controlled trials. The story of these six is given in this review.

Nusinersen versus Sham Control in Later-Onset Spinal Muscular Atrophy.Publié le 15 02 2018

Background Nusinersen is an antisense oligonucleotide drug that modulates pre-messenger RNA splicing of the survival motor neuron 2 ( SMN2) gene. It has been developed for the treatment of spinal muscular atrophy (SMA). Methods We conducted a multicenter, double-blind, sham-controlled, phase 3 trial of nusinersen in 126 children with SMA who had symptom onset after 6 months of age. The children were randomly assigned, in a 2:1 ratio, to undergo intrathecal administration of nusinersen at a dose of 12 mg (nusinersen group) or a sham procedure (control group) on days 1, 29, 85, and 274. The primary end point was the least-squares mean change from baseline in the Hammersmith Functional Motor Scale-Expanded (HFMSE) score at 15 months of treatment; HFMSE scores range from 0 to 66, with higher scores indicating better motor function. Secondary end points included the percentage of children with a clinically meaningful increase from baseline in the HFMSE score (?3 points), an outcome that indicates improvement in at least two motor skills. Results In the prespecified interim analysis, there was a least-squares mean increase from baseline to month 15 in the HFMSE score in the nusinersen group (by 4.0 points) and a least-squares mean decrease in the control group (by -1.9 points), with a significant between-group difference favoring nusinersen (least-squares mean difference in change, 5.9 points; 95% confidence interval, 3.7 to 8.1; P<0.001). This result prompted early termination of the trial. Results of the final analysis were consistent with results of the interim analysis. In the final analysis, 57% of the children in the nusinersen group as compared with 26% in the control group had an increase from baseline to month 15 in the HFMSE score of at least 3 points (P<0.001), and the overall incidence of adverse events was similar in the nusinersen group and the control group (93% and 100%, respectively). Conclusions Among children with later-onset SMA, those who received nusinersen had significant and clinically meaningful improvement in motor function as compared with those in the control group. (Funded by Biogen and Ionis Pharmaceuticals; CHERISH ClinicalTrials.gov number, NCT02292537 .).

Increasing Agrin Function Antagonizes Muscle Atrophy and Motor Impairment in Spinal Muscular Atrophy.Publié le 15 02 2018

Spinal muscular atrophy (SMA) is a pediatric genetic disease, characterized by motor neuron (MN) death, leading to progressive muscle weakness, respiratory failure, and, in the most severe cases, to death. Abnormalities at the neuromuscular junction (NMJ) have been reported in SMA, including neurofilament (NF) accumulation at presynaptic terminals, immature and smaller than normal endplates, reduced transmitter release, and, finally, muscle denervation. Here we have studied the role of agrin in SMA?7 mice, the experimental model of SMAII. We observed a 50% reduction in agrin expression levels in quadriceps of P10 SMA mice compared to age-matched WT controls. To counteract such condition, we treated SMA mice from birth onwards with therapeutic agrin biological NT-1654, an active splice variant of agrin retaining synaptogenic properties, which is also resistant to proteolytic cleavage by neurotrypsin. Mice were analyzed for behavior, muscle and NMJ histology, and survival. Motor behavior was significantly improved and survival was extended by treatment of SMA mice with NT-1654. At P10, H/E-stained sections of the quadriceps, a proximal muscle early involved in SMA, showed that NT-1654 treatment strongly prevented the size decrease of muscle fibers. Studies of NMJ morphology on whole-mount diaphragm preparations revealed that NT-1654-treated SMA mice had more mature NMJs and reduced NF accumulation, compared to vehicle-treated SMA mice. We conclude that increasing agrin function in SMA has beneficial outcomes on muscle fibers and NMJs as the agrin biological NT-1654 restores the crosstalk between muscle and MNs, delaying muscular atrophy, improving motor performance and extending survival.

Advances in spinal muscular atrophy therapeutics.Publié le 13 02 2018

Spinal muscular atrophy (SMA) is a progressive, recessively inherited neuromuscular disease, characterized by the degeneration of lower motor neurons in the spinal cord and brainstem, which leads to weakness and muscle atrophy. SMA currently represents the most common genetic cause of infant death. SMA is caused by the lack of survival motor neuron (SMN) protein due to mutations, which are often deletions, in the SMN1 gene. In the absence of treatments able to modify the disease course, a considerable burden falls on patients and their families. Greater knowledge of the molecular basis of SMA pathogenesis has fuelled the development of potential therapeutic approaches, which are illustrated here. Nusinersen, a modified antisense oligonucleotide that modulates the splicing of the SMN2 mRNA transcript, is the first approved drug for all types of SMA. Moreover, the first gene therapy clinical trial using adeno-associated virus (AAV) vectors encoding SMN reported positive results in survival and motor milestones achievement. In addition, other strategies are in the pipeline, including modulation of SMN2 transcripts, neuroprotection, and targeting an increasing number of other peripheral targets, including the skeletal muscle. Based on this premise, it is reasonable to expect that therapeutic approaches aimed at treating SMA will soon be changed, and improved, in a meaningful way. We discuss the challenges with regard to the development of novel treatments for patients with SMA, and depict the current and future scenarios as the field enters into a new era of promising effective treatments.

Degeneration of the corticofugal tract from the secondary motor area in a Parkinson's disease patient with limb-kinetic apraxia: A case report.Publié le 13 02 2018

RATIONALE: In this case report, we describe a Parkinson's disease (PD) patient with limb-kinetic apraxia (LKA) in whom degeneration of the corticofugal tract (CFT) from the supplementary motor area (SMA) was observed in diffusion tensor tractography (DTT).
PATIENT CONCERNS: A 63-year-old woman presented with a loss of dexterity in both upper extremities, which indicated LKA, and typical PD-related symptoms, including a gait disturbance with a short step, resting tremor in both upper extremities, and rigidity, and these symptoms had been present for 2 years. The F-florinated-N-3-fluoropropyl-2-?-carboxymethoxy-3-?-(4-lodophenyl) nortropane positron emission tomography scanning findings were consistent with PD. Based on the clinical symptoms and imaging findings, we diagnosed the patient with PD. In a coin-rotation test that was used to evaluate the severity of the LKA, the patient's results significantly decreased compared to the results of the normal controls.
DIAGNOSES: The DTT showed that the CFTs from the SMAs in both hemispheres were partially torn and thinned. The fractional anisotropy values and CFT volumes in both SMAs were >2 standard deviations lower than those of the normal controls.
INTERVENTIONS: The patient was treated with an initial dose of 150/37.5?mg/day of levodopa/benserazide, and the dose was gradually increased to 400/100?mg/day.
OUTCOMES: After treatment, although the bradykinesia, rigidity, and resting tremor of the patient significantly decreased, the dexterity of the patient's hands did not improve.
LESSONS: These observations indicated degeneration of the CFTs from the SMAs in both hemispheres in the patient. This degeneration might have, at least in part, contributed to the patient's LKA. The results of this study suggest that CFT degeneration could be one of the pathological mechanisms underlying LKA in patients with PD.

Cell freezing protocol suitable for ATAC-Seq on motor neurons derived from human induced pluripotent stem cells.Publié le 13 02 2018

In recent years, the assay for transposase-accessible chromatin using sequencing (ATAC-Seq) has become a fundamental tool of epigenomic research. However, it is difficult to perform this technique on frozen samples because freezing cells before extracting nuclei can impair nuclear integrity and alter chromatin structure, especially in fragile cells such as neurons. Our aim was to develop a protocol for freezing neuronal cells that is compatible with ATAC-Seq; we focused on a disease-relevant cell type, namely motor neurons differentiated from induced pluripotent stem cells (iMNs) from a patient affected by spinal muscular atrophy. We found that while flash-frozen iMNs are not suitable for ATAC-Seq, the assay is successful with slow-cooled cryopreserved cells. Using this method, we were able to isolate high quality, intact nuclei, and we verified that epigenetic results from fresh and cryopreserved iMNs quantitatively agree.

Advances in therapy for spinal muscular atrophy: promises and challenges.Publié le 10 02 2018

Spinal muscular atrophy (SMA) is a devastating motor neuron disease that predominantly affects children and represents the most common cause of hereditary infant mortality. The condition results from deleterious variants in SMN1, which lead to depletion of the survival motor neuron protein (SMN). Now, 20 years after the discovery of this genetic defect, a major milestone in SMA and motor neuron disease research has been reached with the approval of the first disease-modifying therapy for SMA by US and European authorities - the antisense oligonucleotide nusinersen. At the same time, promising data from early-stage clinical trials of SMN1 gene therapy have indicated that additional therapeutic options are likely to emerge for patients with SMA in the near future. However, the approval of nusinersen has generated a number of immediate and substantial medical, ethical and financial implications that have the potential to resonate beyond the specific treatment of SMA. Here, we provide an overview of the rapidly evolving therapeutic landscape for SMA, highlighting current achievements and future opportunities. We also discuss how these developments are providing important lessons for the emerging second generation of combinatorial ('SMN-plus') therapies that are likely to be required to generate robust treatments that are effective across a patient's lifespan.

Minimally Invasive Surgery for Neuromuscular Scoliosis: Results and Complications in a Series of one hundred Patients.Publié le 09 02 2018

STUDY DESIGN: A retrospective review.
OBJECTIVES: To report the results of an alternative technique using a minimally invasive fusionless surgery. The originality is based on the progressive correction of the deformities with proximal and distal fixation and on the reliability of the pelvic fixation using ilio-sacral screws on osteoporotic bones.
SUMMARY OF BACKGROUND DATA: Spinal deformities are common in neuromuscular diseases. Conventional treatment involves bracing, followed by spinal instrumented fusion. Growing rod techniques are increasingly advocated but have a high rate of complications.
METHODS: The technique relies on a bilateral double rod sliding construct anchored proximally by 4 hooks claws and distally to the pelvis by ilio-sacral screws through a minimally invasive approach.100 patients with neuromuscular scoliosis underwent the same fusionless surgery extended from T1 to the pelvis. The average age at initial surgery was 11+6y. Diagnoses included cerebral palsy (61), spinal muscular atrophy (22), muscular dystrophy (10), and other neurological etiologies (7).Cobb angle and pelvic obliquity were measured before and after initial surgery, and at final follow-up. Complications were reviewed.
RESULTS: At latest follow-up 3+9 y (range 2y - 6+3y), the mean Cobb angle improved from 89° to 35° which corresponds to 61% correction. Mean pelvic obliquity improved from 29° to 5° which corresponds to 83% correction. Mean T1-S1 length increased from 30.02?cm to 37.28?cm. Mean preoperative hyper kyphosis was reduced from 68.44° to 33.29°. Complications occurred in 22 patients including mechanical complications (12) and wound infections (16). No arthrodesis was required at last follow-up.
CONCLUSION: This original fusionless technique is safe and effective, preserving spinal and thoracic growth. It provides a significant correction of spinal deformities and pelvic obliquity with a reduced complications rate. The strength and stability of this modular construct over time allow the avoidance of final arthrodesis.
LEVEL OF EVIDENCE: xxxxThis is an open access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0.

The potential of antisense oligonucleotide therapies for inherited childhood lung diseases.Publié le 08 02 2018

Antisense oligonucleotides are an emerging therapeutic option to treat diseases with known genetic origin. In the age of personalised medicines, antisense oligonucleotides can sometimes be designed to target and bypass or overcome a patient's genetic mutation, in particular those lesions that compromise normal pre-mRNA processing. Antisense oligonucleotides can alter gene expression through a variety of mechanisms as determined by the chemistry and antisense oligomer design. Through targeting the pre-mRNA, antisense oligonucleotides can alter splicing and induce a specific spliceoform or disrupt the reading frame, target an RNA transcript for degradation through RNaseH activation, block ribosome initiation of protein translation or disrupt miRNA function. The recent accelerated approval of eteplirsen (renamed Exondys 51™) by the Food and Drug Administration, for the treatment of Duchenne muscular dystrophy, and nusinersen, for the treatment of spinal muscular atrophy, herald a new and exciting era in splice-switching antisense oligonucleotide applications to treat inherited diseases. This review considers the potential of antisense oligonucleotides to treat inherited lung diseases of childhood with a focus on cystic fibrosis and disorders of surfactant protein metabolism.

Development of gene therapies-lessons from nusinersen.Publié le 08 02 2018

The nusinersen development and approval process provide important lessons regarding the pathway to marketing approval for gene therapies. These lessons emphasize rigorous clinical trial design, flexibility in trial design and analysis, a collaborative effort with regular communications between the drug developer and the Food and Drug Administration (FDA), and use of FDA's expedited programs. These lessons are critical to the development of gene therapies for the treatment of serious or life-threatening rare diseases.

Spinal muscular atrophy approval boosts antisense drugs.Publié le 08 02 2018

PMID: 28178250 [PubMed - indexed for MEDLINE]

New quantitative method for evaluation of motor functions applicable to spinal muscular atrophy.Publié le 06 02 2018

OBJECTIVE: The aim of this study was to develop and introduce new method to quantify motor functions of the upper extremity.
METHODS: The movement was recorded using a three-dimensional motion capture system, and the movement trajectory was analyzed using newly developed two indices, which measure precise repeatability and directional smoothness. Our target task was shoulder flexion repeated ten times. We applied our method to a healthy adult without and with a weight, simulating muscle impairment. We also applied our method to assess the efficacy of a drug therapy for amelioration of motor functions in a non-ambulatory patient with spinal muscular atrophy. Movement trajectories before and after thyrotropin-releasing hormone therapy were analyzed.
RESULTS: In the healthy adult, we found the values of both indices increased significantly when holding a weight so that the weight-induced deterioration in motor function was successfully detected. From the efficacy assessment of drug therapy in the patient, the directional smoothness index successfully detected improvements in motor function, which were also clinically observed by the patient's doctors.
CONCLUSION: We have developed a new quantitative evaluation method of motor functions of the upper extremity. Clinical usability of this method is also greatly enhanced by reducing the required number of body-attached markers to only one. This simple but universal approach to quantify motor functions will provide additional insights into the clinical phenotypes of various neuromuscular diseases and developmental disorders.

Increase of HCN current in the aberrant excitability of spinal muscular atrophy.Publié le 03 02 2018

Objective The pathophysiology of spinal muscular atrophy (SMA) is still unclear. Methods The nerve excitability test in SMA patients and a mouse model of SMA was carried out to explore the pathophysiology of nodal and internodal currents, and quantitative PCR, Western blotting and whole-cell patch-clamp recording were used for the identified hypothesis. Results The nerve excitability test in SMA patients showed increased inward rectification in the current-threshold relationship and increased overshoot after hyperpolarizing threshold electrotonus, which indicates increased hyperpolarization-activated cyclic nucleotide-gated (HCN) current; these findings correlated with disease severity. Increased inward rectification in the current-threshold relationship was reproducible in a mouse model of mild SMA and the abnormality preceded the decline of compound motor action potential amplitudes. Furthermore, quantitative PCR of spinal cord tissues and Western blotting of the spinal cord and sciatic nerves showed increased HCN1 and HCN2 expression in the SMA mice, and voltage-clamp recording in dissociated spinal motor neurons from SMA mice also showed increased HCN current density. Treatment with ZD7288, an HCN channel blocker, also reduced early mortality, improved motor function, and restored neuromuscular junction architecture in a mouse model of severe SMA. Interpretation This study shows that increased HCN current underlies the pathophysiology of SMA and can be a novel non-SMN-target for SMA therapy. This article is protected by copyright. All rights reserved.

[Weak respiratory muscles as a first sign of ALS: symptoms may put the physician on the wrong track].Publié le 03 02 2018

BACKGROUND: Patients with decreased exercise tolerance and orthopnoea are often referred to an internist, a cardiologist or a pulmonologist. These symptoms can also be caused by weakness of the respiratory muscles, as an indication of a neuromuscular disease. If these symptoms are not recognized as such, this may result in a delay in timely diagnosis.
CASE DESCRIPTION: An 82-year-old man had suffered from decreased exercise tolerance for 18 months. For the last months he had been sleeping upright and had lost 20 kg in weight. Analyses by the cardiologist and the internist had not led to a definitive diagnosis. He was finally brought to the emergency department with loss of consciousness and hypercapnic respiratory insufficiency. Neurological examination was suggestive of motor neuron disease such as progressive spinal muscular atrophy or amyotrophic lateral sclerosis. The patient died within 24 hours of admission.
CONCLUSION: Patients with symptoms resulting from respiratory muscle weakness are commonly referred to non-neurological specialists, leading to a delay in diagnosis and treatment of an underlying neuromuscular disease.

Small-molecule flunarizine increases SMN protein in nuclear Cajal bodies and motor function in a mouse model of spinal muscular atrophy.Publié le 03 02 2018

The hereditary neurodegenerative disorder spinal muscular atrophy (SMA) is characterized by the loss of spinal cord motor neurons and skeletal muscle atrophy. SMA is caused by mutations of the survival motor neuron (SMN) gene leading to a decrease in SMN protein levels. The SMN deficiency alters nuclear body formation and whether it can contribute to the disease remains unclear. Here we screen a series of small-molecules on SMA patient fibroblasts and identify flunarizine that accumulates SMN into Cajal bodies, the nuclear bodies important for the spliceosomal small nuclear RNA (snRNA)-ribonucleoprotein biogenesis. Using histochemistry, real-time RT-PCR and behavioural analyses in a mouse model of SMA, we show that along with the accumulation of SMN into Cajal bodies of spinal cord motor neurons, flunarizine treatment modulates the relative abundance of specific spliceosomal snRNAs in a tissue-dependent manner and can improve the synaptic connections and survival of spinal cord motor neurons. The treatment also protects skeletal muscles from cell death and atrophy, raises the neuromuscular junction maturation and prolongs life span by as much as 40 percent (p?<?0.001). Our findings provide a functional link between flunarizine and SMA pathology, highlighting the potential benefits of flunarizine in a novel therapeutic perspective against neurodegenerative diseases.

Therapy for Spinal Muscular Atrophy.Publié le 01 02 2018

PMID: 29385371 [PubMed - in process]

Does stabilization of the degenerative lumbar spine itself produce multifidus atrophy?Publié le 01 02 2018

The effect of stabilization of the degenerative segment on changes in the pattern of paraspinal muscle activity was investigated using a previously developed musculoskeletal model. Muscle activity change depending on L4-L5 segment stabilization with and without taking into account the presence of multifidus atrophy according to direct invasion of the back muscle during surgery (MADIBM) was analysed in erect standing and 20° flexed postures. For the stabilization of the degenerative segment, a fusion or non-fusion stabilization with a pedicle-based dynamic stabilization system (PBDS) was applied. During erect standing, fusion generated a 12% reduction in the total multifidus muscle force, while its reduction was 6.6% with PBDS application. The presence of MADIBM produced 23.0% and 22.5% reductions in fusion and with PBDS application, respectively. During 20° flexion, 10.5% and 9.3% reductions were produced for fusion and PBDS application, respectively, and the corresponding values were 23.4% and 23.0%, respectively, in the presence of MADIBM. Increased facet joint contact forces were produced at the non-stabilized levels after stabilization while in erect standing posture. Alterations in muscle activity, which could be regarded as adaptions to altered spinal stability, may generate unexpected secondary problems in the spine.

Overview of Current Drugs and Molecules in Development for Spinal Muscular Atrophy Therapy.Publié le 31 01 2018

Spinal muscular atrophy (SMA) is a neurodegenerative disease primarily characterized by a loss of spinal motor neurons, leading to progressive paralysis and premature death in the most severe cases. SMA is caused by homozygous deletion of the survival motor neuron 1 (SMN1) gene, leading to low levels of SMN protein. However, a second SMN gene (SMN2) exists, which can be therapeutically targeted to increase SMN levels. This has recently led to the first disease-modifying therapy for SMA gaining formal approval from the US Food and Drug Administration (FDA) and European Medicines Agency (EMA). Spinraza (nusinersen) is a modified antisense oligonucleotide that targets the splicing of SMN2, leading to increased SMN protein levels, capable of improving clinical phenotypes in many patients. In addition to Spinraza, several other therapeutic approaches are currently in various stages of clinical development. These include SMN-dependent small molecule and gene therapy approaches along with SMN-independent strategies, such as general neuroprotective factors and muscle strength-enhancing compounds. For each therapy, we provide detailed information on clinical trial design and pharmacological/safety data where available. Previous clinical studies are also discussed to provide context on SMA clinical trial development and the insights these provided for the design of current studies.

Severe toxicity in nonhuman primates and piglets following high-dose intravenous administration of an AAV vector expressing human SMN.Publié le 31 01 2018

Neurotropic AAV serotypes such as AAV9 have been demonstrated to transduce spinal alpha motor neurons when administered intravenously at high doses. This observation led to the recent successful application of intravenous AAV9 delivery to treat infants with spinal muscular atrophy (SMA), an inherited deficiency of the survival of motor neuron (SMN) protein characterized by selective death of lower motor neurons. To evaluate the efficiency of motor neuron transduction with an AAV9 variant (AAVhu68) using this approach, we treated three juvenile nonhuman primates (NHPs; age 14 months) and three piglets (age 7-30 days) with an intravenous injection of an AAVhu68 vector carrying a human SMN transgene at a dose similar to that employed in the SMA clinical trial. Administration of 2x1014 genome copies per kilogram body weight resulted in widespread transduction of spinal motor neurons in both species. However, severe toxicity occurred in both NHPs and piglets. All three NHPs exhibited marked transaminase elevations. In two NHPs the transaminase elevations resolved without clinical sequelae, while one NHP developed acute liver failure and shock and was euthanized 4 days after vector injection. Degeneration of dorsal root ganglia (DRG) sensory neurons was also observed, although NHPs exhibited no clinically apparent sensory deficits. There was no correlation between clinical findings and T-cell responses to the vector capsid or transgene product in NHPs. Piglets demonstrated no evidence of hepatic toxicity, but within 14 days of vector injection all three animals exhibited proprioceptive deficits and ataxia which profoundly impaired ambulation and necessitated euthanasia. These clinical findings correlated with more severe DRG sensory neuron lesions than those observed in NHPs. The liver and sensory neuron findings appear to be a direct consequence of AAV transduction independent of an immune response to the capsid or transgene product. The present results and those of another recent study utilizing a different AAV9 variant and transgene indicate that systemic and sensory neuron toxicity may be general properties of intravenous delivery of AAV vectors at high doses irrespective of the capsid serotype or transgene. Preclinical and clinical studies involving high systemic doses of AAV vectors should include careful monitoring for similar toxicities.

The Cross-Sectional Area of Paraspinal Muscles Predicts the Efficacy of Deep Drain Stimulation for Camptocormia.Publié le 31 01 2018

BACKGROUND: Camptocormia, a disturbance of posture, is a well-described clinical feature of PD and other parkinsonian syndromes. Previous reports have shown that DBS of the subthalamic nucleus (STN) or globus pallidus internus is effective in treating camptocormia. However, the efficacy of DBS for camptocormia varies.
OBJECTIVE: To determine a clinical marker for selecting an appropriate therapy for camptocormia, a disabling manifestation of Parkinson's disease (PD) that has a variable response to systemic and local therapies.
METHODS: We obtained pre-operative lumbar magnetic resonance imaging of 14 consecutive PD patients with camptocormia who underwent subthalamic nucleus deep brain stimulation (STN-DBS) in this retrospective-designed study. Lumbar MRI was performed three to six months prior to the operation. We measured the cross-sectional area (CSA) and width of each participant's paraspinal muscles.
RESULTS: Four (28.6%) patients were effective (EF), five (35.7%) were partially effective (PE), and five (35.7%) were non-effective (NE) to STN-DBS. The lumbar paraspinal CSA and width were significantly larger in the EF group than in the PE and NE groups.
CONCLUSIONS: The CSA of paraspinal muscles and erector spinae width can be good predictive markers for improving camptocormia in patients with PD after deep brain stimulation.

Splicing solutions: Companies explore new techniques to fix splicing errors.Publié le 31 01 2018

PMID: 27603128 [PubMed - indexed for MEDLINE]

[Intrathecal Nursinersen Therapy in Children with Spinal Muscular Atrophy and Spinal Deformities].Publié le 30 01 2018

PMID: 29378349 [PubMed - as supplied by publisher]

"Transcriptomics": molecular diagnosis of inborn errors of metabolism via RNA-sequencing.Publié le 27 01 2018

Exome wide sequencing techniques have revolutionized molecular diagnostics in patients with suspected inborn errors of metabolism or neuromuscular disorders. However, the diagnostic yield of 25-60% still leaves a large fraction of individuals without a diagnosis. This indicates a causative role for non-exonic regulatory variants not covered by whole exome sequencing. Here we review how systematic RNA-sequencing analysis (RNA-seq, "transcriptomics") lead to a molecular diagnosis in 10-35% of patients in whom whole exome sequencing failed to do so. Importantly, RNA-sequencing based discoveries cannot only guide molecular diagnosis but might also unravel therapeutic intervention points such as antisense oligonucleotide treatment for splicing defects as recently reported for spinal muscular atrophy.

Describing nutrition in spinal muscular atrophy: A systematic review.Publié le 27 01 2018

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease of variable severity. Progressive muscle wasting and impairment in functional ability in SMA have a profound influence on nutritional outcomes. This systematic review summarises the existing evidence on nutrition in SMA. The search strategy was conducted across five databases in August 2014, and updated in March 2016, using key terms relating to growth, nutrition requirements, dietary intake and nutrition management. Studies were selected for inclusion using a two pass method, and data systematically extracted using standardised forms. Thirty-nine studies met eligibility criteria. Body composition is abnormal in patients with SMA, and feeding and swallowing issues are prevalent among sufferers of SMA types I and II. Nutritional management practices vary internationally. There is a paucity of literature regarding nutrition requirements in SMA, although it appears that energy expenditure may be reduced. Children with SMA require individualised nutritional management in order to address their growth and nutrition requirements. There is an urgent need for larger, coordinated, prospective intervention studies of nutrition in SMA.

Recurrent de novo BICD2 mutation associated with arthrogryposis multiplex congenita and bilateral perisylvian polymicrogyria.Publié le 27 01 2018

Autosomal dominantly inherited mutations of BICD2 are associated with congenital-onset spinal muscular atrophy characterised by lower limb predominance. A few cases have also showed upper motor neuron pathology, including presenting with features resembling hereditary spastic paraplegia. The age-of-onset for the published families is usually at birth but also included cases with childhood- and adult-onset disease. In this report we described two isolated probands that presented in utero with features associated with reduced fetal movements. Both cases were diagnosed at birth with arthrogryposis multiplex congenita (AMC) and hypotonia. Other variable features included congenital fractures, hip dislocation, micrognathia, respiratory insufficiency, microcephaly and bilateral perisylvian polymicrogyria. Patient 1 is 4 years of age and stable, but shows significant motor developmental delay and delayed speech. Patient 2 passed away at 7 weeks of age. Through next generation sequencing we identified the same missense substitution in BICD2 (p.Arg694Cys) in both probands. Sanger sequencing showed that in both cases the mutation arose de novo. The in utero onset in both cases suggests that the p.Arg694Cys substitution may have a more deleterious effect on BICD2 function than previously described mutations. Our results broaden the phenotypes associated with BICD2 mutations to include AMC and cortical malformations and therefore to a similar phenotypic spectrum to that associated with its binding partner DYNC1H1.

Military genomics: a perspective on the successes and challenges of genomic medicine in the Armed Services.Publié le 21 01 2018

We describe the impact genomics has on the health and readiness of the military service member, highlight several examples of the current and future plans for genomic medicine within the military, discuss challenges to implementation and provide recommendations to address some of those challenges.

RNA-Targeted Therapies and Amyotrophic Lateral Sclerosis.Publié le 19 01 2018

Amyotrophic lateral sclerosis (ALS) is a fatal motor disease in adults. Its pathophysiology remains mysterious, but tremendous advances have been made with the discovery of the most frequent mutations of its more common familial form linked to the C9ORF72 gene. Although most cases are still considered sporadic, these genetic mutations have revealed the role of RNA production, processing and transport in ALS, and may be important players in all ALS forms. There are no disease-modifying treatments for adult human neurodegenerative diseases, including ALS. As in spinal muscular atrophy, RNA-targeted therapies have been proposed as potential strategies for treating this neurodegenerative disorder. Successes achieved in various animal models of ALS have proven that RNA therapies are both safe and effective. With careful consideration of the applicability of such therapies in humans, it is possible to anticipate ongoing in vivo research and clinical trial development of RNA therapies for treating ALS.

Effects of Arm Cycling Exercise in Spinal Muscular Atrophy Type II Patients: A Pilot Study.Publié le 13 01 2018

Exercise studies in neuromuscular diseases like spinal muscular atrophy (SMA), a devastating disease caused by survival of motor neuron 1 ( SMN1) gene mutations, are drawing attention due to its beneficial effects. In this study, we presented a constructed arm cycling exercise protocol and evaluated the benefits on SMA patients. Five SMA type II patients performed 12 weeks of supervised arm cycling exercise. The physical functions were evaluated together with the SMN2 copy numbers, SMN protein levels, insulin-like growth factor 1(IGF1) and binding protein 3 (IGFBP3) levels. The active cycling distance and duration of patients significantly improved. Significant changes could not have detected either SMN or IGF1 and IGFBP3 levels in response to exercise. The findings demonstrated that the patients tolerated the exercise protocol and gained a benefit from arm cycling but benefits could not be associated with SMN2 copy number, SMN protein level, IGF1, or IGFBP3 levels.

Investigation of New Morpholino Oligomers to Increase Survival Motor Neuron Protein Levels in Spinal Muscular Atrophy.Publié le 11 01 2018

Spinal muscular atrophy (SMA) is an autosomal-recessive childhood motor neuron disease and the main genetic cause of infant mortality. SMA is caused by deletions or mutations in the survival motor neuron 1 (SMN1) gene, which results in SMN protein deficiency. Only one approved drug has recently become available and allows for the correction of aberrant splicing of the paralogous SMN2 gene by antisense oligonucleotides (ASOs), leading to production of full-length SMN protein. We have already demonstrated that a sequence of an ASO variant, Morpholino (MO), is particularly suitable because of its safety and efficacy profile and is both able to increase SMN levels and rescue the murine SMA phenotype. Here, we optimized this strategy by testing the efficacy of four new MO sequences targeting SMN2. Two out of the four new MO sequences showed better efficacy in terms of SMN protein production both in SMA induced pluripotent stem cells (iPSCs) and SMA?7 mice. Further, the effect was enhanced when different MO sequences were administered in combination. Our data provide an important insight for MO-based treatment for SMA. Optimization of the target sequence and validation of a treatment based on a combination of different MO sequences could support further pre-clinical studies and the progression toward future clinical trials.

Time Is Motor Neuron: Therapeutic Window and Its Correlation with Pathogenetic Mechanisms in Spinal Muscular Atrophy.Publié le 03 01 2018

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by the degeneration of lower motor neurons (MNs) in the spinal cord and brain stem, which results in relentless muscle weakness and wasting, leading to premature death due to respiratory complications. The identification of the specific mutations in the survival motor neuron 1 (SMN1) gene that causes SMA has led to the development of experimental therapeutic strategies to increase SMN protein expression, including antisense oligonucleotides, small molecules, and gene therapy, which have so far shown promising results. The timing of therapeutic intervention is crucial since most of the degeneration in MNs occurs in the first months of life in patients with SMA type 1, which is the most severe and common form of SMA. Nevertheless, a precise temporal window for therapeutic intervention has not yet been identified. Evidence from in vivo studies in mice and large animals suggested that early therapeutic intervention for SMA correlated with better motor performance, longer survival, and, occasionally, rescue of the pathological phenotype. Indeed, the need to compensate for the loss of SMN protein function seemed to diminish during adulthood (even though repair ability after nerve injury remained impaired), suggesting the possibility of tapering the therapy administration late in the disease course. Moreover, recent clinical trials on children afflicted with SMA type 1 have shown a more rapid achievement of motor milestones and diminished disease severity when therapy was administered at an early age and earlier in the disease course. Finally, these results highlight the importance of newborn screening for SMA to facilitate early diagnosis and present the patient with available treatments while they are still in the presymptomatic stage.

Lysine-Less Variants of Spinal Muscular Atrophy SMN and SMN?7 Proteins Are Degraded by the Proteasome Pathway.Publié le 03 01 2018

Spinal muscular atrophy is due to mutations affecting the SMN1 gene coding for the full-length protein (survival motor neuron; SMN) and the SMN2 gene that preferentially generates an exon 7-deleted protein (SMN?7) by alternative splicing. To study SMN and SMN?7 degradation in the cell, we have used tagged versions at the N- (Flag) or C-terminus (V5) of both proteins. Transfection of those constructs into HeLa cells and treatment with cycloheximide showed that those protein constructs were degraded. Proteasomal degradation usually requires prior lysine ubiquitylation. Surprisingly, lysine-less variants of both proteins tagged either at N- (Flag) or C-terminus (V5) were also degraded. The degradation of the endogenous SMN protein, and the protein constructs mentioned above, was mediated by the proteasome, as it was blocked by lactacystin, a specific and irreversible proteasomal inhibitor. The results obtained allowed us to conclude that SMN and SMN?7 proteasomal degradation did not absolutely require internal ubiquitylation nor N-terminal ubiquitylation (prevented by N-terminal tagging). While the above conclusions are firmly supported by the experimental data presented, we discuss and justify the need of deep proteomic techniques for the study of SMN complex components (orphan and bound) turn-over to understand the physiological relevant mechanisms of degradation of SMN and SMN?7 in the cell.

Spinal Muscular Atrophy Type I: Is It Ethical to Standardize Supportive Care Intervention in Clinical Trials?Publié le 03 01 2018

The natural history of spinal muscular atrophy type I (SMA-I) has changed as improved medical support has become available. With investigational drugs for spinal muscular atrophy now in clinical trials, efficient trial design focuses on enrolling recently diagnosed infants, providing best available supportive care, and minimizing subject variation. The quandary has arisen whether it is ethically appropriate to specify a predefined level of nutritional and/or ventilation support for spinal muscular atrophy type I subjects while participating in these studies. We conducted a survey at 2 spinal muscular atrophy investigator meetings involving physician investigators, clinical evaluators, and study coordinators from North America, Europe, and Asia-Pacific. Each group endorsed the concept that having a predefined degree of nutritional and ventilation support was warranted in this context. We discuss how autonomy, beneficence/non-maleficence, noncoercion, social benefit, and equipoise can be maintained when a predefined level of supportive care is proposed, for participation in a clinical trial.

Home Mechanical Ventilation: An Overview.Publié le 30 12 2017

Prevalence studies have shown heterogeneous use of home mechanical ventilation in different conditions, with a marked increase in uptake especially in users of noninvasive ventilation. Although randomized controlled trials have examined noninvasive ventilation in acute exacerbations of chronic obstructive pulmonary disease, for weaning from invasive ventilation and for postextubation respiratory failure, the evidence base for long-term noninvasive ventilation and comparisons with invasive ventilation are less well developed. The combination of noninvasive ventilation and cough-assist devices has reduced the indications for tracheotomy ventilation in some situations (e.g., Duchenne muscular dystrophy, spinal muscular atrophy, myopathies, and amyotrophic lateral sclerosis) and has also prolonged survival. Several excellent overviews have been written on the history of home mechanical ventilation and its evolution from negative pressure to positive pressure techniques, including a systematic review of outcomes. This review, instead, will cover recent trials, trends in the field, outcomes, and safety. Because the greatest growth has been in home noninvasive ventilation, this will be the main focus of this article.

Motor Neuron Gene Therapy: Lessons from Spinal Muscular Atrophy for Amyotrophic Lateral Sclerosis.Publié le 24 12 2017

Spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS) are severe nervous system diseases characterized by the degeneration of lower motor neurons. They share a number of additional pathological, cellular, and genetic parallels suggesting that mechanistic and clinical insights into one disorder may have value for the other. While there are currently no clinical ALS gene therapies, the splice-switching antisense oligonucleotide, nusinersen, was recently approved for SMA. This milestone was achieved through extensive pre-clinical research and patient trials, which together have spawned fundamental insights into motor neuron gene therapy. We have thus tried to distil key information garnered from SMA research, in the hope that it may stimulate a more directed approach to ALS gene therapy. Not only must the type of therapeutic (e.g., antisense oligonucleotide vs. viral vector) be sensibly selected, but considerable thought must be applied to the where, which, what, and when in order to enhance treatment benefit: to where (cell types and tissues) must the drug be delivered and how can this be best achieved? Which perturbed pathways must be corrected and can they be concurrently targeted? What dosing regime and concentration should be used? When should medication be administered? These questions are intuitive, but central to identifying and optimizing a successful gene therapy. Providing definitive solutions to these quandaries will be difficult, but clear thinking about therapeutic testing is necessary if we are to have the best chance of developing viable ALS gene therapies and improving upon early generation SMA treatments.

Intrathecal Injections in Children With Spinal Muscular Atrophy: Nusinersen Clinical Trial Experience.Publié le 22 12 2017

Nusinersen (ISIS-SMNRx or ISIS 396443) is an antisense oligonucleotide drug administered intrathecally to treat spinal muscular atrophy. We summarize lumbar puncture experience in children with spinal muscular atrophy during a phase 1 open-label study of nusinersen and its extension. During the studies, 73 lumbar punctures were performed in 28 patients 2 to 14 years of age with type 2/3 spinal muscular atrophy. No complications occurred in 50 (68%) lumbar punctures; in 23 (32%) procedures, adverse events were attributed to lumbar puncture. Most common adverse events were headache (n = 9), back pain (n = 9), and post-lumbar puncture syndrome (n = 8). In a subgroup analysis, adverse events were more frequent in older children, children with type 3 spinal muscular atrophy, and with a 21- or 22-gauge needle compared to a 24-gauge needle or smaller. Lumbar punctures were successfully performed in children with spinal muscular atrophy; lumbar puncture-related adverse event frequency was similar to that previously reported in children.

AAV gene delivery to the spinal cord: serotypes, methods, candidate diseases, and clinical trials.Publié le 19 12 2017

INTRODUCTION: Adeno-associated viral (AAV) vector-mediated gene delivery to the spinal cord has finally entered the pathway towards regulatory approval. Phase 1 clinical trials using AAV gene therapy for pediatric disorders - spinal muscular atrophy (SMA) and giant axonal neuropathy (GAN) - are now underway. Areas covered: This review addresses the latest progress in the field of AAV gene delivery to the spinal cord, particularly focusing on the most prominent AAV serotypes and delivery methodologies to the spinal cord. Candidate diseases and scaling up experiments in large animals are also discussed. Expert opinion: Intravenous (IV) and intrathecal (IT) deliveries seem to undoubtedly be the preferred routes of administration for diffuse spinal cord delivery of therapeutic AAV vectors that can cross the blood-brain barrier (BBB) and correct inherited genetic disorders. Conversely, intraparenchymal delivery is still an undervalued but very viable approach for segmental therapy in afflictions such as ALS or Pompe Disease as a means to prevent respiratory dysfunction.

The relative frequency of common neuromuscular diagnoses in a reference center.Publié le 15 12 2017

The diagnostic procedure in neuromuscular patients is complex. Knowledge of the relative frequency of neuromuscular diseases within the investigated population is important to allow the neurologist to perform the most appropriate diagnostic tests.
OBJECTIVE: To report the relative frequency of common neuromuscular diagnoses in a reference center.
METHODS: A 17-year chart review of patients with suspicion of myopathy.
RESULTS: Among 3,412 examinations, 1,603 (46.98%) yielded confirmatory results: 782 (48.78%) underwent molecular studies, and 821 (51.21%) had muscle biopsies. The most frequent diagnoses were: dystrophinopathy 460 (28.70%), mitochondriopathy 330 (20.59%), spinal muscular atrophy 158 (9.86%), limb girdle muscular dystrophy 157 (9.79%), Steinert myotonic dystrophy 138 (8.61%), facioscapulohumeral muscular dystrophy 99 (6.17%), and other diagnoses 261 (16.28%).
CONCLUSION: Using the presently-available diagnostic techniques in this service, a specific limb girdle muscular dystrophy subtype diagnosis was reached in 61% of the patients. A neuromuscular-appropriate diagnosis is important for genetic counseling, rehabilitation orientation, and early treatment of respiratory and cardiac complications.

More Clinical Mimics of Infant Botulism.Publié le 14 12 2017

OBJECTIVE: To ascertain the actual diagnoses of 76 patients (2005-2015) whose clinical presentations so closely resembled infant botulism that the patients were treated with Human Botulism Immune Globulin Intravenous (BIG-IV; BabyBIG), but whose illnesses subsequently were not laboratory confirmed as infant botulism ("clinical mimics" of infant botulism).
STUDY DESIGN: The California Department of Public Health produces BIG-IV and distributes it nationwide as a public service (ie, not-for-profit) orphan drug to treat patients hospitalized with suspected infant botulism. During the study period, admission records and discharge summaries for all patients treated with BIG-IV but who lacked a laboratory-confirmed diagnosis of infant botulism were collected and abstracted. The patients' discharge diagnoses were identified, categorized, and compared with previously reported clinical mimics categories for 32 patients (1992-2005).
RESULTS: From 2005 to 2015, 76 clinical mimic illnesses were identified. These illnesses were distributed into the 5 categories previously reported of (1) probable infant botulism lacking confirmatory testing (26.3%); (2) spinal muscular atrophy (19.7%); (3) miscellaneous (15.8%); (4) metabolic disorders (11.8%); and (5) other infectious diseases (10.6%). Of the 76 clinical mimic illnesses, 15.8% had no alternate diagnosis established and were therefore categorized as undetermined.
CONCLUSIONS: Over the 23 years 1992-2015, patients presenting with illnesses so clinically similar to infant botulism that they were treated with BIG-IV had actual diagnoses that were distributed into 5 main categories. These categories and their individual components constitute a working bedside differential diagnosis of infant botulism.

Denosumab Treatment of Severe Disuse Osteoporosis in a Boy With Spinal Muscular Atrophy.Publié le 14 12 2017

Denosumab is a fully human recombinant monoclonal antibody to the receptor activator of nuclear factor-?B ligand. Denosumab is used in the treatment of postmenopausal osteoporosis and cancer-related bone disorders. There are only very scarce data on denosumab treatment in children. 14-year-old boy with spinal muscular atrophy (SMA) and severe disuse osteoporosis (spinal bone mineral density L1-L4 BMD-6.2SD Z-score) and two prevalent fragility fractures was treated with denosumab. He received 60 mg  subcutaneous injection at the baseline and seven months later. Six months after the initial injection there was a 19% increase in L1-L4 BMD. The injections were well tolerated without any adverse reactions. Calcemia remained stable (2.3-2.4 mmol/L). He was scheduled for the third denosumab injection six months later. Prior to this date, he acquired pneumonia and died due to respiratory failure, which is a frequent cause of death in patients with SMA. There was no relation to the denosumab treatment. In conclusion, one dose of denosumab significantly increased BMD in a child with severe osteoporosis.

Long-term treatment with leuprorelin for spinal and bulbar muscular atrophy: natural history-controlled study.Publié le 14 12 2017

OBJECTIVE: To evaluate the prognosis and progression of spinal and bulbar muscular atrophy (SBMA), a rare X-linked motor neuron disorder caused by trinucleotide repeat expansion in the AR (androgen receptor) gene, after long-term androgen suppression with leuprorelin acetate treatment.
METHODS: In the present natural history-controlled study, 36 patients with SBMA treated with leuprorelin acetate for up to 84 months (leuprorelin acetate-treated group; LT group) and 29 patients with SBMA with no specific treatment (non-treated group; NT group) were analysed. Disease progression was evaluated by longitudinal quantitative assessment of motor functioning using the revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R), and the modified Norris score. In addition, we selected two major clinical endpoint events, namely the occurrence of pneumonia requiring hospitalisation and death, to evaluate disease prognosis following long-term leuprorelin acetate treatment.
RESULTS: In our analysis of the longitudinal disease progression using the random slope model, we observed a significant difference in the ALSFRS-R total score, the Limb Norris Score, and the Norris Bulbar Score (p=0.005, 0.026 and 0.020, respectively), with the LT group exhibiting a slower per-12-months decline compared with the NT group. As for the event analysis, the prognosis of the LT group was better in comparison to the NT group as for the event-free survival period (p=0.021).
CONCLUSION: Long-term treatment with leuprorelin acetate appears to delay the functional decline and suppress the incidence of pneumonia and death in subjects with SBMA.

Motor milestone assessment of infants with spinal muscular atrophy using the hammersmith infant neurological Exam-Part 2: Experience from a nusinersen clinical study.Publié le 14 12 2017

INTRODUCTION: In this study we examined the feasibility of assessing motor milestone performance of infants with spinal muscular atrophy (SMA) using the Hammersmith Infant Neurological Exam-Part 2 (HINE-2) in a phase 2 study of nusinersen.
METHODS: Nineteen SMA infants were assessed using the HINE-2 at baseline (?7 months of age), and periodically up to 39 months of age. We evaluated whether the HINE-2 was feasible, reliable, and sensitive to change.
RESULTS: Motor milestone assessments in SMA infants were feasible using the HINE-2. Baseline test-retest reliability was excellent (R = 0.987; P < 0.0001). SMA infants were extremely low functioning at baseline and the HINE-2 was able to detect changes over time in 16 of 19 infants within all 8 domains. HINE-2 improvements were correlated with changes in other neuromuscular outcome measures.
CONCLUSION: Results support the use of the HINE-2 motor milestone assessment in clinical trials of SMA infants. Muscle Nerve 57: 143-146, 2017.

Ethical Challenges Confronted When Providing Nusinersen Treatment for Spinal Muscular Atrophy.Publié le 12 12 2017

The US Food and Drug Administration's December 2016 approval of nusinersen for the treatment of patients with all subtypes of spinal muscular atrophy ushered in a new era for patients with spinal muscular atrophy, their families, and all those involved in their care. The extreme cost of the medication and the complicated logistical requirements for administering nusinersen via lumbar puncture have created practical challenges that raise important ethical considerations. We discuss 6 challenges faced at the institutional level in the United States: cost, limited evidence, informed consent, treatment allocation, fair distribution of responsibilities, and transparency with stakeholders. These challenges must be understood to ensure that patients with spinal muscular atrophy benefit from treatment, are protected from harm, and are treated fairly.

Downregulation of Survivin contributes to cell-cycle arrest during postnatal cardiac development in a severe spinal muscular atrophy mouse model.Publié le 09 12 2017

Spinal muscular atrophy (SMA) is the leading genetic cause of infant mortality, characterized by progressive degeneration of spinal-cord motor neurons, leading to atrophy of skeletal muscles. However, accumulating evidence indicates that it is a multi-system disorder, particularly in its severe forms. Several studies delineated structural and functional cardiac abnormalities in SMA patients and mouse models, yet the abnormalities have been primarily attributed to autonomic dysfunction. Here, we show in a severe mouse model that its cardiomyocytes undergo G0/G1 cell-cycle arrest and enhanced apoptosis during postnatal development. Microarray and real-time RT-PCR analyses revealed that a set of genes associated with cell cycle and apoptosis were dysregulated in newborn pups. Of particular interest, the Birc5 gene, which encodes Survivin, an essential protein for heart development, was down-regulated even on pre-symptomatic postnatal day 0. Interestingly, cultured cardiomyocytes depleted of SMN recapitulated the gene expression changes including downregulation of Survivin and abnormal cell-cycle progression; and overexpression of Survivin rescued the cell-cycle defect. Finally, increasing SMN in SMA mice with a therapeutic antisense oligonucleotide improved heart pathology and recovered expression of deregulated genes. Collectively, our data demonstrate that the cardiac malfunction of the severe SMA mouse model is mainly a cell-autonomous defect, caused by widespread gene deregulation in heart tissue, particularly of Birc5, resulting in developmental abnormalities through cell-cycle arrest and apoptosis.

Restoration of SMN expression in mesenchymal stem cells derived from gene-targeted patient-specific iPSCs.Publié le 07 12 2017

Spinal muscular atrophy (SMA) is primarily a neurodegenerative disease caused by the homozygous deletion of the survival motor neuron 1 (SMN1) gene, thereby reducing SMN protein expression. Mesenchymal stem cells (MSCs) have been implicated in the treatment of SMA. In the present study, we overexpressed exogenous SMN1 at the ribosomal DNA (rDNA) locus of induced pluripotent stem cells (iPSCs) generated from a SMA patient using an rDNA-targeting vector. The gene-targeted patient iPSCs differentiated into MSCs (SMN1-MSCs). A 2.1-fold higher expression level of SMN protein was detected in SMN1-MSCs than that detected in MSCs derived from patient iPSCs, and the results of the immunofluorescence analysis showed no difference in the quantity of SMN nuclear structures (gems) between SMN1-MSCs and MSCs derived from normal human iPSCs (h-MSCs). These findings provide a novel strategy for obtaining gene-targeted MSCs for potential clinical applications in autologous cell-based therapy.

Single-center experience with intrathecal administration of Nusinersen in children with spinal muscular atrophy type 1.Publié le 07 12 2017

BACKGROUND: Spinal muscular atrophy (SMA) is a neuromuscular disorder mainly characterized by proximal muscle weakness. There have been enormous advances in therapeutic development with the possibility to influence the clinical course of the disease. Nusinersen is the first approved drug to treat SMA. It is administered intrathecally and acts as splicing modifier of the SMN2 gene.
METHODS: Lumbar punctures were performed using a standardized protocol. To evaluate safety and feasibility of the intrathecal treatment, vital signs and the need for sedation, analgesia or mechanical ventilation during the procedure were monitored. Furthermore, the number of puncture attempts, the injection site and the macroscopic appearance of cerebrospinal fluid were documented.
RESULTS: Treatment with Nusinersen was initiated in 20 children aged from 2 to 50 months. Administration of a local anesthetic cream on the puncture site and a peripheral analgesic led to an adequate pain management. We observed a beneficial distraction through the possibility to watch a movie or listen to music during the procedure. In some cases, an additional sedation was necessary. In patients accustomed to non-invasive ventilation, this was used during lumbar punctures. On average, 1.5 ± 1.0 puncture attempts were performed between L 4/5 and L 2/3. If required, the position of the medullary cone was identified by ultrasound to guarantee a safe puncture above L 3/4.
CONCLUSIONS: Lumbar punctures for intrathecal administration of Nusinersen could be performed without any relevant complications. With the described approach lumbar punctures were tolerated well in all investigated age groups.

Neuromuscular Diseases: Diagnosis and Management.Publié le 04 12 2017

Neuromuscular diseases (NMDs) affect the peripheral nervous system, which includes the motor neurons and sensory neurons; the muscle itself; or the neuromuscular junction. Thus, the term NMDs encompasses a vast array of different syndromes. Some of these syndromes are of direct relevance to paediatric orthopaedic surgeons, either because the presenting manifestation is a functional sign (e.g., toe walking) or deformity (e.g., pes cavus or scoliosis) suggesting a need for orthopaedic attention or because orthopaedic abnormalities requiring treatment develop during the course of a known NMD. The main NMDs relevant to the orthopaedic surgeon are infantile spinal muscular atrophy (a motor neuron disease), peripheral neuropathies (chiefly Charcot-Marie-Tooth disease), congenital muscular dystrophies, progressive muscular dystrophies, and Steinert myotonic dystrophy (or myotonic dystrophy type 1). Muscle weakness is a symptom shared by all these conditions. The paediatric orthopaedic surgeon must be familiar, not only with the musculoskeletal system, but also with many other domains (particularly respiratory and cardiac function and nutrition) that may interfere with the treatment and require pre-operative management. Good knowledge of the natural history of each NMD is essential to ensure optimal timing of the therapeutic interventions, which must be performed under the best possible conditions in these usually frail patients. Timing is particularly crucial for the treatment of spinal deformities due to paraspinal muscle hypotonia during growth: depending on the disease and natural history, the treatment may involve non-operative methods or growing rods, followed by spinal fusion. A multidisciplinary approach is always required. Finally, the survival gains achieved in recent years increasingly require attention to preparing for adult life, to orthopaedic problems requiring treatment before the patient leaves the paediatric environment, and to the transition towards the adult healthcare system.

Muscle strength and motor function throughout life in a cross- sectional cohort of 180 patients with SMA types 1c-4.Publié le 02 12 2017

BACKGROUND: Natural history studies in SMA have primarily focused on infants and children. Natural history studies encompassing all age groups and SMA types are important for the interpretation of treatment effects of recently introduced SMN augmenting therapies.
METHODS: We conducted a cross-sectional study to investigate muscle strength, Hammersmith Functional Motor Scale (Expanded) scores and the patterns of muscle weakness in relation to age and SMA type.
RESULTS: We included 180 patients with SMA types 1-4 in the age range 1-77.5 years and median disease duration of 18 years (range 0-65.8 years). With the exception of the early phases of disease in which children with SMA types 2 and 3 may achieve new motor skills and show a temporary increase in muscle strength, cross sectional data suggest that declining muscle strength and loss of motor skills over time are characteristic for all SMA types. Mean loss of strength is at least 1 point on the MRC and 0.5 point on the HFMS(E) scores per year. Trend lines compatible with deterioration of motor function and muscle strength start in childhood and continue into adulthood. The age at loss of specific motor skills is associated with disease severity. Triceps, deltoid, iliopsoas and quadriceps are the weakest muscles in all patients. Hierarchical cluster analysis did not show a segmental distribution of muscle weakness as was suggested previously.
CONCLUSIONS: Progressive muscle weakness, and loss of motor function are characteristic of all SMA types and all ages. This article is protected by copyright. All rights reserved.

Antisense oligonucleotides: the next frontier for treatment of neurological disorders.Publié le 02 12 2017

Antisense oligonucleotides (ASOs) were first discovered to influence RNA processing and modulate protein expression over two decades ago; however, progress translating these agents into the clinic has been hampered by inadequate target engagement, insufficient biological activity, and off-target toxic effects. Over the years, novel chemical modifications of ASOs have been employed to address these issues. These modifications, in combination with elucidation of the mechanism of action of ASOs and improved clinical trial design, have provided momentum for the translation of ASO-based strategies into therapies. Many neurological conditions lack an effective treatment; however, as research progressively disentangles the pathogenic mechanisms of these diseases, they provide an ideal platform to test ASO-based strategies. This steady progress reached a pinnacle in the past few years with approvals of ASOs for the treatment of spinal muscular atrophy and Duchenne muscular dystrophy, which represent landmarks in a field in which disease-modifying therapies were virtually non-existent. With the rapid development of improved next-generation ASOs toward clinical application, this technology now holds the potential to have a dramatic effect on the treatment of many neurological conditions in the near future.

SMN regulation in SMA and in response to stress: new paradigms and therapeutic possibilities.Publié le 02 12 2017

Low levels of the survival of motor neuron (SMN) protein cause the neurodegenerative disease spinal muscular atrophy (SMA). SMA is a pediatric disease characterized by spinal motor neuron degeneration. SMA exhibits several levels of severity ranging from early antenatal fatality to only mild muscular weakness, and disease prognosis is related directly to the amount of functional SMN protein that a patient is able to express. Current therapies are being developed to increase the production of functional SMN protein; however, understanding the effect that natural stresses have on the production and function of SMN is of critical importance to ensuring that these therapies will have the greatest possible effect for patients. Research has shown that SMN, both on the mRNA and protein level, is highly affected by cellular stress. In this review we will summarize the research that highlights the roles of SMN in the disease process and the response of SMN to various environmental stresses.

Modulation of aberrant splicing in human RNA diseases by chemical compounds.Publié le 02 12 2017

Pre-mRNA splicing is an essential step for gene expression in higher eukaryotes. Alternative splicing contributes to diversity of the expressed proteins from the limited number of genes. Disruption of splicing regulation often results in hereditary and sporadic diseases called as 'RNA diseases'. Modulation of splicing by small chemical compounds and nucleic acids has been tried to target aberrant splicing in those diseases. Several RNA diseases and splicing-target therapeutic approaches will be briefly introduced in this review. Accumulating knowledge about molecular mechanism of aberrant splicing and their correction by chemical compounds is important not only for RNA biologists, but also for clinicians who desire therapies for those diseases.

Two Cases of Spinal Muscular Atrophy Type II with Eosinophilic Oesophagitis.Publié le 26 11 2017

Although primarily characterised by loss of motor neurons from the anterior horn of spinal cord and muscle atrophy, spinal muscular atrophy (SMA) is now recognised as a multi-systemic disorder. Here, we report two SMA Type II patients with eosinophilic oesophagitis (EoE), a rare, chronic immune/antigen-mediated condition. One patient presented with dysphagia and poor weight gain, and the second patient had symptoms of gastro-oesophageal reflux (GOR) and poor weight gain. In both patients, macroscopic observations during gastroscopy indicated typical signs of EoE, which were verified during histological examination of oesophageal biopsies. Given that there is a specific treatment strategy for EoE, these cases highlight the importance of considering this condition in clinical investigations - especially for patients with SMA - who have GOR, discomfort, and oral aversion.

Newborn genetic screening for spinal muscular atrophy in the UK: The views of the general population.Publié le 24 11 2017

BACKGROUND: Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder and a leading genetic cause of infant death worldwide. However, there is no routine screening program for SMA in the UK. Lack of treatments and the inability of screening tests to accurately predict disease severity are among the key reasons implementation of screening has faltered in the UK. With the recent release of the first therapy for SMA (Nusinersen), calls are being made for a reconsideration of this stance; however, very little is known about the views of the general public.
METHODS: An online survey was administered to 232 individuals with no prior relationship with SMA to assess their attitudes toward a newborn screening program for it. Results are compared with previously gathered data on the views of SMA-affected families toward screening.
RESULTS: Eighty-four percent of participants were in favor of newborn screening. Key reasons for support were a belief that it would lead to better healthcare and life expectancy for affected infants and facilitate informed decision-making for future pregnancies. Key reasons for nonsupport were a belief in the potential for significant negative impact on the family unit in terms of bonding and stress.
CONCLUSIONS: Public acceptability is a key component in the evaluation of any potential screening program in the UK. This study demonstrates that newborn screening for SMA is viewed largely positively by people unfamiliar with the condition. The importance of early identification overrode all other social and ethical concerns about screening for the majority of participants.

Self-oligomerization regulates stability of Survival Motor Neuron (SMN) protein isoforms by sequestering an SCF(Slmb) degron.Publié le 24 11 2017

Spinal muscular atrophy (SMA) is caused by homozygous mutations in human SMN1 Expression of a duplicate gene (SMN2) primarily results in skipping of exon 7 and production of an unstable protein isoform, SMN?7. Although SMN2 exon skipping is the principal contributor to SMA severity, mechanisms governing stability of SMN isoforms are poorly understood. We used a Drosophila model system and label-free proteomics to identify the SCF(Slmb) ubiquitin E3 ligase complex as a novel SMN binding partner. SCF(Slmb) interacts with a phospho-degron embedded within the human and fruitfly SMN YG-box oligomerization domains. Substitution of a conserved serine (S270A) interferes with SCF(Slmb) binding and stabilizes SMN?7. SMA-causing missense mutations that block multimerization of full-length SMN are also stabilized in the degron mutant background. Overexpression of SMN?7(S270A), but not wild-type SMN?7, provides a protective effect in SMA model mice and human motor neuron cell culture systems. Our findings support a model wherein the degron is exposed when SMN is monomeric, and sequestered when SMN forms higher-order multimers.

miRNA in spinal muscular atrophy pathogenesis and therapy.Publié le 22 11 2017

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease characterized by the selective death of lower motor neurons in the brain stem and spinal cord. SMA is caused by mutations in the survival motor neuron 1 gene (SMN1), leading to the reduced expression of the full-length SMN protein. microRNAs (miRNAs) are small RNAs that regulate post-transcriptional gene expression. Recent findings have suggested an important role for miRNAs in the pathogenesis of motor neuron diseases, including SMA. Motor neuron-specific miRNA dysregulation in SMA might be implicated in their selective vulnerability. In this study, we discuss recent findings regarding the consequences of SMN defects on miRNAs and their target mRNAs in motor neurons. Taken together, these data suggest that cell-specific changes in miRNAs are not only involved in the SMA motor neuron phenotype but can also be used as biomarkers and therapeutic targets.

Natural History of Infantile-Onset Spinal Muscular Atrophy.Publié le 18 11 2017

OBJECTIVE: Infantile-onset spinal muscular atrophy (SMA) is the most common genetic cause of infant mortality, typically resulting in death prior to age 2. Clinical trials in this population require an understanding of disease progression and identification of meaningful biomarkers to hasten therapeutic development and predict outcomes.
METHODS: A longitudinal, multi-center, prospective natural history study enrolled 26 SMA infants, and 27 control infants less than six months of age. Recruitment occurred at 14 centers over 21 months within the NINDS-sponsored NeuroNEXT Network. Infant motor function scales (TIMPSI, CHOP-INTEND and AIMS) and putative physiologic and molecular biomarkers were assessed prior to 6 months of age and at 6, 9, 12, 18 and 24-months with progression, correlations between motor function and biomarkers and hazard ratios were analyzed.
RESULTS: Motor function scores (MFS) and CMAP decreased rapidly in SMA infants, whereas MFS in all healthy infants rapidly increased. Correlations were identified between TIMPSI and CMAP in SMA infants. TIMPSI at first study visit was associated with risk of combined endpoint of death or permanent invasive ventilation in SMA infants. Post hoc analysis of survival to combined endpoint in SMA infants with 2 copies of SMN2 indicated a median age of 8 months at death (95%CI: 6,17).
INTERPRETATION: These data of SMA and control outcome measures delineates meaningful change in clinical trials in infantile-onset SMA. The power and utility of NeuroNEXT to provide "real world", prospective natural history data sets to accelerate public and private drug development programs for rare disease is demonstrated. This article is protected by copyright. All rights reserved.

Spinal Muscular Atrophy: The Treatment Approved.Publié le 17 11 2017

Spinal muscular atrophy (SMA) is a rare genetic neuromuscular disorder resulting in progressive muscle weakness and atrophy. It is universally fatal, especially if the respiratory muscles are involved leading to repetitive aspiration and respiratory failure. Historically, the treatment for this disease was only supportive. Herein we describe an adult patient who presented with worsening weakness and fatigue and was subsequently diagnosed with spinal muscular atrophy. Increased awareness of this condition and a new treatment modality is required.

Binding to SMN2 pre-mRNA-protein complex elicits specificity for small molecule splicing modifiers.Publié le 15 11 2017

Small molecule splicing modifiers have been previously described that target the general splicing machinery and thus have low specificity for individual genes. Several potent molecules correcting the splicing deficit of the SMN2 (survival of motor neuron 2) gene have been identified and these molecules are moving towards a potential therapy for spinal muscular atrophy (SMA). Here by using a combination of RNA splicing, transcription, and protein chemistry techniques, we show that these molecules directly bind to two distinct sites of the SMN2 pre-mRNA, thereby stabilizing a yet unidentified ribonucleoprotein (RNP) complex that is critical to the specificity of these small molecules for SMN2 over other genes. In addition to the therapeutic potential of these molecules for treatment of SMA, our work has wide-ranging implications in understanding how small molecules can interact with specific quaternary RNA structures.

Transforaminal intrathecal delivery of nusinersen using cone-beam computed tomography for children with spinal muscular atrophy and extensive surgical instrumentation: early results of technical success and safety.Publié le 14 11 2017

BACKGROUND: Nusinersen, the only treatment approved by the United States Food and Drug Administration for spinal muscular atrophy (SMA), is delivered intrathecally. Many children with SMA have extensive spinal instrumentation and deformities, often precluding the use of standard approaches for gaining intrathecal access. Furthermore the anatomical distortion that often occurs with rotoscoliosis can complicate the use of fluoroscopic guidance. Compared to fluoroscopy, CT affords superior guidance for complex needle placements. This opens up alternatives to the posterior (interlaminar) technique, including transforaminal and caudal approaches.
OBJECTIVE: This study describes the early results of technical success, complications and radiation dose of intrathecal delivery of nusinersen using cone-beam CT guidance with two-axis fluoroscopic navigational overlay.
MATERIALS AND METHODS: We conducted a retrospective review of 15 consecutive nusinersen injections performed in four children with SMA and extensive spinal hardware precluding standard posterior lumbar puncture techniques. These children were treated using transforaminal thecal access employing cone-beam CT with navigational overlay. We analyzed results including technical success, complications and total fluoroscopy time.
RESULTS: All procedures were technically successful. No major complications and one minor complication were reported; the minor complication was a post-procedural neuropathic headache that was attributed to procedural positioning and was treated successfully with gabapentin. The average procedural fluoroscopy time and air kerma were 1.9 min and 55.8 mGy, respectively.
CONCLUSION: Cone-beam CT guidance with two-axis navigational overlay is a safe, effective method for gaining transforaminal intrathecal access in children with spinal abnormalities and hardware precluding the use of standard techniques.

Rescue of Metabolic Alterations in AR113Q Skeletal Muscle by Peripheral Androgen Receptor Gene Silencing.Publié le 14 11 2017

Spinal and bulbar muscular atrophy (SBMA), a progressive degenerative disorder, is caused by a CAG/glutamine expansion in the androgen receptor (polyQ AR). Recent studies demonstrate that skeletal muscle is an important site of toxicity that contributes to the SBMA phenotype. Here, we sought to identify critical pathways altered in muscle that underlie disease manifestations in AR113Q mice. This led to the unanticipated identification of gene expression changes affecting regulators of carbohydrate metabolism, similar to those triggered by denervation. AR113Q muscle exhibits diminished glycolysis, altered mitochondria, and an impaired response to exercise. Strikingly, the expression of genes regulating muscle energy metabolism is rescued following peripheral polyQ AR gene silencing by antisense oligonucleotides (ASO), a therapeutic strategy that alleviates disease. Our data establish the occurrence of a metabolic imbalance in SBMA muscle triggered by peripheral expression of the polyQ AR and indicate that alterations in energy utilization contribute to non-neuronal disease manifestations.

[Spinal muscular atrophy : Time for newborn screening?]Publié le 05 11 2017

The most common neurodegenerative disease in childhood is spinal muscular atrophy (SMA). The severe infantile type 1 (Werdnig-Hoffman disease) makes 60% of SMA in total. These children usually die within 18 months without ventilation. New therapeutic approaches have led from the theoretical concept to randomized controlled clinical trials in patients. For the first time, a pharmacological treatment of SMA has been approved. The early detection of the disease is decisive for the success of therapy. All previous data suggest starting treatment early and when possible prior to the onset of symptoms considerably improves the outcome in comparison to a delayed start. The goal must be the presymptomatic diagnosis in order to initiate treatment before motor neuron degeneration. Technical and ethical prerequisites for a molecular genetic newborn screening are given.

The Dilemma of Two Innovative Therapies for Spinal Muscular Atrophy.Publié le 04 11 2017

PMID: 29091554 [PubMed - indexed for MEDLINE]

Nusinersen: antisense oligonucleotide to increase SMN protein production in spinal muscular atrophy.Publié le 04 11 2017

Patients with spinal muscular atrophy (SMA) have an autosomal recessive disease that limits their ability to produce survival motor neuron (SMN) protein in the CNS resulting in progressive wasting of voluntary muscles. Detailed studies over several years have demonstrated that phosphorothioate and 2'-O-methoxyethyl- modified antisense oligonucleotides (ASOs) targeting the ISS-N1 site increase SMN2 exon 7 inclusion, thus increasing levels of SMN protein in a dose- and time-dependent manner in liver, kidney and skeletal muscle, and CNS tissues only when administered intrathecally. On a dose basis, nusinersen was found to be the most potent ASO for SMN2 splicing correction in the CNS of adult mice. After nusinersen was found to increase levels of SMN protein in the CNS of mice and subhuman primates without causing significant adverse events, it was advanced into clinical studies in patients with SMA. These trials in SMA patients have demonstrated significant improvements in various measures of motor function and in progression to movement developments not normally seen in SMA patients. In addition, there have been significant extensions in life expectancy. These findings led to the U.S. and European approval of nusinersen for use in SMA patients of all ages.

Segmental Pedicle Screw Instrumentation and Fusion Only to L5 in the Surgical Treatment of Flaccid Neuromuscular Scoliosis.Publié le 03 11 2017

STUDY DESIGN: A retrospective cohort study was performed.
OBJECTIVE: The purpose of this study was to determine the efficacy and safety of stopping segmental pedicle screw instrumentation constructs at L5 in the treatment of neuromuscular scoliosis.
SUMMARY OF BACKGROUND DATA: Duchenne muscular dystrophy and spinal muscular atrophy are flaccid neuromuscular disorders in which gradual deterioration is the hallmark and have a lot of characteristics in common despite differences in etiology. Instrumentation and fusion to the sacrum/pelvis has been a mainstay in the surgical treatment of flaccid neuromuscular scoliosis and recommended to correct pelvic obliquity. However, the caudal extent of instrumentation and fusion in the surgical treatment of flaccid neuromuscular scoliosis has remained a matter of considerable debate and there have been few studies on the use of segmental pedicle screw instrumentation for flaccid neuromuscular scoliosis.
METHOD: From 2005 to 2007, a total of 27 consecutive patients with neuromuscular disorders (20 Duchenne muscular dystrophy and 7 spinal muscular atrophy), aged 11 to 17 years, underwent segmental pedicle screw instrumentation and fusion only to L5. Assessment was performed clinically and with radiologic measurements. Minimum 2-year follow-up was required for inclusion in this study.
RESULTS: Twenty patients were enrolled in this study. No patient was lost to follow-up. All patients had L5 tilt of less than 15° and a coronal curve with apex L2 or higher preoperatively. Preoperative coronal curve averaged 70° (range: 51°-88°), with a postoperative mean of 15° (range: 5°-25°) and 17° (range: 6°-27°) at the last follow-up. The pelvic obliquity improved from 15° (range: 9°-25°) preoperatively to 5° (range: 3°-8°) postoperatively and 6° (range: 3°-8°) at the last follow-up. The L5 tilt improved from 9° (range: 2°-14°) preoperatively to 2° (range: 0°-4°) postoperatively and 2° (range: 0°-5°) at the last follow-up. Physiologic sagittal plane alignment was recreated after surgery and maintained long-term. There was no significant loss of correction of coronal curve and pelvic obliquity. There was no major complication.
CONCLUSION: Segmental pedicle screw instrumentation and fusion to L5 was safe and effective in patients with flaccid neuromuscular scoliosis with apex L2 or higher and minimal L5 tilt of less than 15°. Segmental pedicle screw instrumentation ending at L5 offered the ability to correct spinal deformity and pelvic obliquity initially, intermediate and even long-term, with no major complications. This method in appropriate patients can be a viable alternative to instrumentation and fusion to the sacrum/pelvis in the surgical treatment of flaccid neuromuscular scoliosis.

Nusinersen versus Sham Control in Infantile-Onset Spinal Muscular Atrophy.Publié le 02 11 2017

Background Spinal muscular atrophy is an autosomal recessive neuromuscular disorder that is caused by an insufficient level of survival motor neuron (SMN) protein. Nusinersen is an antisense oligonucleotide drug that modifies pre-messenger RNA splicing of the SMN2 gene and thus promotes increased production of full-length SMN protein. Methods We conducted a randomized, double-blind, sham-controlled, phase 3 efficacy and safety trial of nusinersen in infants with spinal muscular atrophy. The primary end points were a motor-milestone response (defined according to results on the Hammersmith Infant Neurological Examination) and event-free survival (time to death or the use of permanent assisted ventilation). Secondary end points included overall survival and subgroup analyses of event-free survival according to disease duration at screening. Only the first primary end point was tested in a prespecified interim analysis. To control the overall type I error rate at 0.05, a hierarchical testing strategy was used for the second primary end point and the secondary end points in the final analysis. Results In the interim analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (21 of 51 infants [41%] vs. 0 of 27 [0%], P<0.001), and this result prompted early termination of the trial. In the final analysis, a significantly higher percentage of infants in the nusinersen group than in the control group had a motor-milestone response (37 of 73 infants [51%] vs. 0 of 37 [0%]), and the likelihood of event-free survival was higher in the nusinersen group than in the control group (hazard ratio for death or the use of permanent assisted ventilation, 0.53; P=0.005). The likelihood of overall survival was higher in the nusinersen group than in the control group (hazard ratio for death, 0.37; P=0.004), and infants with a shorter disease duration at screening were more likely than those with a longer disease duration to benefit from nusinersen. The incidence and severity of adverse events were similar in the two groups. Conclusions Among infants with spinal muscular atrophy, those who received nusinersen were more likely to be alive and have improvements in motor function than those in the control group. Early treatment may be necessary to maximize the benefit of the drug. (Funded by Biogen and Ionis Pharmaceuticals; ENDEAR ClinicalTrials.gov number, NCT02193074 .).

Single-Dose Gene-Replacement Therapy for Spinal Muscular Atrophy.Publié le 02 11 2017

Background Spinal muscular atrophy type 1 (SMA1) is a progressive, monogenic motor neuron disease with an onset during infancy that results in failure to achieve motor milestones and in death or the need for mechanical ventilation by 2 years of age. We studied functional replacement of the mutated gene encoding survival motor neuron 1 (SMN1) in this disease. Methods Fifteen patients with SMA1 received a single dose of intravenous adeno-associated virus serotype 9 carrying SMN complementary DNA encoding the missing SMN protein. Three of the patients received a low dose (6.7×10(13) vg per kilogram of body weight), and 12 received a high dose (2.0×10(14) vg per kilogram). The primary outcome was safety. The secondary outcome was the time until death or the need for permanent ventilatory assistance. In exploratory analyses, we compared scores on the CHOP INTEND (Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders) scale of motor function (ranging from 0 to 64, with higher scores indicating better function) in the two cohorts and motor milestones in the high-dose cohort with scores in studies of the natural history of the disease (historical cohorts). Results As of the data cutoff on August 7, 2017, all 15 patients were alive and event-free at 20 months of age, as compared with a rate of survival of 8% in a historical cohort. In the high-dose cohort, a rapid increase from baseline in the score on the CHOP INTEND scale followed gene delivery, with an increase of 9.8 points at 1 month and 15.4 points at 3 months, as compared with a decline in this score in a historical cohort. Of the 12 patients who had received the high dose, 11 sat unassisted, 9 rolled over, 11 fed orally and could speak, and 2 walked independently. Elevated serum aminotransferase levels occurred in 4 patients and were attenuated by prednisolone. Conclusions In patients with SMA1, a single intravenous infusion of adeno-associated viral vector containing DNA coding for SMN resulted in longer survival, superior achievement of motor milestones, and better motor function than in historical cohorts. Further studies are necessary to confirm the safety and efficacy of this gene therapy. (Funded by AveXis and others; ClinicalTrials.gov number, NCT02122952 .).

Free-Aspire: A new device for the management of airways clearance in patient with ineffective cough.Publié le 31 10 2017

A 3-year-old girl with Spinal Muscular Atrophy type I presented with a right pneumonia. On physical examination pulmonary auscultation revealed an asymmetry of breath sounds between the 2 hemithoraces, owing to decreased breath sounds in the right hemithorax. Blood tests were normal. The initial working diagnosis was a suspected area of mucus accumulation. A treatment with Free Aspire was started. Within a few days, the girl was discharged with a normal physical examination and X-ray study result. Spinal Muscular Atrophy is a rare neuromuscular disorder characterized by loss of motor neurons and progressive muscle wasting. Cough in these patients result ineffective. Free-Aspire is an electromedical machine for removing bronchoalveolar secretions. The case show that Free Aspire in patients with ineffective cough and impaired removal of secretions is a safe and effective device for the removal of bronchial secretions and could be an another help in the management of airway clearance.

Long-term ventilation in spinal muscular atrophy: the price of progress.Publié le 31 10 2017

PMID: 28691265 [PubMed - indexed for MEDLINE]

A Historical and Current Review of Newborn Screening for Neuromuscular Disorders From Around the World: Lessons for the United States.Publié le 29 10 2017

BACKGROUND: We aimed to review the history of newborn screening for three neuromuscular disorders (Duchenne muscular dystrophy, Pompe disease, and spinal muscular atrophy [SMA]) to determine best practices.
METHODS: The history of newborn screening for Duchenne muscular dystrophy began in 1975 with the measurement of creatinine kinase on newborn male blood spots from two Midwestern hospitals in the United States. Over the next 40 years, ten programs were implemented around the globe although none currently remain. The first experimental pilot program for Pompe disease began in 2005 in Taiwan. In 2013, Missouri was the first US state to implement Pompe newborn screening before its inclusion in the Recommended Uniform Screening Panel (RUSP) in 2015 by the Advisory Committee on Heritable Disorders in Newborns and Children (United States). In 2008, SMA was reviewed and rejected for inclusion in the RUSP because no treatment existed. With the approval of nusinersen in late 2016, spinal muscular atrophy is being reconsidered for the RUSP.
RESULTS: A condition should meet public health screening criteria to be included in the RUSP. Duchenne muscular dystrophy, Pompe, and SMA challenge traditional screening criteria: Duchenne muscular dystrophy does not present in infancy and lacks effective treatment; Pompe and SMA may not present until adulthood; and safety and efficacy of long-term intrathecal treatment for SMA is unknown. Potential reproductive benefit and improved research recruitment do not justify a public health screening program.
CONCLUSIONS: This review provides lessons that could benefit US public health departments as they consider expanding screening to include neuromuscular disorders like Duchenne muscular dystrophy, Pompe, and SMA.

Segmental Spinal Muscular Atrophy Localised to the Lower Limbs: First case from Oman.Publié le 25 10 2017

Spinal muscular atrophy (SMA) is a genetic lower motor neuron disease. It usually involves all of the skeletal muscles innervated by the anterior horn cells of the spinal cord. In rare cases, there is also localised involvement of the spinal cord. We report a 10-year-old boy who presented to the Sultan Qaboos University Hospital, Muscat, Oman, in 2015 with muscle weakness restricted to the lower limbs. The presence of a homozygous deletion within the survival of motor neuron 1 gene confirmed the diagnosis of SMA. To the best of the authors' knowledge, this is the first report of an Omani patient with segmental SMA involving only the lower limbs. Treatment for this rare and relatively benign form of SMA is symptomatic and includes physiotherapy.

Population screening for spinal muscular atrophy: A mixed methods study of the views of affected families.Publié le 25 10 2017

Autosomal recessive conditions are a significant health burden with few treatments. Population carrier screening has been suggested as a means to tackle them. Little is known about the views of affected families despite the potential for direct impacts on them. Data are presented on attitudes among families affected by Spinal Muscular Atrophy (SMA) toward two population screening programs, pre-conception, and prenatal. Data were gathered through qualitative interviews (n?=?36) and a survey (n?=?337). Eighty-two survey participants had SMA and 255 were family members. The majority were in favor of screening (75%). Reasons for supporting pre-conception screening support were a belief that it would reduce SMA-related terminations and raise awareness of SMA in the population. For prenatal screening, reasons for support included a belief in the importance of informed decision-making and the need to reduce suffering. Key reasons for non-support of pre-conception screening included concerns about carrier stigmatization and social engineering. For prenatal screening, concerns focused on the collateral loss of high quality of life lives affected by SMA. This study highlights that those affected by SMA are predominantly in favor of screening, although pre-conception screening is most favored. While family members and adults with SMA had largely consistent views, perceptions varied according to the severity (type) of SMA, with those affected by SMA type II the least likely to support screening. These findings suggest that screening for SMA is a complex issue for affected families, underscoring the need to consider and include their views when planning and implementing screening programs. © 2016 Wiley Periodicals, Inc.

Pathophysiological Concepts and Treatment of Camptocormia.Publié le 22 10 2017

Camptocormia is a disabling pathological, non-fixed, forward bending of the trunk. The clinical definition using only the bending angle is insufficient; it should include the subjectively perceived inability to stand upright, occurrence of back pain, typical individual complaints, and need for walking aids and compensatory signs (e.g. back-swept wing sign). Due to the heterogeneous etiologies of camptocormia a broad diagnostic approach is necessary. Camptocormia is most frequently encountered in movement disorders (PD and dystonia) and muscles diseases (myositis and myopathy, mainly facio-scapulo-humeral muscular dystrophy (FSHD)). The main diagnostic aim is to discover the etiology by looking for signs of the underlying disease in the neurological examination, EMG, muscle MRI and possibly biopsy. PD and probably myositic camptocormia can be divided into an acute and a chronic stage according to the duration of camptocormia and the findings in the short time inversion recovery (STIR) and T1 sequences of paravertebral muscle MRI. There is no established treatment of camptocormia resulting from any etiology. Case series suggest that deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) is effective in the acute but not the chronic stage of PD camptocormia. In chronic stages with degenerated muscles, treatment options are limited to orthoses, walking aids, physiotherapy and pain therapy. In acute myositic camptocormia an escalation strategy with different immunosuppressive drugs is recommended. In dystonic camptocormia, as in dystonia in general, case reports have shown botulinum toxin and DBS of the globus pallidus internus (GPi-DBS) to be effective. Camptocormia in connection with primary myopathies should be treated according to the underlying illness.

Challenges and Advances in Gene Therapy Approaches for Neurodegenerative Disorders.Publié le 17 10 2017

INTRODUCTION: The recent approval of Spinraza (nusinersen), an antisense oligonucleotide, by U.S. Food and Drug Administration to treat patients with spinal muscular atrophy, has reignited interests of researchers in designing and testing new gene therapy approaches to treat neurological disorders, in particular, to curb neurodegenerative diseases of the central nervous system which represent an everincreasing public health burden to today's society.
CONCLUSION: This review highlights several key factors to be taken into consideration to design successful preclinical and clinical gene therapy experiments with respect to the vehicle of delivery and the route of administration to CNS-specific targets, with an additional focus on antisense oligonucleotide therapy and recent clinical trial developments.

Functional characterizations of rare UBA1 variants in X-linked Spinal Muscular Atrophy.Publié le 17 10 2017

Background: X-linked spinal muscular atrophy (XL-SMA) results from mutations in the Ubiquitin-Like Modifier Activating Enzyme 1 ( UBA1). Previously, four novel closely clustered mutations have been shown to cause this fatal infantile disorder affecting only males. These mutations, three missense and one synonymous, all lie within Exon15 of the UBA1 gene, which contains the active adenylation domain (AAD). Methods: In this study, our group characterized the three known missense variants in vitro. Using a novel Uba1 assay and other methods, we investigated Uba1 adenylation, thioester, and transthioesterification reactions in vitro to determine possible biochemical effects of the missense variants. Results: Our data revealed that only one of the three XL-SMA missense variants impairs the Ubiquitin-adenylating ability of Uba1. Additionally, these missense variants retained Ubiquitin thioester bond formation and transthioesterification rates equal to that found in the wild type. Conclusions: Our results demonstrate a surprising shift from the likelihood of these XL-SMA mutations playing a damaging role in Uba1's enzymatic activity with Ubiquitin, to other roles such as altering UBA1 mRNA splicing via the disruption of splicing factor binding sites, similar to a mechanism in traditional SMA, or disrupting binding to other important in vivo binding partners.  These findings help to narrow the search for the areas of possible dysfunction in the Ubiquitin-proteasome pathway that ultimately result in XL-SMA. Moreover, this investigation provides additional critical understanding of the mutations' biochemical mechanisms, vital for the development of future effective diagnostic assays and therapeutics.

Predictors of radial nerve palsy recovery in humeral shaft fractures: A retrospective review of 17 patients.Publié le 13 10 2017

BACKGROUND: Radial nerve injury is common in humeral shaft fractures and fails to recover spontaneously in 30% of cases. Few studies have evaluated predictors of recovery. The objectives of this study were to identify predictors of radial nerve palsy recovery and to assess the usefulness of surgical radial nerve exploration in patients with preoperative radial nerve palsy.
HYPOTHESIS: Factors predicting the outcome of radial nerve palsy can be identified.
METHODS: Of 373 patients with humeral shaft fractures between 2005 and 2012, 43 had radial nerve palsy, including 23 who were lost to follow-up and 17 who were evaluated retrospectively at a mean of 26 months (range, 12-84 months) after internal fixation. The following were studied: age, smoking history, energy of the trauma, fracture type and displacement, skin integrity and intra-operative appearance of the radial nerve.
RESULTS: Of the 17 palsies, 13 were present preoperatively, including 10 that recovered (PreR group) and 3 that did not recover (PreNR group). Plate fixation and radial nerve exploration were performed in all patients. Of the 10 PreR patients, 6 had nerve contusion and 2-nerve entrapment. Of the 3 PreNR patients, 2 had gross nerve damage and 1 nerve contusion and a history of spinal muscular atrophy. Only age and presence of gross nerve damage differed significantly between the PreR and PreNR groups; trends towards significant differences were noted for skin breach and fracture displacement. Of the 4 postoperative radial nerve palsies, 2 recovered fully and 2 partially; mean age was higher in the 2 patients with partial recovery.
DISCUSSION: These findings are consistent with the few previous studies of outcome predictors in radial nerve palsy. Factors such as major fracture displacement and high-grade skin wounds probably promote the occurrence of gross nerve lesions. The high incidence of nerve entrapment and stretching supports routine nerve exploration during internal fixation in patients with preoperative radial nerve palsy.
LEVEL OF EVIDENCE: IV, retrospective study with no control group.

Treatment Advances in Spinal Muscular Atrophy.Publié le 07 10 2017

PURPOSE OF REVIEW: Spinal muscular atrophy (SMA) is a genetic disorder of motor neurons in the anterior horns of the spinal cord and brainstem that results in muscle atrophy and weakness. SMA is an autosomal recessive disease linked to deletions of the SMN1 gene on chromosome 5q. Humans have a duplicate gene (SMN2) whose product can mitigate disease severity, leading to the variability in severity and age of onset of disease, and is therefore a target for drug development.
RECENT FINDINGS: Advances in preclinical and clinical trials have paved the way for novel therapeutic options for SMA patients, including many currently in clinical trials. In 2016, the first treatment for SMA has been approved in the USA, an antisense oligonucleotide that increases full-length protein product derived from SMN2. The approval of a first treatment for SMA and the rapid advances in clinical trials provide the prospect for multiple approaches to disease modification. There are several other promising therapeutics in different stages of development, based on approaches such as neuroprotection, or gene therapy.

Activation of a cryptic 5' splice site reverses the impact of pathogenic splice site mutations in the spinal muscular atrophy gene.Publié le 06 10 2017

Spinal muscular atrophy (SMA) is caused by deletions or mutations of the Survival Motor Neuron 1 (SMN1) gene coupled with predominant skipping of SMN2 exon 7. The only approved SMA treatment is an antisense oligonucleotide that targets the intronic splicing silencer N1 (ISS-N1), located downstream of the 5' splice site (5'ss) of exon 7. Here, we describe a novel approach to exon 7 splicing modulation through activation of a cryptic 5'ss (Cr1). We discovered the activation of Cr1 in transcripts derived from SMN1 that carries a pathogenic G-to-C mutation at the first position (G1C) of intron 7. We show that Cr1-activating engineered U1 snRNAs (eU1s) have the unique ability to reprogram pre-mRNA splicing and restore exon 7 inclusion in SMN1 carrying a broad spectrum of pathogenic mutations at both the 3'ss and 5'ss of the exon 7. Employing a splicing-coupled translation reporter, we demonstrate that mRNAs generated by an eU1-induced activation of Cr1 produce full-length SMN. Our findings underscore a wider role for U1 snRNP in splicing regulation and reveal a novel approach for the restoration of SMN exon 7 inclusion for a potential therapy of SMA.

Spinal muscular atrophy: antisense oligonucleotide therapy opens the door to an integrated therapeutic landscape.Publié le 05 10 2017

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of spinal cord motor neurons, muscle atrophy and infantile death or severe disability. It is caused by severe reduction of the ubiquitously expressed survival motor neuron (SMN) protein, owing to loss of the SMN1 gene. This would be completely incompatible with survival without the presence of a quasi-identical duplicated gene, SMN2, specific to humans. SMN2 harbours a silent point mutation that favours the production of transcripts lacking exon 7 and a rapidly degraded non-functional SMN?7 protein, but from which functional full length SMN protein is produced at very low levels (?10%). Since the seminal discovery of the SMA-causing gene in 1995, research has focused on the development of various SMN replacement strategies culminating, in December 2016, in the approval of the first precise molecularly targeted therapy for SMA (nusinersen), and a pivotal proof of principle that therapeutic antisense oligonucleotide (ASO) treatment can effectively target the central nervous system (CNS) to treat neurological and neuromuscular disease. Nusinersen is a steric block ASO that binds the SMN2 messenger RNA and promotes exon 7 inclusion and thus increases full length SMN expression. Here, we consider the implications of this therapeutic landmark for SMA therapeutics and discuss how future developments will need to address the challenges of delivering ASO therapies to the CNS, with appropriate efficiency and activity, and how SMN-based therapy should be used in combination with complementary strategies to provide an integrated approach to treat CNS and peripheral pathologies in SMA.

Application of urine cells in drug intervention for spinal muscular atrophy.Publié le 01 10 2017

Spinal muscular atrophy (SMA) is a lethal childhood neurodegenerative disorder that is caused by the homozygous deletion of survival motor neuron 1 (SMN1). To date, no effective treatments are available. In the current study, urine cells taken from SMA patients were cultured and the application of patient-derived urine cells was determined in drug intervention. A total of 13 SMA patient-derived urine cell lines and 40 control cell lines were established. SMN was highly expressed in the nucleus and cytoplasm. Patient-derived urine cells expressed low levels of SMN protein compared with controls, they exhibited good tolerance to chemical and electrical damage. SMN expression was upregulated following treatment with histone deacetylase inhibitors and the effect was greater in groups treated with morpholino modified antisense oligo, which targets ISS-N1 in SMN2 intron 7. The results of the current study indicated that SMA patient-derived urine cells may be useful in the initial screening of potential compounds and drugs to treat SMA.

Genome engineering: a new approach to gene therapy for neuromuscular disorders.Publié le 30 09 2017

For many neuromuscular disorders, including Duchenne muscular dystrophy, spinal muscular atrophy and myotonic dystrophy, the genetic causes are well known. Gene therapy holds promise for the treatment of these monogenic neuromuscular diseases, and many such therapies have made substantial strides toward clinical translation. Recently, genome engineering tools, including targeted gene editing and gene regulation, have become available to correct the underlying genetic mutations that cause these diseases. In particular, meganucleases, zinc finger nucleases, TALENs, and the CRISPR-Cas9 system have been harnessed to make targeted and specific modifications to the genome. However, for most gene therapy applications, including genome engineering, gene delivery remains the primary hurdle to clinical translation. In preclinical models, genome engineering tools have been delivered via gene-modified cells or by non-viral or viral vectors to correct a diverse array of genetic diseases. In light of the positive results of these studies, genome engineering therapies are being enthusiastically explored for several genetic neuromuscular disorders. This Review summarizes the genome engineering strategies that are currently under preclinical evaluation for the treatment of degenerative neuromuscular disorders, with a focus on the molecular tools that show the greatest potential for clinical translation of these therapies.

p.Val19Glyfs*21 and p.Leu228* variants in the survival of motor neuron 1 trigger nonsense-mediated mRNA decay causing the SMN1 PTC+ transcripts degradation.Publié le 28 09 2017

Spinal Muscular Atrophy (SMA) results from loss-of-function mutations in the survival of motor neuron 1 (SMN1) gene. Our previous research showed that 40% of variants were nonsense or frameshift variants and SMN1 mRNA levels in the patients carrying these variants were significantly decreased. Here we selected one rare variant (p.Val19Glyfs*21) and one common variant (p.Leu228*) to explore the degradation mechanism of mutant transcripts. The levels of full-length (FL)-SMN1 transcripts and SMN protein in the cell lines from the patients with these variants were both significantly reduced (p<0.01). Treatment with two translation inhibitors (puromycin and Cycloheximide (CHX)) markedly increased the levels of FL-SMN1 transcripts with premature translation termination codons (PTCs) (p<0.01) and showed time-dependent (10h>5.5h) but not dose-dependent effects. Moreover, the knockdown of UPF1, a key factor in nonsense-mediated mRNA decay (NMD) by lentivirus, led to a 3.1-fold increase (p<0.01) in FL-SMN1 transcript levels in patient fibroblasts. Our research provides evidence that these two PTC-generating variants (p.Val19Glyfs*21 and p.Leu228*) can trigger NMD, causing rapid degradation of SMN1 transcripts thereby resulting in SMN protein deficiency. These two variants are highly pathogenic and are associated with more severe SMA phenotypes. Varying NMD efficiency after treatment with puromycin and CHX in different cell types was also observed.

Treatment of Mild Camptocormia with Selegiline in Patients with Parkinson's Disease.Publié le 28 09 2017

BACKGROUND: Camptocormia in Parkinson's disease (PD) is unresponsive to various therapies and induced difficulties in their day-to-day life.
OBJECTIVE: This study, an open trial, was aimed at assessing the efficacy of selegiline in the treatment of mild camptocormia in PD patients.
METHODS: Participants were administered 5 mg of selegiline for the first 8 weeks and 7.5 mg for the second 8 weeks.
RESULTS: As primary endpoints, the degree of thoracolumbar anteflexion decreased from 23.2° (mean) (11.8° (SD)) at baseline to 18.3° (7.1°) at 16 weeks, and the area of postural sway measured using a Gravicorder increased. However, the differences were not significant. Thoracolumbar anteflexion improved in 60% of the participants.
CONCLUSIONS: In this study, 60% of the participants showed an improvement in anteflexion of the thoracolumbar spine with selegiline, but the change in the degree of anteflexion was 5°, which was not statistically significant. Participants with significant improvement in thoracolumbar anteflexion had an increased postural sway. This change was induced by a decrease in truncal muscle tonus or change in the center of gravity. This study combined the study of anteflexion and stability, and provides information on the treatment of short-term or mild camptocormia.

In vitro and in vivo effects of 2,4 diaminoquinazoline inhibitors of the decapping scavenger enzyme DcpS: Context-specific modulation of SMN transcript levels.Publié le 26 09 2017

C5-substituted 2,4-diaminoquinazoline inhibitors of the decapping scavenger enzyme DcpS (DAQ-DcpSi) have been developed for the treatment of spinal muscular atrophy (SMA), which is caused by genetic deficiency in the Survival Motor Neuron (SMN) protein. These compounds are claimed to act as SMN2 transcriptional activators but data underlying that claim are equivocal. In addition it is unclear whether the claimed effects on SMN2 are a direct consequence of DcpS inhibitor or might be a consequence of lysosomotropism, which is known to be neuroprotective. DAQ-DcpSi effects were characterized in cells in vitro utilizing DcpS knockdown and 7-methyl analogues as probes for DcpS vs non-DcpS-mediated effects. We also performed analysis of Smn transcript levels, RNA-Seq analysis of the transcriptome and SMN protein in order to identify affected pathways underlying the therapeutic effect, and studied lysosomotropic and non-lysosomotropic DAQ-DCpSi effects in 2B/- SMA mice. Treatment of cells caused modest and transient SMN2 mRNA increases with either no change or a decrease in SMN?7 and no change in SMN1 transcripts or SMN protein. RNA-Seq analysis of DAQ-DcpSi-treated N2a cells revealed significant changes in expression (both up and down) of approximately 2,000 genes across a broad range of pathways. Treatment of 2B/- SMA mice with both lysomotropic and non-lysosomotropic DAQ-DcpSi compounds had similar effects on disease phenotype indicating that the therapeutic mechanism of action is not a consequence of lysosomotropism. In striking contrast to the findings in vitro, Smn transcripts were robustly changed in tissues but there was no increase in SMN protein levels in spinal cord. We conclude that DAQ-DcpSi have reproducible benefit in SMA mice and a broad spectrum of biological effects in vitro and in vivo, but these are complex, context specific, and not the result of simple SMN2 transcriptional activation.

Short (16-mer) locked nucleic acid splice-switching oligonucleotides restore dystrophin production in Duchenne Muscular Dystrophy myotubes.Publié le 26 09 2017

Splice-switching antisense oligonucleotides (SSOs) offer great potential for RNA-targeting therapies, and two SSO drugs have been recently approved for treating Duchenne Muscular Dystrophy (DMD) and Spinal Muscular Atrophy (SMA). Despite promising results, new developments are still needed for more efficient chemistries and delivery systems. Locked nucleic acid (LNA) is a chemically modified nucleic acid that presents several attractive properties, such as high melting temperature when bound to RNA, potent biological activity, high stability and low toxicity in vivo. Here, we designed a series of LNA-based SSOs complementary to two sequences of the human dystrophin exon 51 that are most evolutionary conserved and evaluated their ability to induce exon skipping upon transfection into myoblasts derived from a DMD patient. We show that 16-mers with 60% of LNA modification efficiently induce exon skipping and restore synthesis of a truncated dystrophin isoform that localizes to the plasma membrane of patient-derived myotubes differentiated in culture. In sum, this study underscores the value of short LNA-modified SSOs for therapeutic applications.

Role of Ethnicity in Alignment Compensation: Propensity Matched Analysis of Differential Compensatory Mechanism Recruitment Patterns for Sagittal Malalignment in 288 ASD Patients From Japan, Korea, and United States.Publié le 22 09 2017

STUDY DESIGN: Retrospective review of adult spinal deformity patients in a multiethnic database.
OBJECTIVE: To investigate the role of ethnicity on recruitment of compensatory mechanisms for sagittal spinal deformity.
SUMMARY OF BACKGROUND DATA: While the impacts of age, sex, and pelvic morphology on the ability to compensate for sagittal malalignment have been investigated, the role of ethnicity in compensatory mechanism recruitment is poorly understood.
METHODS: Patients from USA (85% Caucasian) >25?y/o were propensity matched by age, sex, and pelvic incidence with patients from Korea and Japan. Only primary patients or those with existing fusion below T12 were retained for analysis. Groups were subclassified by deformity severity (aligned: sagittal vertical axis (SVA)?<50?mm; moderate malalignment: SVA 50-100?mm; severe malalignment: SVA >100?mm). Radiographic measurements including pelvic retroversion, thoracic kyphosis, loss of lumbar lordosis (PI minus LL), cervical lordosis, and cervical SVA were compared between the groups.
RESULTS: There were 288 patients (96 each in USA, KOR, JPN), with similar age (64-67 yr) and PI (49-53°). USA had smaller pelvic incidence minus lumbar lordosis in every alignment group (P?<0.05). In moderate malalignment, JPN had more pelvic retroversion than USA (30° vs. 20°), and KOR had more thoracic hypokyphosis than USA (15 vs. 31°). In severe malalignment, JPN had more pelvic retroversion than USA (39° vs. 27°), and KOR had more thoracic hypokyphosis than USA (15° vs. 31°). KOR had smaller cSVA than USA in both aligned (11 vs. 27?mm) and moderate (19 vs. 31?mm) malalignment. In severe malalignment, KOR had less cervical lordosis (13° KOR vs. 15° USA vs. 27° JPN). All differences with P?<0.05.
CONCLUSION: Compensation for sagittal is ethnicity dependent. Korean patients favor thoracic compensation via hypokyphosis, and Japanese patients favor pelvic compensation via retroversion. Patient ethnicity should be considered when evaluating the sagittal plane and surgical correction strategies.

Gestational Age-Dependent Increase of Survival Motor Neuron Protein in Umbilical Cord-Derived Mesenchymal Stem Cells.Publié le 21 09 2017

BACKGROUND: Spinal muscular atrophy (SMA) is the most common genetic neurological disease leading to infant death. It is caused by loss of survival motor neuron (SMN) 1 gene and subsequent reduction of SMN protein in motor neurons. Because SMN is ubiquitously expressed and functionally linked to general RNA metabolism pathway, fibroblasts (FBs) are most widely used for the assessment of SMN expression in SMA patients but usually isolated from skin biopsy samples after the onset of overt symptoms. Although recent translational studies of SMN-targeted therapies have revealed the very limited time window for effective SMA therapies during perinatal period, the exact time point when SMN shortage became evident is unknown in human samples. In this study, we analyzed SMN mRNA and protein expression during perinatal period by using umbilical cord-derived mesenchymal stem cells (UC-MSCs) obtained from preterm and term infants.
METHODS: UC-MSCs were isolated from 16 control infants delivered at 22-40?weeks of gestation and SMA fetus aborted at 19?weeks of gestation (UC-MSC-Control and UC-MSC-SMA). FBs were isolated from control volunteer and SMA patient (FB-Control and FB-SMA). SMN mRNA and protein expression in UC-MSCs and FBs was determined by RT-qPCR and Western blot.
RESULTS: UC-MSC-Control and UC-MSC-SMA expressed the comparable level of MSC markers on their cell surface and were able to differentiate into adipocytes, osteocytes, and chondrocytes. At steady state, SMN mRNA and protein expression was decreased in UC-MSC-SMA compared to UC-MSC-Control, as observed in FB-SMA and FB-Control. In response to histone deacetylase inhibitor valproic acid, SMN mRNA and protein expression in UC-MSC-SMA and FB-SMA was increased. During perinatal development from 22 to 40?weeks of gestation, SMN mRNA and protein expression in UC-MSC-Control was positively correlated with gestational age.
CONCLUSION: UC-MSCs isolated from 17 fetus/infant of 19-40?weeks of gestation are expressed functional SMN mRNA and protein. SMN mRNA and protein expression in UC-MSCs is increased with gestational age during perinatal development.

ERK and ROCK functionally interact in a signaling network that is compensationally upregulated in Spinal Muscular Atrophy.Publié le 17 09 2017

Spinal Muscular Atrophy (SMA) is a motoneuron disease caused by low levels of functional survival of motoneuron protein (SMN). Molecular disease mechanisms downstream of functional SMN loss are still largely unknown. Previous studies suggested an involvement of Rho kinase (ROCK) as well as the extracellular signal-regulated kinases (ERK) pathways in the pathomechanism. Both pathways are bi-directionally linked and inhibit each other. Thus, we hypothesize that both pathways regulate SMA pathophysiology in vivo in a combined manner rather than acting separately. Here, we applied the repurposed drugs, selumetinib, an ERK inhibitor, and the ROCK inhibitor fasudil to severe SMA mice. Thereby, separately applied inhibitors as well as a combination enabled us to explore the impact of the ROCK-ERK signaling network on SMA pathophysiology. ROCK inhibition specifically ameliorated the phenotype of selumetinib-treated SMA mice demonstrating an efficient ROCK to ERK crosstalk relevant for the SMA pathophysiology. However, ERK inhibition alone aggravated the condition of SMA mice and reduced the number of motoneurons indicating a compensatory hyper-activation of ERK in motoneurons. Taken together, we identified a regulatory network acting downstream of SMN depletion and upstream of the SMA pathophysiology thus being a future treatment target in combination with SMN dependent strategies.

Palliative care in neuromuscular diseases.Publié le 16 09 2017

PURPOSE OF REVIEW: Palliative care is an approach that improves the quality of life of patients and their families facing the problem associated with life-threatening illness. Neuromuscular disorders (NMDs) are characterized by progressive muscle weakness, leading to pronounced and incapacitating physical disabilities. Most NMDs are not amenable to curative treatment and would thus qualify for palliative care. Amyotrophic lateral sclerosis is a relentlessly progressive disease, which leads to death about 2 years after onset due to respiratory muscle weakness. Increasingly, neurologists caring for these patients learn to apply the principles of palliative care. However, this does not yet apply to other well known and frequently occurring NMDs.
RECENT FINDINGS: There is sparse literature on palliative care in NMDs such as Duchenne muscular dystrophy, spinal muscular atrophy, muscular dystrophies, some congenital myopathies, Pompe's disease and myotonic dystrophy type 1. These NMDs are often associated with imminent respiratory insufficiency and/or heart failure leading to a reduced life expectancy. Reasons for underutilization may include misconceptions about palliative care amongst patients, family carers and healthcare professionals or lack of awareness of the usefulness of this approach in these severely affected patients and the possibilities of integration of palliative principles into care for children and adults with NMDs.
SUMMARY: There is an urgent need for increased attention to the development of palliative care in chronic progressive neuromuscular diseases associated with increasing functional incapacities and premature death. This will require education and training of the healthcare professionals, involvement of patient associations and funding to perform research.

The water extract of Liuwei dihuang possesses multi-protective properties on neurons and muscle tissue against deficiency of survival motor neuron protein.Publié le 14 09 2017

BACKGROUND: Deficiency of survival motor neuron (SMN) protein, which is encoded by the SMN1 and SMN2 genes, induces widespread splicing defects mainly in spinal motor neurons, and leads to spinal muscular atrophy (SMA). Currently, there is no effective treatment for SMA. Liuwei dihuang (LWDH), a traditional Chinese herbal formula, possesses multiple therapeutic benefits against various diseases via modulation of the nervous, immune and endocrine systems. Previously, we demonstrated water extract of LWDH (LWDH-WE) protects dopaminergic neurons and improves motor activity in models of Parkinson's disease.
PURPOSE: This study aimed to investigate the potential protection of LWDH-WE on SMN deficiency-induced neurodegeneration and muscle weakness.
STUDY DESIGN: The effects of LWDH-WE on SMN deficiency-induced neurotoxicity and muscle atrophy were examined by using SMN-deficient NSC34 motor neuron-like cells and SMA-like mice, respectively.
METHODS: Inducible SMN-knockdown NSC34 motor neuron-like cells were used to mimic SMN-deficient condition. Doxycycline (1?µg/ml) was used to induce SMN deficiency in stable NSC34 cell line carrying SMN-specific shRNA. SMA?7 mice were used as a severe type of SMA mouse model. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Apoptotic cells and neurite length were observed by inverted microscope. Protein expressions were examined by western blots. Muscle strength of animals was evaluated by hind-limb suspension test.
RESULTS: LWDH-WE significantly increased SMN protein level, mitochondrial membrane potential and cell viability of SMN-deficient NSC34 cells. LWDH-WE attenuated SMN deficiency-induced down-regulation of B-cell lymphoma-2 (Bcl-2) and up-regulation of cytosolic cytochrome c and cleaved caspase-3. Moreover, LWDH-WE prevented SMN deficiency-induced inhibition of neurite outgrowth and activation of Ras homolog gene family, member A (RhoA)/ Rho-associated protein kinase (ROCK2)/ phospho-LIM kinase (p-LIMK)/ phospho-cofilin (p-cofilin) pathway. Furthermore, in SMA-like mice, LWDH-WE improved muscle strength and body weight accompanied with up-regulation of SMN protein in spinal cord, brain, and gastrocnemius muscle tissues.
CONCLUSION: The present study demonstrated that LWDH-WE protects motor neurons against SMN deficiency-induced neurodegeneration, and it also improves the muscle strength of SMA-like mice, suggesting the potential benefits of LWDH-WE as a complementary prescription for SMN deficiency-related diseases.

Treating pediatric neuromuscular disorders: The future is now.Publié le 11 09 2017

Pediatric neuromuscular diseases encompass all disorders with onset in childhood and where the primary area of pathology is in the peripheral nervous system. These conditions are largely genetic in etiology, and only those with a genetic underpinning will be presented in this review. This includes disorders of the anterior horn cell (e.g., spinal muscular atrophy), peripheral nerve (e.g., Charcot-Marie-Tooth disease), the neuromuscular junction (e.g., congenital myasthenic syndrome), and the muscle (myopathies and muscular dystrophies). Historically, pediatric neuromuscular disorders have uniformly been considered to be without treatment possibilities and to have dire prognoses. This perception has gradually changed, starting in part with the discovery and widespread application of corticosteroids for Duchenne muscular dystrophy. At present, several exciting therapeutic avenues are under investigation for a range of conditions, offering the potential for significant improvements in patient morbidities and mortality and, in some cases, curative intervention. In this review, we will present the current state of treatment for the most common pediatric neuromuscular conditions, and detail the treatment strategies with the greatest potential for helping with these devastating diseases.

Nusinersen for the treatment of spinal muscular atrophy.Publié le 09 09 2017

INTRODUCTION: Spinal muscular atrophy (SMA) is an autosomal recessive degenerative neuromuscular disorder characterized by loss of spinal motor neurons leading to muscle weakness. This review article focuses on a novel antisense oligonucleotide treatment, first ever approved for SMA (nusinersen, Spinraza(TM)) and describes the exciting journey from early ASO clinical trials to regulatory approval of the first ever known effective treatment for SMA. Areas covered: This article reviews the results of the published open label nusinersen studies in infants and children, and briefly covers the preliminary findings of the recently completed but as yet unpublished nusinersen-sham controlled trials, as well as the presymptomatic nusinersen trial known as Nurture. Clinical use of nusinersen is also reviewed. Expert commentary: Collectively, the studies show improvement in motor function across SMA of all types, including SMA type 3. Best motor response was observed with early treatment; presymptomatic treatment prevented disease manifestations. Nusinersen was found to be safe and well tolerated across all age groups studied. Nusinersen has irrevocably altered the natural history of SMA and allowed for the first time children to transition between SMA types. Nusinersen should be considered as standard of care for the treatment of SMA of all types.

Seeking a better landscape for therapy development in neuromuscular disorders.Publié le 08 09 2017

While the neuromuscular field has seen accelerated approval of a drug for Duchenne muscular dystrophy (DMD) and full approval of one for spinal muscular atrophy, these experiences have shown that objective data and an adequate level of effect are essential for drug approval and reimbursement. The appropriateness and validity of biomarkers and clinically meaningful endpoints, and an understanding of disease progression rates, all played essential roles in the levels of evidence for these drugs. Such tools are best developed through integration of clinical data. The siloing of clinical data for rare neuromuscular diseases represents a considerable barrier to achieving better care and novel therapies for patients living with neuromuscular diseases. We discuss a data-sharing model implemented for DMD and urge cultural changes in the ways natural history and clinical trial data are collected and shared across all neuromuscular diseases in order to benefit the primary stakeholder, the patient. This article is protected by copyright. All rights reserved.

CBP-mediated SMN acetylation modulates Cajal body biogenesis and the cytoplasmic targeting of SMN.Publié le 08 09 2017

The survival of motor neuron (SMN) protein plays an essential role in the biogenesis of spliceosomal snRNPs and the molecular assembly of Cajal bodies (CBs). Deletion of or mutations in the SMN1 gene cause spinal muscular atrophy (SMA) with degeneration and loss of motor neurons. Reduced SMN levels in SMA lead to deficient snRNP biogenesis with consequent splicing pathology. Here, we demonstrate that SMN is a novel and specific target of the acetyltransferase CBP (CREB-binding protein). Furthermore, we identify lysine (K) 119 as the main acetylation site in SMN. Importantly, SMN acetylation enhances its cytoplasmic localization, causes depletion of CBs, and reduces the accumulation of snRNPs in nuclear speckles. In contrast, the acetylation-deficient SMNK119R mutant promotes formation of CBs and a novel category of promyelocytic leukemia (PML) bodies enriched in this protein. Acetylation increases the half-life of SMN protein, reduces its cytoplasmic diffusion rate and modifies its interactome. Hence, SMN acetylation leads to its dysfunction, which explains the ineffectiveness of HDAC (histone deacetylases) inhibitors in SMA therapy despite their potential to increase SMN levels.

Amphiphilic lipopeptide significantly enhances uptake of charge-neutral splice switching morpholino oligonucleotide in spinal muscular atrophy patient-derived fibroblasts.Publié le 03 09 2017

Splice-switching antisense oligonucleotides (SSOs) are emerging therapeutics with two SSOs recently approved by the FDA for Duchenne muscular dystrophy and spinal muscular atrophy. SSOs are administered without any delivery vector and require large doses to achieve the therapeutic benefit, primarily due to their poor cellular uptake. Although cell-penetrating peptides (CPP) have shown great potential in delivering SSOs into cells, their capacity as delivery vector is limited. Here we have studied the effect of lipid conjugation on the cell permeability of a known CPP (ApoE). Myristic acid, was coupled at the N-terminus of ApoE to a C-terminal cysteine residue. The myristoylated ApoE (Myr-ApoE) was conjugated to a maleimide functionalised phosphorodiamidate morpholino oligonucleotide (PMO). The Myr-ApoE-PMO conjugate showed no cytoxicity and had significantly higher efficiency in cell permeability with 30% higher splice-switching activity compared to ApoE-PMO. The self-assembly properties of this amphiphilic lipopeptide-PMO conjugate was assessed. Transmission electron microscopy showed formation of nanoparticles with amphiphile behaviour and spherical structure. The self-assembly of Myr-ApoE-PMO into nanoparticles enabled it to better bind to cell membranes and to be more efficiently taken up by fibroblast cells. These results showed that modification of physico-chemical properties of peptides to produce peptide amphiphiles enhances cellular uptake and can be used as an efficient delivery vector for therapeutic SSOs.

Clinical Trial of L-Carnitine and Valproic Acid in Spinal Muscular Atrophy Type I.Publié le 24 08 2017

INTRODUCTION: To explore safety and therapeutic potential of L-carnitine and valproic acid (VPA) in infants with spinal muscular atrophy (SMA).
METHODS: Open-label phase 2 multicenter trial of L-carnitine and VPA in infants with SMA type I with retrospective comparison to an untreated, matched cohort. Primary outcomes were safety and adverse events (AEs); secondary outcomes were survival, time to death/> 16 hours/day ventilator support, motor outcomes and maximum ulnar compound motor action potential amplitude.
RESULTS: 245 AEs were observed in 35 of 37 treated subjects (95%). Respiratory events accounted for 49% of all AEs, resulting in 14 deaths. Survival was not significantly different between treated and untreated cohorts.
DISCUSSION: This trial provides evidence that in infants with SMA type I, L-carnitine/VPA is ineffective in altering survival. The substantial proportion of infants reaching endpoints within 6 months of enrollment underscores the urgent need for pre-symptomatic treatment in SMA type I. This article is protected by copyright. All rights reserved.

Social/economic costs and health-related quality of life in patients with spinal muscular atrophy (SMA) in Spain.Publié le 20 08 2017

BACKGROUND: The aim of this study was to determine the economic burden and health-related quality of life (HRQOL) of patients with Spinal Muscular Atrophy (SMA) and their caregivers in Spain.
METHODS: This was a cross-sectional and retrospective study of patients diagnosed with SMA in Spain. We adopted a bottom up, prevalence approach design to study patients with SMA. The patient's caregivers completed an anonymous questionnaire regarding their socio-demographic characteristics, use of healthcare services and non-healthcare services. Costs were estimated from a societal perspective (including healthcare costs and non-healthcare costs), and health-related quality of life (HRQOL) was assessed using the EQ-5D questionnaire. The main caregivers also answered a questionnaire on their characteristics and on their HRQOL.
RESULTS: A total of 81 caregivers of patients with different subtypes of SMA completed the questionnaire. Based on the reference unitary prices for 2014, the average annual costs per patient were € 33,721. Direct healthcare costs were € 10,882 (representing around 32.3% of the total cost) and the direct non-healthcare costs were € 22,839 (67.7% of the total cost). The mean EQ-5D social tariff score for patients was 0.16, and the mean score of the EQ-5D visual analogue scale was 54. The mean EQ-5D social tariff score for caregivers was 0.49 and their mean score on the EQ-5D visual analogue scale was 69.
CONCLUSION: The results highlight the burden that SMA has in terms of costs and decreased HRQOL, not only for patients but also for their caregivers. In particular, the substantial social/economic burden is mostly attributable to the high direct non-healthcare costs.

Bent spine syndrome as the initial symptom of late-onset Pompe disease.Publié le 20 08 2017

INTRODUCTION: Late-onset Pompe disease (LOPD) is a rare disorder characterized by progressive proximal muscle weakness and early respiratory insufficiency, for which enzyme replacement therapy (ERT) is available.
METHODS: Having diagnosed a case of LOPD presenting with bent spine syndrome, we conducted a brief survey in the French centers involved in management of Pompe disease, from which we collected data on 3 other cases.
RESULTS: The patients (3 women and 1 man) had a mean age of 64 years (range 51-77 years) and a delay in diagnosis of approximately 10 years (range 8-42 years). At diagnosis, 3 patients already had respiratory symptoms. All had normal or very mildly raised creatine kinase levels and magnetic resonance imaging abnormalities in the paraspinal muscles. They exhibited the most frequent mutation in Pompe disease (c.-32-13?T>G).
CONCLUSION: Clinicians should be aware of this atypical presentation of LOPD to enable earlier diagnosis and treatment. Muscle Nerve 56: 167-170, 2017.

[Radiation-Induced Radiculopathy with Paresis of the Neck and Autochthonous Back Muscles with Additional Myopathy].Publié le 18 08 2017

Radiation-induced tissue damage is caused by ionizing radiation mainly affecting the skin, vascular, neuronal or muscle tissue. Early damages occur within weeks and months while late damages may occur months or even decades after radiation.Radiation-induced paresis of the spine or the trunk muscles with camptocormia or dropped-head syndrome are rare but have already been described as long-term sequelae after treatment of Hodgkin's lymphoma. The differential diagnosis includes limb-girdle muscular dystrophy, fascioscapulohumeral muscular dystrophy (FSHD) or lysosomal storage diseases (e.?g. Acid Maltase Deficiency). We present the case of a patient with long lasting diagnostics over many months due to different inconclusive results.

Regulation of Survival Motor Neuron Protein by the Nuclear Factor-Kappa B Pathway in Mouse Spinal Cord Motoneurons.Publié le 17 08 2017

Survival motor neuron (SMN) protein deficiency causes the genetic neuromuscular disorder spinal muscular atrophy (SMA), characterized by spinal cord motoneuron degeneration. Since SMN protein level is critical to disease onset and severity, analysis of the mechanisms involved in SMN stability is one of the central goals of SMA research. Here, we describe the role of several members of the NF-?B pathway in regulating SMN in motoneurons. NF-?B is one of the main regulators of motoneuron survival and pharmacological inhibition of NF-?B pathway activity also induces mouse survival motor neuron (Smn) protein decrease. Using a lentiviral-based shRNA approach to reduce the expression of several members of NF-?B pathway, we observed that IKK and RelA knockdown caused Smn reduction in mouse-cultured motoneurons whereas IKK or RelB knockdown did not. Moreover, isolated motoneurons obtained from the severe SMA mouse model showed reduced protein levels of several NF-?B members and RelA phosphorylation. We describe the alteration of NF-?B pathway in SMA cells. In the context of recent studies suggesting regulation of altered intracellular pathways as a future pharmacological treatment of SMA, we propose the NF-?B pathway as a candidate in this new therapeutic approach.

Clinical Characteristics of Spinal Muscular Atrophy in Korea Confirmed by Genetic Analysis.Publié le 11 08 2017

The objective of this study was to review the clinical characteristics of patients with spinal muscular atrophy and to emphasize the importance of performing genetic mutational analysis at initial patient assessment. This is a single center oriented, retrospective, and descriptive study conducted in Seoul, South Korea. Genetic mutational analysis to detect the deletion of exon 7 of the SMN1 gene on chromosome 5q13 was performed by multiplex ligation-dependent probe amplification. Clinical features, electrodiagnostic study results, muscle biopsy results, and laboratory test results were reviewed from patient medical records. Of all 28 patients (15 males and 13 females), all showed bilateral symmetric proximal dominant weakness. Among them, 3 patients were classified as type I, 14 patients as type II, and 11 patients as type III. Twenty-five patients had scoliosis and eight of these patients received surgical treatment for scoliosis with improvement in clinical outcomes. Ventilator support was used in 15 patients. In terms of the diagnostic process, 15 patients had completed an electrodiagnostic study and muscle biopsy before genetic testing, and six of these patients were initially misdiagnosed with myopathy. Owing to the similar clinical features of SMA and congenital myopathy, an electrodiagnostic study and muscle biopsy could create confusion in the correct diagnosis in some cases. Therefore, it is recommended that genetic mutation analysis should be conducted along with an electrodiagnostic study or muscle biopsy in the diagnostic process for spinal muscular atrophy.

Outcomes of Primary Posterior Spinal Fusion for Scoliosis in Spinal Muscular Atrophy: Clinical, Radiographic, and Pulmonary Outcomes and Complications.Publié le 08 08 2017

BACKGROUND: Spinal muscular atrophy (SMA) is a progressive neuromuscular disease commonly including progressive scoliosis resulting in severe deformity and negatively affecting pulmonary function. Surgical correction and stabilization of this progressive deformity is generally recommended; however, the timing and method of surgical fixation remains controversial.
METHODS: Retrospective review of clinical, radiographic, and pulmonary function data from 16 children with SMA and surgically treated scoliosis between 1985 and 2013. Radiographic data included direct measures of major curve, coronal balance, pelvic obliquity, T1-T12 height, T1-S1 height, and T1-rod length. Estimations of rib collapse, thoracic cavity shape, and space-available-for-lung (T6:T12, width ratio; T6:T10, rib-vertebral-angle difference ratios; and lung height) were determined. Eleven patients were able to complete pulmonary function testing. Results were compared with published outcomes for growing rod constructs.
RESULTS: Posterior spinal fusion was performed at an average age of 9.8±3.6 years. The mean age at most recent follow-up was 19.4 years (range, 10 to 37 y), with a mean follow-up of 10.1 years (range, 3.1 to 26 y). Radiographic measurements improved from preoperative to latest follow-up as follows: major curve, 78±20 degrees to 27±24 degrees; coronal balance, 4.1±4.0 cm to 1.9±2.2 cm; pelvic obliquity (median), 23 to 5 degrees; T1-T12 height, 19±3 cm to 22±3 cm; T1-S1 height, 31±7 cm to 36±6 cm; T1-rod length, 0.8±1.1 cm (postop) to 2.8±1.6 cm (final); and space-available-for-lung ratio, 0.88±0.26 to 0.95±0.25. Rib collapse continued throughout the follow-up period in all but 1 patient. Pulmonary function testing demonstrated a decrease in rate of decline in forced vital capacity and forced expiratory volume when comparing preoperative with postoperative rates. Mean length of stay was 7.8±4.4 days. Complications included reintubation for low tidal volumes (n=1), pneumonia (n=1), superficial wound breakdown (n=1), and superficial infection (n=1).
CONCLUSIONS: Definitive posterior spinal fusion for treatment of scoliosis associated with SMA is effective at controlling curve progression and pelvic obliquity without negatively impacting the space-available-for-lung ratio, trunk height, or pulmonary function at 10 years follow-up.
LEVEL OF EVIDENCE: Therapeutic Level IV.

Therapeutic strategies for spinal muscular atrophy: SMN and beyond.Publié le 08 08 2017

Spinal muscular atrophy (SMA) is a devastating neuromuscular disorder characterized by loss of motor neurons and muscle atrophy, generally presenting in childhood. SMA is caused by low levels of the survival motor neuron protein (SMN) due to inactivating mutations in the encoding gene SMN1 A second duplicated gene, SMN2, produces very little but sufficient functional protein for survival. Therapeutic strategies to increase SMN are in clinical trials, and the first SMN2-directed antisense oligonucleotide (ASO) therapy has recently been licensed. However, several factors suggest that complementary strategies may be needed for the long-term maintenance of neuromuscular and other functions in SMA patients. Pre-clinical SMA models demonstrate that the requirement for SMN protein is highest when the structural connections of the neuromuscular system are being established, from late fetal life throughout infancy. Augmenting SMN may not address the slow neurodegenerative process underlying progressive functional decline beyond childhood in less severe types of SMA. Furthermore, individuals receiving SMN-based treatments may be vulnerable to delayed symptoms if rescue of the neuromuscular system is incomplete. Finally, a large number of older patients living with SMA do not fulfill the present criteria for inclusion in gene therapy and ASO clinical trials, and may not benefit from SMN-inducing treatments. Therefore, a comprehensive whole-lifespan approach to SMA therapy is required that includes both SMN-dependent and SMN-independent strategies that treat the CNS and periphery. Here, we review the range of non-SMN pathways implicated in SMA pathophysiology and discuss how various model systems can serve as valuable tools for SMA drug discovery.

Spinal muscular atrophy: A changing phenotype beyond the clinical trials.Publié le 08 08 2017

Spinal muscular atrophy is a monogenic, progressive motor neuron disorder caused by deletion or mutation in the SMN1 gene. A broad range of phenotypic severity, from very weak infants (Type 1) to ambulant children (type 3), is modified mainly by the number of copies of the "backup" SMN2 gene. Since the discovery of the role of both genes, basic research into the pathobiology of SMA, with in vitro and animal model studies, has identified therapeutic targets. Development of clinical outcome measures, natural history studies and standard of care guidelines have contributed to the development of protocols for therapeutic drugs now under clinical investigation. Following regulatory approval of the first drug treatment for SMA in the US (December, 2016) and marketing authorization in Europe (June, 2017), the prospects for care of these patients have changed. The evolution of the phenotype of SMA now needs to be considered beyond the clinical trials. This perspective review discusses potential new trajectories in the phenotype of SMA and the need for multidisciplinary teams to prepare for this changing landscape.

[Congenital neuromuscular diseases with neonatal respiratory failure excluding myotonic dystrophy type 1 and infantile spinal muscular atrophy. Diagnosis strategy according to a 19-child series].Publié le 08 08 2017

UNLABELLED: Apart from spinal muscular atrophy (SMA) and myotonic dystrophy type 1 (DM1), congenital neuromuscular diseases with early neonatal symptoms mean diagnostic and prognostic challenges mainly when infants require ventilatory support.
OBJECTIVES: Consider a standardized strategy for infants suspected of congenital neuromuscular disease from analysis of the literature and retrospective experience with floppy and ventilatory support-dependent infants, after exclusion of well-known diseases (DM1, SMA).
PATIENTS AND METHODS: Floppy infants requiring ventilatory support in their 1st month of life, but showing no evidence of DM1, SMA, Prader-Willi syndrome, or encephalopathy. The retrospective multicenter study was based on the response of regional referent neuropediatricians in the Reference Centre for Neuromuscular Diseases of Greater Southwest France to an inquiry about prenatal and perinatal history, investigations, diagnosis, and outcome of the child and family. It was conducted between 2007 and 2012.
RESULTS: Among the 19 newborns studied, all had severe hypotonia. Prenatal and perinatal features were similar. Their outcome was generally severe: the median survival as measured by the Kaplan-Meier method was 6.9 months. Thirteen children died at a median age of 61 days; ten of them were treated with a palliative procedure. Five children had achieved respiratory independence but suffered from a small delay in motor development. Among the three children who continuously required ventilatory support, only one survived (follow-up period: 23 months); he was the only one undergoing tracheostomy in the cohort. Diagnostic processes were different, leading to pathological and genetic diagnosis for only six infants. There was only histological orientation for seven and no specific diagnostic orientation for the last six. These difficulties have led us to propose an exploration process based on the literature.
CONCLUSION: This study highlights difficulties in obtaining a diagnosis and a precise prognosis for floppy ventilated infants. An exploration-standardized process for infants suspected of congenital neuromuscular diseases was made in order to standardize procedures. It could be used as a tool for all professionals involved.

Nusinersen: The First Option Beyond Supportive Care for Spinal Muscular Atrophy.Publié le 30 07 2017

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by degeneration of spinal motor neurons and poses significant adverse outcome in affected population. Survival motor neuron 1 (SMN1) protein encoded by SMN1 gene located on 5q(13) is critical for survival and functioning of motor neurons. Almost identical gene SMN2, present on the same chromosome, produces a small truncated protein (SMN2) because of skipping of exon 7 from translation due to translation silent C6U substitution in exon 7 of SMN2 pre-mRNA transcript. Only 10% of the SMN2 mRNAs produce full length SMN2 protein by including exon 7 in healthy individuals. A large deletion or sometimes a point mutation in SMN1 gene is responsible for SMA. In this case the number of copies of SMN2 genes in an individual determines the severity of disease (the more the number of copies the less severe the disease). Nusinersen (ISIS 396443) binds to intron splicing silencer-N1 (ISS-N1; a site present ten nucleotides down to the junction of exon 7 and intron 7), modulating the splicing of SMN2 pre-mRNA transcript to increase the inclusion of exon 7, thereby increasing the production of full length SMN2 protein. Major evidence of its efficacy came from a sham controlled phase 3 clinical study ENDEAR. The study was stopped early based on significantly favorable results in interim analysis and all the patients were transitioned to receive nusinersen in an ongoing open-label, phase 3 study, SHINE, which will evaluate the long-term efficacy, safety and tolerability of the drug. Nusinersen is globally the first drug approved (by the US FDA) for treatment of SMA in children and adults.

Management of neuromuscular diseases and spinal muscular atrophy in Latin America.Publié le 29 07 2017

Latin America (LA) has a population of ~645 million people distributed over 33 countries with marked political, cultural, and economic differences. In LA, patients with inherited neuromuscular diseases (NMD) often do not have access to specialized medical centres and many of them go undiagnosed. General management and care of spinal muscular dystrophy (SMA) patients in the region varies due to heterogeneous health care. An active generation of young clinical neurologists is being trained for the specialized care of SMA and other NM patients, both in the private and public sectors. The Euro-Latin-American Summer School of Myology (EVELAM) as well as efforts of professionals at large public centres in the major cities of LA play a leading role in this development. Different regional academic-scientific organizations as well as the expanding number of Telethon Centres and the creation of parent organizations, mostly concerning SMA, all together are contributing to the increased quality of the management of NMD patients. Over the past years, academic and clinical research, as well as the establishment of qualified centres for the molecular testing of NMD are pushing forward the creation of patient registries and the development of specific clinical trials, with Argentina and Brazil having a major role in this field. Nevertheless, increased awareness and further training of specialized health professionals are necessary to reach patients that are currently lacking care throughout the region.Gene Therapy accepted article preview online, 28 July 2017. doi:10.1038/gt.2017.68.

Assessment of striatal & postural deformities in patients with Parkinson's disease.Publié le 22 07 2017

BACKGROUND & OBJECTIVES: Though striatal and postural deformities are known to occur commonly in atypical Parkinsonism patients, these may also be seen in patients with Parkinson's disease (PD). These are frequently misdiagnosed as joint or orthopaedic pathology leading to unnecessary investigations. This study was conducted to observe the various striatal and postural deformities among patients with PD in India.
METHODS: This study was conducted at a tertiary care teaching institute in north# India. Seventy consecutive patients with PD diagnosed as per the modified UK Brain Bank criteria were included. Various striatal (hand & foot) and postural (antecollis, camptocormia, scoliosis & Pisa syndrome) deformities and their relation with the duration of disease, severity [measured by the Unified Parkinson's Disease Rating Scale (UPDRS)] and levodopa intake were analyzed.
RESULTS: Of the 70 patients with PD, 34 (48.57%) had either striatal or postural deformities. Striatal foot was the most common deformity observed (25.71%). Camptocormia was the second most common deformity (20%). Striatal and postural deformities were seen in more advanced PD as suggested by significantly higher UPDRS and Hoehn and Yahr scale (P<0.001). Striatal deformities were more ipsilateral to PD symptom onset side (agreement 94.44%). Pisa and scoliosis concavity were more on contralateral side to PD symptoms onset side (66.67%).
INTERPRETATION & CONCLUSIONS: Our results showed that striatal and postural deformities were common and present in about half of the patients with PD. These deformities we more common in patients with advanced stage of PD.

The role of experiential knowledge within attitudes towards genetic carrier screening: A comparison of people with and without experience of spinal muscular atrophy.Publié le 14 07 2017

PURPOSE: Autosomal recessive conditions, while individually rare, are a significant health burden with limited treatment options. Population carrier screening has been suggested as a means of tackling them. Little is known, however, about the attitudes of the general public towards such carrier screening and still less about the views of people living with candidate genetic diseases. Here, we focus on the role that such experience has on screening attitudes by comparing views towards screening of people with and without prior experience of the monogenetic disorder, Spinal Muscular Atrophy.
METHODS: An exploratory sequential mixed methods design was adopted. In-depth qualitative interviews were used to develop two surveys. The surveys addressed attitudes towards carrier screening (pre-conceptual and prenatal) for SMA.
PARTICIPANTS: 337 participants with SMA experience completed the SMA Screening Survey (UK) and 336 participants with no prior experience of SMA completed the UK GenPop Survey, an amended version of the SMA Screening Survey (UK).
RESULTS: The majority of both cohorts were in favour of pre-conception and prenatal carrier screening, however people with experience of type II SMA were least likely to support either. Key differences emerged around perceptions of SMA, with those without SMA experience taking a dimmer view of the condition than those with.
CONCLUSION: This study underscores the significance of prior experience with the condition to screening attitudes. It highlights the need for accurate and high-quality educational resources to support any future carrier screening programmes, that particularly in relation to rare genetic disorders like SMA that will fall outside the remit of everyday experience for the majority of the population.

AJRCCM: 100-Year Anniversary. Homeward Bound: A Centenary of Home Mechanical Ventilation.Publié le 14 07 2017

The evolution of home mechanical ventilation is an intertwined chronicle of negative and positive pressure modes and their role in managing ventilatory failure in neuromuscular diseases and other chronic disorders. The uptake of noninvasive positive pressure ventilation has resulted in widespread growth in home ventilation internationally and fewer patients being ventilated invasively. As with many applications of domiciliary medical technology, home ventilatory support has either led or run in parallel with acute hospital applications and has been influenced by medical and societal shifts in the approach to chronic care, the creation of community support teams, a preference of recipients to be treated at home, and economic imperatives. This review summarizes the trends and growing evidence base for ventilatory support outside the hospital.

Antisense rescues babies from killer disease.Publié le 14 07 2017

PMID: 27980162 [PubMed - indexed for MEDLINE]

Medical use of cannabis in Switzerland: analysis of approved exceptional licences.Publié le 12 07 2017

AIMS OF THE STUDY: In recent years, the Swiss Federal Office of Public Health (FOPH) granted exceptional licenses for the medical use of cannabinoids, typically for 6 months with possible extensions. A systematic review of cannabinoids for medical use commissioned by the FOPH supports the use of cannabinoids for the treatment of chronic pain and spasticity. However, little is known about the patients treated with cannabinoids. We aimed to study medical uses of cannabinoids as part of the FOPH's programme of exceptional licenses.
METHODS: We examined all requests for medical use of cannabinoids sent to FOPH in 2013 and 2014. A standardised data sheet was developed to extract data from the files of approved requests. We extracted the duration of the licence, the year it was granted, and the payer of the therapy. At the level of the patient we collected the date of birth, sex, region of residence, diagnosis and the indication. Ethical approval was granted by the Ethics Committee of the Canton of Bern.
RESULTS: We analysed 1193 patients licenced for cannabinoid treatment in 2013 or 2014. During 2013, 542 patients were treated under the exceptional licencing programme (332 requesting physicians) compared with 825 in 2014 (446 physicians). Over half of patients (685; 57%) were women. The mean age was 57 years (standard deviation 15.0), chronic pain (49%) and spasticity (40%) were the most common symptoms, and co-medication was reported for 39% of patients. Seventy-eight different diagnoses were recorded, including multiple sclerosis (257 patients, 22%), soft tissue disorders (119, 10%), dorsalgia (97, 8.1%), spinal muscular atrophy (65, 5.5%) and paraplegia/tetraplegia (62, 5.2%). Licence extensions were granted to 143 patients (26.4%) in 2013 and 324 patients (39.3%) in 2014. There were substantial regional variations of the rates of patients treated with cannabinoids. On average, eight patients per 100 000 residents received an exceptional licence. Most patients (1083, 91%) paid out of pocket.
CONCLUSIONS: Exceptional licences for medical use of cannabinoids have increased substantially in Switzerland, with the programme including patients with a wide range of conditions.

Modifier genes: Moving from pathogenesis to therapy.Publié le 08 07 2017

This commentary will focus on how we can use our knowledge about the complexity of human disease and its pathogenesis to identify novel approaches to therapy. We know that even for single gene Mendelian disorders, patients with identical mutations often have different presentations and outcomes. This lack of genotype-phenotype correlation led us and others to examine the roles of modifier genes in the context of biological networks. These investigations have utilized vertebrate and invertebrate model organisms. Since one of the goals of research on modifier genes and networks is to identify novel therapeutic targets, the challenges to patient access and compliance because of the high costs of medications for rare genetic diseases must be recognized. A recent article explored protective modifiers, including plastin 3 (PLS3) and coronin 1C (CORO1C), in spinal muscular atrophy (SMA). SMA is an autosomal recessive deficit of survival motor neuron protein (SMN) caused by mutations in SMN1. However, the severity of SMA is determined primarily by the number of SMN2 copies, and this results in significant phenotypic variability. PLS3 was upregulated in siblings who were asymptomatic compared with those who had SMA2 or SMA3, but identical homozygous SMN1 deletions and equal numbers of SMN2 copies. CORO1C was identified by interrogation of the PLS3 interactome. Overexpression of these proteins rescued endocytosis in SMA models. In addition, antisense RNA for upregulation of SMN2 protein expression is being developed as another way of modifying the SMA phenotype. These investigations suggest the practical application of protective modifiers to rescue SMA phenotypes. Other examples of the potential therapeutic value of novel protective modifiers will be discussed, including in Duchenne muscular dystrophy and glycerol kinase deficiency. This work shows that while we live in an exciting era of genomic sequencing, a functional understanding of biology, the impact of its disruption, and possibilities for its repair have never been more important as we search for new therapies.

Use of sugammadex in a patient with progressive muscular atrophy and in a patient with amyotrophic lateral sclerosis: Case report.Publié le 07 07 2017

INTRODUCTION: We herein present 2 cases involving the combination of rocuronium and sugammadex in patients with motor neuron disease. The patients were a 54-year-old man with progressive muscular atrophy who underwent removal of internal fixators in the arm and leg, and a 66-year-old woman with amyotrophic lateral sclerosis who underwent skin grafting in the left lower leg. General anesthesia was induced with propofol, rocuronium, and remifentanil and maintained with desflurane and remifentanil. At the end of the surgical procedure, we administered sugammadex. Three or 4 minutes after administration of sugammadex, the patients began to breathe spontaneously and were extubated without complications.
CONCLUSION: Sugammadex can be used successfully to reverse neuromuscular blockade in patients with motor neuron disease.

The Experience of Families With Children With Spinal Muscular Atrophy Type I Across Health Care Systems.Publié le 05 07 2017

Spinal muscular atrophy type I is a genetic disease characterized by degeneration of spinal cord motor neurons resulting in weakness, technology dependence and early demise. While the newly approved treatment nusinersen may alter the morbidity/mortality of this disease there continues to be complex treatment challenges to consider. The aim of this qualitative study was to understand from the parent's perspective, experiences of the family and child in the emergency center, hospital, and clinical care settings to identify gaps in care. Nineteen families interviewed had 22 children with spinal muscular atrophy I (11 deceased, 11 living). Three overarching themes emerged from parent interviews describing a range of experiences surrounding diagnosis, informed medical decision making and acute care practice. Identified quality improvements include development of a diagnostic screening tool, a medical decision tool, and emergency center informational template individualized to the child and providing an overview of spinal muscular atrophy I.

Splicing-Correcting Therapy for SMA.Publié le 01 07 2017

Spinal muscular atrophy (SMA) is caused by deficiency of SMN protein, which is crucial for spliceosome subunits biogenesis. Most SMA patients have SMN1 deletions, leaving SMN2 as sole SMN source; however, a C?T substitution converts an exonic-splicing enhancer (ESE) to a silencer (ESS), causing frequent exon7 skipping in SMN2 pre-mRNA and yielding a truncated protein. Antisense treatment to SMN2 intron7-splicing silencer (ISS) improves SMN expression and motor function. To view this Bench to Bedside, open or download the PDF.

The effects of C5-substituted 2,4-diaminoquinazolines on selected transcript expression in spinal muscular atrophy cells.Publié le 01 07 2017

C5-substituted 2,4-diaminoquinazolines (2,4-DAQs) ameliorate disease severity in SMA mice. It is uncertain, however, that these compounds increase SMN protein levels in vivo even though they were identified as activators of the SMN2 promoter. These compounds also regulate the expression of other transcripts in neuroblastoma cells. In this study, we investigate the mechanism by which the 2,4-DAQs regulate the expression of SMN2 as well as other targets. D156844, D158872, D157161 and D157495 (RG3039) increased SMN2 promoter-driven reporter gene activity by at least 3-fold in NSC-34 cells. These compounds, however, did not significantly increase SMN2 mRNA levels in type II SMA fibroblasts nor in NSC-34 cells, although there was a trend for these compounds increasing SMN protein in SMA fibroblasts. The number of SMN-containing gems was increased in SMA fibroblasts in response to 2,4-DAQ treatment in a dose-dependent manner. ATOH7 mRNA levels were significantly lower in type II SMA fibroblasts. 2,4-DAQs significantly increased ATOH7, DRNT1 and DRTN2 transcript levels in type II SMA fibroblasts and restored ATOH7 levels to those observed in healthy fibroblasts. These compounds also increase Atoh7 mRNA expression in NSC-34 cells. In conclusion, 2,4-DAQs regulate SMN2 by increasing protein levels and gem localization. They also increase ATOH7, DRNT1 and DRNT2 transcript levels. This study reveals that the protective effects of 2,4-DAQs in SMA may be independent of SMN2 gene regulation. These compounds could be used in concert with a proven SMN2 inducer to develop a multi-faceted approach to treating SMA.

Cyclic tetrapeptide HDAC inhibitors as potential therapeutics for spinal muscular atrophy: Screening with iPSC-derived neuronal cells.Publié le 27 06 2017

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that is caused by inactivating mutations in the Survival of motor neuron 1 (SMN1) gene, resulting in decreased SMN protein expression. Humans possess a paralog gene, SMN2, which contains a splicing defect in exon 7 leading to diminished expression of full-length, fully functional SMN protein. Increasing SMN2 expression has been a focus of therapeutic development for SMA. Multiple studies have reported the efficacy of histone deacetylase inhibitors (HDACi) in this regard. However, clinical trials involving HDACi have been unsatisfactory, possibly because previous efforts to identify HDACi to treat SMA have employed non-neuronal cells as the screening platform. To address this issue, we generated an SMA-patient specific, induced pluripotent stem cell (iPSC) derived neuronal cell line that contains homogenous Tuj1+neurons. We screened a small library of cyclic tetrapeptide HDACi using this SMA neuronal platform and discovered compounds that elevate SMN2 expression by an impressive twofold or higher. These candidates are also capable of forming gems intranuclearly in SMA neurons, demonstrating biological activity. Our study identifies new potential HDACi therapeutics for SMA screened using a disease-relevant SMA neuronal cellular model.

Counting the cost of spinal muscular atrophy.Publié le 27 06 2017

PMID: 27310871 [PubMed - indexed for MEDLINE]

The economic burden of spinal muscular atrophy.Publié le 27 06 2017

AIM: To evaluate the economic burden of spinal muscular atrophy (SMA).
MATERIALS AND METHODS: This study used Department of Defense Military Healthcare System (MHS) data from 2003-2012. Healthcare costs were determined for patients with at least one inpatient or three outpatient claims with a diagnosis of SMA before 18 years of age and who had ? 6 months of data after first SMA diagnosis or expired within 6 months of initial diagnosis. A comparator cohort was selected using a 3:1 match based on age and gender.
RESULTS: A total of 239 individuals with SMA diagnosis met the inclusion criteria along with 717 matched comparator patients. More patients with SMA had hospitalizations (69.5%) compared to the comparator cohort (17.2%, p?<?0.001). Median total expenditures across all years of data for patients with SMA were $83 652 (25-75th percentile = $29 620-228 754) vs the comparator group of $4329 (25-75(th) percentile = $1229-10 062 (p?<?0.001)) over an average (SD) of 6.9?±?3.6 years. The annualized mean costs of total healthcare expenditures were significantly higher for the SMA cases than the comparison cohort, $47 862?±?88 607 compared to $1861?±?6374, respectively (p?<?0.001). The sub-group of patients with early diagnosis (n?=?45) had 4.3?±?2.9 years of observation with a median cost of $167 921 ($53 349-678 412). Mean age (SD) at first observed SMA diagnosis was 7.5?±?6.4 years. Mean (SD) duration of follow-up after initial SMA diagnosis was 4.8?±?3.3 years, with a median post-diagnosis cost of $60 213 ($18 229-192 559). The major costs for all patients were outpatient visits [median = $53 152 ($23 902-136 150)], followed by inpatient costs [median = $11 258 ($0-51 987)] and total prescription costs [median = $3167 ($943-13 283)].
LIMITATIONS: The analysis is limited to the data available and may under-estimate the total cost of SMA.
CONCLUSIONS: Individuals with SMA have a high degree of morbidity, particularly those diagnosed during infancy. SMA patients have significant medical expenditures and high utilization of healthcare services.

Gene therapy for spinomuscular atrophy: a biomedical advance, a missed opportunity for more equitable drug pricing.Publié le 25 06 2017

An experimental approach for gene therapy of spinomuscular atrophy has been reported to prevent development of the neuromuscular features of this lethal and previously untreatable disorder. The approach involves treatment of patients suffering from SMN1-associated infantile form of the disease with a splice-switching antisense oligonucleotide (ASO) that corrects aberrant splicing of the nearly identical SMN2 gene to allow the generation of functional SMN protein, thereby mitigating the development of the disease. This technique represents the first apparently effective therapy for spinal muscular atrophy (SMA) and an important documentation for ASO technology for therapy of neurodegenerative disease. These results with one form of SMA are likely to be relevant for similar applications to other SMA types and are likely to inspire application to a number of other intractable neurodegenerative diseases such as Huntington's disease, amyotrophic lateral sclerosis and possibly even the extremely common Parkinson's and Alzheimer's diseases and others. Nevertheless, the scientific and medical importance of this advance is marred by a pricing policy by the corporate sponsors that may complicate accessibility of the drug for some desperate patients.Gene Therapy advance online publication, 22 June 2017; doi:10.1038/gt.2017.48.

The clinical landscape for SMA in a new therapeutic era.Publié le 25 06 2017

Despite significant advances in basic research, the treatment of degenerative diseases of the nervous system remains one of the greatest challenges for translational medicine. The childhood onset motor neuron disorder spinal muscular atrophy (SMA) has been viewed as one of the more tractable targets for molecular therapy, due to a detailed understanding of the molecular genetic basis of the disease. In SMA, inactivating mutations in the SMN1 gene can be partially compensated for by limited expression of SMN protein from a variable number of copies of the SMN2 gene, which provides both a molecular explanation for phenotypic severity and a target for therapy. The advent of the first tailored molecular therapy for SMA, based on modulating the splicing behaviour of the SMN2 gene, provides for the first time a treatment which alters the natural history of motor neuron degeneration. Here we consider how this will change the landscape for diagnosis, clinical management and future therapeutic trials in SMA, as well as the implications for the molecular therapy of other neurological diseases.Spinal muscular atrophy is a genetic neuromuscular disorder, in which the mainstay of management is physiotherapy, respiratory care and nutritional support, measures which do not affect the underlying biological progression of the disease. The treatment of SMA has now fundamentally changed with the demonstration that nusinersen (Spinraza™), a drug which alters the way in which RNA is processed, can increase the amount of SMN, the protein that is missing from children with SMA. This prevents nerve-muscle connections degenerating and is effective in limiting the severity of the disease, allowing young children to reach developmental milestones which are never normally achieved in SMA. This is a major landmark in the treatment of neurological disease, but only the beginning of the path to making SMA definitively treatable. A number of problems must be solved, including how to deliver the drug efficiently into the brain and spinal cord without the need for a lumbar puncture. There is uncertainty as to whether nusinersen will work for older children and adults with SMA. Despite these unresolved issues the advent of the first effective treatment for SMA ushers in a new era of therapy for this devastating disease and offers hope for the treatment of other neurodegenerative and neuromuscular disorders.Gene Therapy accepted article preview online, 23 June 2017. doi:10.1038/gt.2017.52.

Inherited Paediatric Motor Neuron Disorders: Beyond Spinal Muscular Atrophy.Publié le 22 06 2017

Paediatric motor neuron diseases encompass a group of neurodegenerative diseases characterised by the onset of muscle weakness and atrophy before the age of 18 years, attributable to motor neuron loss across various neuronal networks in the brain and spinal cord. While the genetic underpinnings are diverse, advances in next generation sequencing have transformed diagnostic paradigms. This has reinforced the clinical phenotyping and molecular genetic expertise required to navigate the complexities of such diagnoses. In turn, improved genetic technology and subsequent gene identification have enabled further insights into the mechanisms of motor neuron degeneration and how these diseases form part of a neurodegenerative disorder spectrum. Common pathophysiologies include abnormalities in axonal architecture and function, RNA processing, and protein quality control. This review incorporates an overview of the clinical manifestations, genetics, and pathophysiology of inherited paediatric motor neuron disorders beyond classic SMN1-related spinal muscular atrophy and describes recent advances in next generation sequencing and its clinical application. Specific disease-modifying treatment is becoming a clinical reality in some disorders of the motor neuron highlighting the importance of a timely and specific diagnosis.

Efficient SMN Rescue following Subcutaneous Tricyclo-DNA Antisense Oligonucleotide Treatment.Publié le 19 06 2017

Spinal muscular atrophy (SMA) is a recessive disease caused by mutations in the SMN1 gene, which encodes the protein survival motor neuron (SMN), whose absence dramatically affects the survival of motor neurons. In humans, the severity of the disease is lessened by the presence of a gene copy, SMN2. SMN2 differs from SMN1 by a C-to-T transition in exon 7, which modifies pre-mRNA splicing and prevents successful SMN synthesis. Splice-switching approaches using antisense oligonucleotides (AONs) have already been shown to correct this SMN2 gene transition, providing a therapeutic avenue for SMA. However, AON administration to the CNS presents additional hurdles. In this study, we show that systemic delivery of tricyclo-DNA (tcDNA) AONs in a type III SMA mouse augments retention of exon 7 in SMN2 mRNA both in peripheral organs and the CNS. Mild type III SMA mice were selected as opposed to the severe type I model in order to test tcDNA efficacy and their ability to enter the CNS after maturation of the blood brain barrier (BBB). Furthermore, subcutaneous treatment significantly improved the necrosis phenotype and respiratory function. In summary, our data support that tcDNA oligomers effectively cross the blood-brain barrier and offer a promising systemic alternative for treating SMA.

LNA/DNA mixmer-based antisense oligonucleotides correct alternative splicing of the SMN2 gene and restore SMN protein expression in type 1 SMA fibroblasts.Publié le 18 06 2017

Spinal muscular atrophy (SMA) is an autosomal recessive disorder affecting motor neurons, and is currently the most frequent genetic cause of infant mortality. SMA is caused by a loss-of-function mutation in the survival motor neuron 1 (SMN1) gene. SMN2 is an SMN1 paralogue, but cannot compensate for the loss of SMN1 since exon 7 in SMN2 mRNA is excluded (spliced out) due to a single C-to-T nucleotide transition in the exon 7. One of the most promising strategies to treat SMA is antisense oligonucleotide (AON)-mediated therapy. AONs are utilized to block intronic splicing silencer number 1 (ISS-N1) on intron 7 of SMN2, which causes exon 7 inclusion of the mRNA and the recovery of the expression of functional SMN protein from the endogenous SMN2 gene. We developed novel locked nucleic acid (LNA)-based antisense oligonucleotides (LNA/DNA mixmers), which efficiently induce exon 7 inclusion in SMN2 and restore the SMN protein production in SMA patient fibroblasts. The mixmers are highly specific to the targeted sequence, and showed significantly higher efficacy than an all-LNA oligonucleotide with the equivalent sequence. These data suggest that use of LNA/DNA mixmer-based AONs may be an attractive therapeutic strategy to treat SMA.

Rescue of a Mouse Model of Spinal Muscular Atrophy With Respiratory Distress Type 1 by AAV9-IGHMBP2 Is Dose Dependent.Publié le 18 06 2017

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an autosomal recessive disease occurring during childhood. The gene responsible for disease development is a ubiquitously expressed protein, IGHMBP2. Mutations in IGHMBP2 result in the loss of ?-motor neurons leading to muscle atrophy in the distal limbs accompanied by respiratory complications. Although genetically and clinically distinct, proximal SMA is also caused by the loss of a ubiquitously expressed gene (SMN). Significant preclinical success has been achieved in proximal SMA using viral-based gene replacement strategies. We leveraged the technologies employed in SMA to demonstrate gene replacement efficacy in an SMARD1 animal model. Intracerebroventricular (ICV) injection of single-stranded AAV9 expressing the full-length cDNA of IGHMBP2 in a low dose led to a significant level of rescue in treated SMARD1 animals. Consistent with drastically increased survival, weight gain, and strength, the rescued animals demonstrated a significant improvement in muscle, NMJ, motor neurons, and axonal pathology. In addition, increased levels of IGHMBP2 in lumbar motor neurons verified the efficacy of the virus to transduce the target tissues. Our results indicate that AAV9-based gene replacement is a viable strategy for SMARD1, although dosing effects and potential negative impacts of high dose and ICV injection should be thoroughly investigated.

MiR-298 Counteracts Mutant Androgen Receptor Toxicity in Spinal and Bulbar Muscular Atrophy.Publié le 18 06 2017

Spinal and bulbar muscular atrophy (SBMA) is a currently untreatable adult-onset neuromuscular disease caused by expansion of a polyglutamine repeat in the androgen receptor (AR). In SBMA, as in other polyglutamine diseases, a toxic gain of function in the mutant protein is an important factor in the disease mechanism; therefore, reducing the mutant protein holds promise as an effective treatment strategy. In this work, we evaluated a microRNA (miRNA) to reduce AR expression. From a list of predicted miRNAs that target human AR, we selected microRNA-298 (miR-298) for its ability to downregulate AR mRNA and protein levels when transfected in cells overexpressing wild-type and mutant AR and in SBMA patient-derived fibroblasts. We showed that miR-298 directly binds to the 3'-untranslated region of the human AR transcript, and counteracts AR toxicity in vitro. Intravenous delivery of miR-298 with adeno-associated virus serotype 9 vector resulted in efficient transduction of muscle and spinal cord and amelioration of the disease phenotype in SBMA mice. Our findings support the development of miRNAs as a therapeutic strategy for SBMA and other neurodegenerative disorders caused by toxic proteins.

Bovine spastic paresis: A review of the genetic background and perspectives for the future.Publié le 16 06 2017

Bovine spastic paresis (BSP) is a sporadic, progressive neuromuscular disease that is thought to affect all breeds of cattle. The disease manifests as a unilateral or bilateral hyperextension of the hind limb due to increased muscle tone or permanent spasm of mainly the gastrocnemius and/or the quadriceps muscle. Clinical signs only appear in rising, standing and moving animals, which is an important diagnostic feature. Although several medical treatments have been described, surgical procedures such as neurectomy or tenectomy are generally indicated. Even though complete recovery can be achieved, BSP-affected animals should not be used for breeding, since BSP is commonly considered a hereditary disease. The condition therefore negatively affects animal welfare, economics and breeding. When first described in 1922, BSP was already assumed to be heritable, and this assumption has been perpetuated by subsequent authors who have only discussed its possible modes of inheritance, which included monogenetic and polygenetic modes and gene-environment interactions. Besides some clinical aspects and the consideration of the tarsal joint angle as a BSP-correlated trait, this review mainly focuses on the assumed genetic aspects of BSP. Evaluation of the published literature demonstrates that to date, irrevocable proof for the assumed heritability of BSP is still missing. The assumption of heredity is further contradicted by known allele frequencies and incidences of proven hereditary diseases in cattle, such as arachnomelia or bovine spinal muscular atrophy. Consequently, future research is needed to determine the cause of spastic paresis. Procedures that will help test the null-hypothesis ('BSP is not hereditary') and possible modes of inheritance are discussed in this review.

Splice-Switching Therapy for Spinal Muscular Atrophy.Publié le 13 06 2017

Spinal muscular atrophy (SMA) is a genetic disorder with severity ranging from premature death in infants to restricted motor function in adult life. Despite the genetic cause of this disease being known for over twenty years, only recently has a therapy been approved to treat the most severe form of this disease. Here we discuss the genetic basis of SMA and the subsequent studies that led to the utilization of splice switching oligonucleotides to enhance production of SMN protein, which is absent in patients, through a mechanism of exon inclusion into the mature mRNA. Whilst approval of oligonucleotide-based therapies for SMA should be celebrated, we also discuss some of the limitations of this approach and alternate genetic strategies that are currently underway in clinical trials.

Relationships between long-term observations of motor milestones and genotype analysis results in childhood-onset Japanese spinal muscular atrophy patients.Publié le 12 06 2017

AIM: To clarify the long-term natural history of SMA in Japanese patients by investigating the peak motor milestones of cases 7months through 57years of age, in efforts to contribute to evaluating outcomes of new therapeutic interventions.
METHODS: We sub-classified 112 SMA type I-III cases into type Ia, type Ib, type IIa, type IIb, type IIIa and type IIIb, according to peak motor milestone achieved, and analyzed the SMN1, SMN2 and NAIP genes in relation to clinical subtypes.
RESULTS: In type I cases, there was a significant difference (p<0.0001), depending on whether or not head control was obtained, in the time of ventilation support being required. In type II cases as well, the time at which the ability to maintain the sitting position independently was lost also differed significantly (p<0.01) between those acquiring the ability to sit unaided within eight months after birth and those acquiring this ability after eight months of age. In type III cases, being able versus unable to climb stairs was associated with a significant difference (p=0.02) in the median time until loss of walking independently. Positive correlations were also seen between copy numbers and the clinical severity of SMA.
CONCLUSION: Our long-term results show peak motor milestone evaluations distinguishing between subtypes to be useful not only as outcome measures for assessing treatment efficacy in clinical trials but also for predicting the clinical courses of Japanese SMA patients.

Parents' Experiences and Wishes at End of Life in Children with Spinal Muscular Atrophy Types I and II.Publié le 10 06 2017

OBJECTIVE: To explore experiences and wishes of bereaved parents concerning end-of-life care for their child with severe spinal muscular atrophy.
STUDY DESIGN: A follow-up survey was conducted in 2013 on parents of deceased Swedish children who were born between 2000 and 2010 and later diagnosed with spinal muscular atrophy type I or II (n = 48). The questions used in this study covered location of death (LoD), support from health care staff, and parents' wishes and concerns about their child's end-of-life care.
RESULTS: One-half of those who had wishes about LoD (16/32) wanted their child to die at home, rather than at the hospital. All of those who wanted the child to die at the hospital had their wishes fulfilled. Among those who wanted the child to die at home, 10 of 16 got their wish. Among parents who talked with a physician about how they wanted their child to pass away (n = 26), all but 2 had their wishes fulfilled. Thirty-six parents (75%) reported that their child had siblings: 12 reported that the sibling was too young for professional psychological support, and only 4 of the remaining 24 siblings received such support after the death of their brother or sister.
CONCLUSIONS: Parents' communication with the physician about their wishes and concerns regarding their child's end-of-life care and preferred LoD contributed to their wishes being fulfilled. The wish of hospital death was fulfilled more often than the wish of home deaths. A vast majority of siblings did not receive psychological support after death of their brother or sister.

Analysis of Azithromycin Monohydrate as a Single or a Combinatorial Therapy in a Mouse Model of Severe Spinal Muscular Atrophy.Publié le 10 06 2017

BACKGROUND: Spinal muscular atrophy (SMA) is a neurodegenerative autosomal recessive disorder characterized by the loss of ?-motor neurons. A variety of molecular pathways are being investigated to elevate SMN protein expression in SMA models and in the clinic. One of these approaches involves stabilizing the SMN?7 protein by inducing translational read-through. Previous studies have demonstrated that functionality and stability are partially restored to the otherwise unstable SMN?7 by the addition of non-specific C-terminal peptide sequences, or by inducing a similar molecular event through the use of read-through inducing compounds such as aminoglycosides.
OBJECTIVE: The objective was to determine the efficacy of the macrolide Azithromycin (AZM), an FDA approved read-through-inducing compound, in the well-established severe mouse model of SMA.
METHODS: Initially, dosing regimen following ICV administrations of AZM at different post-natal days and concentrations was determined by their impact on SMN levels in disease-relevant tissues. Selected dose was then tested for phenotypic parameters changes as compared to the appropriate controls and in conjugation to another therapy.
RESULTS: AZM increases SMN protein in disease relevant tissues, however, this did not translate into similar improvements in the SMA phenotype in a severe mouse model of SMA. Co-administration of AZM and a previously developed antisense oligonucleotide that increases SMN2 splicing, resulted in an improvement in the SMA phenotype beyond either AZM or ASO alone, including a highly significant extension in survival with improvement in body weight and movement.
CONCLUSIONS: It is important to explore various approaches for SMA therapeutics, hence compounds that specifically induce SMN?7 read-through, without having prohibitive toxicity, may provide an alternative platform for a combinatorial treatment. Here we established that AZM activity at a low dose can increase SMN protein in disease-relevant animal model and can impact disease severity.

Cellular uptake and trafficking of antisense oligonucleotides.Publié le 07 06 2017

Antisense oligonucleotides (ASOs) modified with phosphorothioate (PS) linkages and different 2' modifications can be used either as drugs (e.g., to treat homozygous familial hypercholesterolemia and spinal muscular atrophy) or as research tools to alter gene expression. PS-ASOs can enter cells without additional modification or formulation and can be designed to mediate sequence-specific cleavage of different types of RNA (including mRNA and non-coding RNA) targeted by endogenous RNase H1. Although PS-ASOs function in both the cytoplasm and nucleus, localization to different subcellular regions can affect their therapeutic potency. Cellular uptake and intracellular distribution of PS ASOs are mediated by protein interactions. The main proteins involved in these processes have been identified, and intracellular sites in which PS ASOs are active, or inactive, cataloged.

Diagnosis and New Treatment Avenues in Spinal Muscular Atrophy.Publié le 03 06 2017

PMID: 28571100 [PubMed - as supplied by publisher]

Respiratory involvement in neuromuscular disorders.Publié le 02 06 2017

PURPOSE OF REVIEW: In numerous neuromuscular disorders (NMDs), respiratory muscle weakness is present, and acute or chronic respiratory failure may evolve. Very often, respiratory involvement substantially adds to the burden of disease, impairs quality of life, or reduces life expectancy. This article summarizes new aspects of both diagnosis and management of respiratory muscle weakness in patients with NMDs.
RECENT FINDINGS: Drugs like deflazacort, ataluren, eteplirsen, and nusinersen are now approved treatments for Duchenne Muscular Dystrophy and Spinal Muscular Atrophy, and others are on their way in NMDs. Although observing how innovative drugs will change the natural history of these diseases, including respiratory function over time, adequate symptomatic treatment remains meaningful and is strongly recommended. Physicians should systematically take respiratory involvement into account to improve patients' quality of life and prognosis.
SUMMARY: First, it is outlined in which subtypes of NMD respiratory muscle dysfunction is particularly relevant. Second, new developments regarding diagnostic procedures, including respiratory muscle strength testing, spirometry, and sleep studies, are covered. Third, this article gives an overview on current concepts of ventilatory support and management of secretions in patients with NMD.

The SMA Trust: the role of a disease-focused research charity in developing treatments for SMA.Publié le 02 06 2017

SMA is a rare hereditary neuromuscular disease that causes weakness and muscle wasting as a result of the loss of spinal motor neurons. In its most severe form, SMA is the commonest genetic cause of death in infants, and children with less severe forms of SMA face the prospect of lifelong disability from progressive muscle wasting, loss of mobility and limb weakness. The initial discovery of the defective gene has been followed by major advances in our understanding of the genetic, cellular and molecular basis of SMA, providing the foundation for a range of approaches to treatment including gene therapy, antisense oligonucleotide treatments and more traditional drug-based approaches to slow or halt disease progression. The approval by the U.S. Food and Drug Administration (FDA) of Spinraza™ (nusinersen), the first targeted treatment for spinal muscular atrophy (SMA), is a historic moment. Disease-focused research charities, such as The SMA Trust (UK), continue to have a crucial role in promoting the development of additional treatments for SMA, both by funding translational research and by promoting links between researchers, people living with SMA and other stakeholders including pharmaceutical companies and healthcare providers.Gene Therapy accepted article preview online, 31 May 2017. doi:10.1038/gt.2017.47.

Therapeutic approaches for spinal muscular atrophy (SMA).Publié le 02 06 2017

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disorder characterized by progressive muscle wasting and loss of muscle function due to severe motor neuron dysfunction, secondary to mutations in the survival motor neuron 1 (SMN1) gene. A second neighboring centromeric gene, SMN2, is intact in all patients but contains a C-to-T variation in exon 7 that affects a splice enhancer and determines exclusion of exon 7 in the majority of its transcript, leading to an unstable protein that cannot substitute for mutant SMN1. Following successful studies on disease models and intensive studies on SMN functions in the past decade, SMN upregulation targeting SMN2, has been suggested as a possible therapeutic approach. Recently we have witnessed an historical turning point with the first disease-modifying treatment receiving Food and Drug Administration (FDA) approval and now being available to patients also outside the clinical trial. This innovative treatment is an antisense oligonucleotide (ASOs) which, administered intrathecally, is able to increase exon 7 inclusion in the majority of the SMN2 mRNA, and increase the production of fully functional SMN protein. Alternative advanced therapies, such as viral vector mediated gene therapy and orally available small molecules are also showing promising results in early clinical trial phases.Gene Therapy accepted article preview online, 31 May 2017. doi:10.1038/gt.2017.45.

Developmental regulation of SMN expression: pathophysiological implications and perspectives for therapy development in spinal muscular atrophy.Publié le 31 05 2017

Spinal muscular atrophy (SMA), the predominant form of motoneuron diease in children and young adults is caused by loss of function of the SMN protein. On the basis of a disrupted splice acceptor site in exon 7, transcripts from a second SMN gene in humans called SMN2 cannot give rise to SMN protein at sufficient levels for maintaining function of motoneurons and motor circuits. First clinical trials with Spinraza/Nusinersen, a drug that counteracts disrupted splicing of SMN2 transcripts, have shown that elevating SMN levels can successfully interfere with motoneuron dysfunction. This review summarizes current knowledge about the pathophysiological alterations in Smn deficient motoneurons which lead to defective neuromuscular transmission and altered spinal circuit formation. Both pathological mechanisms are important targets for therapeutic intervention. However, the developmental time window when therapeutic interventions ideally should start is not known. Endogenous SMN expression both from SMN1 and SMN2 genes is high at early developmental stages and declines progressively in humans and mice. Thus, therapeutic SMN up-regulation should start just before SMN declines below a critical threshold, and before irreversible defects occur at neuromuscular junctions and in spinal circuits. Previous results indicate that loss of Smn function leads to synaptic dysfunction during a stage of neuromuscular development when synaptic strength determines which synapses are maintained or not. This time window appears as an important target for therapy, which possibly could be supported by additional strategies which strengthen synaptic transmission.Gene Therapy accepted article preview online, 30 May 2017. doi:10.1038/gt.2017.46.

Utility of repetitive nerve stimulation test for ALS diagnosis.Publié le 31 05 2017

OBJECTIVE: Decremental responses in the repetitive nerve stimulation (RNS) test in amyotrophic lateral sclerosis (ALS) patients have been reported, although their possible diagnostic role has received little investigation. We investigated their diagnostic role in differentiation between ALS and cervical spondylotic amyotrophy (CSA), an important ALS mimic especially in Japan.
METHODS: Patients were prospectively enrolled and the diagnosis was confirmed by follow-up. RNS was performed on the abductor pollicis brevis (APB), upper trapezius (trapezius) and deltoid muscles.
RESULTS: Enrolled subjects consisted of 53 ALS and 37 CSA patients. Abnormal decremental responses (>5%) were observed in 32%, 51% and 75% of ALS patients and 3%, 0% and 20% of CSA patients for the APB, trapezius and deltoid muscles, respectively. The sensitivity for 23 ALS patients with upper-limb onset was 78% for the trapezius and 100% for the deltoid muscles.
CONCLUSIONS: An abnormal decremental response in the trapezius muscle was 100% specific to ALS in comparison with CSA: abnormal decrement in this muscle would strongly suggest ALS. No decrement in the deltoid muscle might exclude ALS in patients having symptoms with upper-limb onset.
SIGNIFICANCE: RNS is useful in differentiation between ALS and CSA.

Genome Editing of Monogenic Neuromuscular Diseases: A Systematic Review.Publié le 30 05 2017

Importance: Muscle weakness, the most common symptom of neuromuscular disease, may result from muscle dysfunction or may be caused indirectly by neuronal and neuromuscular junction abnormalities. To date, more than 780 monogenic neuromuscular diseases, linked to 417 different genes, have been identified in humans. Genome-editing methods, especially the CRISPR (clustered regularly interspaced short palindromic repeats)-Cas9 (CRISPR-associated protein 9) system, hold clinical potential for curing many monogenic disorders, including neuromuscular diseases such as Duchenne muscular dystrophy, spinal muscular atrophy, amyotrophic lateral sclerosis, and myotonic dystrophy type 1.
Objectives: To provide an overview of genome-editing approaches; to summarize published reports on the feasibility, efficacy, and safety of current genome-editing methods as they relate to the potential correction of monogenic neuromuscular diseases; and to highlight scientific and clinical opportunities and obstacles toward permanent correction of disease-causing mutations responsible for monogenic neuromuscular diseases by genome editing.
Evidence Review: PubMed and Google Scholar were searched for articles published from June 30, 1989, through June 9, 2016, using the following keywords: genome editing, CRISPR-Cas9, neuromuscular disease, Duchenne muscular dystrophy, spinal muscular atrophy, amyotrophic lateral sclerosis, and myotonic dystrophy type 1. The following sources were reviewed: 341 articles describing different approaches to edit mammalian genomes; 330 articles describing CRISPR-Cas9-mediated genome editing in cell culture lines (in vitro) and animal models (in vivo); 16 websites used to generate single-guide RNA; 4 websites for off-target effects; and 382 articles describing viral and nonviral delivery systems. Articles describing neuromuscular diseases, including Duchenne muscular dystrophy, spinal muscular atrophy, amyotrophic lateral sclerosis, and myotonic dystrophy type 1, were also reviewed.
Findings: Multiple proof-of-concept studies reveal the feasibility and efficacy of genome-editing-meditated correction of monogenic neuromuscular diseases in cultured cells and animal models.
Conclusions and Relevance: Genome editing is a rapidly evolving technology with enormous translational potential once efficacy, delivery, and safety issues are addressed. The clinical impact of this technology is that genome editing can permanently correct disease-causing mutations and circumvent the hurdles of traditional gene- and cell-based therapies.

Subtly modulating Glycogen Synthase Kinase 3 ?: allosteric inhibitors development and their potential for the treatment of chronic diseases.Publié le 28 05 2017

Glycogen synthase kinase 3 ? (GSK-3?) is a central target in several unmet diseases. To increase the specificity of GSK-3? inhibitors in chronic treatments we are developing small molecules allowing subtle modulation of GSK-3? activity. Design synthesis, structure-activity relationships and binding mode of quinoline-3-carbohydrazide derivatives as allosteric modulators of GSK-3? are here presented. Furthermore, we show how allosteric binders may overcome the ?-catenin side effects associated to strong GSK-3? inhibition. The therapeutic potential of some of these modulators has been tested in human samples from patients with congenital myotonic dystrophy type 1 (CDM1) and spinal muscular atrophy (SMA) patients. We found that compound 53 improves delayed myogenesis in CDM1 myoblasts, while compounds 34 and 53 have neuroprotective properties in SMA-derived cells. These findings suggest that the allosteric modulators of GSK-3? may be used for future development of drugs for DM1, SMA and other chronic diseases where GSK-3? inhibition exhibits therapeutic effects.

Subthalamic nucleus stimulation improves Parkinson's disease-associated camptocormia in parallel to its preoperative levodopa responsiveness.Publié le 28 05 2017

OBJECTIVE: The aim of this work was to identify factors predictive of postoperative improvement of camptocormia in patients with Parkinson's disease (PD) treated by subthalamic nucleus (STN) stimulation.
BACKGROUND: Camptocormia, one of the most disabling features of PD, often responds poorly to medical therapies. The reported effects of deep brain stimulation on PD-associated camptocormia vary, and preoperative characteristics affecting the surgical outcome remain unclear.
METHODS: We evaluated 17 patients with camptocormia whose preoperative off-medication thoracolumbar angle exceeded 45°. We used photographs to measure their thoracolumbar angle preoperatively, 3?months after surgery, and at the last follow-up (mean 36.5?months postoperatively) in status on-medication and off-medication. The patient age, duration of PD and camptocormia, daily medications, Unified Parkinson's Disease Rating Scale (UPDRS) subscores and the Schwab-England activity of daily living scale (S-E) were also recorded. Univariate analysis was performed to identify factors predictive of the postoperative improvement of camptocormia.
RESULTS: STN stimulation significantly improved the UPDRS subscores and S-E, and resulted in a reduction of daily medications 3?months post-treatment. The preoperative thoracolumbar angle (mean±SD) in status off-medication (84.0±29.5°) was significantly ameliorated 3?months postoperatively (49.8±29.3°) and at the last follow-up (54.8±28.3°). There was no correlation between the postoperative camptocormia improvement rate and preoperative parameters other than the duration and severity of camptocormia and the levodopa responsiveness of the thoracolumbar angle. Symptom duration negatively affected levodopa responsiveness.
CONCLUSIONS: STN stimulation improves PD-associated camptocormia in parallel with preoperative levodopa responsiveness. Long symptom duration interferes with levodopa responsiveness.

[Possible treatments for infantile spinal atrophy].Publié le 20 05 2017

The new treatments of spinal muscular atrophy (SMA) due by SMN1 gene deletions are reviewed. There are several ways to increase the protein SMN, its activity and persistence in the tissues. Neuroprotective drugs as olesoxime or riluzole, and drugs acting by epigenetic mechanisms, as histone deacetylase inhibitors, have shown positive effects in preclinical studies but no clear efficacy in clinical trials. They might give in the future added benefits when used associated to other genetic modifying drugs. The best improvements in murine models of SMA and in clinical trials have been reached with antisense oligonucleotides, drugs that modify the splicing of SMN2, and they are expected to get better in the near future. Nusinersen, a methoxi-ethyl phosphotioate antisense oligonucleotide has recently approved for treatment of patients with SMA type 1 after having proved its efficacy in clinical trial phase 3. The results of nusinersen are reviewed. New modifications of antisense oligonucleotides with better access to brain, spinal cord and peripheral tissues are on the way. There are data of the efficacy of the genetic therapy with SMN1 gene through adenoassociated virus, now in phase 1 trial. A constant feature of these new treatments is that the earlier the treatment, the best are the results, and they are even better in presymptomatic stage. The general standards of care, particularly nutrition and respiratory management are needed in order to reach optimal results with the new therapies.

Cure SMA and our patient community celebrate the first approved drug for SMA.Publié le 17 05 2017

Cure SMA is dedicated to the treatment and cure of spinal muscular atrophy (SMA), the number one genetic cause of death for infants. We fund groundbreaking research and provide families the support they need for today. Today, we have more than 115 000 members and supporters, with 35 volunteer chapters throughout the United States. In the last year, Cure SMA provided direct services to several thousand families. Since 1984, we've led and invested in the research that has made today's breakthroughs possible. With deep connections and expertise in both the patient and research communities, we have been uniquely positioned to direct funds to where they can make the greatest difference as quickly as possible. With the size of our community and the strength of our connections, our goal is to direct research on a comprehensive level with efficiency.Gene Therapy accepted article preview online, 15 May 2017. doi:10.1038/gt.2017.39.

Defective Ribonucleoproteins, Mistakes in RNA Processing, and Diseases.Publié le 17 05 2017

Ribonucleoproteins (RNPs) are vital to many cellular events. To this end, many neurodegenerative diseases and cancers have been linked to RNP malfunction, particularly as this relates to defective processing of cellular RNA. The connection of RNPs and diseases has also propagated a shift of focus onto RNA targeting from traditional protein targeting treatments. However, therapeutic development in this area has been limited by incomplete molecular insight into the specific contributions of RNPs to disease. This review outlines the role of several RNPs in diseases, focusing on molecular defects in processes that affect proper RNA handling in the cell. This work also evaluates the contributions of recently developed methods to understanding RNP association and function. We review progress in this area by focusing on molecular malfunctions of RNPs associated with the onset and progression of several neurodegenerative diseases and cancer and conclude with a brief discussion of RNA-based therapeutic efforts.

Longitudinal characterization of biomarkers for spinal muscular atrophy.Publié le 12 05 2017

OBJECTIVE: Recent advances in understanding Spinal Muscular Atrophy (SMA) etiopathogenesis prompted development of potent intervention strategies and raised need for sensitive outcome measures capable of assessing disease progression and response to treatment. Several biomarkers have been proposed; nevertheless, no general consensus has been reached on the most feasible ones. We observed a wide range of measures over 1 year to assess their ability to monitor the disease status and progression.
METHODS: 18 SMA patients and 19 healthy volunteers (HV) were followed in this 52-weeks observational study. Quantitative-MRI (qMRI) of both thighs and clinical evaluation of motor function was performed at baseline, 6, 9 and 12 months follow-up. Blood samples were taken in patients for molecular characterization at screening, 9 and 12 month follow-up. Progression, responsiveness and reliability of collected indices were quantified. Correlation analysis was performed to test for potential associations.
RESULTS: QMRI indices, clinical scales and molecular measures showed high to excellent reliability. Significant differences were found between qMRI of SMA patients and HV. Significant associations were revealed between multiple qMRI measures and functional clinical scales. None of the qMRI, clinical, or molecular measures was able to detect significant disease progression over 1 year.
INTERPRETATION: We probed a variety of quantitative measures for SMA in a slowly-progressing disease population over 1 year. The presented measures demonstrated potential to provide a closer link to underlying disease biology as compared to conventional functional scales. The proposed biomarker framework can guide implementation of more sensitive endpoints in future clinical trials and prove their utility in search for novel disease-modifying therapies.

How the discovery of ISS-N1 led to the first medical therapy for spinal muscular atrophy.Publié le 10 05 2017

Spinal muscular atrophy (SMA), a prominent genetic disease of infant mortality, is caused by low levels of survival motor neuron (SMN) protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1 present in humans, cannot compensate for the loss of SMN1 due to predominant skipping of exon 7 during pre-mRNA splicing. With the recent FDA approval of nusinersen (Spinraza™), the potential for correction of SMN2 exon 7 splicing as a SMA therapy has been affirmed. Nusinersen is an antisense oligonucleotide that targets intronic splicing silencer N1 (ISS-N1) discovered in 2004 at the University of Massachusetts Medical School. ISS-N1 has emerged as the model target for testing the therapeutic efficacy of antisense oligonucleotides using different chemistries as well as different mouse models of SMA. Here we provide a historical account of events that led to the discovery of ISS-N1 and describe the impact of independent validations that raised the profile of ISS-N1 as one of the most potent antisense targets for the treatment of a genetic disease. Recent approval of nusinersen provides a much-needed boost for antisense technology that is just beginning to realize its potential. Beyond treating SMA, the ISS-N1 target offers myriad potentials for perfecting various aspects of the nucleic-acid-based technology for the amelioration of the countless number of pathological conditions.Gene Therapy accepted article preview online, 09 May 2017. doi:10.1038/gt.2017.34.

Discovery of a Small Molecule Probe that Post-translationally Stabilizes the Survival Motor Neuron Protein for the Treatment of Spinal Muscular Atrophy.Publié le 10 05 2017

Spinal muscular atrophy (SMA) is the leading genetic cause of infant death. We previously developed a high-throughput assay that employs an SMN2-luciferase reporter allowing identification of compounds that act transcriptionally, enhance exon recognition, or stabilize the SMN protein. We describe optimization and characterization of an analog suitable for in vivo testing. Initially, we identified analog 4m that had good in vitro properties, but low plasma and brain exposure in a mouse PK experiment due to short plasma stability; this was overcome by reversing the amide bond and changing the heterocycle. Thiazole 27 showed excellent in vitro properties and a promising mouse PK profile, making it suitable for in vivo testing. This series post-translationally stabilizes the SMN protein, unrelated to global proteasome or autophagy inhibition, revealing a novel therapeutic mechanism that should complement other modalities for treatment of SMA.

Neurocalcin Delta Suppression Protects against Spinal Muscular Atrophy in Humans and across Species by Restoring Impaired Endocytosis.Publié le 05 05 2017

Homozygous SMN1 loss causes spinal muscular atrophy (SMA), the most common lethal genetic childhood motor neuron disease. SMN1 encodes SMN, a ubiquitous housekeeping protein, which makes the primarily motor neuron-specific phenotype rather unexpected. SMA-affected individuals harbor low SMN expression from one to six SMN2 copies, which is insufficient to functionally compensate for SMN1 loss. However, rarely individuals with homozygous absence of SMN1 and only three to four SMN2 copies are fully asymptomatic, suggesting protection through genetic modifier(s). Previously, we identified plastin 3 (PLS3) overexpression as an SMA protective modifier in humans and showed that SMN deficit impairs endocytosis, which is rescued by elevated PLS3 levels. Here, we identify reduction of the neuronal calcium sensor Neurocalcin delta (NCALD) as a protective SMA modifier in five asymptomatic SMN1-deleted individuals carrying only four SMN2 copies. We demonstrate that NCALD is a Ca(2+)-dependent negative regulator of endocytosis, as NCALD knockdown improves endocytosis in SMA models and ameliorates pharmacologically induced endocytosis defects in zebrafish. Importantly, NCALD knockdown effectively ameliorates SMA-associated pathological defects across species, including worm, zebrafish, and mouse. In conclusion, our study identifies a previously unknown protective SMA modifier in humans, demonstrates modifier impact in three different SMA animal models, and suggests a potential combinatorial therapeutic strategy to efficiently treat SMA. Since both protective modifiers restore endocytosis, our results confirm that endocytosis is a major cellular mechanism perturbed in SMA and emphasize the power of protective modifiers for understanding disease mechanism and developing therapies.

New treatments for serious conditions: Ethical implications.Publié le 04 05 2017

Approval of Spinraza (nusinersen) for treatment of spinal muscular atrophy prompts consideration of a number of ethical issues that arise whenever a new treatment is proposed for a serious condition, especially one that is rare and can devastatingly affect children. Patients, families, clinicians, researchers, institutions, and policymakers all must take account of the ways that newly available treatments affect informed and shared decision-making about therapeutic and research options. The issues to consider include: addressing what is still uncertain and unknown; the possibility that potential benefits will be exaggerated and potential harms underemphasized in the media, by advocacy organizations, and in consent forms and processes; the high cost of many novel drugs and biologics; the effects of including conditions of variable phenotype in state-mandated newborn screening panels; and how new treatments can change the standard of care, altering what is and is not known about a disorder and posing challenges for decision-making at both individual and policy levels. The good news that Spinraza brings thus requires additional attention to its ethical and policy implications, in order to improve counseling and shared decision-making about treatment and research options for patients and all involved in their care.Gene Therapy accepted article preview online, 03 May 2017. doi:10.1038/gt.2017.32.

Safety and efficacy of olesoxime in patients with type 2 or non-ambulatory type 3 spinal muscular atrophy: a randomised, double-blind, placebo-controlled phase 2 trial.Publié le 04 05 2017

BACKGROUND: Spinal muscular atrophy (SMA) is a progressive motor neuron disease causing loss of motor function and reduced life expectancy, for which limited treatment is available. We investigated the safety and efficacy of olesoxime in patients with type 2 or non-ambulatory type 3 SMA.
METHODS: This randomised, double-blind, placebo-controlled, phase 2 study was done in 22 neuromuscular care centres in Belgium, France, Germany, Italy, Netherlands, Poland, and the UK. Safety and efficacy of olesoxime were assessed in patients aged 3-25 years with genetically confirmed type 2 or non-ambulatory type 3 SMA. A centralised, computerised randomisation process allocated patients (2:1 with stratification by SMA type and centre) to receive olesoxime (10 mg/kg per day) in an oral liquid suspension or placebo for 24 months. Patients, investigators assessing outcomes, and sponsor study personnel were masked to treatment assignment. The primary outcome measure was change from baseline compared with 24 months between the two treatment groups in functional domains 1 and 2 of the Motor Function Measure (MFM D1?+?D2) assessed in the full analysis population. A shorter, 20-item version of the MFM, which was specifically adapted for young children, was used to assess patients younger than 6 years. Safety was assessed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT01302600.
FINDINGS: The trial was done between Nov 18, 2010, and Oct 9, 2013. Of 198 patients screened, 165 were randomly assigned to olesoxime (n=108) or placebo (n=57). Five patients in the olesoxime group were not included in the primary outcome analysis because of an absence of post-baseline assessments. The change from baseline to month 24 on the primary outcome measure was 0·18 for olesoxime and -1·82 for placebo (treatment difference 2·00 points, 96% CI -0·25 to 4·25, p=0·0676). Olesoxime seemed to be safe and generally well tolerated, with an adverse event profile similar to placebo. The most frequent adverse events in the olesoxime group were pyrexia (n=34), cough (n=32), nasopharyngitis (n=25), and vomiting (n=25). There were two patient deaths (one in each group), but these were not deemed to be related to the study treatment.
INTERPRETATION: Olesoxime was safe at the doses studied, for the duration of the trial. Although the primary endpoint was not met, secondary endpoints and sensitivity analyses suggest that olesoxime might maintain motor function in patients with type 2 or type 3 SMA over a period of 24 months. Based on these results, olesoxime might provide meaningful clinical benefits for patients with SMA and, given its mode of action, might be used in combination with other drugs targeting other mechanisms of disease, although additional evidence is needed.
FUNDING: AFM Téléthon and Trophos SA.

A-44G transition in SMN2 intron 6 protects patients with spinal muscular atrophy.Publié le 02 05 2017

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by reduced expression of survival of motor neuron (SMN), a protein expressed in humans by two paralogous genes, SMN1 and SMN2. These genes are nearly identical, except for 10 single-nucleotide differences and a 5-nucleotide insertion in SMN2. SMA is subdivided into four main types, with type I being the most severe. SMN2 copy number is a key positive modifier of the disease, but it is not always inversely correlated with clinical severity. We previously reported the c.859G>C variant in SMN2 exon 7 as a positive modifier in several patients. We have now identified A-44G as an additional positive disease modifier, present in a group of patients carrying 3 SMN2 copies but displaying milder clinical phenotypes than other patients with the same SMN2 copy number. One of the three SMN2 copies appears to have been converted from SMN1, but except for the C6T transition, no other changes were detected. Analyzed with minigenes, SMN1C6T displayed a ?20% increase in exon 7 inclusion, compared to SMN2. Through systematic mutagenesis, we found that the improvement in exon 7 splicing is mainly attributable to the A-44G transition in intron 6. Using RNA-affinity chromatography and mass spectrometry, we further uncovered binding of the RNA-binding protein HuR to the -44 region, where it acts as a splicing repressor. The A-44G change markedly decreases the binding affinity of HuR, resulting in a moderate increase in exon 7 inclusion.

Discovery of a Novel Class of Survival Motor Neuron 2 Splicing Modifiers for the Treatment of Spinal Muscular Atrophy.Publié le 27 04 2017

Spinal muscular atrophy (SMA) is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene, resulting in low levels of functional SMN protein. We have reported recently the identification of small molecules (coumarins, iso-coumarins and pyrido-pyrimidinones) that modify the alternative splicing of SMN2, a paralogous gene to SMN1, restoring the survival motor neuron (SMN) protein level in mouse models of SMA. Herein, we report our efforts to identify a novel chemotype as one strategy to potentially circumvent safety concerns from earlier derivatives, such as in-vitro phototoxicity and in-vitro mutagenicity associated with compounds 1 and 2 or the in-vivo retinal findings observed in a long term chronic tox study with 3 at high exposures only. Optimized representative compounds modify the alternative splicing of SMN2, increase the production of full length SMN2 mRNA and therefore levels of full length SMN protein upon oral administration in two mouse models of SMA.

Motor neuropathies and lower motor neuron syndromes.Publié le 25 04 2017

Motor or motor-predominant neuropathies may arise from disease processes affecting the motor axon and/or its surrounding myelin. Lower motor neuron syndrome (LMNS) arises from a disease process affecting the spinal motor neuron itself. The term LMNS is more generally used, rather than motor neuronopathy, although both entities are clinically similar. Common features are muscle weakness (distal or proximal) with atrophy and hyporeflexia, but no sensory involvement. They can be acquired or hereditary. Immune-mediated neuropathies (multifocal motor neuropathy, motor-predominant chronic inflammatory demyelinating polyneuropathy) are important to identify, as effective treatments are available. Other acquired neuropathies, such as infectious, paraneoplastic and radiation-induced neuropathies are also well known. Focal LMNS is an amyotrophic lateral sclerosis (ALS)-mimicking syndrome especially affecting young adults. The main hereditary LMNSs in adulthood are Kennedy's disease, late-onset spinal muscular atrophy and distal hereditary motor neuropathies. Motor neuropathies and LMNS are all clinical entities that should be better known, despite being rare diseases. They can sometimes be difficult to differentially diagnose from other diseases, particularly from the more frequent ALS in its pure LMN form. Nevertheless, correct identification of these syndromes is important because their treatment and prognoses are definitely different.

Design of Potent mRNA Decapping Scavenger Enzyme (DcpS) Inhibitors with Improved Physicochemical Properties To Investigate the Mechanism of Therapeutic Benefit in Spinal Muscular Atrophy (SMA).Publié le 25 04 2017

The C-5 substituted 2,4-diaminoquinazoline RG3039 (compound 1), a member of a chemical series that was identified and optimized using an SMN2 promoter screen, prolongs survival and improves motor function in a mouse model of spinal muscular atrophy (SMA). It is a potent inhibitor of the mRNA decapping scavenger enzyme (DcpS), but the mechanism whereby DcpS inhibition leads to therapeutic benefit is unclear. Compound 1 is a dibasic lipophilic molecule that is predicted to accumulate in lysosomes. To understand if the in vivo efficacy is due to DcpS inhibition or other effects resulting from the physicochemical properties of the chemotype, we undertook structure based molecular design to identify DcpS inhibitors with improved physicochemical properties. Herein we describe the design, synthesis, and in vitro pharmacological characterization of these DcpS inhibitors along with the in vivo mouse CNS PK profile of PF-DcpSi (compound 24), one of the analogs found to be efficacious in SMA mouse model.

Bioenergetic status modulates motor neuron vulnerability and pathogenesis in a zebrafish model of spinal muscular atrophy.Publié le 21 04 2017

Degeneration and loss of lower motor neurons is the major pathological hallmark of spinal muscular atrophy (SMA), resulting from low levels of ubiquitously-expressed survival motor neuron (SMN) protein. One remarkable, yet unresolved, feature of SMA is that not all motor neurons are equally affected, with some populations displaying a robust resistance to the disease. Here, we demonstrate that selective vulnerability of distinct motor neuron pools arises from fundamental modifications to their basal molecular profiles. Comparative gene expression profiling of motor neurons innervating the extensor digitorum longus (disease-resistant), gastrocnemius (intermediate vulnerability), and tibialis anterior (vulnerable) muscles in mice revealed that disease susceptibility correlates strongly with a modified bioenergetic profile. Targeting of identified bioenergetic pathways by enhancing mitochondrial biogenesis rescued motor axon defects in SMA zebrafish. Moreover, targeting of a single bioenergetic protein, phosphoglycerate kinase 1 (Pgk1), was found to modulate motor neuron vulnerability in vivo. Knockdown of pgk1 alone was sufficient to partially mimic the SMA phenotype in wild-type zebrafish. Conversely, Pgk1 overexpression, or treatment with terazosin (an FDA-approved small molecule that binds and activates Pgk1), rescued motor axon phenotypes in SMA zebrafish. We conclude that global bioenergetics pathways can be therapeutically manipulated to ameliorate SMA motor neuron phenotypes in vivo.

ISS-N1 makes the First FDA-approved Drug for Spinal Muscular Atrophy.Publié le 14 04 2017

Spinal muscular atrophy (SMA) is one of the leading genetic diseases of children and infants. SMA is caused by deletions or mutations of Survival Motor Neuron 1 (SMN1) gene. SMN2, a nearly identical copy of SMN1, cannot compensate for the loss of SMN1 due to predominant skipping of exon 7. While various regulatory elements that modulate SMN2 exon 7 splicing have been proposed, intronic splicing silencer N1 (ISS-N1) has emerged as the most promising target thus far for antisense oligonucleotide-mediated splicing correction in SMA. Upon procuring exclusive license from the University of Massachussets Medical School in 2010, Ionis Pharmaceuticals (formerly ISIS Pharamaceuticals) began clinical development of Spinraza(™) (synonyms: Nusinersen, IONIS-SMNRX, ISIS-SMNRX), an antisense drug based on ISS-N1 target. Spinraza(™) showed very promising results at all steps of the clinical development and was approved by US Food and Drug Administration (FDA) on December 23, 2016. Spinraza(™) is the first FDA-approved treatment for SMA and the first antisense drug to restore expression of a fully functional protein via splicing correction. The success of Spinraza(™) underscores the potential of intronic sequences as promising therapeutic targets and sets the stage for further improvement of antisense drugs based on advanced oligonucleotide chemistries and delivery protocols.

VEPTR: Are We Reducing Respiratory Assistance Requirements?Publié le 12 04 2017

BACKGROUND: The assisted ventilation rating (AVR) indicates the degree of external respiratory support required in children with thoracic insufficiency syndrome (TIS) and early onset scoliosis. For skeletally immature patients with TIS, the vertical expandable prosthetic titanium rib (VEPTR) device can be used to improve lung volume and growth. We hypothesized that patients who underwent early thoracic reconstruction by VEPTR treatment had an improved respiratory status.
METHODS: Preoperative and postoperative AVR ratings were prospectively collected in a multicenter study group and compared with determine change after VEPTR treatment. Patients under 10 years of age at initial implant with minimum of 2-year follow-up data were included. Patients were excluded if there was incomplete data or if initial AVR was normal (breathing on room air). Statistical analysis was performed on groups which had stable, declined, and improved AVR at final follow-up.
RESULTS: Database search yielded 77 patients with initial abnormal AVR. Average follow-up was 5.6 years. The most frequent primary diagnoses were congenital scoliosis (n=14) and spinal muscular atrophy (n=14). In total, 19 (24%) demonstrated improvement, 9 (12%) patients deteriorated, and 49 (64%) remained at the same level. The average preoperative major curve in those with improvement (58.4 degrees) and those with no change (63.5 degrees) was less than in those with deterioration (85.5 degrees) (P=0.014). The average age in years at implant of those with improvement (4) was less than those declined (6.7) and those with no change (5.5). In total, 16 (84.2%) of those that improved had a normal AVR and did not require respiratory support at last follow-up.
CONCLUSIONS: There is evidence that there is a subset of patients with early onset scoliosis and TIS, who received early thoracic reconstruction with VEPTR treatment show complete resolution of pulmonary support at final follow-up. In total, 89% of 79 patients did not experience respiratory deterioration. A total of 24% (n=19) had a positive change with over 84% (n=16) of this group no longer requiring support.
LEVEL OF EVIDENCE: Level III-prognostic.

Combination of valproic acid and morpholino splice-switching oligonucleotide produces improved outcomes in spinal muscular atrophy patient-derived fibroblasts.Publié le 10 04 2017

Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality worldwide, is characterised by the homozygous loss of the survival motor neuron 1 (SMN1) gene. The consequent degeneration of spinal motor neurons and progressive atrophy of voluntary muscle groups results in paralysis and eventually premature infantile death. Humans possess a second nearly identical copy of SMN1, known as SMN2. However, SMN2 produces only 10-20% functional SMN protein due to aberrant splicing of its pre-mRNA that leads to the exclusion of exon 7. This level of SMN is insufficient to rescue the phenotype. Recently developed splice-switching antisense oligonuclotides (SSO) have shown great promise in correcting the aberrant splicing of SMN2 towards producing functional SMN protein. Several FDA approved drugs are being repurposed for SMA treatment including valproic acid (VPA), a histone deacetylase inhibitor, which has been shown to increase overall SMN2 expression. In this study, we have characterised the effects of single and combined treatment of VPA and a SSO based on phosphorodiamidate morpholino oligomer (PMO) chemistry. We conjugated both VPA and PMO to a single cell-penetrating peptide (Apolipoprotein E (ApoE)) for their simultaneous intracellular delivery. Treatment of SMA Type I patient-derived fibroblasts with the conjugates showed no additive increase in the level of full-length SMN2 mRNA expression over both 4 and 16 h treatments indicating that conjugation of VPA to ApoE-PMO has limited benefit. However, treatment with a combination of VPA and ApoE-PMO induced more favourable splice switching activity than either agent alone, promoting exon 7 inclusion in SMN2 transcripts. Our results suggest that combination therapy of VPA and ApoE-PMO is superior in upregulating SMN2 production in vitro, as compared to singular treatment of each compound at both transcriptional and protein levels. This study provides the first indication of a novel dual therapy approach for the potential treatment of SMA.

Antisense Oligonucleotide-Based Therapy for Neuromuscular Disease.Publié le 07 04 2017

Neuromuscular disorders such as Duchenne Muscular Dystrophy and Spinal Muscular Atrophy are neurodegenerative genetic diseases characterized primarily by muscle weakness and wasting. Until recently there were no effective therapies for these conditions, but antisense oligonucleotides, a new class of synthetic single stranded molecules of nucleic acids, have demonstrated promising experimental results and are at different stages of regulatory approval. The antisense oligonucleotides can modulate the protein expression via targeting hnRNAs or mRNAs and inducing interference with splicing, mRNA degradation, or arrest of translation, finally, resulting in rescue or reduction of the target protein expression. Different classes of antisense oligonucleotides are being tested in several clinical trials, and limitations of their clinical efficacy and toxicity have been reported for some of these compounds, while more encouraging results have supported the development of others. New generation antisense oligonucleotides are also being tested in preclinical models together with specific delivery systems that could allow some of the limitations of current antisense oligonucleotides to be overcome, to improve the cell penetration, to achieve more robust target engagement, and hopefully also be associated with acceptable toxicity. This review article describes the chemical properties and molecular mechanisms of action of the antisense oligonucleotides and the therapeutic implications these compounds have in neuromuscular diseases. Current strategies and carrier systems available for the oligonucleotides delivery will be also described to provide an overview on the past, present and future of these appealing molecules.

A qualitative study of perceptions of meaningful change in spinal muscular atrophy.Publié le 07 04 2017

BACKGROUND: This qualitative study examined how individuals with Spinal Muscular Atrophy (SMA), their caregivers, and clinicians defined meaningful change, primarily in the Type II and non-ambulant type III patient populations, associated with treatment of this condition. In addition, we explored participants' views about two measures of motor function routinely used in clinical trials for these SMA subtypes, namely the expanded version of the Hammersmith Functional Motor Scale (HFMSE) and the Upper Limb Module (ULM).
METHODS: The 123 participants (21 with SMA, 64 parents, and 11 clinicians), recruited through SMA advocacy organizations, participated in one of 16 focus groups or 37 interviews. The sessions were audio-recorded, and verbatim transcripts were analyzed using a grounded theory approach.
RESULTS: For the participants, meaningful change was relative to functional ability, and small changes in motor function could have an important impact on quality of life. Because patients and families feared progressive loss of functional ability, the participants saw maintenance of abilities as a meaningful outcome. They believed that measures of motor function covered important items, but worried that the HFMSE and ULM might not be sensitive enough to capture small changes. In addition, they felt that outcome measures should assess other important features of life with SMA, including the ability to perform daily activities, respiratory function, swallowing, fatigue, and endurance.
CONCLUSIONS: Given the heterogeneity of SMA, it is important to expand the assessment of treatment effects to a broader range of outcomes using measures sensitive enough to detect small changes.

Newborn screening for spinal muscular atrophy: The views of affected families and adults.Publié le 05 04 2017

Spinal muscular atrophy (SMA) is one of the leading genetic causes of infant death worldwide. However, due to a lack of treatments, SMA has historically fallen short of Wilson-Jungner criteria. While studies have explored the acceptability of expanded newborn screening to the general public, the views of affected families have been largely overlooked. This is in spite of the potential for direct impacts on them and their unique positioning to consider the value of early diagnosis. We have previously reported data on attitudes toward pre-conception and prenatal genetic screening for SMA among affected families (adults with SMA [n?=?82] and family members [n?=?255]). Here, using qualitative interview [n?=?36] and survey data [n?=?337], we report the views of this same cohort toward newborn screening. The majority (70%) of participants were in favor, however, all subgroups (except adults with type II) preferred pre-conception and/or prenatal screening to newborn screening. Key reasons for newborn screening support were: (1) the potential for improved support; (2) the possibility of enrolling pre-symptomatic children on clinical trials. Key reasons for non-support were: (1) concerns about impact on the early experiences of the family; (2) inability to treat. Importantly, participants did not view the potential for inaccurate typing as a significant obstacle to the launch of a population-wide screening program. This study underscores the need to include families affected by genetic diseases within consultations on screening. This is particularly important for conditions such as SMA which challenge traditional screening criteria, and for which new therapeutics are emerging.

Population Pharmacokinetics of Nusinersen in the Cerebral Spinal Fluid and Plasma of Pediatric Patients With Spinal Muscular Atrophy Following Intrathecal Administrations.Publié le 04 04 2017

Nusinersen is an antisense oligonucleotide intended for the treatment of spinal muscular atrophy. The pharmacokinetics of nusinersen, following intrathecal administrations, in the cerebrospinal fluid (CSF) and plasma of 72 pediatric patients (3 months to 17 years) with spinal muscular atrophy across 5 clinical trials was analyzed via population-based modeling. With sparse data in the CSF and profile data in the plasma, a linear 4-compartment model simultaneously described the time-concentration profiles in both matrices. The typical population parameters were: Qp = 0.572 L/h, QCSF = 0.069 L/h, CLp = 2.50 L/h, CLCSF = 0.133 L/hr, VCSF = 0.441 L, Vp = 32.0 L, Vsystemic_tissue = 429 L, and VCNS_tissue = 258 L. A full covariate modeling approach identified baseline body weight to be a statistically and clinically relevant covariate on VCSF , Vp , and CLp . The model predicted that the CSF volume of distribution increased steadily with age from 0 to 2 years but became relatively steady for children >2 years. Simulations from the final model showed that age-based dosing in children under 2 years ensured a more comparable exposure (peak concentration and area under the concentration-time curve) across subjects in the population relative to a fixed dosing scheme. However, because no dose-limiting toxicity has been reported in any of the trials, a fixed-dose scheme (12 mg across all age groups) was recommended. The median terminal half-life of nusinersen in the CSF was determined from the model to be 163 days, which supported infrequent dosing, once every 4 to 6 months in pediatric patients with spinal muscular atrophy.

Brachial Diparesis due to Motor Neuronopathy as One of the Predominant Presenting Signs of Occult Small Cell Lung Carcinoma.Publié le 28 03 2017

Sensory neuronopathy is a well-established presentation in paraneoplastic neurological syndromes that is mostly associated with small cell lung cancer and anti-Hu antibodies. Motor neuronopathy, on the other hand, is an extremely rare observation in this syndrome. A 56-year-old man presented with asymmetric brachial diparesis and sensory ataxia. Electrophysiological studies revealed sensory ganglionopathy and progressive anterior horn degeneration in cervical segments. Small cell lung carcinoma with associated anti-Hu antibodies was later diagnosed. The patient did not improve despite the administration of steroids and chemotherapy. Paraneoplastic syndromes may exceptionally present with a bilateral arm weakness. Cases accompanied by sensory ganglionopathy should therefore be promptly investigated for any underlying malignancy.

Stakeholder collaboration for spinal muscular atrophy therapy development.Publié le 23 03 2017

PMID: 28327335 [PubMed - in process]

Deliberative Discussion Focus Groups.Publié le 21 03 2017

This article discusses a new approach for the conduct of focus groups in health research. Identifying ways to educate and inform participants about the topic of interest prior to the focus group discussion can promote more quality data from informed opinions. Data on this deliberative discussion approach are provided from research within three federally funded studies. As healthcare continues to improve from scientific and technological advancements, educating the research participants prior to data collection about these complexities is essential to gather quality data.

Matching pairs difficulty in children with spinal muscular atrophy type I.Publié le 21 03 2017

This study aimed to investigate the performance on pair-matching tasks in children with Spinal Muscular Atrophy type I (SMA-I) and the relationship between this performance and motor function, functional independence and quality of life. SMA-I (n?=?12; 6.0?±?2.3?yrs; 9 boys, 3 girls) and control sex-, age-matched children (n?=?12; 6.2?±?2.6?yrs) performed four pair-matching figure, number and letter tasks. The eye tracker detected eye movements. SMA-I children were assessed with CHOP INTEND, Pediatric Evaluation of Disability Inventory, and Pediatric Quality of Life Inventory. Analysis of variance showed that SMA-I children had a lower percentage of correct answers and longer timed performance compared to controls (p?<?0.05). Pediatric Evaluation of Disability Inventory score (social function domain) was correlated to the percentage of correct answers on the pair-matching tasks on task 1 (r?=?0.81; p?=?0.001) and task 2 (r?=?0.66; p?=?0.020). Pair-matching performance of SMA-I children was poorer than the performance of control children. There was a relationship between pair-matching performance and social function. The restricted interaction with the environment, due to severe paralysis and poor verbal communication, is associated with cognitive difficulties in SMA-I children. The eye tracker was helpful in cognitive assessment of SMA-I children, who responded to the cognitive tests with eye movements.

Maximum inspiratory pressure as a clinically meaningful trial endpoint for neuromuscular diseases: a comprehensive review of the literature.Publié le 21 03 2017

Respiratory muscle strength is a proven predictor of long-term outcome of neuromuscular disease (NMD), including amyotrophic lateral sclerosis, Duchenne muscular dystrophy, and spinal muscular atrophy. Maximal inspiratory pressure (MIP), a sensitive measure of respiratory muscle strength, one of several useful tests of respiratory muscle strength, is gaining interest as a therapeutic clinical trial endpoint for NMD. In this comprehensive review we investigate the use of MIP as a measure of respiratory muscle strength in clinical trials of therapeutics targeting respiratory muscle, examine the correlation of MIP with survival, quality of life, and other measures of pulmonary function, and outline the role of MIP as a clinically significantly meaningful outcome measure. Our analysis supports the utility of MIP for the early evaluation of respiratory muscle strength, especially of the diaphragm, in patients with NMD and as a surrogate endpoint in clinical trials of therapies for NMD.

Plastin-3 extends survival and reduces severity in mouse models of spinal muscular atrophy.Publié le 16 03 2017

Spinal muscular atrophy (SMA) is a leading genetic cause of infantile death and is caused by the loss of survival motor neuron-1 (SMN1). Importantly, a nearly identical gene is present called SMN2; however, the majority of SMN2-derived transcripts are alternatively spliced and encode a truncated, dysfunctional protein. Recently, several compounds designed to increase SMN protein have entered clinical trials, including antisense oligonucleotides (ASOs), traditional small molecules, and gene therapy. Expanding beyond SMN-centric therapeutics is important, as it is likely that the breadth of the patient spectrum and the inherent complexity of the disease will be difficult to address with a single therapeutic strategy. Several SMN-independent pathways that could impinge upon the SMA phenotype have been examined with varied success. To identify disease-modifying pathways that could serve as stand-alone therapeutic targets or could be used in combination with an SMN-inducing compound, we investigated adeno-associated virus-mediated (AAV-mediated) gene therapy using plastin-3 (PLS3). Here, we report that AAV9-PLS3 extends survival in an intermediate model of SMA mice as well as in a pharmacologically induced model of SMA using a splice-switching ASO that increases SMN production. PLS3 coadministration improves the phenotype beyond the ASO, demonstrating the potential utility of combinatorial therapeutics in SMA that target SMN-independent and SMN-dependent pathways.

Transversus abdominis plane block for analgesia in spinal muscular atrophy patient.Publié le 14 03 2017

PMID: 27555167 [PubMed - indexed for MEDLINE]

New Therapy for Spinal Muscular Atrophy Offers Modest Bang for Pharamaceutical Buck.Publié le 09 03 2017

Spinraza is a breakthrough, no doubt. It is a survival SMN-2-directed antisense oligonucleotide indicated for the treatment of SMA in pediatric and adult patients and is administered by injections into the spinal fluid (intrathecally). But it is another ultraexpensive drug, and the evidence so far points to a modest improvement in motor milestones.

SMN Blood Levels in a Porcine Model of Spinal Muscular Atrophy.Publié le 09 03 2017

BACKGROUND: Spinal Muscular Atrophy (SMA) is an autosomal recessive motor neuron disease that results in loss of spinal motor neurons, muscular weakness and, in severe cases, respiratory failure and death. SMA is caused by a deletion or mutation of the SMN1 gene and retention of the SMN2 gene that leads to low SMN expression levels.The measurement of SMN mRNA levels in peripheral blood samples has been used in SMA clinical studies as a pharmacodynamic biomarker for response to therapies designed to increase SMN levels. We recently developed a postnatal porcine model of SMA by the viral delivery of a short-hairpin RNA (shRNA) targeting porcine SMN (pSMN). scAAV9-mediated knockdown of pSMN mRNA at postnatal day 5 results in denervation, weakness and motor neuron and ventral root axon loss that begins 3-4 weeks after viral delivery, and this phenotype can be ameliorated by subsequent viral delivery of human SMN (hSMN).
OBJECTIVE: To determine if the effect of modulating SMN levels using gene therapy can be measured in blood.
METHODS: We measured expression of pSMN mRNA and hSMN mRNA by quantitative droplet digital PCR (ddPCR).
RESULTS: We found that the endogenous expression of pSMN mRNA in blood increases in the first month of life. However, there were no significant differences in blood levels of pSMN mRNA after knock-down or of human SMN mRNA after gene therapy.
CONCLUSIONS: Our results, obtained in a large animal model of SMA that is similar in size and anatomy to human infants, suggest that measurement of SMN mRNA levels in blood may not be informative in SMA clinical trials involving intrathecal delivery of SMN-modulating therapies.

Low bone mineral density and fractures are highly prevalent in pediatric patients with spinal muscular atrophy regardless of disease severity.Publié le 05 03 2017

Patients with Spinal Muscular Atrophy (SMA) are at risk for poor bone health. The prevalence of fractures, low areal bone mineral density (aBMD; Z-score ?-2.0) of the lateral distal femur and of osteoporosis by SMA subtype is not known. We aimed to describe the natural history of bone health in patients with SMA prior to bisphosphonate treatment. We reviewed data from 85 eligible patients with SMA ages 12 months to 18 years, seen at a single institution between January 2005 and July 2016. Fracture history was reported at annual clinic visits. aBMD was obtained from dual energy x-ray absorptiometry scans of the lumbar spine, total body, and lateral distal femur. 85% of patients had aBMD Z-scores ?-2.0 SD and were progressively lower with worsening SMA severity. Longitudinal aBMD Z-scores of the lateral distal femur decreased with age. Fractures occurred in 38% (32/85) of patients with the femur being the most common location (25 of 57 fractures). Thirteen percent of patients fulfilled criteria for osteoporosis. Low aBMD and femur fractures are highly prevalent in all SMA subtypes from a young age; however, few patients met the criteria for osteoporosis. Poor bone health may be an under-recognized comorbidity of SMA.

Pharmaceutical Approval Update.Publié le 03 03 2017

Insulin degludec/liraglutide (Xultophy 100/3.6) for type-2 diabetes; rucaparib (Rubraca) for the treatment of deleterious BRCA mutation-associated ovarian cancer; and nusinersen (Spinraza) for the treatment of spinal muscular atrophy.

Content validity and clinical meaningfulness of the HFMSE in spinal muscular atrophy.Publié le 27 02 2017

BACKGROUND: Reports on the clinical meaningfulness of outcome measures in spinal muscular atrophy (SMA) are rare. In this two-part study, our aim was to explore patients' and caregivers' views on the clinical relevance of the Hammersmith Functional Motor Scale Expanded- (HFMSE).
METHODS: First, we used focus groups including SMA patients and caregivers to explore their views on the clinical relevance of the individual activities included in the HFMSE. Then we asked caregivers to comment on the clinical relevance of possible changes of HFMSE scores over time. As functional data of individual patients were available, some of the questions were tailored according to their functional level on the HFMSE.
RESULTS: Part 1: Sixty-three individuals participated in the focus groups. This included 30 caregivers, 25 patients and 8 professionals who facilitated the discussion. The caregivers provided a comparison to activities of daily living for each of the HFMSE items. Part 2: One hundred and forty-nine caregivers agreed to complete the questionnaire: in response to a general question, 72% of the caregivers would consider taking part in a clinical trial if the treatment was expected to slow down deterioration, 88% if it would stop deterioration and 97% if the treatment was expected to produce an improvement. Caregivers were informed of the first three items that their child could not achieve on the HFMSE. In response 75% indicated a willingness to take part in a clinical trial if they could achieve at least one of these abilities, 89% if they could achieve two, and 100% if they could achieve more than 2.
CONCLUSIONS: Our findings support the use of the HFMSE as a key outcome measure in SMA clinical trials because the individual items and the detected changes have clear content validity and clinical meaningfulness for patients and their caregivers.

Nusinersen: First Global Approval.Publié le 24 02 2017

Spinal muscular atrophy (SMA) is a rare autosomal recessive disorder characterized by muscle atrophy and weakness resulting from motor neuron degeneration in the spinal cord and brainstem. It is most commonly caused by insufficient levels of survival motor neuron (SMN) protein (which is critical for motor neuron maintenance) secondary to deletions or mutations in the SMN1 gene. Nusinersen (SPINRAZA™) is a modified antisense oligonucleotide that binds to a specific sequence in the intron, downstream of exon 7 on the pre-messenger ribonucleic acid (pre-mRNA) of the SMN2 gene. This modulates the splicing of the SMN2 mRNA transcript to include exon 7, thereby increasing the production of full-length SMN protein. Nusinersen is approved in the USA for intrathecal use in paediatric and adult patients with SMA. Regulatory assessments for nusinersen as a treatment for SMA are underway in the EU and several other countries. This article summarizes the milestones in the development of nusinersen leading to this first approval for SMA in paediatric and adult patients.

Revised Hammersmith Scale for spinal muscular atrophy: A SMA specific clinical outcome assessment tool.Publié le 22 02 2017

Recent translational research developments in Spinal Muscular Atrophy (SMA), outcome measure design and demands from regulatory authorities require that clinical outcome assessments are 'fit for purpose'. An international collaboration (SMA REACH UK, Italian SMA Network and PNCRN USA) undertook an iterative process to address discontinuity in the recorded performance of the Hammersmith Functional Motor Scale Expanded and developed a revised functional scale using Rasch analysis, traditional psychometric techniques and the application of clinical sensibility via expert panels. Specifically, we intended to develop a psychometrically and clinically robust functional clinician rated outcome measure to assess physical abilities in weak SMA type 2 through to strong ambulant SMA type 3 patients. The final scale, the Revised Hammersmith Scale (RHS) for SMA, consisting of 36 items and two timed tests, was piloted in 138 patients with type 2 and 3 SMA in an observational cross-sectional multi-centre study across the three national networks. Rasch analysis demonstrated very good fit of all 36 items to the construct of motor performance, good reliability with a high Person Separation Index PSI 0.98, logical and hierarchical scoring in 27/36 items and excellent targeting with minimal ceiling. The RHS differentiated between clinically different groups: SMA type, World Health Organisation (WHO) categories, ambulatory status, and SMA type combined with ambulatory status (all p < 0.001). Construct and concurrent validity was also confirmed with a strong significant positive correlation with the WHO motor milestones rs = 0.860, p < 0.001. We conclude that the RHS is a psychometrically sound and versatile clinical outcome assessment to test the broad range of physical abilities of patients with type 2 and 3 SMA. Further longitudinal testing of the scale with regards change in scores over 6 and 12 months are required prior to its adoption in clinical trials.

Gene activation of SMN by selective disruption of lncRNA-mediated recruitment of PRC2 for the treatment of spinal muscular atrophy.Publié le 15 02 2017

Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by progressive motor neuron loss and caused by mutations in SMN1 (Survival Motor Neuron 1). The disease severity inversely correlates with the copy number of SMN2, a duplicated gene that is nearly identical to SMN1. We have delineated a mechanism of transcriptional regulation in the SMN2 locus. A previously uncharacterized long noncoding RNA (lncRNA), SMN-antisense 1 (SMN-AS1), represses SMN2 expression by recruiting the Polycomb Repressive Complex 2 (PRC2) to its locus. Chemically modified oligonucleotides that disrupt the interaction between SMN-AS1 and PRC2 inhibit the recruitment of PRC2 and increase SMN2 expression in primary neuronal cultures. Our approach comprises a gene-up-regulation technology that leverages interactions between lncRNA and PRC2. Our data provide proof-of-concept that this technology can be used to treat disease caused by epigenetic silencing of specific loci.

European Human Genetics Conference, May 21-24, 2016, Barcelona, Spain.Publié le 15 02 2017

PMID: 27423189 [PubMed - indexed for MEDLINE]

Single-Cell Analysis of SMN Reveals Its Broader Role in Neuromuscular Disease.Publié le 09 02 2017

The mechanism underlying selective motor neuron (MN) death remains an essential question in the MN disease field. The MN disease spinal muscular atrophy (SMA) is attributable to reduced levels of the ubiquitous protein SMN. Here, we report that SMN levels are widely variable in MNs within a single genetic background and that this heterogeneity is seen not only in SMA MNs but also in MNs derived from controls and amyotrophic lateral sclerosis (ALS) patients. Furthermore, cells with low SMN are more susceptible to cell death. These findings raise the important clinical implication that some SMN-elevating therapeutics might be effective in MN diseases besides SMA. Supporting this, we found that increasing SMN across all MN populations using an Nedd8-activating enzyme inhibitor promotes survival in both SMA and ALS-derived MNs. Altogether, our work demonstrates that examination of human neurons at the single-cell level can reveal alternative strategies to be explored in the treatment of degenerative diseases.

The experiences of families living with the anticipatory loss of a school-age child with spinal muscular atrophy - the parents' perspectives.Publié le 09 02 2017

AIMS AND OBJECTIVES: To probe into parents' anticipatory loss of school-age children with Type I or II spinal muscular atrophy.
BACKGROUND: Spinal muscular atrophy is a rare disorder that causes death. Children die early due to either gradual atrophy or an infection of the lungs. Therefore, family members experience anticipatory loss, which causes grief before the actual loss. Family members feel physically and mentally exhausted, which results in a family crisis. Therefore, it is important to explore their experiences related to anticipatory loss to assist with the adjustment of the families to their circumstances.
DESIGN: This study applied a phenomenology method and purposive sampling.
PARTICIPANTS: The 19 parents who participated in this study were referred to us by two medical centers in Taiwan. Their average age was 32-49 years.
METHODS: Using in-depth interviews, this study explored parents' anticipatory loss. The interviews were recorded and transcribed. Meanings were extracted using Giorgi analysis, and precision was assessed according to Guba and Lincoln, which was treated as the evaluation standard.
RESULTS: Four themes were identified from the parents' interviews. The themes included enduring the helplessness and pressure of care, suffering due to the child's rare and unknown condition, loss of hope and a reinforcement of the parent-child attachment, and avoiding the pressure of death and enriching the child's life.
CONCLUSIONS: The research findings help nurses identify anticipatory loss among parents of school-age children with type I or II spinal muscular atrophy. They enhance health professionals' understanding of the panic that occurs in the society surrounding the families, family members' dynamic relationships, and the families' demands for care.
RELEVANCE TO CLINICAL PRACTICE: In an attempt to providing intersubjective empathy and support with family having a child with type I and II SMA, nurses may recognize relevant family reactions and enhancing their hope and parent-child attachment. Encourage family members and child go beyond the pressure of death and create customized care plans meeting families' emotional and medical needs.

Spinal muscular atrophy: Factors that modulate motor neurone vulnerability.Publié le 06 02 2017

Spinal muscular atrophy (SMA), a leading genetic cause of infant death, is a neurodegenerative disease characterised by the selective loss of particular groups of motor neurones in the anterior horn of the spinal cord with concomitant muscle weakness. To date, no effective treatment is available, however, there are ongoing clinical trials are in place which promise much for the future. However, there remains an ongoing problem in trying to link a single gene loss to motor neurone degeneration. Fortunately, given successful disease models that have been established and intensive studies on SMN functions in the past ten years, we are fast approaching the stage of identifying the underlying mechanisms of SMA pathogenesis Here we discuss potential disease modifying factors on motor neurone vulnerability, in the belief that these factors give insight into the pathological mechanisms of SMA and therefore possible therapeutic targets.

Securinine enhances SMN2 exon 7 inclusion in spinal muscular atrophy cells.Publié le 03 02 2017

Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by the degeneration of motor neurons in the spinal cord, leading to muscular atrophy. SMA is caused by deletions or mutations in the survival motor neuron gene (SMN1) on chromosome 5q13. A second copy of the SMN gene (SMN2) also exists on chromosome 5, and both genes can produce functional protein. However, due to alternative splicing of the exon 7, the majority of SMN protein produced by SMN2 is truncated and unable to compensate for the loss of SMN1. Increasing full-length SMN protein production by promoting the exon 7 inclusion in SMN2 mRNA or increasing SMN2 gene transcription could be a therapeutic approach for SMA. In this study, we screened for the compounds that enhance SMN2 exon 7 inclusion by using SMN2 minigene-luciferase reporter system. We found that securinine can increase luciferase activity, indicating that securinine promoted SMN2 exon 7 inclusion. In addition, securinine increased full-length SMN2 mRNA and SMN protein expression in SMA patient-derived lymphoid cell lines. To investigate the mechanism of securinine effect on SMN2 splicing, we compared the protein levels of relevant splicing factors between securinine-treated and untreated cells. We found that securinine downregulated hnRNP A1 and Sam68 and upregulated Tra2-?1 expression. However, securinine, unlike HDAC inhibitors, did not enhance tra2-?1 gene transcription, indicating a post-transcriptional mechanism for Tra2-?1 upregulation. Furthermore, we treated SMA-like mice with securinine by i.p. injection and found that securinine treatment increased SMN2 exon 7 inclusion and SMN protein expression in the brain and spinal cord. According to our results, securinine might have the potential to become a therapeutic drug for SMA disease.

[Neuronal cells derived from induced pluripotent stem cells to model motoneuron diseases].Publié le 31 01 2017

Among motor neuron diseases, spinal muscular atrophy type 1 and amyotrophic lateral sclerosis are very aggressive diseases with no cure. With the breakthrough of human induced pluripotent stem cells, iPS, researchers have now at their disposal a powerful tool to generate human motor neurons in culture and study the pathological defects in patient cells. In this review, we will see which tools for the study of patients motoneurons were developed from iPS cells and the different cellular models that were generated. We will also see how these models were validated and current research to identify new therapeutic leads.

miRNAs as biomarkers of neurodegenerative disorders.Publié le 27 01 2017

Neurodegenerative diseases (NDDs) are the result of progressive deterioration of neurons, ultimately leading to disabilities. There is no effective cure for NDDs at present; ongoing therapies are mainly aimed at treating the most bothersome symptoms. Since early treatment is crucial in NDDs, there is an urgent need for specific and sensitive biomarkers that can aid in early diagnosis of these disorders. Recently, altered expression of miRNAs has been implicated in several neurological disorders, including NDDs. miRNA expression has been extensively investigated in the cells, tissues and body fluids of patients with different types of NDDs. The aim of this review is to provide a comprehensive overview of miRNAs as biomarkers and therapeutic targets for NDDs.

Identification of a Peptide for Systemic Brain Delivery of a Morpholino Oligonucleotide in Mouse Models of Spinal Muscular Atrophy.Publié le 26 01 2017

Splice-switching antisense oligonucleotides are emerging treatments for neuromuscular diseases, with several splice-switching oligonucleotides (SSOs) currently undergoing clinical trials such as for Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA). However, the development of systemically delivered antisense therapeutics has been hampered by poor tissue penetration and cellular uptake, including crossing of the blood-brain barrier (BBB) to reach targets in the central nervous system (CNS). For SMA application, we have investigated the ability of various BBB-crossing peptides for CNS delivery of a splice-switching phosphorodiamidate morpholino oligonucleotide (PMO) targeting survival motor neuron 2 (SMN2) exon 7 inclusion. We identified a branched derivative of the well-known ApoE (141-150) peptide, which as a PMO conjugate was capable of exon inclusion in the CNS following systemic administration, leading to an increase in the level of full-length SMN2 transcript. Treatment of newborn SMA mice with this peptide-PMO (P-PMO) conjugate resulted in a significant increase in the average lifespan and gains in weight, muscle strength, and righting reflexes. Systemic treatment of adult SMA mice with this newly identified P-PMO also resulted in small but significant increases in the levels of SMN2 pre-messenger RNA (mRNA) exon inclusion in the CNS and peripheral tissues. This work provides proof of principle for the ability to select new peptide paradigms to enhance CNS delivery and activity of a PMO SSO through use of a peptide-based delivery platform for the treatment of SMA potentially extending to other neuromuscular and neurodegenerative diseases.

Future of rAAV gene therapy: Platform for RNAi, Gene Editing and Beyond.Publié le 13 01 2017

The use of recombinant adeno-associated viruses (rAAVs) ushered in a new millennium of gene transfer for therapeutic treatment of a number of conditions including congenital blindness, hemophilia, and spinal muscular atrophy (SMA). rAAV vectors have remarkable staying power from a therapeutic standpoint withstanding several ebbs and flows. As new technologies such as clustered regularly interspaced short palindromic repeat (CRISPR) genome editing emerge, it is now the delivery tool - the AAV vector - that is the stalwart. The longstanding safety of this vector in a multitude of clinical settings makes rAAV a selling point in the advancement of approaches for gene replacement, gene knockdown, gene editing and genome modification/engineering. The research community is building on these advances to develop more tailored delivery approaches and to tweak the genome in new and unique ways. Intertwining these approaches with newly engineered rAAV vectors is greatly expanding the available tools to manipulate gene expression with a therapeutic intent.

[Respiratory Muscle Training: State of the Art].Publié le 10 01 2017

Specific respiratory muscle training (IMT) improves the function of the inspiratory muscles. According to literature and clinical experience, there are 3 established methods: 1.) resistive load 2.) threshold load and 3.) normocapnic hyperpnea. Each training method and the associated devices have specific characteristics. Setting up an IMT should start with specific diagnostics of respiratory muscle function and be followed by detailed individual introduction to training. The aim of this review is to take a closer look at the different training methods for the most relevant indications and to discuss these results in the context of current literature. The group of neuromuscular diseases includes muscular dystrophy, spinal muscular atrophy, amyotrophic lateral sclerosis, paralysis of the phrenic nerve, and injuries to the spinal cord. Furthermore, interstitial lung diseases, sarcoidosis, left ventricular heart failure, pulmonary arterial hypertension (PAH), kyphoscoliosis and obesity are also discussed in this context. COPD, asthma, cystic fibrosis (CF) and non-CF-bronchiectasis are among the group of obstructive lung diseases. Last but not least, we summarize current knowledge on weaning from respirator in the context of physical activity.

SMN deficiency negatively impacts red pulp macrophages and spleen development in mouse models of Spinal Muscular Atrophy.Publié le 08 01 2017

Spinal muscular atrophy (SMA) is a progressive neurodegenerative disease that is the leading genetic cause of infantile death. It is caused by severe deficiency of the ubiquitously expressed Survival Motor Neuron (SMN) protein. SMA is characterized by ?-lower motor neuron loss and muscle atrophy, however, there is a growing list of tissues impacted by SMN deficiency beyond motor neurons. The non-neuronal defects are observed in the most severe Type I SMA patients and most of the widely used SMA mouse models, however, as effective therapeutics are developed, it is unclear whether additional symptoms will be uncovered in longer lived patients. Recently, the immune system and inflammation has been identified as a contributor to neurodegenerative diseases such as ALS. To determine whether the immune system is comprised in SMA, we analyzed the spleen and immunological components in SMA mice. In this report, we identify: a significant reduction in spleen size in multiple SMA mouse models and a pathological reduction in red pulp and extramedullary hematopoiesis. Additionally, red pulp macrophages, a discrete subset of yolk sac-derived macrophages, were found to be altered in SMA spleens even in pre-symptomatic post-natal day 2 animals. These cells, which are involved in iron metabolism and the phagocytosis of erythrocytes and blood-borne pathogens are significantly reduced prior to the development of the neurodegenerative hallmarks of SMA, implying a differential role of SMN in myeloid cell ontogeny. Collectively, these results demonstrate that SMN deficiency impacts spleen development and suggests a potential role for immunological development in SMA.

Raise the Roof: Boosting the Efficacy of a Spinal Muscular Atrophy Therapy.Publié le 06 01 2017

Spinal muscular atrophy is the most common genetic killer of infants. A therapy shows promise in the clinic, but there is a potential limit to its efficacy. In this issue of Neuron, d'Ydewalle et al. (2017) devise a new way to make it more effective.

Protein kinase CK2 modulates HSJ1 function through phosphorylation of the UIM2 domain.Publié le 30 12 2016

HSJ1 (DNAJB2), a member of the DNAJ family of molecular chaperones, is a key player in neuronal proteostasis maintenance. It binds ubiquitylated proteins through its Ubiquitin Interacting Motifs (UIMs) and facilitates their delivery to the proteasome for degradation. Mutations in the DNAJB2 gene lead to inherited neuropathies such as Charcot-Marie-Tooth type-2, distal hereditary motor neuropathies, spinal muscular atrophy with parkinsonism and the later stages can resemble amyotrophic lateral sclerosis. HSJ1 overexpression can reduce aggregation of neurodegeneration-associated proteins in vitro and in vivo; however, the regulation of HSJ1 function is little understood. Here we show that CK2, a ubiquitous and constitutively active protein kinase, phosphorylates HSJ1 within its second UIM, at the dominant site Ser250 and the hierarchical site Ser247. A phospho-HSJ1 specific antibody confirmed phosphorylation of endogenous HSJ1a and HSJ1b. A tandem approach of phospho-site mutation and treatment with CK2 specific inhibitors demonstrated that phosphorylation at these sites is accompanied by a reduced ability of HSJ1 to bind ubiquitylated clients and to exert its chaperone activity. Our results disclose a novel interplay between ubiquitin- and phosphorylation-dependent signaling, and represent the first report of a regulatory mechanism for UIM-dependent function. They also suggest that CK2 inhibitors could release the full neuroprotective potential of HSJ1, and deserve future interest as therapeutic strategies for neurodegenerative disease.

Emerging therapies and challenges in Spinal Muscular Atrophy.Publié le 28 12 2016

Spinal muscular atrophy (SMA) is a hereditary neurodegenerative disease with severity ranging from progressive infantile paralysis and premature death (Type I) to limited motor neuron loss and normal life expectancy (Type IV). Without disease-modifying therapies, the impact is profound for patients and their families. Improved understanding of the molecular basis of SMA, disease pathogenesis, natural history and recognition of the impact of standardized care on outcomes has yielded progress towards the development of novel therapeutic strategies and are summarised. Therapeutic strategies in the pipeline are appraised, ranging from SMN1 gene replacement to modulation of SMN2 encoded transcripts, to neuroprotection, to an expanding repertoire of peripheral targets, including muscle. With the advent of preliminary trial data, it can be reasonably anticipated that the SMA treatment landscape will transform significantly. Advancement in presymptomatic diagnosis and screening programmes will be critical, with pilot newborn screening studies underway to facilitate preclinical diagnosis. The development of disease-modifying therapies will necessitate monitoring programmes to determine the long-term impact, careful evaluation of combined treatments and further acceleration of improvements in supportive care. In advance of upcoming clinical trial results, we consider the challenges and controversies related to the implementation of novel therapies for all patients and set the scene as the field prepares to enter an era of novel therapies. This article is protected by copyright. All rights reserved.

The Antisense Transcript SMN-AS1 Regulates SMN Expression and Is a Novel Therapeutic Target for Spinal Muscular Atrophy.Publié le 27 12 2016

The neuromuscular disorder spinal muscular atrophy (SMA), the most common inherited killer of infants, is caused by insufficient expression of survival motor neuron (SMN) protein. SMA therapeutics development efforts have focused on identifying strategies to increase SMN expression. We identified a long non-coding RNA (lncRNA) that arises from the antisense strand of SMN, SMN-AS1, which is enriched in neurons and transcriptionally represses SMN expression by recruiting the epigenetic Polycomb repressive complex-2. Targeted degradation of SMN-AS1 with antisense oligonucleotides (ASOs) increases SMN expression in patient-derived cells, cultured neurons, and the mouse central nervous system. SMN-AS1 ASOs delivered together with SMN2 splice-switching oligonucleotides additively increase SMN expression and improve survival of severe SMA mice. This study is the first proof of concept that targeting a lncRNA to transcriptionally activate SMN2 can be combined with SMN2 splicing modification to ameliorate SMA and demonstrates the promise of combinatorial ASOs for the treatment of neurogenetic disorders.

Generation of KCL026 research grade human embryonic stem cell line carrying a mutation in SMN1 gene.Publié le 21 12 2016

The KCL026 human embryonic stem cell line was derived from an embryo donated for research that carried a mutation in the SMN1 gene encoding survival of motor neuron 1, telomeric (exons 7 and 8 deletion). Mutations in this gene are associated with spinal muscular atrophy. The ICM was isolated using laser microsurgery and plated on ?-irradiated human foreskin fibroblasts. Both the derivation and cell line propagation were performed in an animal product-free environment. Pluripotent state and differentiation potential were confirmed by in vitro assays.

Long-term exercise-specific neuroprotection in spinal muscular atrophy-like mice.Publié le 20 12 2016

KEY POINTS: The real impact of physical exercise parameters, i.e. intensity, type of contraction and solicited energetic metabolism, on neuroprotection in the specific context of neurodegeneration remains poorly explored. In this study behavioural, biochemical and cellular analyses were conducted to compare the effects of two different long-term exercise protocols, high intensity swimming and low intensity running, on motor units of a type 3 spinal muscular atrophy (SMA)-like mouse model. Our data revealed a preferential SMA-induced death of intermediate and fast motor neurons which was limited by the swimming protocol only, suggesting a close relationship between neuron-specific protection and their activation levels by specific exercise. The exercise-induced neuroprotection was independent of SMN protein expression and associated with specific metabolic and behavioural adaptations with notably a swimming-induced reduction of muscle fatigability. Our results provide new insight into the motor units' adaptations to different physical exercise parameters and will contribute to the design of new active physiotherapy protocols for patient care.
ABSTRACT: Spinal muscular atrophy (SMA) is a group of autosomal recessive neurodegenerative diseases differing in their clinical outcome, characterized by the specific loss of spinal motor neurons, caused by insufficient level of expression of the protein survival of motor neuron (SMN). No cure is at present available for SMA. While physical exercise might represent a promising approach for alleviating SMA symptoms, the lack of data dealing with the effects of different exercise types on diseased motor units still precludes the use of active physiotherapy in SMA patients. In the present study, we have evaluated the efficiency of two long-term physical exercise paradigms, based on either high intensity swimming or low intensity running, in alleviating SMA symptoms in a mild type 3 SMA-like mouse model. We found that 10 months' physical training induced significant benefits in terms of resistance to muscle damage, energetic metabolism, muscle fatigue and motor behaviour. Both exercise types significantly enhanced motor neuron survival, independently of SMN expression, leading to the maintenance of neuromuscular junctions and skeletal muscle phenotypes, particularly in the soleus, plantaris and tibialis of trained mice. Most importantly, both exercises significantly improved neuromuscular excitability properties. Further, all these training-induced benefits were quantitatively and qualitatively related to the specific characteristics of each exercise, suggesting that the related neuroprotection is strongly dependent on the specific activation of some motor neuron subpopulations. Taken together, the present data show significant long-term exercise benefits in type 3 SMA-like mice providing important clues for designing rehabilitation programmes in patients.

Tracheal extubation in children with difficult airways: a descriptive cohort analysis.Publié le 20 12 2016

BACKGROUND: Tracheal extubation in children with difficult airways may be associated with an increased risk of perioperative adverse events.
AIMS: The aim of this study was to describe the exubation techniques used/ success rates/ adverse events related to tracheal extubation practices in children with difficult airways.
METHODS: A retrospective analysis of tracheal extubation practices in the difficult airway population over a 78-month period was performed. Difficult airway was defined as a Cormack and Lehane Grade 3 view or greater, and/or tracheal intubation requiring ? 3 attempts, and/or the need for an alternate device to direct laryngoscopy for successful tracheal intubation, and/or difficult mask ventilation. Reasons for difficult airway, demographic/surgical data, technique(s) for tracheal extubation, success/failure of tracheal extubation, and adverse events were recorded. A failed tracheal extubation was defined as any adverse event related to the airway occurring within 6 h of extubation requiring reintubation.
RESULTS: A total of 519 patients were reported to have a difficult airway during this study period in a tertiary care pediatric center. Of these, 137 patients (26%) met inclusion criteria. Tracheal extubation was successfully performed in 130 patients (95%). The majority of tracheal exubations were performed without the use of additional airway adjuncts straight onto anesthesia face mask (121/137; 88%). Extubation failure occurred in seven cases (5%). Among the failed extubations, 6/7 children (85%) had evidence of severe upper airway obstruction and were <10 kg in weight. Of these children, one child required emergency tracheostomy, and two children (one with tracheal stenosis and other with spinal muscular atrophy) suffered from hypoxemic cardiac arrest and anoxic brain damage, respectively, and eventually died.
CONCLUSIONS: In the studied population of children with difficult airways handled in a tertiary center environment, the majority of tracheal extubations could be performed without the use of airway adjuncts. In a minority of patients, tracheal extubation was associated with severe adverse outcomes.

[Infantile spinal atrophy: our experience in the last 25 years].Publié le 16 12 2016

OBJECTIVES: To determine the incidence of spinal muscular atrophy (SMA) in our study population and genetic distribution and epidemiological and clinical characteristics and to analyze the level of care and development.
MATERIAL AND METHOD: Retrospective descriptive study of patients treated in our hospital in the past 25 years (from 1987 to early 2013), with a clinical and neurophysiological diagnosis of SMA.
RESULTS: A total of 37 patients were found, representing an incidence for our reference population and year of 1 case per 10,000 live births. Males predominated (male/female ratio: 1.6/1). The type of SMA diagnosed more frequently was, type i (26 cases), followed by type ii (9 cases), one case with SMA type iii, and one case of spinal muscular atrophy with respiratory distress type 1 (SMARD1). The most frequent genetic alteration was homozygous deletion of exons 7 and 8 of SMN1 gene in 31 cases, while five patients had atypical genetics. The median survival for type i was 8.0 months and 15.8 years for type ii.
CONCLUSIONS: The incidence in our population remains stable at around 1/10.000. Most cases presented with, predominantly male, typical genetics. In approximately 1/10 patients the genetic alteration was different from the classical one to the SMN gene. The prevalence of AME unrelated SMN gene was 1/37. The level of care has increased in line with social and welfare demands in recent years.

A rapidly progressive defective spermatogenesis in a Mexican family affected by spino-bulbar muscular atrophy.Publié le 15 12 2016

Spino-bulbar muscular atrophy (SBMA) is an X-linked recessive adult progressive disorder affecting motor neurons. It is caused by a poly-glutamine tract expansion in the androgen receptor (AR) which generates protein aggregates that cannot be processed by proteasomes. A secondary mild androgen resistance is developed by AR dysfunction and patients present endocrine abnormalities including gynecomastia and poor function of testosterone in tissues; however, normally they are fertile. In this report we describe a Mexican family with three affected brothers with primary infertility caused by a progressive impairment of spermatogenesis leading to azoospermia before 40 years of age. They presented common features associated to patients affected by SMBA, such as gynecomastia, high level of CPK, muscle cramps, fasciculations, muscle wastage, and impaired swallowing. Two intracytoplasmic sperm injection (ICSI) cycles were performed in one of the patients resulting in fertilization failure. Molecular analysis of AR gene exon 1 revealed 54 CAG repeats in DNA extracted from leukocytes in affected patients and 22 repeats in the fertile non-affected brother. Severe impaired spermatogenesis of rapid progression has not been associated before to SBMA. This is the first report of assisted reproduction techniques indicated by male infertility in patients with this rare disorder. Further studies are required to confirm the unusual result of intracytoplasmic sperm injection cycles. We discuss the implications and possible pathogenesis of these unique features of SBMA in this family.

A Case Report of Camptocormia Coinciding With Olanzapine Use.Publié le 15 12 2016

PMID: 26872119 [PubMed - indexed for MEDLINE]

Outcome of deep brain stimulation in slowly progressive multiple system atrophy: A clinico-pathological series and review of the literature.Publié le 15 12 2016

OBJECTIVES: To highlight the risk of clinical worsening after deep brain stimulation in histologically proven multiple system atrophy (MSA) patients presenting slow and relatively benign disease progression mimicking Parkinson's disease (PD). In such cases but also in more typical MSA patients, the results of deep brain stimulation have been mostly reported as case reports and small patient series.
METHODS: The present study describes the outcome of the largest series of histologically proven MSA patients who underwent deep brain stimulation (DBS) of the subthalamic nucleus because they were considered as having PD at the time of surgery.
RESULTS: Three patients showed significant improvement of motor signs after surgery while two did not. Clinical improvement was short-lasting and rapidly followed by the occurrence of disabling manifestations of MSA that counteracted DBS benefits.
CONCLUSIONS: Together with previous reports, our study demonstrates that DBS should not be recommended for MSA patients. It also underlines that detecting subtle red flags is crucial to avoid DBS surgery in this population.

Treatment of infantile-onset spinal muscular atrophy with nusinersen: a phase 2, open-label, dose-escalation study.Publié le 14 12 2016

BACKGROUND: Nusinersen is a 2'-O-methoxyethyl phosphorothioate-modified antisense drug being developed to treat spinal muscular atrophy. Nusinersen is specifically designed to alter splicing of SMN2 pre-mRNA and thus increase the amount of functional survival motor neuron (SMN) protein that is deficient in patients with spinal muscular atrophy.
METHODS: This open-label, phase 2, escalating dose clinical study assessed the safety and tolerability, pharmacokinetics, and clinical efficacy of multiple intrathecal doses of nusinersen (6 mg and 12 mg dose equivalents) in patients with infantile-onset spinal muscular atrophy. Eligible participants were of either gender aged between 3 weeks and 7 months old with onset of spinal muscular atrophy symptoms between 3 weeks and 6 months, who had SMN1 homozygous gene deletion or mutation. Safety assessments included adverse events, physical and neurological examinations, vital signs, clinical laboratory tests, cerebrospinal fluid laboratory tests, and electrocardiographs. Clinical efficacy assessments included event free survival, and change from baseline of two assessments of motor function: the motor milestones portion of the Hammersmith Infant Neurological Exam-Part 2 (HINE-2) and the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) motor function test, and compound motor action potentials. Autopsy tissue was analysed for target engagement, drug concentrations, and pharmacological activity. HINE-2, CHOP-INTEND, and compound motor action potential were compared between baseline and last visit using the Wilcoxon signed-rank test. Age at death or permanent ventilation was compared with natural history using the log-rank test. The study is registered at ClinicalTrials.gov, number NCT01839656.
FINDINGS: 20 participants were enrolled between May 3, 2013, and July 9, 2014, and assessed through to an interim analysis done on Jan 26, 2016. All participants experienced adverse events, with 77 serious adverse events reported in 16 participants, all considered by study investigators not related or unlikely related to the study drug. In the 12 mg dose group, incremental achievements of motor milestones (p<0·0001), improvements in CHOP-INTEND motor function scores (p=0·0013), and increased compound muscle action potential amplitude of the ulnar nerve (p=0·0103) and peroneal nerve (p<0·0001), compared with baseline, were observed. Median age at death or permanent ventilation was not reached and the Kaplan-Meier survival curve diverged from a published natural history case series (p=0·0014). Analysis of autopsy tissue from patients exposed to nusinersen showed drug uptake into motor neurons throughout the spinal cord and neurons and other cell types in the brainstem and other brain regions, exposure at therapeutic concentrations, and increased SMN2 mRNA exon 7 inclusion and SMN protein concentrations in the spinal cord.
INTERPRETATION: Administration of multiple intrathecal doses of nusinersen showed acceptable safety and tolerability, pharmacology consistent with its intended mechanism of action, and encouraging clinical efficacy. Results informed the design of an ongoing, sham-controlled, phase 3 clinical study of nusinersen in infantile-onset spinal muscular atrophy.
FUNDING: Ionis Pharmaceuticals, Inc and Biogen.

Normalization of Patient-Identified Plasma Biomarkers in SMN?7 Mice following Postnatal SMN Restoration.Publié le 03 12 2016

INTRODUCTION AND OBJECTIVE: Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disorder. SMA is caused by homozygous loss of the SMN1 gene and retention of the SMN2 gene resulting in reduced levels of full length SMN protein that are insufficient for motor neuron function. Various treatments that restore levels of SMN are currently in clinical trials and biomarkers are needed to determine the response to treatment. Here, we sought to investigate in SMA mice a set of plasma analytes, previously identified in patients with SMA to correlate with motor function. The goal was to determine whether levels of plasma markers were altered in the SMN?7 mouse model of SMA and whether postnatal SMN restoration resulted in normalization of the biomarkers.
METHODS: SMN?7 and control mice were treated with antisense oligonucleotides (ASO) targeting ISS-N1 to increase SMN protein from SMN2 or scramble ASO (sham treatment) via intracerebroventricular injection on postnatal day 1 (P1). Brain, spinal cord, quadriceps muscle, and liver were analyzed for SMN protein levels at P12 and P90. Ten plasma biomarkers (a subset of biomarkers in the SMA-MAP panel available for analysis in mice) were analyzed in plasma obtained at P12, P30, and P90.
RESULTS: Of the eight plasma biomarkers assessed, 5 were significantly changed in sham treated SMN?7 mice compared to control mice and were normalized in SMN?7 mice treated with ASO.
CONCLUSION: This study defines a subset of the SMA-MAP plasma biomarker panel that is abnormal in the most commonly used mouse model of SMA. Furthermore, some of these markers are responsive to postnatal SMN restoration. These findings support continued clinical development of these potential prognostic and pharmacodynamic biomarkers.

A Comparative Study of SMN Protein and mRNA in Blood and Fibroblasts in Patients with Spinal Muscular Atrophy and Healthy Controls.Publié le 29 11 2016

BACKGROUND: Clinical trials to test safety and efficacy of drugs for patients with spinal muscular atrophy (SMA) are currently underway. Biomarkers that document treatment-induced effects are needed because disease progression in childhood forms of SMA is slow and clinical outcome measures may lack sensitivity to detect meaningful changes in motor function in the period of 1-2 years of follow-up during randomized clinical trials.
OBJECTIVE: To determine and compare SMN protein and mRNA levels in two cell types (i.e. PBMCs and skin-derived fibroblasts) from patients with SMA types 1-4 and healthy controls in relation to clinical characteristics and SMN2 copy numbers.
MATERIALS AND METHODS: We determined SMN1, SMN2-full length (SMN2-FL), SMN2-delta7 (SMN2-?7), GAPDH and 18S mRNA levels and SMN protein levels in blood and fibroblasts from a total of 150 patients with SMA and 293 healthy controls using qPCR and ELISA. We analyzed the association with clinical characteristics including disease severity and duration, and SMN2 copy number.
RESULTS: SMN protein levels in PBMCs and fibroblasts were higher in controls than in patients with SMA (p<0.01). Stratification for SMA type did not show differences in SMN protein (p>0.1) or mRNA levels (p>0.05) in either cell type. SMN2 copy number was associated with SMN protein levels in fibroblasts (p = 0.01), but not in PBMCs (p = 0.06). Protein levels in PBMCs declined with age in patients (p<0.01) and controls (p<0.01)(power 1-beta = 0.7). Ratios of SMN2-?7/SMN2-FL showed a broad range, primarily explained by the variation in SMN2-?7 levels, even in patients with a comparable SMN2 copy number. Levels of SMN2 mRNA did not correlate with SMN2 copy number, SMA type or age in blood (p = 0.7) or fibroblasts (p = 0.09). Paired analysis between blood and fibroblasts did not show a correlation between the two different tissues with respect to the SMN protein or mRNA levels.
CONCLUSIONS: SMN protein levels differ considerably between tissues and activity is age dependent in patients and controls. SMN protein levels in fibroblasts correlate with SMN2 copy number and have potential as a biomarker for disease severity.

ML372 blocks SMN ubiquitination and improves spinal muscular atrophy pathology in mice.Publié le 25 11 2016

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease and one of the leading inherited causes of infant mortality. SMA results from insufficient levels of the survival motor neuron (SMN) protein, and studies in animal models of the disease have shown that increasing SMN protein levels ameliorates the disease phenotype. Our group previously identified and optimized a new series of small molecules, with good potency and toxicity profiles and reasonable pharmacokinetics, that were able to increase SMN protein levels in SMA patient-derived cells. We show here that ML372, a representative of this series, almost doubles the half-life of residual SMN protein expressed from the SMN2 locus by blocking its ubiquitination and subsequent degradation by the proteasome. ML372 increased SMN protein levels in muscle, spinal cord, and brain tissue of SMA mice. Importantly, ML372 treatment improved the righting reflex and extended survival of a severe mouse model of SMA. These results demonstrate that slowing SMN degradation by selectively inhibiting its ubiquitination can improve the motor phenotype and lifespan of SMA model mice.

Activin Receptor Type IIB Inhibition Improves Muscle Phenotype and Function in a Mouse Model of Spinal Muscular Atrophy.Publié le 22 11 2016

Spinal muscular atrophy (SMA) is a devastating neurodegenerative disorder that causes progressive muscle atrophy and weakness. Using adeno-associated virus-mediated gene transfer, we evaluated the potential to improve skeletal muscle weakness via systemic, postnatal inhibition of either myostatin or all signaling via the activin receptor type IIB (ActRIIB). After demonstrating elevated p-SMAD3 content and differential content of ActRIIB ligands, 4-week-old male C/C SMA model mice were treated intraperitoneally with 1x1012 genome copies of pseudotype 2/8 virus encoding a soluble form of the ActRIIB extracellular domain (sActRIIB) or protease-resistant myostatin propeptide (dnMstn) driven by a liver specific promoter. At 12 weeks of age, muscle mass and function were improved in treated C/C mice by both treatments, compared to controls. The fast fiber type muscles had a greater response to treatment than did slow muscles, and the greatest therapeutic effects were found with sActRIIB treatment. Myostatin/activin inhibition, however, did not rescue C/C mice from the reduction in motor unit numbers of the tibialis anterior muscle. Collectively, this study indicates that myostatin/activin inhibition represents a potential therapeutic strategy to increase muscle mass and strength, but not neuromuscular junction defects, in less severe forms of SMA.

Gait Assessment with SoleSound Instrumented Footwear in Spinal Muscular Atrophy.Publié le 21 11 2016

BACKGROUND: Gait impairment is common in spinal muscular atrophy (SMA) and is described using clinical assessments and instrumented walkways. Continuous over-ground walking has not been studied.
METHODS: Nine SMA participants completed the six-minute walk test (6MWT) and 10-meter walk/run wearing instrumented footwear (SoleSound). Data were simultaneously collected using a reference system (GAITRite(TM) ). The root mean square error (RMSE) indicated criterion validity. The decrease in walking speed represented fatigue. Foot loading patterns were evaluated using force sensors.
RESULTS: The RMSE for stride time, length, and velocity ranged from 1.3-1.7%. Fatigue was 11.6±9.1%, which corresponded to an average deceleration of 0.37±0.28mm/s(2) . Participants spent most of stance without heel contact. Forefoot contact occurred early in the gait cycle.
CONCLUSIONS: These results suggest that footwear-based devices are an alternative to specialized equipment for gait assessment. Better understanding of gait disturbances should inform ongoing treatment efforts and provide a more sensitive outcome measure. This article is protected by copyright. All rights reserved.

Stress-Induced Ketoacidosis in Spinal Muscular Atrophy: An Under-Recognized Complication.Publié le 18 11 2016

Ketoacidosis is an important but under-recognized complication of neuromuscular disease, in particular spinal muscular atrophy. This easily treatable condition is largely overlooked in best practice guidelines, and lack of awareness contributes to adverse outcomes in this patient population. Neuromyopathy associated ketosis should be considered in all patients with severe muscle wasting presenting with an elevated anion gap metabolic ketoacidosis. Treatment is simple, effective, and should be instituted early. Our report of a 50-year-old patient with type 2 spinal muscular atrophy who presents with recurrent ketoacidosis aims to increase awareness of neuromyopathy associated ketosis as a clinical entity, and to enhance its early recognition and timely treatment in order to improve patient outcomes.

Therapeutic Potential of Tricyclo-DNA antisense oligonucleotides.Publié le 18 11 2016

Oligonucleotide therapeutics hold great promise for the treatment of various diseases and the antisense field is constantly gaining interest due to the development of more potent and nuclease resistant chemistries. Despite a rather low success rate with only three antisense drugs being clinically approved, the frontiers of AON therapeutic applications have increased over the past three decades and continue to expand thanks to a steady increase in understanding the mechanisms of action of these molecules, progress in chemical modification and delivery.In this review, we will examine the recent advances obtained with the tricyclo-DNA chemistry which displays unique pharmacological properties and unprecedented uptake in many tissues after systemic administration. We will review their specific properties and their therapeutic applications mainly for neuromuscular disorders, including exon-skipping for Duchenne muscular dystrophy and exon-inclusion for spinal muscular atrophy, but also aberrant splicing correction for Pompe disease. Finally, we will discuss their advantages and potential limitations, with a focus on the need for careful toxicological screen early in the process of AON drug development.

Spontaneous Breathing Pattern as Respiratory Functional Outcome in Children with Spinal Muscular Atrophy (SMA).Publié le 09 11 2016

INTRODUCTION: SMA is characterised by progressive motor and respiratory muscle weakness. We aimed to verify if in SMA children 1)each form is characterized by specific ventilatory and thoraco-abdominal pattern(VTAp) during quiet breathing(QB); 2)VTAp is affected by salbutamol therapy, currently suggested as standard treatment, or by the natural history(NH) of SMA; 3)the severity of global motor impairment linearly correlates with VTAp.
MATERIALS AND METHODS: VTAp was analysed on 32 SMA type I (SMA1,the most severe form), 51 type II (SMA2,the moderate), 8 type III (SMA3,the mildest) and 20 healthy (HC) using opto-electronic plethysmography. Spirometry, cough and motor function were measured in a subgroup of patients.
RESULTS: In SMA1, a normal ventilation is obtained in supine position by rapid and shallow breathing with paradoxical ribcage motion. In SMA2, ventilation is within a normal range in seated position due to an increased respiratory rate(p<0.05) with reduced tidal volume(p<0.05) secondary to a poor contribution of pulmonary ribcage(%?VRC,P, p<0.001). Salbutamol therapy had no effect on VTAp during QB(p>0.05) while tachypnea occurred in type I NH. A linear correlation(p<0.001) was found between motor function scales and VTAp.
CONCLUSION: A negative or reduced %?VRC,P, indicative of ribcage muscle weakness, is a distinctive feature of SMA1 and SMA2 since infancy. Its quantitative assessment represents a non-invasive, non-volitional index that can be obtained in all children, even uncollaborative, and provides useful information on the action of ribcage muscles that are known to be affected by the disease.Low values of motor function scales indicate impairment of motor but also of respiratory function.

The effect of scoliosis surgery on pulmonary function in spinal muscular atrophy type II patients.Publié le 06 11 2016

PURPOSE: Various results of the previous literature related to surgical effect on pulmonary function of spinal muscular atrophy (SMA) patients might be due to different SMA type, different fusion level and technique. The aim of this study was to determine the value of scoliosis surgery for SMA type II patients with regard to pulmonary function, under the same fusion level, fusion technique and average long-term follow-up.
METHODS: Ten SMA II patients who underwent spinal correction procedures from 1993 to 2010 were identified. Data on clinical features and pulmonary function, including forced vital capacity (FVC) and forced expiratory volume in 1st second (FEV1), were collected. The data on pulmonary function were divided into preoperative, postoperative short-term (0-5 years), mid-term (5-10 years), and long-term (>10 years). Statistical comparisons were made using the Wilcoxon test for pulmonary function and body weight analysis. Questions were answered by parents on how surgery influenced the frequency of respiratory infection and the ability to sit at school.
RESULTS: The average length of postoperative pulmonary function follow-up was 12.3 years (range 4.9-15.9 years). There was no significant difference in FVC or FEV1 between preoperative and each postoperative period. However, a significant decline from mid-term to long-term was observed (p = 0.028). Body weight increased significantly in all postoperative periods and was moderately correlated to pulmonary function (r = 0.526 for FVC). The answers to the questionnaire revealed that 80% of the patients had obvious improvement in the frequency of respiratory infection and 100% were tolerable sitting at school.
CONCLUSIONS: Surgical correction for scoliosis in SMA II patients results in pulmonary function being maintained during long-term follow-up. In addition, the advantages of surgery also include body weight gain, better sitting tolerance, and reduced frequency of respiratory infection.

Translational development of splice-modifying antisense oligomers.Publié le 03 11 2016

INTRODUCTION: Antisense nucleic acid analogues can interact with pre-mRNA motifs and influence exon or splice site selection and thereby alter gene expression. Design of antisense molecules to target specific motifs can result in either exon exclusion or exon inclusion during splicing. Novel drugs exploiting the antisense concept are targeting rare, life-limiting diseases; however, the potential exists to treat a wide range of conditions by antisense-mediated splice intervention. Areas covered: In this review, the authors discuss the clinical translation of novel molecular therapeutics to address the fatal neuromuscular disorders Duchenne muscular dystrophy and spinal muscular atrophy. The review also highlights difficulties posed by issues pertaining to restricted participant numbers, variable phenotype and disease progression, and the identification and validation of study endpoints. Expert opinion: Translation of novel therapeutics for Duchenne muscular dystrophy and spinal muscular atrophy has been greatly advanced by multidisciplinary research, academic-industry partnerships and in particular, the engagement and support of the patient community. Sponsors, supporters and regulators are cooperating to deliver new drugs and identify and define meaningful outcome measures. Non-conventional and adaptive trial design could be particularly suited to clinical evaluation of novel therapeutics and strategies to treat serious, rare diseases that may be problematic to study using more conventional clinical trial structures.

Expanded carrier screening: A review of early implementation and literature.Publié le 02 11 2016

Carrier screening is the practice of testing individuals to identify those at increased risks of having children affected by genetic diseases. Professional guidelines on carrier screening have been available for more than 15 years, and have historically targeted specific diseases that occur at increased frequencies in defined ethnic populations. Enabled by rapidly evolving technology, expanded carrier screening aims to identify carriers for a broader array of diseases and may be applied universally (equally across all ethnic groups). This new approach deviates from the well-established criteria for screening models. In this review, we summarize the rationale for expanded carrier screening using available literature regarding clinical and technical data, as well as provider perspectives. We also discuss important avenues for further research in this burgeoning field.

Willingness to Pay for a Newborn Screening Test for Spinal Muscular Atrophy.Publié le 24 10 2016

OBJECTIVES: The current US mandatory newborn screening panel does not include spinal muscular atrophy, the most common fatal genetic disease among children. We assessed population preferences for newborn screening for spinal muscular atrophy, and how test preferences varied depending on immediate treatment implications.
METHODS: We conducted an online willingness-to-pay survey of US adults (n = 982). Respondents were asked to imagine being parents of a newborn. Each respondent was presented with two hypothetical scenarios following the spinal muscular atrophy screening test: current standard of care (no treatment available) and one of three randomly assigned scenarios (new treatment available to improve functioning, survival, or both). We used a bidding game to elicit willingness to pay for the spinal muscular atrophy test, and performed a two-part model to estimate median and mean willingness-to-pay values.
RESULTS: Most respondents (79% to 87%) would prefer screening their newborns for spinal muscular atrophy. People expressed a willingness to pay for spinal muscular atrophy screening even without an available therapy (median: $142; mean: $253). Willingness to pay increased with treatment availability (median: $161 to $182; mean: $270 to $297) and respondent income. Most respondents considered test accuracy, treatment availability, and treatment effectiveness very important or important factors in deciding willingness to pay.
CONCLUSIONS: Most people would prefer and would be willing to pay for testing their newborn for spinal muscular atrophy, even in the absence of direct treatment. People perceive the spinal muscular atrophy test more valuable if treatment were available to improve the newborn's functioning and survival. Despite preferences for the test information, adding spinal muscular atrophy to newborn screening programs remains controversial. Future studies are needed to determine how early detection may impact long-term patient outcomes.

Developmental milestones in type I spinal muscular atrophy.Publié le 24 10 2016

The aim of this retrospective multicentric study was to assess developmental milestones longitudinally in type I SMA infants using the Hammersmith Infant Neurological Examination. Thirty-three type I SMA infants, who classically do not achieve the ability to sit unsupported, were included in the study. Our results confirmed that all patients had a score of 0 out of a scale of 4 on items assessing sitting, rolling, crawling, standing or walking. A score of more than 0 was only achieved in three items: head control (n?=?13), kicking (n?=?15) and hand grasp (n?=?18). In these items, the maximal score achieved was 1 out of a scale of 4, indicating only partial achievement of the milestone. Infants with symptom onset after 6 months of age had longer preservation of a score of 1 when compared to those with onset before 6 months of age. Our results suggest that even when current standards of care are applied, developmental milestones are rarely even partially achieved as part of natural history in type I SMA infants. No infants in this study achieved a major milestone such as rolling over, or sitting independently, which would therefore represent robust outcomes in future interventional trials.

Perceived efficacy of salbutamol by persons with spinal muscular atrophy: A mixed methods study.Publié le 22 10 2016

INTRODUCTION: The aim of this study was to assess the perceived effect of salbutamol in adult patients with spinal muscular atrophy and to evaluate the usefulness of the World Health Organization Disability Assessment Schedule II (WHODAS II) and Fatigue Severity Scale (FSS) for its measurement.
METHODS: A longitudinal mixed methods study was performed. Ten patients were interviewed and completed WHODAS II and FSS questionnaires to assess disability and fatigue at 2 time-points. Inductive thematic analysis was used for qualitative data. The non-parametric Wilcoxon test was performed for quantitative analysis.
RESULTS: All participants reported an improvement in their condition after salbutamol consumption. WHODAS II and FSS reliably captured changes in patients' disability and fatigue.
CONCLUSIONS: The mixed methods design allowed us to identify the functional domains in which participants experienced effects of salbutamol. Patients were satisfied with the treatment as shown by decreased fatigue, improved functioning, and infrequent side effects. Muscle Nerve, 2016 Muscle Nerve 54: 843-849, 2016.

Distribution and Penetration of Intracerebroventricularly Administered 2'OMePS Oligonucleotide in the Mouse Brain.Publié le 20 10 2016

Antisense oligonucleotide (AON) therapy is emerging as a potential treatment strategy for neurodegenerative diseases, such as spinal muscular atrophy, Huntington's disease, and amyotrophic lateral sclerosis. AONs function at the cellular level by, for example, direct interference with the expression of gene products or the molecular activation of neuroprotective pathways. However, AON therapy faces a major obstacle limiting its clinical application for central nervous system (CNS) disorders: the blood-brain barrier. Systemic administration of AONs leads to rapid clearance and breakdown of its molecules in the periphery. One way to overcome this obstacle is intracerebroventricular (ICV) delivery of the therapeutics directly to cerebrospinal fluid (CSF). Given the particular molecular structure of oligonucleotides, the (pharmaco) kinetic and distribution pattern of these compounds in the brain are yet to be clarified. In this study, 2'OMePS oligonucleotide delivered through ICV into CSF reached the most key structures in the brain. The distribution of this oligonucleotide differed when comparing specific brain structures and cell groups. After 48?h post-infusion, the distribution of the oligonucleotide reached its maximum and was found intracellularly in many key brain structures. These findings help understanding the kinetic and distribution pattern of 2'OMePS oligonucleotide in the brain and will direct more rational and effective use of ICV drug delivery and unleash its full therapeutic potential in managing CNS diseases.

Altered mRNA Splicing in SMN-Depleted Motor Neuron-Like Cells.Publié le 14 10 2016

Spinal muscular atrophy (SMA) is an intractable neurodegenerative disease afflicting 1 in 6-10,000 live births. One of the key functions of the SMN protein is regulation of spliceosome assembly. Reduced levels of the SMN protein that are observed in SMA have been shown to result in aberrant mRNA splicing. SMN-dependent mis-spliced transcripts in motor neurons may cause stresses that are particularly harmful and may serve as potential targets for the treatment of motor neuron disease or as biomarkers in the SMA patient population. We performed deep RNA sequencing using motor neuron-like NSC-34 cells to screen for SMN-dependent mRNA processing changes that occur following acute depletion of SMN. We identified SMN-dependent splicing changes, including an intron retention event that results in the production of a truncated Rit1 transcript. This intron-retained transcript is stable and is mis-spliced in spinal cord from symptomatic SMA mice. Constitutively active Rit1 ameliorated the neurite outgrowth defect in SMN depleted NSC-34 cells, while expression of the truncated protein product of the mis-spliced Rit1 transcript inhibited neurite extension. These results reveal new insights into the biological consequence of SMN-dependent splicing in motor neuron-like cells.

Therapy-resistant symptoms in Parkinson's disease.Publié le 13 10 2016

In recent years, the management of Parkinson's disease (PD) has come a long way, leading to an increase in therapeutic options that now include oral and transdermal drug delivery, infusion as well as surgical treatments. Nonetheless, in the evolution of this complex neurodegenerative disorder, several symptoms remain refractory to dopaminergic therapy. It is our aim to review the literature to date and to bring them into focus, as well as emphasizing on pathophysiological mechanisms, profile of risk factors in their development, and therapeutic options. We will focus on freezing of gait, camptocormia, dysphagia and dysphonia, as well as cognitive impairment and dementia because they represent the far end of therapy-resistant symptoms, encompassing poor health-related quality of life and often a more reserved prognosis with either a rapid evolution of the disease, and/or merely a more severe clinical picture. Pathophysiological mechanisms and brain neurotransmitter abnormalities behind these symptoms seem to overlap to some extent, and a better understanding of these correlations is desirable. We believe that further research is paramount to expand our knowledge of the dopamine-resistant symptoms and, consequently, to develop specific therapeutic strategies.

Scoliosis and the impact in neuromuscular disease.Publié le 08 10 2016

Scoliosis can alter respiratory mechanics by changing the orientation of the muscles and joints of the respiratory system and in severe forms can put a patient at risk of severe respiratory morbidity or respiratory failure. However, perhaps the most important factor in determining the pulmonary morbidity in scoliosis is the balance between the "load" or altered respiratory mechanics and the "pump" or the respiratory muscle strength. Therefore, scoliosis in patients with neuromuscular disease will both lead to increased "load" and a weakened "pump", an exceptionally unfortunate combination. While progressive neuromuscular disease by its nature does not respond favorably to attempts to improve respiratory muscle strength, the natural approach of early proactive management of the "load" and in the case of scoliosis a variety of different strategies have been tried with variable short term and long term results. Figuring this out requires both an understanding of the underlying pathophysiology of a particular neuromuscular condition and the available options for and timing of surgical intervention.

Physician driven variation in the care of children with spinal muscular atrophy type 1.Publié le 01 10 2016

BACKGROUND: Increasing numbers of families are requesting active supportive management for their child with spinal muscular atrophy type 1 (SMA1), leading to longer survival and greater prevalence of affected children. Strong opinions exist among physicians for and against the provision of care measures prolonging life.
OBJECTIVE: To describe current practice in the care of SMA1 in Canada, and explore the factors underlying inter-physician variability.
METHODS: A cross-sectional survey of Canadian hospital-based pediatric neurologists and pediatric respirologists was performed in 2015. Odds ratios and 95% confidence intervals were calculated to compare proportions between groups.
RESULTS: There was a 54% completion rate (99 physicians). Over half of participants believed that a disease modifying therapy was likely within 10 years. Quebec respirologists were 50 times less likely to offer long-term non-invasive ventilation (NIV) than respirologists in other provinces (OR 50.6, 95% CI 2.4-1075.3), and 20 times less likely to discuss tracheostomy with families (OR 20.4, 95% CI 2.0-211.8). High raters of perceived happiness of affected children were more likely to find NIV an acceptable measure for acute (OR 6.7, 95% CI 1.7-26.0) and chronic (OR 13.7, 95% CI 4.0-46.4) respiratory failure and prophylactic use (OR 5.8, 95% CI 2.2-15.6).
CONCLUSION: Physician knowledge, opinions, subjective perception of child happiness, and regional factors, all influence physicians' practices and the shared decision-making process. Parents may not be informed or offered all the services available to their child. Knowledge translation initiatives are needed to enhance SMA1 care. Pediatr Pulmonol. 2016; 9999:1-7. © 2016 Wiley Periodicals, Inc.

Prevention and treatment of scoliosis by Garches Brace in children with type Ib SMA.Publié le 28 09 2016

OBJECTIVE: To evaluate the effectiveness of use of Garches Brace (GB) on prevention and treatment of scoliosis and its impact on quality of life, in a group of patients with spinal muscular atrophy (SMA) type Ib.
MATERIAL/PATIENTS AND METHODS: We identified 102 patients with SMA not acquiring sitting position, but acquiring head dress (type Ib SMA) followed at our center between 1975 and 2009. We reviewed the charts and identified 25 patients that were treated by GB and had a follow-up in our department of three years or more. We collected and analyzed data including functional aspects in activities of daily living, quality of life, respiratory management, radiological Cobb angle (taken in lying position without brace).
RESULTS: The GB treatment started at a mean age of 2,08 years (range 0,74-5,77) and GB was worn for a mean of 10,63 years (SD 2,55) before spinal fusion. Eighteen patients (72%) had spinal fusion, of whom 16 patients (64%) had less than 50° of Cobb angle when arriving at the age of spinal fusion, with a mean preoperative Cobb angle of 46,70° (range 0-85). Evolution of Cobb angle function to age was 2,4° per year. Sixteen patients (64%) gained mobility with an electric wheelchair and 12 patients (48%) accessed to school.
DISCUSSION - CONCLUSION: Current studies on orthopedic management of scoliosis in most severe SMA patients are limited to type 2 and 3 SMA with scoliosis evolving between 54 and 95°Cobbangle before spinal surgery. There is not available data on the therapeutic effects of orthopedic treatment of spine in type 1b SMA patients. The Garches Brace has shown to be an effective tool in the prevention and management of spinal deformities and in the stabilization of the pelvis. Besides, it allows stable sitting and upright head position, contributing to a better quality of life and a better accessibility to activities of daily living. The Garches Brace is generally well tolerated in children without significant side effects.

TBCE Mutations Cause Early-Onset Progressive Encephalopathy with Distal Spinal Muscular Atrophy.Publié le 28 09 2016

Tubulinopathies constitute a family of neurodevelopmental/neurodegenerative disorders caused by mutations in several genes encoding tubulin isoforms. Loss-of-function mutations in TBCE, encoding one of the five tubulin-specific chaperones involved in tubulin folding and polymerization, cause two rare neurodevelopmental syndromes, hypoparathyroidism-retardation-dysmorphism and Kenny-Caffey syndrome. Although a missense mutation in Tbce has been associated with progressive distal motor neuronopathy in the pmn/pmn mice, no similar degenerative phenotype has been recognized in humans. We report on the identification of an early-onset and progressive neurodegenerative encephalopathy with distal spinal muscular atrophy resembling the phenotype of pmn/pmn mice and caused by biallelic TBCE mutations, with the c.464T>A (p.Ile155Asn) change occurring at the heterozygous/homozygous state in six affected subjects from four unrelated families originated from the same geographical area in Southern Italy. Western blot analysis of patient fibroblasts documented a reduced amount of TBCE, suggestive of rapid degradation of the mutant protein, similarly to what was observed in pmn/pmn fibroblasts. The impact of TBCE mutations on microtubule polymerization was determined using biochemical fractionation and analyzing the nucleation and growth of microtubules at the centrosome and extracentrosomal sites after treatment with nocodazole. Primary fibroblasts obtained from affected subjects displayed a reduced level of polymerized ?-tubulin, similarly to tail fibroblasts of pmn/pmn mice. Moreover, markedly delayed microtubule re-polymerization and abnormal mitotic spindles with disorganized microtubule arrangement were also documented. Although loss of function of TBCE has been documented to impact multiple developmental processes, the present findings provide evidence that hypomorphic TBCE mutations primarily drive neurodegeneration.

Camptocormia and Pisa syndrome as manifestations of acute myasthenia gravis exacerbation.Publié le 28 09 2016

PMID: 26671078 [PubMed - indexed for MEDLINE]

Efficacy and biodistribution analysis of intracerebroventricular administration of an optimized scAAV9-SMN1 vector in a mouse model of spinal muscular atrophy.Publié le 22 09 2016

Spinal muscular atrophy (SMA) is an autosomal recessive disease of variable severity caused by mutations in the SMN1 gene. Deficiency of the ubiquitous SMN function results in spinal cord ?-motor neuron degeneration and proximal muscle weakness. Gene replacement therapy with recombinant adeno-associated viral (AAV) vectors showed therapeutic efficacy in several animal models of SMA. Here, we report a study aimed at analyzing the efficacy and biodistribution of a serotype-9, self-complementary AAV vector expressing a codon-optimized human SMN1 coding sequence (coSMN1) under the control of the constitutive phosphoglycerate kinase (PGK) promoter in neonatal SMN?7 mice, a severe animal model of the disease. We administered the scAAV9-coSMN1 vector in the intracerebroventricular (ICV) space in a dose-escalating mode, and analyzed survival, vector biodistribution and SMN protein expression in the spinal cord and peripheral tissues. All treated mice showed a significant, dose-dependent rescue of lifespan and growth with a median survival of 346 days. Additional administration of vector by an intravenous route (ICV+IV) did not improve survival, and vector biodistribution analysis 90 days postinjection indicated that diffusion from the cerebrospinal fluid to the periphery was sufficient to rescue the SMA phenotype. These results support the preclinical development of SMN1 gene therapy by CSF vector delivery.

Polyarticular Arthritis and Spinal Muscular Atrophy in Acid Ceramidase Deficiency.Publié le 22 09 2016

Survival of motor neuron 1-------negative spinal muscular atrophy (SMA) is heterogeneous and remains a diagnostic challenge. The clinical spectrum continues to expand and ?33 genes have been identified to date. The present report describes a 9-year-old girl with novel clinical phenotype of a patient with polyarticular arthritis followed by symptoms of SMA due to acid ceramidase deficiency. Whole exome sequencing identified compound heterozygous pathogenic mutation in the N-acylsphingosine amidohydrolase 1 gene. Functional assay with leukocyte acid ceramidase activity showed a decreased level in the proband confirming pathogenicity of the mutations. Mutations of N-acylsphingosine amidohydrolase 1 are known to separately cause Farber disease (arthritis, subcutaneous nodules, and dysphonia) or SMA with progressive myoclonic epilepsy. The present combined phenotype is novel, bringing together SMA with progressive myoclonic epilepsy and Farber disease and establishing a phenotypic spectrum. Acid ceramidase deficiency is an important consideration in patients presenting with polyarticular arthritis and motor neuron disease.

Treatment of camptocormia with botulinum toxin.Publié le 20 09 2016

Camptocormia is defined as an involuntary axial postural distortion of >45° flexion which occurs in the upright position, increases whilst walking and resolves when supine (Ashour and Jankovic, 2006). Unlike orthopaedic or age related kyphosis it is not a fixed structural deformity and produces kyphosis at predominantly lumbar and thoracic rather than cervical regions. Camptocormia has been reported due to a wide range of neurologic, psychiatric, muscular and orthopaedic conditions as well as rare reports of its emergence following the initiation of a number of medications (Finsterer and Strobl, 2010). Parkinson's disease (PD) includes prominent motor features of bradykinesia, rigidity and reduced postural balance responses in all those affected with this disease, but can also cause a range of other motor and non-motor features. Camptocormia is reported in a minority of patients with PD, and it is usually associated with longer disease duration and greater disease burden (Tiple et al., 2009). The aetiology of camptocormia in PD is debated, and responses to treatment have been generally poor and variable between studies. Recent studies have suggested the use of botulinum toxin may improve posture in some affected individuals.

Radiographic and Respiratory Effects of Growing Rods in Children With Spinal Muscular Atrophy.Publié le 18 09 2016

BACKGROUND: Respiratory weakness and spinal deformity are common in patients with spinal muscular atrophy (SMA). Posterior (distraction type) growing rods have recently gained favor as a treatment option in this population, due to their ability to prevent spinal deformity progression and their potential to allow lung volumes to increase over time. The objective of this study was to determine the impact of posterior growing rods on the spinal alignment and respiratory function in children with SMA with intermediate term follow-up.
METHODS: A single center, retrospective review was performed on SMA patients treated with growing rods, inserted between 2004 and 2010, with a minimum of 2-year follow-up. SMA type, changes in the route of bi-level positive airway pressure respiratory support and the amount of time receiving respiratory support are reported. Pulmonary function tests (PFTs) and radiographs were reviewed and data evaluated preinsertion, postinsertion, and at latest follow-up.
RESULTS: Sixteen children with SMA (5 type I, 11 type II) met inclusion criteria. The average age of insertion was 5.8 (±1.5) years, the median number of lengthenings was 4 (range, 3 to 5), and the median time between insertion and last clinical review was 4.7 (range, 2.7 to 9.5) years. Radiographic review demonstrated significant (P<0.05) improvements in the following: Spinal curve magnitude, pelvic obliquity, space available for the lung, rib vertebral angle difference, and thoracic kyphosis following growing rod implantation. Thoracic and lumbar height and chest width and depth increased significantly (P<0.05) over the lengthening process. None of the patients initially required more than noninvasive positive pressure ventilation support. Fifteen of the 16 experienced no changes in their noninvasive positive pressure ventilation support needs throughout the study duration, requiring support only at night and naps. Serial PFTs were available for 6 children with SMA type II. PFTs demonstrated significant improvements in absolute forced vital capacity (FVC), minimal changes in the maximal inspiratory and expiratory pressures, and a gradual worsening of percent predicted FVC.
CONCLUSIONS: Clinical respiratory support requirements appear to stabilize following the insertion and lengthening of posterior based growing rods in the SMA population. Similar to previous studies, increased spinal height and thoracic cavity size were noted throughout the process. Despite an increasing absolute FVC, the percent predicted FVC diminished over time.
LEVEL OF EVIDENCE: Level IV-therapeutic.

The Big Bluff of Amyotrophic Lateral Sclerosis Diagnosis: The Role of Neurodegenerative Disease Mimics.Publié le 15 09 2016

Neurodegenerative diseases include a significant number of pathologies affecting the nervous system. Generally, the primary cause of each disease is specific; however, recently, it was shown that they may be correlated at molecular level. This aspect, together with the exhibition of similar symptoms, renders the diagnosis of these disorders difficult. Amyotrophic lateral sclerosis is one of these pathologies. Herein, we report several cases of amyotrophic lateral sclerosis misdiagnosed as a consequence of features that are common to several neurodegenerative diseases, such as Parkinson's, Huntington's and Alzheimer's disease, spinal muscular atrophy, progressive bulbar palsy, spastic paraplegia and frontotemporal dementia, and mostly with the lysosomal storage disorder GM2 gangliosidosis. Overall reports highlight that the differential diagnosis for amyotrophic lateral sclerosis should include correlated mechanisms.

Systemic peptide-mediated oligonucleotide therapy improves long-term survival in spinal muscular atrophy.Publié le 15 09 2016

The development of antisense oligonucleotide therapy is an important advance in the identification of corrective therapy for neuromuscular diseases, such as spinal muscular atrophy (SMA). Because of difficulties of delivering single-stranded oligonucleotides to the CNS, current approaches have been restricted to using invasive intrathecal single-stranded oligonucleotide delivery. Here, we report an advanced peptide-oligonucleotide, Pip6a-morpholino phosphorodiamidate oligomer (PMO), which demonstrates potent efficacy in both the CNS and peripheral tissues in severe SMA mice following systemic administration. SMA results from reduced levels of the ubiquitously expressed survival motor neuron (SMN) protein because of loss-of-function mutations in the SMN1 gene. Therapeutic splice-switching oligonucleotides (SSOs) modulate exon 7 splicing of the nearly identical SMN2 gene to generate functional SMN protein. Pip6a-PMO yields SMN expression at high efficiency in peripheral and CNS tissues, resulting in profound phenotypic correction at doses an order-of-magnitude lower than required by standard naked SSOs. Survival is dramatically extended from 12 d to a mean of 456 d, with improvement in neuromuscular junction morphology, down-regulation of transcripts related to programmed cell death in the spinal cord, and normalization of circulating insulin-like growth factor 1. The potent systemic efficacy of Pip6a-PMO, targeting both peripheral as well as CNS tissues, demonstrates the high clinical potential of peptide-PMO therapy for SMA.

Repeated low doses of morpholino antisense oligomer: an intermediate mouse model of spinal muscular atrophy to explore the window of therapeutic response.Publié le 14 09 2016

The human SMN2 transgenic mice are well-established models of spinal muscular atrophy (SMA). While the severe type I mouse model has a rapidly progressive condition mimicking type I SMA in humans, the mild type III mice do not faithfully recapitulate chronic SMA variants affecting children. A SMA mouse model that clinically mimics the features of type II and III SMA in human is therefore needed. In this study, we generated intermediately affected SMA mice by delivering low-dose morpholino oligomer (PMO25) into the existing severe SMA mice. We show that a single low-dose administration of PMO25 moderately extended the survival of severe type I SMA mice. The neuromuscular pathology is also modestly but significantly improved in these mice. A second administration of PMO25 at postnatal day 5 (PND5) demonstrated an additive effect on survival. Additional systemic administration of low-dose PMO25 at 2-week intervals suppressed the occurrence of distal necrosis beyond postnatal day 100, and induced more complete phenotypic rescue than a single bolus high-dose injection at PND0. Our study demonstrates that survival of motor neuron (SMN) is required early at a critical threshold to prevent symptoms and suggests that subsequent systemic administration of low-dose PMO25 in SMA mice can provide therapeutic benefit and phenotypic rescue, presumably via peripheral SMN restoration. Our work also provides additional insight into the time window of response to administration of antisense oligonucleotides to SMA mice with an intermediate phenotype. This information is crucial at a time when a number of therapeutic interventions are in clinical trials in SMA patients.

Neuroprotective Effect of Non-viral Gene Therapy Treatment Based on Tetanus Toxin C-fragment in a Severe Mouse Model of Spinal Muscular Atrophy.Publié le 09 09 2016

Spinal muscular atrophy (SMA) is a hereditary childhood disease that causes paralysis and progressive degeneration of skeletal muscles and spinal motor neurons. SMA is associated with reduced levels of full-length Survival of Motor Neuron (SMN) protein, due to mutations in the Survival of Motor Neuron 1 gene. Nowadays there are no effective therapies available to treat patients with SMA, so our aim was to test whether the non-toxic carboxy-terminal fragment of tetanus toxin heavy chain (TTC), which exhibits neurotrophic properties, might have a therapeutic role or benefit in SMA. In this manuscript, we have demonstrated that TTC enhance the SMN expression in motor neurons "in vitro" and evaluated the effect of intramuscular injection of TTC-encoding plasmid in the spinal cord and the skeletal muscle of SMNdelta7 mice. For this purpose, we studied the weight and the survival time, as well as, the survival and cell death pathways and muscular atrophy. Our results showed that TTC treatment reduced the expression of autophagy markers (Becn1, Atg5, Lc3, and p62) and pro-apoptotic genes such as Bax and Casp3 in spinal cord. In skeletal muscle, TTC was able to downregulate the expression of the main marker of autophagy, Lc3, to wild-type levels and the expression of the apoptosis effector protein, Casp3. Regarding the genes related to muscular atrophy (Ankrd1, Calm1, Col19a1, Fbox32, Mt2, Myod1, NogoA, Pax7, Rrad, and Sln), TTC suggest a compensatory effect for muscle damage response, diminished oxidative stress and modulated calcium homeostasis. These preliminary findings suggest the need for further experiments to depth study the effect of TTC in SMA disease.

[Respiratory treatments in neuromuscular disease].Publié le 09 09 2016

In a previous article, a review was presented of the respiratory pathophysiology of the patient with neuromuscular disease, as well as their clinical evaluation and the major complications causing pulmonary deterioration. This article presents the respiratory treatments required to preserve lung function in neuromuscular disease as long as possible, as well as in special situations (respiratory infections, spinal curvature surgery, etc.). Special emphasis is made on the use of non-invasive ventilation, which is changing the natural history of many of these diseases. The increase in survival and life expectancy of these children means that they can continue their clinical care in adult units. The transition from pediatric care must be an active, timely and progressive process. It may be slightly stressful for the patient before the adaptation to this new environment, with multidisciplinary care always being maintained.

Information and treatment decisions in severe spinal muscular atrophy: A parental follow-up.Publié le 09 09 2016

INTRODUCTION: The parents of children with severe spinal muscular atrophy (SMA) face difficult ethical decisions regarding their child's treatment. This study explored the experience of parents of children with severe SMA concerning information and treatment decisions.
MATERIAL AND METHODS: This nationwide survey, conducted in 2013, is based on parents of children who were born in Sweden between 2000 and 2010 and later diagnosed with SMA type I or II where respiratory support was considered the first year of life (N = 61, participation rate: 87%). The survey involved parents' perception of the child's care and the questions used in this study covered information given and treatment decisions. Descriptive statistics were used.
RESULTS: None of the parents reported that the health care professionals made decisions concerning the child's treatment without informing them first, and 80% reported feeling confident about the decisions made. Of the bereaved parents, 11/48 (23%) reported that they got no information about respiratory support, compared to 2/13 (15%) of non-bereaved. Bereaved parents were more likely to report being satisfied with and understanding the information given about the illness and its treatment than non-bereaved parents.
CONCLUSION: All parents reported having been informed before treatment decisions were made and a vast majority reported feeling confident about the decisions. However, a quarter of the parents declined to have received information about respiratory support, which indicates that the parents did not sufficiently understand the available respiratory treatment options, and that their children may not receive the kind of care that is recommended in guidelines.

Strength Testing in Motor Neuron Diseases.Publié le 09 09 2016

Loss of muscle strength is a cardinal feature of all motor neuron diseases. Functional loss over time, including respiratory dysfunction, inability to ambulate, loss of ability to perform activities of daily living, and others are due, in large part, to decline in strength. Thus, the accurate measurement of limb muscle strength is essential in therapeutic trials to best understand the impact of therapy on vital function. While qualitative strength measurements show declines over time, the lack of reproducibility and linearity of measurement make qualitative techniques inadequate. A variety of quantitative measures have been developed; all have both positive attributes and limitations. However, with careful training and reliability testing, quantitative measures have proven to be reliable and sensitive indicators of both disease progression and the impact of experimental therapy. Quantitative strength measurements have demonstrated potentially important therapeutic effects in both amyotrophic lateral sclerosis and spinobulbar muscular atrophy, and have been shown feasible in children with spinal muscular atrophy. The spectrum of both qualitative and quantitative strength measurements are reviewed and their utility examined in this review.

RNA therapeutics: RNAi and antisense mechanisms and clinical applications.Publié le 31 08 2016

RNA therapeutics refers to the use of oligonucleotides to target primarily ribonucleic acids (RNA) for therapeutic efforts or in research studies to elucidate functions of genes. Oligonucleotides are distinct from other pharmacological modalities, such as small molecules and antibodies that target mainly proteins, due to their mechanisms of action and chemical properties. Nucleic acids come in two forms: deoxyribonucleic acids (DNA) and ribonucleic acids (RNA). Although DNA is more stable, RNA offers more structural variety ranging from messenger RNA (mRNA) that codes for protein to non-coding RNAs, microRNA (miRNA), transfer RNA (tRNA), short interfering RNAs (siRNAs), ribosomal RNA (rRNA), and long-noncoding RNAs (lncRNAs). As our understanding of the wide variety of RNAs deepens, researchers have sought to target RNA since >80% of the genome is estimated to be transcribed. These transcripts include non-coding RNAs such as miRNAs and siRNAs that function in gene regulation by playing key roles in the transfer of genetic information from DNA to protein, the final product of the central dogma in biology(1). Currently there are two main approaches used to target RNA: double stranded RNA-mediated interference (RNAi) and antisense oligonucleotides (ASO). Both approaches are currently in clinical trials for targeting of RNAs involved in various diseases, such as cancer and neurodegeneration. In fact, ASOs targeting spinal muscular atrophy and amyotrophic lateral sclerosis have shown positive results in clinical trials(2). Advantages of ASOs include higher affinity due to the development of chemical modifications that increase affinity, selectivity while decreasing toxicity due to off-target effects. This review will highlight the major therapeutic approaches of RNA medicine currently being applied with a focus on RNAi and ASOs.

Head Lift Exercise Improves Swallowing Dysfunction in Spinal and Bulbar Muscular Atrophy.Publié le 31 08 2016

BACKGROUND: Dysphagia due to bulbar involvement is a major symptom of patients with spinal and bulbar muscular atrophy (SBMA). The aim of this pilot study was to test the efficacy and safety of the head lift exercise for swallowing dysfunction in SBMA.
METHODS: We enrolled 6 subjects with genetically confirmed SBMA and instructed them to perform the head lift exercise for 6 weeks. The efficacy outcome measures were the changes from baseline in tongue pressure, the scores of swallowing functional questionnaires, and the motor functional scales and parameters of videofluorography (VF).
RESULTS: All subjects completed the study and no major adverse effects were recorded. Tongue pressure significantly increased by 19.2 ± 0.15% (p < 0.05) after the 6-week head lift exercise. The scores for oral dysphagia also improved, although there was no significant change in VF parameters or other variables examined pre- and post-exercise.
CONCLUSION: Our findings suggested that the head lift exercise may improve swallowing dysfunction, particularly tongue pressure, in SBMA.

RNA-sequencing of a mouse-model of spinal muscular atrophy reveals tissue-wide changes in splicing of U12-dependent introns.Publié le 26 08 2016

Spinal Muscular Atrophy (SMA) is a neuromuscular disorder caused by insufficient levels of the Survival of Motor Neuron (SMN) protein. SMN is expressed ubiquitously and functions in RNA processing pathways that include trafficking of mRNA and assembly of snRNP complexes. Importantly, SMA severity is correlated with decreased snRNP assembly activity. In particular, the minor spliceosomal snRNPs are affected, and some U12-dependent introns have been reported to be aberrantly spliced in patient cells and animal models. SMA is characterized by loss of motor neurons, but the underlying mechanism is largely unknown. It is likely that aberrant splicing of genes expressed in motor neurons is involved in SMA pathogenesis, but increasing evidence indicates that pathologies also exist in other tissues. We present here a comprehensive RNA-seq study that covers multiple tissues in an SMA mouse model. We show elevated U12-intron retention in all examined tissues from SMA mice, and that U12-dependent intron retention is induced upon siRNA knock-down of SMN in HeLa cells. Furthermore, we show that retention of U12-dependent introns is mitigated by ASO treatment of SMA mice and that many transcriptional changes are reversed. Finally, we report on missplicing of several Ca(2+) channel genes that may explain disrupted Ca(2+) homeostasis in SMA and activation of Cdk5.

Therapeutic activity of modified U1 core spliceosomal particles.Publié le 20 08 2016

Modified U1 snRNAs bound to intronic sequences downstream of the 5' splice site correct exon skipping caused by different types of mutations. Here we evaluate the therapeutic activity and structural requirements of these exon-specific U1 snRNA (ExSpeU1) particles. In a severe spinal muscular atrophy, mouse model, ExSpeU1, introduced by germline transgenesis, increases SMN2 exon 7 inclusion, SMN protein production and extends life span. In vitro, RNA mutant analysis and silencing experiments show that while U1A protein is dispensable, the 70K and stem loop IV elements mediate most of the splicing rescue activity through improvement of exon and intron definition. Our findings indicate that precise engineering of the U1 core spliceosomal RNA particle has therapeutic potential in pathologies associated with exon-skipping mutations.

The Power of Human Protective Modifiers: PLS3 and CORO1C Unravel Impaired Endocytosis in Spinal Muscular Atrophy and Rescue SMA Phenotype.Publié le 09 08 2016

Homozygous loss of SMN1 causes spinal muscular atrophy (SMA), the most common and devastating childhood genetic motor-neuron disease. The copy gene SMN2 produces only ?10% functional SMN protein, insufficient to counteract development of SMA. In contrast, the human genetic modifier plastin 3 (PLS3), an actin-binding and -bundling protein, fully protects against SMA in SMN1-deleted individuals carrying 3-4 SMN2 copies. Here, we demonstrate that the combinatorial effect of suboptimal SMN antisense oligonucleotide treatment and PLS3 overexpression-a situation resembling the human condition in asymptomatic SMN1-deleted individuals-rescues survival (from 14 to >250 days) and motoric abilities in a severe SMA mouse model. Because PLS3 knockout in yeast impairs endocytosis, we hypothesized that disturbed endocytosis might be a key cellular mechanism underlying impaired neurotransmission and neuromuscular junction maintenance in SMA. Indeed, SMN deficit dramatically reduced endocytosis, which was restored to normal levels by PLS3 overexpression. Upon low-frequency electro-stimulation, endocytotic FM1-43 (SynaptoGreen) uptake in the presynaptic terminal of neuromuscular junctions was restored to control levels in SMA-PLS3 mice. Moreover, proteomics and biochemical analysis revealed CORO1C, another F-actin binding protein, whose direct binding to PLS3 is dependent on calcium. Similar to PLS3 overexpression, CORO1C overexpression restored fluid-phase endocytosis in SMN-knockdown cells by elevating F-actin amounts and rescued the axonal truncation and branching phenotype in Smn-depleted zebrafish. Our findings emphasize the power of genetic modifiers to unravel the cellular pathomechanisms underlying SMA and the power of combinatorial therapy based on splice correction of SMN2 and endocytosis improvement to efficiently treat SMA.

Progressive Muscular Atrophy.Publié le 09 08 2016

Progressive muscular atrophy (PMA) is a rare, sporadic, adult-onset motor neuron disease, clinically characterized by isolated lower motor neuron features; however, clinically evident upper motor neuron signs may emerge in some patients. Subclinical upper motor neuron involvement is identified pathologically, radiologically, and neurophysiologically in a substantial number of patients with PMA. Patients with subclinical upper motor neuron involvement do not fulfill the revised El Escorial criteria to participate in amyotrophic lateral sclerosis clinical trials. Intravenous immunoglobulin therapy is only marginally beneficial in a small subgroup of patients with lower motor neuron syndrome without conduction block.

Small Molecules in Development for the Treatment of Spinal Muscular Atrophy.Publié le 05 08 2016

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease resulting from pathologically low levels of survival motor neuron (SMN) protein. The majority of mRNA from the SMN2 allele undergoes alternative splicing and excludes critical codons, causing an SMN protein deficiency. While there is currently no FDA-approved treatment for SMA, early therapeutic efforts have focused on testing repurposed drugs such as phenylbutyrate (2), valproic acid (3), riluzole (6), hydroxyurea (7), and albuterol (9), none of which has demonstrated clinical effectiveness. More recently, clinical trials have focused on novel small-molecule compounds identified from high-throughput screening and medicinal chemistry optimization such as olesoxime (11), CK-2127107, RG7800, LMI070, and RG3039 (17). In this paper, we review both repurposed drugs and small-molecule compounds discovered following medicinal chemistry optimization for the potential treatment of SMA.

Synthetic Nucleic Acids and Treatment of Neurological Diseases.Publié le 03 08 2016

Importance: The ability to control gene expression with antisense oligonucleotides (ASOs) could provide a new treatment strategy for disease.
Objective: To review the use of ASOs for the treatment of neurological disorders.
Evidence Review: Articles were identified through a search of PubMed references from 2000 to 2016 for articles describing the use of ASOs to treat disease, with specific attention to neurological disease. We concentrated our review on articles pertaining to activation of frataxin expression (Friedreich's ataxia) and production of active survival motor neuron 2 (SMN2, spinal muscular atrophy).
Findings: Many neurological diseases are caused by inappropriate expression of a protein. Mutations may reduce expression of a wild-type protein, and strategies to activate expression may provide therapeutic benefit. For other diseases, a mutant protein may be expressed too highly and methods that reduce mutant protein expression might form the basis for drug development. Synthetic ASOs can recognize cellular RNA and control gene expression. Antisense oligonucleotides are not a new concept, but successful clinical development has proceeded at a slow pace. Advances in ASO chemistry, biological understanding, and clinical design are making successful applications more likely.
Conclusions and Relevance: Both laboratory and clinical studies are demonstrating the potential of ASOs as a source of drugs to treat neurological disease.

Advances in modeling and treating spinal muscular atrophy.Publié le 31 07 2016

PURPOSE OF REVIEW: Spinal muscular atrophy (SMA) is an inherited childhood neurodegenerative disorder caused by ubiquitous deficiency of the survival motor neuron (SMN) protein - the hallmarks of which are the selective loss of motor neurons and skeletal muscle atrophy. Here, we highlight recent progress in the understanding of SMA pathology and in the development of therapeutic approaches for its treatment.
RECENT FINDINGS: Phenotypic characterization of mouse models of the disease, combined with analysis of SMN restoration or depletion in a spatially and temporally controlled manner, has yielded key insights into the normal requirement of SMN and SMA pathophysiology. Increasing evidence indicates a higher demand for SMN during neuromuscular development and extends the pathogenic effects of SMN deficiency beyond motor neurons to include additional cells both within and outside the nervous system. These findings have been paralleled by preclinical development of powerful approaches for increasing SMN expression through gene therapy or splicing modulation that are now in human trials.
SUMMARY: Along with the availability of SMN-upregulating drugs, identification of the specific cell types in which SMN deficiency induces the disease and delineation of the window of opportunity for effective treatment are key advances in the ongoing path to SMA therapy.

Enhancing survival motor neuron expression extends lifespan and attenuates neurodegeneration in mutant TDP-43 mice.Publié le 31 07 2016

Defects in the RNA binding proteins survival motor neuron (SMN) and TAR DNA binding protein 43 (TDP-43) cause progressive motor neuron degeneration in spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS), respectively. While low levels of SMN protein in motor neurons result in SMA, recent studies implicate abnormal SMN levels and function in ALS pathogenesis. Here, we determine that SMN protein is upregulated early and progressively in spinal and cortical motor neurons of male transgenic mutant TDP-43(A315T) mice. Cytoplasmic SMN aggregates that contain TDP-43 and HuR were identified in motor neurons of TDP-43(A315T) mice, consistent with incorporation of SMN into stress granules. To test the impact of augmenting SMN levels in TDP-43 proteinopathy, we demonstrate that neuronal overexpression of human SMN in TDP-43(A315T) mice delayed symptom onset and prolonged survival. SMN upregulation also countered motor neuron degeneration, attenuated activation of astrocytes and microglia, and restored AMP kinase activation in spinal cords of TDP-43(A315T) mice. We also reveal that expression of another factor conferring motor neuron vulnerability, androgen receptor (AR), is reduced in spinal cords of male TDP-43(A315T) mice. These results establish that SMN overexpression in motor neurons slows disease onset and outcome by ameliorating pathological signs in this model of mutant TDP-43-mediated ALS. Further approaches to augment SMN levels using pharmacological or gene therapy agents may therefore be warranted in ALS. Our data also reinforce a novel potential link between ALS and spinal bulbar muscular atrophy, another motor neurodegenerative disease mediated by reduced AR function in motor neurons.

Opening the window: The case for carrier and perinatal screening for spinal muscular atrophy.Publié le 28 07 2016

Spinal muscular atrophy (SMA) is the most common genetically inherited neurodegenerative disease that leads to infant mortality worldwide. SMA is caused by genetic deletion or mutation in the survival of motor neuron 1 (SMN1) gene, which results in a deficiency in SMN protein. For reasons that are still unclear, SMN protein deficiency predominantly affects ?-motor neurons, resulting in their degeneration and subsequent paralysis of limb and trunk muscles, progressing to death in severe cases. Emerging evidence suggests that SMN protein deficiency also affects the heart, autonomic nervous system, skeletal muscle, liver, pancreas and perhaps many other organs. Currently, there is no cure for SMA. Patient treatment includes respiratory care, physiotherapy, and nutritional management, which can somewhat ameliorate disease symptoms and increase life span. Fortunately, several novel therapies have advanced to human clinical trials. However, data from studies in animal models of SMA indicate that the greatest therapeutic benefit is achieved through initiating treatment as early as possible, before widespread loss of motor neurons has occurred. In this review, we discuss the merit of carrier and perinatal patient screening for SMA considering the efficacy of emerging therapeutics and the physical, emotional and financial burden of the disease on affected families and society.

Somatic therapy of a mouse SMA model with a U7 snRNA gene correcting SMN2 splicing.Publié le 28 07 2016

Spinal Muscular Atrophy (SMA) is due to the loss of SMN1 gene function. The duplicate gene SMN2 produces some, but not enough, SMN protein because most transcripts lack exon 7. Thus, promoting the inclusion of this exon is a therapeutic option. We show that a somatic gene therapy using the gene for a modified U7 RNA which stimulates this splicing has a profound and persistent therapeutic effect on the phenotype of a severe SMA mouse model. To this end, the U7 gene and vector and the production of pure, highly concentrated self-complementary (sc) AAV9 vector particles were optimized. Introduction of the functional vector into motoneurons of newborn SMA mice by intracerebroventricular injection led to a highly significant, dose-dependent increase in life span and improvement of muscle functions. Besides the central nervous system, the therapeutic U7 RNA is expressed in the heart and liver which may additionally contribute to the observed therapeutic efficacy. This approach provides an additional therapeutic option for SMA and could also be adapted to treat other diseases of the central nervous systems with regulatory small RNA genes.

CNS-restricted Transduction and CRISPR/Cas9-mediated Gene Deletion with an Engineered AAV Vector.Publié le 21 07 2016

Gene therapy using recombinant adeno-associated viral (AAV) vectors is emerging as a promising approach to treat central nervous system disorders such as Spinal muscular atrophy, Batten, Parkinson and Alzheimer disease amongst others. A critical remaining challenge for central nervous system-targeted gene therapy, silencing or gene editing is to limit potential vector dose-related toxicity in off-target cells and organs. Here, we characterize a lab-derived AAV chimeric (AAV2g9), which displays favorable central nervous system attributes derived from both parental counterparts, AAV2 and AAV9. This synthetic AAV strain displays preferential, robust, and widespread neuronal transduction within the brain and decreased glial tropism. Importantly, we observed minimal systemic leakage, decreased sequestration and gene transfer in off-target organs with AAV2g9, when administered into the cerebrospinal fluid. A single intracranial injection of AAV2g9 vectors encoding guide RNAs targeting the schizophrenia risk gene MIR137 (encoding MIR137) in CRISPR/Cas9 knockin mice resulted in brain-specific gene deletion with no detectable events in the liver. This engineered AAV vector is a promising platform for treating neurological disorders through gene therapy, silencing or editing modalities.

Optimization of Morpholino Antisense Oligonucleotides Targeting the Intronic Repressor Element1 in Spinal Muscular Atrophy.Publié le 13 07 2016

Loss of Survival Motor Neuron-1 (SMN1) causes Spinal Muscular Atrophy (SMA), a devastating neurodegenerative disease. SMN2 is a nearly identical copy gene; however SMN2 cannot prevent disease development in the absence of SMN1 since the majority of SMN2-derived transcripts are alternatively spliced, encoding a truncated, unstable protein lacking exon 7. Nevertheless, SMN2 retains the ability to produce low levels of functional protein. Previously we have described a splice-switching Morpholino antisense oligonucleotide (ASO) sequence that targets a potent intronic repressor, Element1 (E1), located upstream of SMN2 exon 7. In this study, we have assessed a novel panel of Morpholino ASOs with the goal of optimizing E1 ASO activity. Screening for efficacy in the SMN?7 mouse model, a single ASO variant was more active in vivo compared to the original E1(MO)-ASO. Sequence variant eleven (E1(MOv11)) consistently showed greater efficacy by increasing the lifespan of severe SMA mice after a single intracerebroventricular (ICV) injection in the CNS, exhibited a strong dose-response across an order of magnitude, and demonstrated excellent target engagement by partially reversing the pathogenic SMN2 splicing event. We conclude that Morpholino modified ASOs are effective in modifying SMN2 splicing and have the potential for future SMA clinical applications.Molecular Therapy (2016); doi:10.1038/mt.2016.145.

Long-term Follow-up of Pulmonary Function and Scoliosis in Patients With Duchenne's Muscular Dystrophy and Spinal Muscular Atrophy.Publié le 13 07 2016

BACKGROUND: Spine surgery for neuromuscular scoliosis in patients with Duchenne's Muscular Dystrophy (DMD) and Spinal Muscular Atrophy (SMA) remained controversial. This study aimed to review the long-term results of spine surgery and its effect on pulmonary function in these patients.
METHODS: A retrospective review was conducted for the above patients who had undergone surgery from 1990 to 2006 in a tertiary hospital. Their yearly lung function tests, clinical records, and x-ray films before and after surgery were reviewed. All patients had at least 2 lung function tests performed before surgery and at least 3 lung function tests performed after surgery. Records of perioperative pulmonary infections that resulted in hospital admissions were also retrieved from the hospital computer system.
RESULTS: Forty patients were reviewed: 29 with DMD, 11 with SMA. The mean follow-up period was 11.6 years. For patients with DMD, the mean correction of Cobb's angle from surgery was 34.1 degrees. The rate of decline of the predicted forced vital capacity preoperatively was 7.80% per year, and was reduced to 4.26% per year postoperatively (P<0.001). For patients with SMA, the mean correction of Cobb's angle from surgery was 44.1 degrees. The rate of decline of the predicted forced vital capacity preoperatively was 5.31% per year, and was reduced to 1.77% per year postoperatively (P<0.001). For both DMD and SMA patients, the difference between the rate of preoperative and postoperative pulmonary infections that resulted in hospital admission were, however, not significant (P=0.433 and 0.452, respectively).
CONCLUSIONS: Scoliosis surgery in patients with DMD and SMA results in a long-term decreased rate of decline in pulmonary function over a follow-up period of more than 10 years. The level of the apical vertebrae of the scoliosis did not demonstrate a significant trend on the pulmonary function. The frequency of chest infections did not improve by scoliosis surgery.
LEVEL OF SIGNIFICANCE: Level III—Retrospective study.

Recent advances in innovative therapeutic approaches for Duchenne muscular dystrophy: from discovery to clinical trials.Publié le 12 07 2016

Duchenne muscular dystrophy (DMD) is an X-linked progressive degenerative muscle disorder caused by the absence of dystrophin. There is no curative therapy, although innovative therapeutic approaches have been aggressively investigated over recent years. Currently, the international clinical trial registry platform for this disease has been constructed and clinical trials for innovative therapeutic approaches are underway. Among these, exon skipping and read-through of nonsense mutations are in the most advanced stages, with exon skipping theoretically applicable to a larger number of patients. To date, exon skipping that targets exons 51, 44, 45, and 53 is being globally investigated including in USA, EU, and Japan. The latest announcement from Japan was made, demonstrating successful dystrophin production in muscles of patients with DMD after treating with exon 53 skipping antisense oligonucleotides (ASOs). However, the innovative therapeutic approaches have demonstrated limited efficacy. To address this issue in exon skipping, studies to unveil the mechanism underlying gymnotic delivery of ASO uptake in living cells have been conducted in an effort to improve in vivo delivery. Further, establishing the infrastructures to integrate multi-institutional clinical trials are needed to facilitate the development of successful therapies for DMD, which ultimately is applicable to other myopathies and neurodegenerative diseases, including spinal muscular atrophy and motor neuron diseases.

UBA1: At the Crossroads of Ubiquitin Homeostasis and Neurodegeneration.Publié le 12 07 2016

Neurodegenerative diseases are a leading cause of disability and early death. A common feature of these conditions is disruption of protein homeostasis. Ubiquitin-like modifier activating enzyme 1 (UBA1), the E1 ubiquitin-activating enzyme, sits at the apex of the ubiquitin cascade and represents an important regulator of cellular protein homeostasis. Critical contributions of UBA1-dependent pathways to the regulation of homeostasis and degeneration in the nervous system are emerging, including specific disruption of UBA1 in spinal muscular atrophy (SMA) and Huntington's disease (HD). In this review we discuss recent findings that put UBA1 at the centre of cellular homeostasis and neurodegeneration, highlighting the potential for UBA1 to act as a promising therapeutic target for a range of neurodegenerative diseases.

Spinal muscular atrophy phenotype is ameliorated in human motor neurons by SMN increase via different novel RNA therapeutic approaches.Publié le 07 07 2016

Spinal muscular atrophy (SMA) is a primary genetic cause of infant mortality due to mutations in the Survival Motor Neuron (SMN) 1 gene. No cure is available. Antisense oligonucleotides (ASOs) aimed at increasing SMN levels from the paralogous SMN2 gene represent a possible therapeutic strategy. Here, we tested in SMA human induced pluripotent stem cells (iPSCs) and iPSC-differentiated motor neurons, three different RNA approaches based on morpholino antisense targeting of the ISSN-1, exon-specific U1 small nuclear RNA (ExSpeU1), and Transcription Activator-Like Effector-Transcription Factor (TALE-TF). All strategies act modulating SMN2 RNA: ASO affects exon 7 splicing, TALE-TF increase SMN2 RNA acting on the promoter, while ExSpeU1 improves pre-mRNA processing. These approaches induced up-regulation of full-length SMN mRNA and differentially affected the Delta-7 isoform: ASO reduced this isoform, while ExSpeU1 and TALE-TF increased it. All approaches upregulate the SMN protein and significantly improve the in vitro SMA motor neurons survival. Thus, these findings demonstrate that therapeutic tools that act on SMN2 RNA are able to rescue the SMA disease phenotype. Our data confirm the feasibility of SMA iPSCs as in vitro disease models and we propose novel RNA approaches as potential therapeutic strategies for treating SMA and other genetic neurological disorders.

Predictive factors relating to prognosis of anterior decompressive surgery for proximal-type cervical spondylotic amyotrophy.Publié le 07 07 2016

BACKGROUND AND OBJECTIVE: Cervical spondylotic amyotrophy (CSA) is a relatively rare disorder. This study was conducted to elucidate the prognosis of proximal-type CSA after anterior decompressive surgery by evaluating clinical factors and imaging findings.
METHODS: Anterior decompressive surgery was performed in 40 patients with proximal-type CSA between March 2000 and December 2011. Patients were classified into 2 categories based on axial T2-weighted magnetic resonance imaging (MRI) findings: "nerve root compression (NRC)", with nerve root compressed at the intervertebral foramen, and "spinal cord compression (SCC)" with spinal cord compressed at the medial or paramedial site of spinal canal. Manual muscle testing (MMT) was used to evaluate the surgical effect. Scapular, deltoid, and biceps brachii muscles of the affected side were tested and the sum scores were calculated. Clinical factors and imaging findings, such as age, duration of disease, preoperative MMT grade, number of affected levels and signal intensity changes of spinal cord, were collected to analyze prognostic factors.
RESULTS: After anterior decompressive surgery, 30 patients (75%) showed an improvement. NRC was observed in 6 patients and SCC in the rest 34 patients based on MRI findings. All patients (100%) with NRC had an improvement, while only 24 patients (70.6%) with SCC improved. In patients with SCC, there was a significant difference in duration of disease between patients who had an improvement and those who had not (P< 0.01).
CONCLUSIONS: Anterior decompressive surgery is effective in the treatment of most patients with CSA. NRC on MRI may indicate a good surgical outcome. In patients with SCC, a long duration of disease is a risk factor for poor prognosis.

Altered Levels of MicroRNA-9, -206, and -132 in Spinal Muscular Atrophy and Their Response to Antisense Oligonucleotide Therapy.Publié le 07 07 2016

The identification of noninvasive biomarkers to monitor the disease progression in spinal muscular atrophy (SMA) is becoming increasingly important. MicroRNAs (miRNAs) regulate gene expression and are implicated in the pathogenesis of neuromuscular diseases, including motor neuron degeneration. In this study, we selectively characterized the expression of miR-9, miR-206, and miR-132 in spinal cord, skeletal muscle, and serum from SMA transgenic mice, and in serum from SMA patients. A systematic analysis of miRNA expression was conducted in SMA mice with different disease severities (severe type I-like and mild type III-like) at different disease stages (pre-, mid-, and late-symptomatic stages), and in morpholino antisense oligonucleotide-treated mice. There was differential expression of all three miRNAs in spinal cord, skeletal muscle and serum samples in SMA mice. Serum miRNAs were altered prior to the changes in spinal cord and skeletal muscle at the presymptomatic stage. The altered miR-132 levels in spinal cord, muscle, and serum transiently reversed to normal level after a single-dose morpholino antisense oligomer PMO25 treatment in SMA mice. We also confirmed a significant alteration of miR-9 and miR-132 level in serum samples from SMA patients. Our study indicates the potential of developing miRNAs as noninvasive biomarkers in SMA.

Imaging Flow Cytometry Analysis to Identify Differences of Survival Motor Neuron Protein Expression in Patients With Spinal Muscular Atrophy.Publié le 30 06 2016

BACKGROUND: Spinal muscular atrophy is a neurodegenerative disorder caused by the deficient expression of survival motor neuron protein in motor neurons. A major goal of disease-modifying therapy is to increase survival motor neuron expression. Changes in survival motor neuron protein expression can be monitored via peripheral blood cells in patients; therefore we tested the sensitivity and utility of imaging flow cytometry for this purpose.
METHODS: After the immortalization of peripheral blood lymphocytes from a human healthy control subject and two patients with spinal muscular atrophy type 1 with two and three copies of SMN2 gene, respectively, we used imaging flow cytometry analysis to identify significant differences in survival motor neuron expression. A bright detail intensity analysis was used to investigate differences in the cellular localization of survival motor neuron protein.
RESULTS: Survival motor neuron expression was significantly decreased in cells derived from patients with spinal muscular atrophy relative to those derived from a healthy control subject. Moreover, survival motor neuron expression correlated with the clinical severity of spinal muscular atrophy according to SMN2 copy number. The cellular accumulation of survival motor neuron protein was also significantly decreased in cells derived from patients with spinal muscular atrophy relative to those derived from a healthy control subject.
CONCLUSIONS: The benefits of imaging flow cytometry for peripheral blood analysis include its capacities for analyzing heterogeneous cell populations; visualizing cell morphology; and evaluating the accumulation, localization, and expression of a target protein. Imaging flow cytometry analysis should be implemented in future studies to optimize its application as a tool for spinal muscular atrophy clinical trials.

An Integrative Transcriptomic Analysis for Identifying Novel Target Genes Corresponding to Severity Spectrum in Spinal Muscular Atrophy.Publié le 23 06 2016

Spinal muscular atrophy (SMA) is an inherited neuromuscular disease resulting from a recessive mutation in the SMN1 gene. This disease affects multiple organ systems with varying degrees of severity. Exploration of the molecular pathological changes occurring in different cell types in SMA is crucial for developing new therapies. This study collected 39 human microarray datasets from ArrayExpress and GEO databases to build an integrative transcriptomic analysis for recognizing novel SMA targets. The transcriptomic analysis was conducted through combining weighted correlation network analysis (WGCNA) for gene module detection, gene set enrichment analysis (GSEA) for functional categorization and filtration, and Cytoscape (visual interaction gene network analysis) for target gene identification. Seven novel target genes (Bmp4, Serpine1, Gata6, Ptgs2, Bcl2, IL6 and Cntn1) of SMA were revealed, and are all known in the regulation of TNF? for controlling neural, cardiac and bone development. Sequentially, the differentially expressed patterns of these 7 target genes in mouse tissues (e.g., spinal cord, heart, muscles and bone) were validated in SMA mice of different severities (pre-symptomatic, mildly symptomatic, and severely symptomatic). In severely symptomatic SMA mice, TNF? was up-regulated with attenuation of Bmp4 and increase of Serpine1 and Gata6 (a pathway in neural and cardiac development), but not in pre-symptomatic and mildly symptomatic SMA mice. The severely symptomatic SMA mice also had the elevated levels of Ptgs2 and Bcl2 (a pathway in skeletal development) as well as IL6 and Cntn1 (a pathway in nervous system development). Thus, the 7 genes identified in this study might serve as potential target genes for future investigations of disease pathogenesis and SMA therapy.

Pain in Neurodegenerative Disease: Current Knowledge and Future Perspectives.Publié le 19 06 2016

Neurodegenerative diseases are going to increase as the life expectancy is getting longer. The management of neurodegenerative diseases such as Alzheimer's disease (AD) and other dementias, Parkinson's disease (PD) and PD related disorders, motor neuron diseases (MND), Huntington's disease (HD), spinocerebellar ataxia (SCA), and spinal muscular atrophy (SMA), is mainly addressed to motor and cognitive impairment, with special care to vital functions as breathing and feeding. Many of these patients complain of painful symptoms though their origin is variable, and their presence is frequently not considered in the treatment guidelines, leaving their management to the decision of the clinicians alone. However, studies focusing on pain frequency in such disorders suggest a high prevalence of pain in selected populations from 38 to 75% in AD, 40% to 86% in PD, and 19 to 85% in MND. The methods of pain assessment vary between studies so the type of pain has been rarely reported. However, a prevalent nonneuropathic origin of pain emerged for MND and PD. In AD, no data on pain features are available. No controlled therapeutic trials and guidelines are currently available. Given the relevance of pain in neurodegenerative disorders, the comprehensive understanding of mechanisms and predisposing factors, the application and validation of specific scales, and new specific therapeutic trials are needed.

Delay in Diagnosis of Spinal Muscular Atrophy: A Systematic Literature Review.Publié le 19 06 2016

BACKGROUND: Spinal muscular atrophy is a rare genetic disease with devastating neurodegenerative consequences. Timing of diagnosis is crucial for spinal muscular atrophy because early diagnosis may lead to early supportive care and reduction in patient and caregiver stress. The purpose of this study was to examine the published literature for diagnostic delay in spinal muscular atrophy.
METHODS: A systematic literature search was conducted in the PubMed and Web of Science databases for studies published between 2000 and 2014 that listed any type of spinal muscular atrophy and without molecular, mouse, or pathology in the keywords. Mean and/or median age of onset and diagnosis and delay in diagnosis was extracted or calculated. All estimates were weighted by the number of patients and descriptive statistics are reported.
RESULTS: A total of 21 studies were included in the final analysis. The weighted mean (standard deviation) ages of onset were 2.5 (0.6), 8.3 (1.6), and 39.0 (32.6) months for spinal muscular atrophy types I, II, and III, respectively, and the weighted mean (standard deviation) ages of confirmed spinal muscular atrophy genetic diagnosis were 6.3 (2.2), 20.7 (2.6), and 50.3 (12.9) months, respectively, for types I, II, and III. For studies reporting both age of onset and diagnosis, the weighted diagnostic delay was 3.6, 14.3, and 43.6 months for types I, II, and III, respectively.
CONCLUSIONS: Diagnostic delay is common in spinal muscular atrophy. The length of delay varied by severity (type) of spinal muscular atrophy. Further studies evaluating this delay and tools such as newborn screening are warranted to end the diagnostic delay in spinal muscular atrophy.

Discovery and optimization of small molecule splicing modifiers of survival motor neuron 2 (SMN2) as a treatment for spinal muscular atrophy.Publié le 17 06 2016

The underlying cause of spinal muscular atrophy (SMA) is a deficiency of the survival motor neuron (SMN) protein. Starting from hits identified in a high throughput screening campaign and through structure-activity relationship (SAR) investigations, we have developed small molecules that potently shift the alternative splicing of the SMN2 exon 7, resulting in increased production of the full-length SMN mRNA and protein. Three novel chemical series, represented by compounds 9, 14, and 20, have been optimized to increase the level of SMN protein by >50% in SMA patient-derived fibroblasts at concentrations < 160 nM. Daily administration of these compounds to severe SMA ?7 mice results in an increased production of SMN protein in disease relevant tissues and a significant increase in median survival time in a dose dependent manner. Our work supports the development of an orally administered small molecule for the treatment of patients with SMA.

Specific correction of alternative survival motor neuron 2 (SMN2) splicing by small molecules: Discovery of a potential novel medicine to treat spinal muscular atrophy.Publié le 17 06 2016

Spinal muscular atrophy (SMA) is the leading genetic cause of infant and toddler mortality, and there is currently no approved therapy available. SMA is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. These mutations or deletions result in low levels of functional SMN protein. SMN2, a paralogous gene to SMN1, undergoes alternative splicing and exclusion of exon 7, producing an unstable, truncated SMN?7 protein. Herein, we report the identification of pyrido-pyrimidinone series of small molecules that modify the alternative splicing of SMN2, increasing the production of full length SMN2 mRNA. Upon oral administration of our small molecules, the levels of full length SMN protein were restored in two mouse models of SMA. In-depth lead optimization in the pyrido-pyrimidinone series culminated in the selection of compound 3 (RG7800), the first small molecule SMN2 splicing modifier to enter human clinical trials.

Splice-switching antisense oligonucleotides as therapeutic drugs.Publié le 12 06 2016

Splice-switching oligonucleotides (SSOs) are short, synthetic, antisense, modified nucleic acids that base-pair with a pre-mRNA and disrupt the normal splicing repertoire of the transcript by blocking the RNA-RNA base-pairing or protein-RNA binding interactions that occur between components of the splicing machinery and the pre-mRNA. Splicing of pre-mRNA is required for the proper expression of the vast majority of protein-coding genes, and thus, targeting the process offers a means to manipulate protein production from a gene. Splicing modulation is particularly valuable in cases of disease caused by mutations that lead to disruption of normal splicing or when interfering with the normal splicing process of a gene transcript may be therapeutic. SSOs offer an effective and specific way to target and alter splicing in a therapeutic manner. Here, we discuss the different approaches used to target and alter pre-mRNA splicing with SSOs. We detail the modifications to the nucleic acids that make them promising therapeutics and discuss the challenges to creating effective SSO drugs. We highlight the development of SSOs designed to treat Duchenne muscular dystrophy and spinal muscular atrophy, which are currently being tested in clinical trials.

Neuron-specific knock-down of SMN1 causes neuron degeneration and death through an apoptotic mechanism.Publié le 05 06 2016

Spinal muscular atrophy is a devastating disease that is characterized by degeneration and death of a specific subclass of motor neurons in the anterior horn of the spinal cord. Although the gene responsible, Smn1, was identified 20 years ago, it has proven difficult to investigate its effects in vivo Consequently, a number of key questions regarding the molecular and cellular functions of this molecule have remained unanswered. We developed a C. elegans model of smn-1 loss-of-function using a neuron-specific RNAi strategy to knock-down smn-1 selectively in a subclass of motor neurons. The transgenic animals presented a cell-autonomous, age-dependent degeneration of motor neurons detected as locomotory defects and the disappearance of presynaptic and cytoplasmic fluorescent markers in targeted neurons. This degeneration led to neuronal death as revelead by positive reactivity to genetic and chemical cell-death markers. We show that genes of the classical apoptosis pathway are involved in the smn-1-mediated neuronal death, and that this phenotype can be rescued by the expression of human Smn1, indicating a functional conservation between the two orthologs. Finally, we determined that Plastin3/plst-1 genetically interacts with smn-1 to prevent degeneration, and that treatment with valproic acid is able to rescue the degenerative phenotype. These results provide novel insights into the cellular and molecular mechanisms that lead to the loss of motor neurons when Smn1 function is reduced.

Impact of Movement Disorders on Management of Spinal Deformity in the Elderly.Publié le 05 06 2016

Spinal deformities are frequent and disabling complications of movement disorders such as Parkinson disease and multiple system atrophy. The most distinct spinal deformities include camptocormia, antecollis, Pisa syndrome, and scoliosis. Spinal surgery has become lower risk and more efficacious for complex spinal deformities, and thus more appealing to patients, particularly those for whom conservative treatment is inappropriate or ineffective. Recent innovations and advances in spinal surgery have revolutionized the management of spinal deformities in elderly patients. However, spinal deformity surgeries in patients with Parkinson disease remain challenging. High rates of mechanical complications can necessitate revision surgery. The success of spinal surgery in patients with Parkinson disease depends on an interdisciplinary approach, including both surgeons and movement disorder specialists, to select appropriate surgical patients and manage postoperative movement in order to decrease mechanical failures. Achieving appropriate correction of sagittal alignment with strong biomechanical instrumentation and bone fusion is the key determinant of satisfactory results.

Perioperative complications of scoliosis surgery in patients with Duchenne muscular dystrophy and spinal muscular atrophy, focussing on wound healing disorders.Publié le 03 06 2016

PURPOSE: Patients with Duchenne muscular dystrophy (DMD) or spinal muscular atrophy (SMA), both neuromuscular diseases, sustain spinal scoliosis in the course of their disease. To reduce the concomitant major morbidity and to improve their quality of life, patients require surgical spine stabilization. This can lead to complications like respiratory, cardiac or neurological complications or wound healing disorders (WHD). To find out the different complexities and risk factors increasing the chance to develop a WHD, the inpatient database was analyzed.
METHODS: We performed a retrospective statistical study. Therefore we analyzed the inpatient database of 180 patients (142 DMD and 38 SMA patients). The focus was on WHD. To figure out the risk factors leading to WHD, we conducted a logistic regression.
RESULTS: Cardiac complications occurred most frequently, followed by pulmonary complications and neurological lesions. 57 out of 180 patients developed a WHD. In 23 cases the WHD was aseptic, in the other 34 cases dermal organisms, pseudomonas species and intestinal organisms were responsible. By means of the logistic regression, we were able to identify two more risk factors, in addition to diagnosis and gender, for developing a WHD in our patients: the year of surgery and the direction of pelvic tilt.
CONCLUSIONS: Most common complications following scoliosis surgery are respiratory and cardiac complications. WHD are a severe complication that implies a prolonged therapy. Some risk factors for developing WHD could be identified in this analysis. Specifically these were the date of surgery and the direction of pelvic tilt.

Transcript, methylation and molecular docking analyses of the effects of HDAC inhibitors, SAHA and Dacinostat, on SMN2 expression in fibroblasts of SMA patients.Publié le 03 06 2016

Several histone deacetylase inhibitors (HDACis) are known to increase Survival Motor Neuron 2 (SMN2) expression for the therapy of spinal muscular atrophy (SMA). We aimed to compare the effects of suberoylanilide hydroxamic acid (SAHA) and Dacinostat, a novel HDACi, on SMN2 expression and to elucidate their acetylation effects on the methylation of the SMN2. Cell-based assays using type I and type II SMA fibroblasts examined changes in transcript expressions, methylation levels and protein expressions. In silico methods analyzed the intermolecular interactions between each compound and HDAC2/HDAC7. SMN2 mRNA transcript levels and SMN protein levels showed notable increases in both cell types, except for Dacinostat exposure on type II cells. However, combined compound exposures showed less pronounced increase in SMN2 transcript and SMN protein level. Acetylation effects of SAHA and Dacinostat promoted demethylation of the SMN2 promoter. The in silico analyses revealed identical binding sites for both compounds in HDACs, which could explain the limited effects of the combined exposure. With the exception on the effect of Dacinostat in Type II cells, we have shown that SAHA and Dacinostat increased SMN2 transcript and protein levels and promoted demethylation of the SMN2 gene.Journal of Human Genetics advance online publication, 2 June 2016; doi:10.1038/jhg.2016.61.

Loganin possesses neuroprotective properties, restores SMN protein and activates protein synthesis positive regulator Akt/mTOR in experimental models of spinal muscular atrophy.Publié le 01 06 2016

Spinal muscular atrophy (SMA) is an autosomal recessive neurodegenerative disease characterized by motor neurons degeneration and muscular atrophy. There is no effective SMA treatment. Loganin is a botanical candidate with anti-inflammatory, anti-oxidant, glucose-lowering and anti-diabetic nephropathy activities. The aim of this study is to investigate the potential protective effects of loganin on SMA using two cellular models, SMN-deficient NSC34 cells and SMA patient fibroblasts, and an animal disease model, SMA?7 mice. In SMN-deficient NSC34 cells, loganin increased cell viability, neurite length, and expressions of SMN, Gemin2, SMN-Gemin2 complex, p-Akt, p-GSK-3?, p-CREB, BDNF and Bcl-2. However, both AG1024 (IGF-1 R antagonist) and IGF-1 R siRNA attenuated the protective effects of loganin on SMN level and cell viability in SMN-deficient NSC34 cells. In SMA patient fibroblasts, loganin up-regulated levels of SMN, FL-SMN2, and Gemins, increased numbers of SMN-containing nuclear gems, modulated splicing factors, and up-regulated p-Akt. Furthermore, in the brain, spinal cord and gastrocnemius muscle of SMA?7 mice, loganin up-regulated the expressions of SMN and p-Akt. Results from righting reflex and hind-limb suspension tests indicated loganin improved muscle strength of SMA?7 mice; moreover, loganin activated Akt/mTOR signal and inhibited atrogin-1/MuRF-1 signal in gastrocnemius muscle of SMA?7 mice. Loganin also increased body weight, but the average lifespan of loganin (20mg/kg/day)-treated SMA mice was 16.80±0.73 days, while saline-treated SMA mice was 10.91±0.96 days. In conclusion, the present results demonstrate that loganin provides benefits to SMA therapeutics via improving SMN restoration, muscle strength and body weight. IGF-1 plays an important role in loganin neuroprotection. Loganin can be therefore a valuable complementary candidate for treatment of neuromuscular diseases via regulation of muscle protein synthesis and neuroprotection.

[Life-threatening hypophosphatemia in 74-year-old woman with recurrent pneumonia and progressive muscular atrophy].Publié le 28 05 2016

UNLABELLED: Although hypophosphatemia can be a serious threat to health and life, it is a problem rarely taken into consideration in the differential diagnosis in the current clinical practice. The aim of the study was to present the description of hypophosphatemia issues in the context of the threat they may pose to the health and life when undiagnosed.
CASE REPORT: 74-year-old internal charged woman , with progressive destruction for a few years, recurrent pneumonia, and a compression fracture of the spine, was admitted to hospital because of fainting and general deterioration. In the course of the performed diagnostics primary hyperparathyroidism was diagnosed with pre-existing inadequate severe hypophosphatemia. Because the presented clinical picture, only partially tie in symptomatology of primary hiperparathyroidism, the diagnostic process was targeted to search for other causes of both hypophosphatemia and symptoms reported by the patient. Finally, in addition to PHPT ( primary hyperparathyroidism) also vitamin D deficiency and tuberculosis was found. The fact that the treatment of infectious disease led to the phosphatemia standardization , and thus to significant improvement of the overall demonstrates, shows the significant contribution of tuberculosis in the pathogenesis of phosphate deficiency in this case.
RESULTS: Our case is an example of confirming the need for a thorough and multidirectional analysis of the clinical picture, which is a prerequisite for a correct diagnosis.

What's in the Literature?Publié le 27 05 2016

One of the first questions asked by patients and family members when a diagnosis of amyotrophic lateral sclerosis is made is "what about stem cells?" The term "stem cells" has attractiveness to it, with the assumption that stem cell treatment (stem nerve cells) can replace lost nerve cells. There are perhaps 2 types of stem cell trials, those that are vetted by the Food and Drug Administration and those that have no official oversight and whose results are infrequently published. The issue of the latter was discussed in the last edition of this column. The results of one of the formal stem cell trials now in the United States have been reported. Spinal muscular atrophy is a form of motor neuron disease affecting children and has a genetic cause, which has led to a feasibility study giving antisense oligonucleotides, and the results have also been reported. Biomarkers of amyotrophic lateral sclerosis are being sought, and the presence of neurofilaments is promising. Inflammatory neuropathies are an important group because they are treatable. Intravenous immune globulin is a commonly used agent, but a number of questions persist: one is efficacy among brands, another is the probability of a response, and a third is optimum dosing and taper schedules. A number of recent articles address these issues. The predictive value of single-fiber electromyography in determining which patients with ocular myasthenia will develop generalized disease, the risk of crisis after thymectomy, and 2 papers discussing new forms of congenital myasthenic syndrome are discussed. The risk of brain tumors, quality of life, and the assessment of trunk muscle strength in patients with type 1 myotonic dystrophy is reviewed. An article describing the discovery of mutations in SCN4A as a cause of congenital myopathy is discussed, as is one describing the occurrence of rhabdomyolysis in a group of patients subsequently discovered to have various forms of muscular dystrophy. Finally, articles describing the features of patients with inflammatory myopathies and Jo-1 and either 3-hydroxy-3-methylglutaryl-conezymea reductase or to signal recognition particle antibodies are reviewed.

Deep brain stimulation as a treatment for Parkinson's disease related camptocormia.Publié le 25 05 2016

In this systematic review, we aimed to profile the various reported interventions for camptocormia in Parkinson's disease (PD) and give an overview of the benefits of deep brain stimulation (DBS). Currently, there is no consensus in the literature regarding this. PD manifests in several ways and camptocormia is one of the commonly encountered problems for both spine and functional neurosurgeons. It is a significant forward flexion of the thoracolumbar spine which resolves in the recumbent position. DBS was introduced in 2002 in the USA, and since then its efficacy and applications have tremendously increased. We reviewed the PubMed and Medical Subject Headings database using the phrases "Parkinson's disease" or "Parkinson" in combination with "spinal deformity" or "camptocormia" or "bent spine syndrome" and "deep brain stimulation". Our review was limited to English language literature and we excluded camptocormia of non-PD origin. Our search yielded 361 articles with 131 patients in the pooled data. The majority (59%) of patients were women and the age range was 48-76 years. While half the patients on levodopa (n=42) saw no improvement of their camptocormia, 71% of the lidocaine group (n=27) and 68% of the DBS group (n=32) showed significant improvement. For mean flexion angle, the spinal surgery and DBS group demonstrated profound improvement in the bending angle, 89.9% and 78.2%, respectively. However, major complications following spinal surgery were noted. Although the results are from a small group of patients, DBS has achieved sustained improvement in camptocormia with low postoperative morbidity, and appears to be a promising treatment option. A larger, long term study is necessary to establish comprehensive outcome data.

[A Case of General Anesthesia in a Patient with Spinal and Bulbar Muscular Atrophy].Publié le 21 05 2016

We report a successful management of anesthesia in a 55-year-old male patient with spinal and bulbar muscular atrophy (SBMA). His respiratory and swallowing functions were preserved preoperatively. He underwent an osteosynthesis for a femoral neck fracture under general anesthesia using nondepolarizing muscle relaxant. The anesthetic concerns in patients with SBMA are the possibility of postoperative respiratory dysfunction due to anesthetics or muscle relaxants and that of postoperative neurological deterioration due to spinal or epidural anesthesia. In this case, the effect of an intubating dose of rocuronium (0.5 mg · kg(-1)) was markedly prolonged, but it was completely reversed by sugammadex (2 mg · kg(-1)). Postoperative course was uneventful and clinical symptoms of SBMA did not become exacerbated.

Histopathological Defects in Intestine in Severe Spinal Muscular Atrophy Mice Are Improved by Systemic Antisense Oligonucleotide Treatment.Publié le 16 05 2016

Gastrointestinal (GI) defects, including gastroesophageal reflux, constipation and delayed gastric emptying, are common in patients with spinal muscular atrophy (SMA). Similar GI dysmotility has been identified in mouse models with survival of motor neuron (SMN) protein deficiency. We previously described vascular defects in skeletal muscle and spinal cord of SMA mice and we hypothesized that similar defects could be involved in the GI pathology observed in these mice. We therefore investigated the gross anatomical structure, enteric vasculature and neurons in the small intestine in a severe mouse model of SMA. We also assessed the therapeutic response of GI histopathology to systemic administration of morpholino antisense oligonucleotide (AON) designed to increase SMN protein expression. Significant anatomical and histopathological abnormalities, with striking reduction of vascular density, overabundance of enteric neurons and increased macrophage infiltration, were detected in the small intestine in SMA mice. After systemic AON treatment in neonatal mice, all the abnormalities observed were significantly restored to near-normal levels. We conclude that the observed GI histopathological phenotypes and functional defects observed in these SMA mice are strongly linked to SMN deficiency which can be rescued by systemic administration of AON. This study on the histopathological changes in the gastrointestinal system in severe SMA mice provides further indication of the complex role that SMN plays in multiple tissues and suggests that at least in SMA mice restoration of SMN production in peripheral tissues is essential for optimal outcome.

Acid ceramidase and the treatment of ceramide diseases: The expanding role of enzyme replacement therapy.Publié le 16 05 2016

Ceramides are a diverse group of sphingolipids that play important roles in many biological processes. Acid ceramidase (AC) is one key enzyme that regulates ceramide metabolism. Early research on AC focused on the fact that it is the enzyme deficient in the rare genetic disorder, Farber Lipogranulomatosis. Recent research has revealed that deficiency of the same enzyme is responsible for a rare form of spinal muscular atrophy associated with myoclonic epilepsy (SMA-PME). Due to their diverse role in biology, accumulation of ceramides also has been implicated in the pathobiology of many other common diseases, including infectious lung diseases, diabetes, cancers and others. This has revealed the potential of AC as a therapy for many of these diseases. This review will focus on the biology of AC and the potential role of this enzyme in the treatment of human disease.

Selective Neuromuscular Denervation in Taiwanese Severe SMA Mouse Can Be Reversed by Morpholino Antisense Oligonucleotides.Publié le 16 05 2016

Spinal muscular atrophy (SMA) is an autosomal recessive motor neuron disease caused by deficiency of the survival of motor neuron (SMN) protein, which leads to synaptic defects and spinal motor neuron death. Neuromuscular junction (NMJ) abnormalities have been found to be involved in SMA pathogenesis in the SMN?7 SMA mouse model. However, whether similar NMJ pathological findings present in another commonly used mouse model, the Taiwanese SMA mouse, has not been fully investigated. To examine the NMJs of the Taiwanese severe SMA mouse model (Smn-/-; SMN2tg/0), which is characterized by severe phenotype and death before postnatal day (P) 9, we investigated 25 axial and appendicular muscles from P1 to P9. We labelled the muscles with anti-neurofilament and anti-synaptophysin antibodies for nerve terminals and ?-bungarotoxin for acetylcholine receptors (AChRs). We found that severe NMJ denervation (<50% fully innervated endplates) selectively occurred in the flexor digitorum brevis 2 and 3 (FDB-2/3) muscles from P5, and an increased percentage of fully denervated endplates correlated with SMA progression. Furthermore, synaptophysin signals were absent at the endplate compared to control littermate mice, suggesting that vesicle transport might only be affected at the end stage. Subsequently, we treated the Taiwanese severe SMA mice with morpholino (MO) antisense oligonucleotides (80 ?g/g) via subcutaneous injection at P0. We found that MO significantly reversed the NMJ denervation in FDB-2/3 muscles and extended the survival of Taiwanese severe SMA mice. We conclude that early NMJ denervation in the FDB-2/3 muscles of Taiwanese severe SMA mice can be reversed by MO treatment. The FDB-2/3 muscles of Taiwanese severe SMA mice provide a very sensitive platform for assessing the effectiveness of drug treatments in SMA preclinical studies.

Rasch analysis of the pediatric evaluation of disability inventory-computer adaptive test (PEDI-CAT) item bank for children and young adults with spinal muscular atrophy.Publié le 16 05 2016

PURPOSE: We evaluated the suitability of a caregiver-reported functional measure, the Pediatric Evaluation of Disability Inventory-Computer Adaptive Test (PEDI-CAT), for children and young adults with spinal muscular atrophy (SMA).
METHODS: PEDI-CAT Mobility and Daily Activities domain item banks were administered to 58 caregivers of children and young adults with SMA. Rasch analysis was used to evaluate test properties across SMA types.
RESULTS: Unidimensional content for each domain was confirmed. The PEDI-CAT was most informative for Type III SMA, with ability levels distributed close to 0.00 logits in both domains. It was less informative for Types I and II SMA, especially for mobility skills. Item and person abilities were not distributed evenly across all types.
CONCLUSIONS: The PEDI-CAT may be used to measure functional performance in SMA, but additional items are needed to identify small changes in function and best represent the abilities of all types of SMA. This article is protected by copyright. All rights reserved.

A Review on Spinal Muscular Atrophy: Awareness, Knowledge, and Attitudes.Publié le 16 05 2016

Spinal Muscular Atrophy (SMA) is one of the most common genetic causes of infant death. There is presently no cure, but the therapeutic pipeline is promising. Given the prevalence of SMA coupled with the potential for new treatment options, universal carrier screening, and newborn screening, we conducted a literature review of the awareness, knowledge, and attitudes held by the public and non-geneticist clinicians about various aspects of SMA. We then identify recommendations for targeting additional research, training, and educational efforts to increase awareness. In the limited available literature, we found that the public is generally unfamiliar with SMA but has favorable views of carrier and newborn screening. Clinicians also had limited understanding of SMA. Further research into knowledge and attitudes of healthcare providers and the general public will help develop a better understanding of education gaps and inform outreach efforts. These educational efforts are needed to complement the momentum as treatments are being developed and tested. Furthermore, professional societies are proposing routine carrier screening and SMA may achieve newborn screening status, which will change the SMA landscape for genetics professionals and families. Thus, it is important to explore knowledge and attitudes about SMA to allow us to prepare for when SMA attains higher public and clinician recognition.

Turkish version of the Egen Klassifikation scale version 2: validity and reliability in the Turkish population.Publié le 16 05 2016

The Egen Klassifikation Scale version 2 (EK2) is an important functional ability assessment scale for nonambulant neuromuscular patients. We investigated the validity and reliability of the EK2 scale in Turkish Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) patients. Forty-one patients were included in the study. An intra/interobserver reliability study of the EK2 scale as translated into Turkish was performed. The Brooke Functional Classification Scale (BFC) for Upper and Lower Extremities, 10-item Modified Barthel's Index for Activities of Daily Living (MBI), and Pulmonary Dysfunction Index (PDI) were used to investigate the validity of the Turkish version of the EK2 scale. Cronbach's alpha was 0.81 and ICC was 0.87 with a 95% confidence interval (r=0.92, p<0.01). There were positive, moderate correlations between the EK2 sum score and the BFC upper extremity level and between the EK2 sum score and the PDI, and a negative, moderate correlation between the EK2 sum score and the MBI (p?0.01). The Turkish version of the EK2 scale was found to be highly reliable and valid.

Bent spine syndrome as an initial manifestation of late-onset multiple acyl-CoA dehydrogenase deficiency: a case report and literature review.Publié le 16 05 2016

BACKGROUND: Late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) is an autosomal recessive inherited disease of metabolic dysfunction clinically characterized by fluctuating proximal muscle weakness, excise intolerance, and dramatic riboflavin responsiveness. Dropped head syndrome can occasionally be observed in some severe patients with late-onset MADD; however, bent spine syndrome as an initial symptom had not been reported in patients with late-onset MADD.
CASE PRESENTATION: A 46-year-old man lost the ability to hold his trunk upright, and had difficulty in raising his head, but he had no obvious symptoms of limb weakness. Meanwhile, he developed persistent numbness of limbs and lips around. Myopathological features and combined elevation of multiple acylcarnitines indicated that the axial myopathy might be caused by lipid storage myopathy. Cervical and lumbosacral MRI revealed a lot of abnormal signals diffusing along paravertebral muscles, while the abnormal signals almost disappeared after riboflavin treatment. Nerve conduction study indicated the patient suffering from predominantly sensory neuropathy and mildly motor neuropathy. Muscle pathology also demonstrated no typical neurogenic change, which was consistent with the electrophysiological findings. Causative mutations were found in the ETFDH gene.
CONCLUSION: We report the first case of late-onset MADD with sensory neuropathy initially manifesting as bent spine syndrome and dropped head syndrome.

Pisa Syndrome.Publié le 16 05 2016

Lateral trunk flexion is often seen in patients with Parkinson disease, sometimes coming on as a subacute phenomenon associated with medication adjustments, and in others with gradual onset that seems related to a neurodegenerative process related to the evolution of the disease.Either acute or subacute presentations seem to be pure abnormalities in the coronal plane and are usually reversible. However, a chronic form occurs often in a combined fashion with anteroposterior flexion (camptocormia), improves only partially, remains stable, or even worsens over time.The acute/subacute phenotype is the condition originally named as Pisa syndrome (PS).The pathophysiology of PS remains poorly understood, and a cholinergic-dopaminergic imbalance has been suggested as being involved in the cause of this disorder. The role of other neurotransmitters and how they become dysfunctional in PS remains to be elucidated.Specific treatments, other than discontinuing the medications responsible for the disorder, whenever possible, are undeveloped because of the unknown etiology.

Intermittent daytime mouthpiece ventilation successfully augments nocturnal non-invasive ventilation, controlling ventilatory failure and maintaining patient independence.Publié le 16 05 2016

A 53-year-old woman with spinal muscular atrophy and a 7-year history of nocturnal non-invasive ventilation (NIV) use via nasal mask and chinstrap was admitted electively. Outpatient review suggested symptomatic hypercapnia and hypoxaemia. Use of her usual NIV resulted in early morning respiratory acidosis due to excess mouth leak, and continuous face mask NIV was instigated while in hospital. Once stabilised, she elected to return to nasal ventilation. At outpatient review, respiratory acidosis reoccurred despite diurnal use of NIV. Using the patient's routine ventilator and a novel mouthpiece and trigger algorithm, intermittent daytime mouthpiece ventilation (MPV) was introduced alongside overnight NIV. Control of respiratory failure was achieved and, vitally, independent living maintained. Intermittent MPV was practicable and effective where the limits of ventilator tolerance had otherwise been reached. MPV may reduce the need for tracheostomy ventilation and this case serves as a reminder of the increasing options routinely available to NIV clinicians.

Plastin 3 Expression Does Not Modify Spinal Muscular Atrophy Severity in the ?7 SMA Mouse.Publié le 16 05 2016

Spinal muscular atrophy is caused by loss of the SMN1 gene and retention of SMN2. The SMN2 copy number inversely correlates with phenotypic severity and is a modifier of disease outcome. The SMN2 gene essentially differs from SMN1 by a single nucleotide in exon 7 that modulates the incorporation of exon 7 into the final SMN transcript. The majority of the SMN2 transcripts lack exon 7 and this leads to a SMN protein that does not effectively oligomerize and is rapidly degraded. However the SMN2 gene does produce some full-length SMN and the SMN2 copy number along with how much full-length SMN the SMN2 gene makes correlates with severity of the SMA phenotype. However there are a number of discordant SMA siblings that have identical haplotypes and SMN2 copy number yet one has a milder form of SMA. It has been suggested that Plastin3 (PLS3) acts as a sex specific phenotypic modifier where increased expression of PLS3 modifies the SMA phenotype in females. To test the effect of PLS3 overexpression we have over expressed full-length PLS3 in SMA mice. To ensure no disruption of functionality or post-translational processing of PLS3 we did not place a tag on the protein. PLS3 protein was expressed under the Prion promoter as we have shown previously that SMN expression under this promoter can rescue SMA mice. High levels of PLS3 mRNA were expressed in motor neurons along with an increased level of PLS3 protein in total spinal cord, yet there was no significant beneficial effect on the phenotype of SMA mice. Specifically, neither survival nor the fundamental electrophysiological aspects of the neuromuscular junction were improved upon overexpression of PLS3 in neurons.

Camptocormia in Parkinson's disease: definition, epidemiology, pathogenesis and treatment modalities.Publié le 16 05 2016

Camptocormia is an axial postural deformity characterised by abnormal thoracolumbar spinal flexion. The symptom usually presents while standing, walking or exercising and is alleviated while sitting, lying in a recumbent position, standing against a wall or using walking support. There is no consensus on the degree of thoracolumbar flexion to define camptocormia. However, most authors usually use an arbitrary number of at least 45° flexion of the thoracolumbar spine when the individual is standing or walking. Aetiologies of camptocormia are heterogeneous, and Parkinson's disease (PD) is one of its many causes. The prevalence of camptocormia in PD ranges from 3% to 18%. Central and peripheral mechanisms might both contribute to its pathogenesis. Although there is no established consensus for treatment of camptocormia in PD, there are non-pharmacological, pharmacological and surgical approaches that can be used.

Survival of a child with spinal muscular atrophy and acute respiratory distress syndrome.Publié le 16 05 2016

Spinal muscular atrophy (SMA), a lower motor neuron anterior horn cell disease, causes significant respiratory morbidity and mortality in children. Acute respiratory distress syndrome (ARDS) accounts for 1-4% of all Pediatric Intensive Care Unit (PICU) admissions. Management outcomes for ARDS in patients with SMA have not been described. We present the case of a 5-year-old boy with Type II SMA and ARDS requiring invasive mechanical ventilation. He improved with meticulous management of mechanical ventilation, airway clearance, fluid/nutrition, and sedation/analgesia. He was successfully extubated after 14 days of invasive mechanical ventilation and discharged home after a 20 day hospitalization.

Upper limb evaluation and one-year follow up of non-ambulant patients with spinal muscular atrophy: an observational multicenter trial.Publié le 16 05 2016

Assessment of the upper limb strength in non-ambulant neuromuscular patients remains challenging. Although potential outcome measures have been reported, longitudinal data demonstrating sensitivity to clinical evolution in spinal muscular atrophy patients are critically lacking. Our study recruited 23 non-ambulant patients, 16 patients (males/females = 6/10; median age 15.4 years with a range from 10.7 to 31.1 years) with spinal muscular atrophy type II and 7 patients (males/females = 2/5; median age 19.9 years with a range from 8.3 to 29.9 years) with type III. The Brooke functional score was on median 3 with a range from 2 to 6. The average total vital capacity was 46%, and seven patients required non-invasive ventilation at night. Patients were assessed at baseline, 6 months, and 1 year using the Motor Function Measure and innovative devices MyoGrip, MyoPinch, and MoviPlate, which assess handgrip strength, key pinch strength, and hand/finger extension-flexion function, respectively. The study demonstrated the feasibility and reliability of these measures for all patients, and sensitivity to negative changes after the age of 14 years. The younger patients showed an increase of the distal force in the follow-up period. The distal force measurements and function were correlated to different functional scales. These data represent an important step in the process of validating these devices as potential outcome measures for future clinical trials.

Spinal muscular atrophy functional composite score: A functional measure in spinal muscular atrophy.Publié le 16 05 2016

INTRODUCTION: With clinical trials underway, our objective was to construct a composite score of global function that could discriminate among people with spinal muscular atrophy (SMA).
METHODS: Data were collected from 126 participants with SMA types 2 and 3. Scores from the Hammersmith Functional Motor Scale-Expanded and Upper Limb Module were expressed as a percentage of the maximum score and 6-minute walk test as percent of predicted normal distance. A principal component analysis was performed on the correlation matrix for the 3 percentage scores.
RESULTS: The first principal component yielded a composite score with approximately equal weighting of the 3 components and accounted for 82% of the total variability. The SMA functional composite score, an unweighted average of the 3 individual percentage scores, correlated almost perfectly with the first principal component.
CONCLUSIONS: This combination of measures broadens the spectrum of ability that can be quantified in type 2 and 3 SMA patients.

Home mechanical ventilation in childhood-onset hereditary neuromuscular diseases: 13 years' experience at a single center in Korea.Publié le 16 05 2016

INTRODUCTION: Children with hereditary neuromuscular diseases (NMDs) are at a high risk of morbidity and mortality related to respiratory failure. The use of home mechanical ventilation (HMV) has saved the lives of many children with NMD but, due to a lack of studies, dependable guidelines are not available. We drew upon our experience to compare the various underlying NMDs and to evaluate HMV with regard to respiratory morbidity, the proper indications and timing for its use, and to develop a policy to improve the quality of home noninvasive ventilation (NIV).
METHODS: We retrospectively analyzed the medical records of 57 children with childhood-onset hereditary NMDs in whom HMV was initiated between January 2000 and May 2013 at Seoul National University Children's Hospital. The degree of respiratory morbidity was estimated by the frequency and duration of hospitalizations caused by respiratory distress.
RESULTS: The most common NMD was spinal muscular atrophy (SMA, n = 33). Emergent mechanical ventilation was initiated in 44% of the patients before the confirmed diagnosis, and the indicators of pre-HMV respiratory morbidity (e.g., extubation trials, hypoxia, hospitalizations, and intensive care unit stay) were greater in these patients than in others. The proportion of post-HMV hospitalizations (range, 0.00-0.52; median, 0.01) was lower than that of pre-HMV hospitalizations (0.02-1.00; 0.99) (P < 0.001). Eight patients were able to maintain home NIV. The main causes of NIV failure were air leakage and a large amount of airway secretions.
CONCLUSIONS: The application of HMV helped reduce respiratory morbidity in children with childhood-onset hereditary NMD. Patients with SMA type I can benefit from an early diagnosis and the timely application of HMV. The choice between invasive and noninvasive HMV should be based on the patient's age and NIV trial tolerance. Systematic follow-up guidelines provided by a multidisciplinary team are needed.

Modulation of alternative splicing with chemical compounds in new therapeutics for human diseases.Publié le 16 05 2016

Alternative splicing is a critical step where a limited number of human genes generate a complex and diverse proteome. Various diseases, including inherited diseases with abnormalities in the "genome code," have been found to result in an aberrant mis-spliced "transcript code" with correlation to the resulting phenotype. Chemical compound-based and nucleic acid-based strategies are trying to target this mis-spliced "transcript code". We will briefly mention about how to obtain splicing-modifying-compounds by high-throughput screening and overview of what is known about compounds that modify splicing pathways. The main focus will be on RNA-binding protein kinase inhibitors. In the main text, we will refer to diseases where splicing-modifying-compounds have been intensively investigated, with comparison to nucleic acid-based strategies. The information on their involvement in mis-splicing as well as nonsplicing events will be helpful in finding better compounds with less off-target effects for future implications in mis-splicing therapy.

Lifestyle Implications of Home Mechanical Insufflation-Exsufflation for Children With Neuromuscular Disease and Their Families.Publié le 16 05 2016

BACKGROUND: Mechanical insufflation-exsufflation (MI-E) is increasingly used in the home management of children with neuromuscular disease. Research to date has focused on the effect of MI-E on physical health. The aim of this study was to qualitatively investigate the impact of home MI-E on the child and family's lifestyle.
METHODS: Eight parents and 3 children participated in semistructured interviews.
RESULTS: Five themes emerged from parent interviews demonstrating: (1) lifestyle implications, (2) parents becoming experts, (3) parents developing a sense of control over their child's condition, (4) an element of extra care, and (5) impacts on the parent-child relationship. Developing themes from the child interviews showed them adjusting to and then relying on the device. Home MI-E medicalized the home, but the overall lifestyle impact was positive.
CONCLUSIONS: Although involving a small number of subjects, this study demonstrated a mixture of opposing impacts of home MI-E on lifestyle, both enabling and disabling, which need to be considered when introducing home MI-E. The positive impacts included greater ability to manage the child's health, including avoidance of hospital admissions. Negative impacts were greatest for those parents who were sole operators of the device, including a frequently disrupted lifestyle.

Appropriate timing of surgical intervention for the proximal type of cervical spondylotic amyotrophy.Publié le 16 05 2016

PURPOSE: The purposes of this study were to evaluate the clinical outcome after surgical treatment of patients with the proximal type of cervical spondylotic amyotrophy (CSA) and to explore the appropriate timing for surgical intervention.
MATERIALS AND METHODS: A retrospective review was performed on a consecutive cohort of 41 patients who underwent surgical treatment for the proximal type of CSA between 1995 and 2011 at the Nagoya Spine Group Hospitals. We collected information regarding age, type of muscle atrophy, preoperative and final manual muscle test, duration of symptoms, high-intensity areas on T2-weighted MRI images, low-intensity areas on T1-weighted MRI images, levels of spinal canal stenosis, the compression lesion site, cervical kyphosis and surgical procedures (laminoplasty, anterior spinal fusion and posterior spinal fusion). Univariate analyses and multivariate logistic regression analysis were performed to identify correlates of a poor outcome. To explore the appropriate timing for performing surgery, we analyzed the data using receiver operating characteristic (ROC) analysis.
RESULTS: The duration of CSA symptoms was 11.6 months on average. The surgical results were excellent for 25 patients, good for six, fair for nine and poor for one. On multivariate logistic regression analysis, the duration of symptoms was statistically associated with a poor surgical outcome (OR 1.393, p = 0.011). ROC analysis demonstrated that 4.3 months from the onset of CSA symptoms was the appropriate time to undergo surgery.
CONCLUSIONS: Our results indicate that we should recommend surgical intervention to patients with the proximal type of CSA within about 4 months after the onset of symptoms if conservative treatment has not been successful.

Perceived efficacy of salbutamol by persons with SMA: a mixed methods study.Publié le 18 03 2016

INTRODUCTION:The aim of this study is to assess the perceived effect of salbutamol in adult patients with spinal muscular atrophy and to evaluate the usefulness of WHO Disability Assessment Schedule II (WHODAS-II) and Fatigue Severity Scale (FSS) to measure it.
METHODS:A longitudinal mixed methods study was performed. Ten patients were interviewed and filled in WHODAS-II and FSS questionnaires to assess disability and fatigue at 2 time points. Inductive thematic analysis was used for qualitative data. The non-parametric Wilcoxon test was performed for quantitative analysis.
RESULTS:All participants reported an improvement in their condition after salbutamol consumption. WHODAS-II and FSS captured changes in patients' disability and fatigue reliably.
CONCLUSIONS:The mixed methods design allowed us to identify the functional domains in which participants experienced effects of salbutamol. Because of decreased fatigue, improved functioning, and few side effects they were satisfied with the treatment. This article is protected by copyright. All rights reserved.

Physical therapy services received by individuals with spinal muscular atrophy (SMA).Publié le 18 03 2016

PURPOSE: The consensus statement for standard of care in SMA recommends multidisciplinary medical care including physical therapy (PT) services. To date there are no reports regarding the implementation of these recommendations and the type of care or services received by individuals with SMA. The purpose of this study is to describe the PT services received by individuals with SMA.
METHODS: Interviews were conducted with patients or their caregivers at the Pediatric Neuromuscular Clinical Research (PNCR) Network sites from October 2011 to September 2012. Questions included information about clinical status of the patient, sociodemographic profile of the patient or caregiver, and PT services received in the past year, including the setting, frequency, duration and type of PT, and therapies administered by caregivers.
RESULTS: Eighty-six percent of 105 participants reported receiving PT services, some in multiple settings: 62% in the neuromuscular clinic, 38% at school, 34% at home, and 13% in an outpatient clinic. Greater frequency of PT services received was associated with younger age and inability to walk, but not SMA type.
CONCLUSION: This is the first multicenter study documenting PT services received by patients with SMA. Further research is needed to better understand the impact of PT services on the natural history of SMA.

Management of scoliosis in patients with Duchenne muscular dystrophy and spinal muscular atrophy: A literature review.Publié le 18 03 2016

Scoliosis occurs in nearly all non-ambulatory children with spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD). Non-operative treatments have not been shown to be effective at preventing progression of scoliosis. Progressive scoliosis can impact the ability of patients to sit comfortably, be cosmetically unappealing, and in severe cases exacerbate pulmonary disease. The main goal of operative treatment is to improve sitting balance and prevent progression of scoliosis. Complication rates are high and there is little data on effect of operative treatment on quality of life in children with SMA and DMD. Comprehensive multi-disciplinary pre-operative evaluations are vital to reduce the risks of operative treatment.

SMN Protein Can Be Reliably Measured in Whole Blood with an Electrochemiluminescence (ECL) Immunoassay: Implications for Clinical Trials.Publié le 18 03 2016

Spinal muscular atrophy (SMA) is caused by defects in the survival motor neuron 1 (SMN1) gene that encodes survival motor neuron (SMN) protein. The majority of therapeutic approaches currently in clinical development for SMA aim to increase SMN protein expression and there is a need for sensitive methods able to quantify increases in SMN protein levels in accessible tissues. We have developed a sensitive electrochemiluminescence (ECL)-based immunoassay for measuring SMN protein in whole blood with a minimum volume requirement of 5?L. The SMN-ECL immunoassay enables accurate measurement of SMN in whole blood and other tissues. Using the assay, we measured SMN protein in whole blood from SMA patients and healthy controls and found that SMN protein levels were associated with SMN2 copy number and were greater in SMA patients with 4 copies, relative to those with 2 and 3 copies. SMN protein levels did not vary significantly in healthy individuals over a four-week period and were not affected by circadian rhythms. Almost half of the SMN protein was found in platelets. We show that SMN protein levels in C/C-allele mice, which model a mild form of SMA, were high in neonatal stage, decreased in the first few weeks after birth, and then remained stable throughout the adult stage. Importantly, SMN protein levels in the CNS correlated with SMN levels measured in whole blood of the C/C-allele mice. These findings have implications for the measurement of SMN protein induction in whole blood in response to SMN-upregulating therapy.

Pharmacokinetics, Pharmacodynamics and Efficacy of a Small Molecule SMN2 Splicing Modifier in Mouse Models of Spinal Muscular Atrophy.Publié le 18 03 2016

Spinal muscular atrophy (SMA) is caused by the loss or mutation of both copies of the survival motor neuron 1 (SMN1) gene. The related SMN2 gene is retained, but due to alternative splicing of exon 7, produces insufficient levels of the SMN protein. Here, we systematically characterize the pharmacokinetic and pharmacodynamics properties of the SMN splicing modifier SMN-C1. SMN-C1 is a low molecular weight compound that promotes the inclusion of exon 7 and increases production of SMN protein in human cells and in two transgenic mouse models of SMA. Furthermore, increases in SMN protein levels in peripheral blood mononuclear cells and skin correlate with those in the central nervous system (CNS), indicating that a change of these levels in blood or skin can be used as a non-invasive surrogate to monitor increases of SMN protein levels in the CNS. Consistent with restored SMN function, SMN-C1 treatment increases the levels of spliceosomal and U7 small nuclear RNAs and corrects RNA processing defects induced by SMN deficiency in the spinal cord of SMN?7 SMA mice. A 100% or greater increase in SMN protein in the CNS of SMN?7 SMA mice robustly improves the phenotype. Importantly, a ?50% increase in SMN leads to long-term survival but the SMA phenotype is only partially corrected, indicating that certain SMA disease manifestations may respond to treatment at lower doses. Overall, we provide important insights for the translation of preclinical data to the clinic and further therapeutic development of this series of molecules for SMA treatment.

Degenerative Cervical Myelopathy: Epidemiology, Genetics, and Pathogenesis.Publié le 18 03 2016

OBJECTIVE: To formally introduce "degenerative cervical myelopathy" (DCM) as the overarching term to describe the various degenerative conditions of the cervical spine that cause myelopathy. Herein, the epidemiology, pathogenesis, and genetics of conditions falling under this hypernym are carefully described.
SUMMARY OF BACKGROUND DATA: Nontraumatic, degenerative forms of cervical myelopathy represent the commonest cause of spinal cord impairment in adults and include cervical spondylotic myelopathy, ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, and degenerative disc disease. Unfortunately, there is neither a specific term nor a specific diagnostic International Classification of Diseases, Tenth Revision code to describe this collection of clinical entities. This has resulted in the inconsistent use of diagnostic terms when referring to patients with myelopathy due to degenerative disease of the cervical spine.
METHODS: Narrative review.
RESULTS: The incidence and prevalence of myelopathy due to degeneration of the spine are estimated at a minimum of 41 and 605 per million in North America, respectively. Incidence of cervical spondylotic myelopathy-related hospitalizations has been estimated at 4.04/100,000 person-years, and surgical rates seem to be rising. Pathophysiologically, myelopathy results from static compression, spinal malalignment leading to altered cord tension and vascular supply, and dynamic injury mechanisms. Occupational hazards, including transportation of goods by weight bearing on top of the head, and other risk factors may accelerate DCM development. Potential genetic factors include those related to MMP-2 and collagen IX for degenerative disc disease, and collagen VI and XI for ossification of the posterior longitudinal ligament. In addition, congenital anomalies including spinal stenosis, Down syndrome, and Klippel-Feil syndrome may predispose to the development of DCM.
CONCLUSION: Although DCMs can present as separate diagnostic entities, they are highly interrelated, frequently manifest concomitantly, present similarly from a clinical standpoint, and seem to be in part a response to compensate and improve stability due to progressive age and wear of the cervical spine. The use of the term "degenerative cervical myelopathy" is advocated.

Association of IgM monoclonal gammopathy with progressive muscular atrophy and multifocal motor neuropathy: a case-control study.Publié le 18 03 2016

Monoclonal gammopathy in patients with amyotrophic lateral sclerosis (ALS) and related disorders has been reported in small studies but the validity of the reported associations remains uncertain. Presence of monoclonal gammopathy may indicate specific pathogenic pathways and may facilitate the development of novel treatment strategies. The objective of this large case-control study was to determine the prevalence of monoclonal gammopathy in motor neuron diseases (MND) and multifocal motor neuropathy (MMN). Monoclonal gammopathy was determined by immunoelectrophoresis and immunofixation in serum from 445 patients with ALS, 158 patients with progressive muscular atrophy (PMA), 60 patients with primary lateral sclerosis (PLS), 88 patients with MMN and in 430 matched healthy controls. Anti-ganglioside antibody titers were determined in sera from patients with MMN and PMA, and in ALS and PLS patients with monoclonal gammopathy. Logistic regression analysis was used to investigate associations of monoclonal gammopathy with motor neuron diseases and clinical characteristics. Neither ALS nor PLS was associated with monoclonal gammopathy. IgM monoclonal gammopathy was more frequent in patients with PMA (8 %) (OR = 4.2; p = 0.001) and MMN (7 %) (OR = 5.8; p = 0.002) than in controls (2 %). High titers of anti-GM1 IgM antibodies were present in 43 % of MMN patients and 7 % of PMA patients. Patients with PMA and IgM monoclonal gammopathy or anti-GM1 antibodies had a higher age at onset, more often weakness of upper legs and more severe outcome than patients with MMN. PMA and MMN, but not ALS and PLS, are significantly associated with IgM monoclonal gammopathy and anti-GM1 antibodies. These results may indicate that a subset of patients presenting with PMA share pathogenic mechanisms with MMN.

Baseline results of the NeuroNEXT spinal muscular atrophy infant biomarker study.Publié le 28 02 2016

OBJECTIVE: This study prospectively assessed putative promising biomarkers for use in assessing infants with spinal muscular atrophy (SMA).
METHODS: This prospective, multi-center natural history study targeted the enrollment of SMA infants and healthy control infants less than 6 months of age. Recruitment occurred at 14 centers within the NINDS National Network for Excellence in Neuroscience Clinical Trials (NeuroNEXT) Network. Infant motor function scales and putative electrophysiological, protein and molecular biomarkers were assessed at baseline and subsequent visits.
RESULTS: Enrollment began November, 2012 and ended September, 2014 with 26 SMA infants and 27 healthy infants enrolled. Baseline demographic characteristics of the SMA and control infant cohorts aligned well. Motor function as assessed by the Test for Infant Motor Performance Items (TIMPSI) and the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) revealed significant differences between the SMA and control infants at baseline. Ulnar compound muscle action potential amplitude (CMAP) in SMA infants (1.4 ± 2.2 mV) was significantly reduced compared to controls (5.5 ± 2.0 mV). Electrical impedance myography (EIM) high-frequency reactance slope (Ohms/MHz) was significantly higher in SMA infants than controls SMA infants had lower survival motor neuron (SMN) mRNA levels in blood than controls, and several serum protein analytes were altered between cohorts.
INTERPRETATION: By the time infants were recruited and presented for the baseline visit, SMA infants had reduced motor function compared to controls. Ulnar CMAP, EIM, blood SMN mRNA levels, and serum protein analytes were able to distinguish between cohorts at the enrollment visit.

Protective effects of butyrate-based compounds on a mouse model for spinal muscular atrophy.Publié le 28 02 2016

Proximal spinal muscular atrophy (SMA) is a childhood-onset degenerative disease resulting from the selective loss of motor neurons in the spinal cord. SMA is caused by the loss of SMN1 (survival motor neuron 1) but retention of SMN2. The number of copies of SMN2 modifies disease severity in SMA patients as well as in mouse models, making SMN2 a target for therapeutics development. Sodium butyrate (BA) and its analog (4PBA) have been shown to increase SMN2 expression in SMA cultured cells. In this study, we examined the effects of BA, 4PBA as well as two BA prodrugs-glyceryl tributyrate (BA3G) and VX563-on the phenotype of SMN?7 SMA mice. Treatment with 4PBA, BA3G and VX563 but not BA beginning at PND04 significantly improved the lifespan and delayed disease end stage, with administration of VX563 also improving the growth rate of these mice. 4PBA and VX563 improved the motor phenotype of SMN?7 SMA mice and prevented spinal motor neuron loss. Interestingly, neither 4PBA nor VX563 had an effect on SMN expression in the spinal cords of treated SMN?7 SMA mice; however, they inhibited histone deacetylase (HDAC) activity and restored the normal phosphorylation states of Akt and glycogen synthase kinase 3?, both of which are altered by SMN deficiency in vivo. These observations show that BA-based compounds with favorable pharmacokinetics ameliorate SMA pathology possibly by modulating HDAC and Akt signaling.

Neuromuscular Junctions as Key Contributors and Therapeutic Targets in Spinal Muscular Atrophy.Publié le 28 02 2016

Spinal muscular atrophy (SMA) is a recessive autosomal neuromuscular disease, representing the most common fatal pediatric pathology. Even though, classically and in a simplistic way, it is categorized as a motor neuron (MN) disease, there is an increasing general consensus that its pathogenesis is more complex than expected. In particular, neuromuscular junctions (NMJs) are affected by dramatic alterations, including immaturity, denervation and neurofilament accumulation, associated to impaired synaptic functions: these abnormalities may in turn have a detrimental effect on MN survival. Here, we provide a description of NMJ development/maintenance/maturation in physiological conditions and in SMA, focusing on pivotal molecules and on the time-course of pathological events. Moreover, since NMJs could represent an important target to be exploited for counteracting the pathology progression, we also describe several therapeutic strategies that, directly or indirectly, aim at NMJs.

Spinal muscular atrophy: A preliminary result toward new therapy.Publié le 28 02 2016

PMID: 26865521 [PubMed - as supplied by publisher]

Results from a phase 1 study of nusinersen (ISIS-SMNRx) in children with spinal muscular atrophy.Publié le 28 02 2016

OBJECTIVE: To examine safety, tolerability, pharmacokinetics, and preliminary clinical efficacy of intrathecal nusinersen (previously ISIS-SMNRx), an antisense oligonucleotide designed to alter splicing of SMN2 mRNA, in patients with childhood spinal muscular atrophy (SMA).
METHODS: Nusinersen was delivered by intrathecal injection to medically stable patients with type 2 and type 3 SMA aged 2-14 years in an open-label phase 1 study and its long-term extension. Four ascending single-dose levels (1, 3, 6, and 9 mg) were examined in cohorts of 6-10 participants. Participants were monitored for safety and tolerability, and CSF and plasma pharmacokinetics were measured. Exploratory efficacy endpoints included the Hammersmith Functional Motor Scale Expanded (HFMSE) and Pediatric Quality of Life Inventory.
RESULTS: A total of 28 participants enrolled in the study (n = 6 in first 3 dose cohorts; n = 10 in the 9-mg cohort). Intrathecal nusinersen was well-tolerated with no safety/tolerability concerns identified. Plasma and CSF drug levels were dose-dependent, consistent with preclinical data. Extended pharmacokinetics indicated a prolonged CSF drug half-life of 4-6 months after initial clearance. A significant increase in HFMSE scores was observed at the 9-mg dose at 3 months postdose (3.1 points; p = 0.016), which was further increased 9-14 months postdose (5.8 points; p = 0.008) during the extension study.
CONCLUSIONS: Results from this study support continued development of nusinersen for treatment of SMA.
CLASSIFICATION OF EVIDENCE: This study provides Class IV evidence that in children with SMA, intrathecal nusinersen is not associated with safety or tolerability concerns.

Rescue of a Mouse Model of Spinal Muscular Atrophy with Respiratory Distress type 1 (SMARD1) by AAV9-IGHMBP2 is Dose Dependent.Publié le 28 02 2016

Spinal Muscular Atrophy with Respiratory Distress (SMARD1) is an autosomal recessive disease occurring during childhood. The gene responsible for disease development is a ubiquitously expressed protein, IGHMBP2. Mutations in IGHMBP2 result in the loss of alpha-motor neurons leading to muscle atrophy in the distal limbs accompanied by respiratory complications. Although genetically and clinically distinct, proximal SMA is also caused by the loss of a ubiquitously expressed gene (SMN). Significant pre-clinical success has been achieved in proximal SMA using viral-based gene replacement strategies. We leveraged the technologies employed in SMA to demonstrate gene replacement efficacy in an SMARD1 animal model. ICV injection of single stranded AAV9 expressing the full-length cDNA of IGHMBP2 in a low dose led to a significant level of rescue in treated SMARD1 animals. Consistent with drastically increased survival, weight gain, and strength, the rescued animals demonstrated a significant improvement in muscle, NMJ, motor neurons, and axonal pathology. In addition, increased levels of IGHMBP2 in lumbar motor neurons verified the efficacy of the virus to transduce the target tissues. Our results indicate that AAV9-based gene replacement is a viable strategy for SMARD1, although dosing effects and potential negative impacts of high dose and ICV injection should be thoroughly investigated.Molecular Therapy (2016); doi:10.1038/mt.2016.33.

Treatment of camptocormia with continuous subcutaneous infusions of apomorphine: 1-year prospective pilot study.Publié le 28 02 2016

Camptocormia is defined as a marked dystonic flexion of the trunk in the sagittal plane. Camptocormia responds poorly to botulinum toxin injections, manipulation with dopaminergic treatment, and deep brain stimulation. We designed a prospective pilot study to assess the effect of apomorphine infusions on camptocormia. Five patients were enrolled. All five patients responded well to this treatment. The fact that camptocormia responds so well to apomorphine may be explained by the sustained stimulation of the ventrolateral striatal D1 receptors, alleviating this type of dystonia.

[A clinical study of laryngotracheal separation in spinal muscular atrophy type I patients].Publié le 11 02 2016

Artificial respiration by tracheostomy is necessary for long-term survival in spinal muscular atrophy (SMA) Type I patients. There are two types of tracheostomy: i )simple tracheostomy and ii) tracheostomy plus aspiration prevention surgery, including laryngotracheal separation. We experienced three cases of SMA type I patients that had good outcomes after undergoing laryngotracheal separation. The patients' ages at onset were 14 days, two months and one and a half months. Laryngotracheal separation was performed at five months, seven months, and 15 years and five months respectively, and the times from diagnosis to surgery were a month, three months and 15 years. The aspiration pneumonia disappeared in all three cases. This study suggests that laryngotracheal separation is an effective surgery to prevent aspiration in SMA type I cases, and also contributes to the improved quality of life of patients and their families.

Myiasis of the Tracheostomy Wound Caused by Sarcophaga (Liopygia) argyrostoma (Diptera: Sarcophagidae): Molecular Identification Based on the Mitochondrial Cytochrome c Oxidase I Gene.Publié le 11 02 2016

Wound myiasis is the infestation of open wounds of mammalian hosts caused by larvae of various species of flies. This kind of myiasis can be a serious problem for immobilized patients with open wounds. Here, we identify a dipteran larva found in the tracheostomy wound of a child affected by a severe spinal muscular atrophy. The collected larva was dissected and microscopically analyzed. DNA was extracted from part of the larva and used for the molecular identification. A 487?bp fragment, including part of 5.8?S, the internal transcribed spacer 2 (ITS2), and part of 28S, was amplified using a novel PCR assay to be cloned and sequenced. The barcode region of cytochrome oxidase I (COI) was also cloned and sequenced after PCR amplification. The larva, designated as SASI1, was identified as a third instar of Sarcophaga sp. The COI sequencing confirmed a low similarity with Sarcophaga ruficornis (F.) (95%), yet COI showed a 100% similarity with Sarcophaga argyrostoma (Robineau-Desvoidy, 1830) species. Therefore, SASI1 was identified as a S. argyrostoma larva on the basis of its COI barcode. This is one of the rare cases of myiasis of tracheostomy wound and the first caused by S. argyrostoma.

Characterization of Mutants of Human Small Heat Shock Protein HspB1 Carrying Replacements in the N-Terminal Domain and Associated with Hereditary Motor Neuron Diseases.Publié le 11 02 2016

Physico-chemical properties of the mutations G34R, P39L and E41K in the N-terminal domain of human heat shock protein B1 (HspB1), which have been associated with hereditary motor neuron neuropathy, were analyzed. Heat-induced aggregation of all mutants started at lower temperatures than for the wild type protein. All mutations decreased susceptibility of the N- and C-terminal parts of HspB1 to chymotrypsinolysis. All mutants formed stable homooligomers with a slightly larger apparent molecular weight compared to the wild type protein. All mutations analyzed decreased or completely prevented phosphorylation-induced dissociation of HspB1 oligomers. When mixed with HspB6 and heated, all mutants yielded heterooligomers with apparent molecular weights close to ~400 kDa. Finally, the three HspB1 mutants possessed lower chaperone-like activity towards model substrates (lysozyme, malate dehydrogenase and insulin) compared to the wild type protein, conversely the environmental probe bis-ANS yielded higher fluorescence with the mutants than with the wild type protein. Thus, in vitro the analyzed N-terminal mutations increase stability of large HspB1 homooligomers, prevent their phosphorylation-dependent dissociation, modulate their interaction with HspB6 and decrease their chaperoning capacity, preventing normal functioning of HspB1.

[Functional assessment for people unable to walk due to spinal muscular atrophy and Duchenne muscular dystrophy. Translation and validation of the Egen Klassifikation 2 scale for the Spanish population].Publié le 11 02 2016

INTRODUCTION: The Egen Klassifikation 2 Scale (EK2), expansion of the EK scale, assesses the functional capacity of people with spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) that are in wheelchair phase. This version is more specific for SMA than its EK predecessor.
AIM: To examine the validity and reliability of the Spanish version of the scale as a tool for measuring the functional capacity in patients with DMD and SMA who are in wheelchairs.
PATIENTS AND METHODS: First, a translation-back-translation into Spanish of the English version of the EK2 was performed; later, we studied the reliability of the translated version. For this, 39 patients, aged between 4 and 60, who were evaluated by two observers, were recruited. To evaluate the intra-observer consistency, two assessments by the same observer were performed, and the inter-observer third assessment was performed by a second observer.
RESULTS: The obtained values based on the total score of the scale items (sum EK2) reflect excellent intra- and inter-observer reliability, 0.993 and 0.988 respectively. Also, for each of the items, reliability was excellent except for one item in which it was good.
CONCLUSIONS: The Spanish version of the EK2 scale is a valid and reliable instrument for the Spanish population as a tool for measuring the functional capacity in patients with SMA and DMD who are in wheelchairs.

CNS uptake of bortezomib is enhanced by P-glycoprotein inhibition: Implications for spinal muscular atrophy.Publié le 24 01 2016

The development of therapeutics for neurological disorders is constrained by limited access to the central nervous system (CNS). ATP-binding cassette (ABC) transporters, particularly P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), are expressed on the luminal surface of capillaries in the CNS and transport drugs out of the endothelium back into the blood against the concentration gradient. Survival motor neuron (SMN) protein, which is deficient in spinal muscular atrophy (SMA), is a target of the ubiquitin proteasome system. Inhibiting the proteasome in a rodent model of SMA with bortezomib increases SMN protein levels in peripheral tissues but not the CNS, because bortezomib has poor CNS penetrance. We sought to determine if we could inhibit SMN degradation in the CNS of SMA mice with a combination of bortezomib and the ABC transporter inhibitor tariquidar. In cultured cells we show that bortezomib is a substrate of P-gp. Mass spectrometry analysis demonstrated that intraperitoneal co-administration of tariquidar increased the CNS penetrance of bortezomib, and reduced proteasome activity in the brain and spinal cord. This correlated with increased SMN protein levels and improved survival and motor function of SMA mice. These findings show that CNS penetrance of treatment for this neurological disorder can be improved by inhibiting drug efflux at the blood-brain barrier.

[Camptocormia: results of rehabilitation in three cases].Publié le 24 01 2016

PMID: 25670051 [PubMed - indexed for MEDLINE]

Palliative care in children with spinal muscular atrophy type I: What do they need?Publié le 22 01 2016

OBJECTIVE: Our aim was to describe the clinical evolution and needs of children with spinal muscular atrophy type I treated in a domiciliary palliative care program.
METHOD: We undertook a retrospective chart review of nine consecutive patients. Descriptions of the clinical and demographic profile of children with spinal muscular atrophy (SMA) type I were referred to a pediatric palliative care team (PPCT).
RESULTS: Six males and three females were admitted to the PPCT, all before six months of age, except for one afflicted with SMA type I with respiratory distress. The median time of attention was 57 days (range 1-150). The domiciliary attention mainly consisted of respiratory care. The patient with SMA type I with respiratory distress required domiciliary mechanical ventilation by tracheotomy. In all cases, a nasogastric tube (NT) was indicated. As end-of-life care, eight required morphine to manage the dyspnea, four received it only by enteral (oral or NT) administration, and four received it first by enteral administration with continuous subcutaneous infusion (CSI) later. Three of the four patients with CSI also received benzodiazepines. While they were attended by the PPCT, none required hospital admission. All the patients died at home except for the one attended to for just one day.
SIGNIFICANCE OF RESULTS: Domiciliary care for these patients is possible. The respiratory morbidity and its management are the main issues. Application of an NT is useful to maintain nutritional balance. Morphine administration is necessary to manage the dyspnea. Palliative sedation is not always necessary.

Patterns of disease progression in type 2 and 3 SMA: Implications for clinical trials.Publié le 19 01 2016

The aim of the study was to establish 12-month changes in the Hammersmith Functional motor scale in a large cohort of SMA patients, to identify patterns of disease progression and the effect of different variables. 268 patients were included in this multicentric study. Their age ranged between 2.5 and 55.5 years at baseline, 68 were ambulant and 200 non-ambulant. The baseline scores ranged between 0 and 66 (mean 23.91, SD 20.09). The 12-month change was between -14 and +9 (mean -0.56, SD 2.72). Of the 268 patients, 206 (76.86%) had changes between -2 and +2 points. Ambulant and non-ambulant subjects had a different relationship between baseline values and age (p for age X ambulation interaction?=?0.007). There was no association with age in ambulant subjects, while there was a significant heterogeneity at different age for non-ambulant patients (p?<?0.001). The 12-month change (adjusted for baseline) was not associated with age in ambulant patients (p?=?0.34), but it was significantly different among various age groups in non-ambulant patients. Our results suggest that there are different profiles of progression in ambulant and non-ambulant patients, and that age may play an important role in the progression of non-ambulant patients.

Pharmacologically-induced mouse model of adult spinal muscular atrophy to evaluate effectiveness of therapeutics after disease onset.Publié le 14 01 2016

Spinal muscular atrophy (SMA) is a genetic disease characterized by atrophy of muscle and loss of spinal motor neurons. SMA is caused by deletion or mutation of the survival motor neuron 1 (SMN1) gene and the nearly identical SMN2 gene fails to generate adequate levels of functional SMN protein due to a splicing defect. Currently several therapeutics targeted to increase SMN protein are in clinical trials. An outstanding issue in the field is whether initiating treatment in symptomatic older patients would confer a therapeutic benefit, an important consideration since the majority of patients with milder forms of SMA are diagnosed at an older age. An SMA mouse model that recapitulates the disease phenotype observed in adolescent and adult SMA patients is needed to address this important question. We demonstrate here that ?7 mice, a model of severe SMA, treated with a sub-optimal dose of an SMN2 splicing modifier show increased SMN protein, survive into adulthood and display SMA disease-relevant pathologies. Increasing the dose of the splicing modifier after the disease symptoms are apparent further mitigates SMA histopathological features in sub-optimally dosed adult ?7 mice. In addition, inhibiting myostatin using intramuscular injection of AAV1-follistatin ameliorates muscle atrophy in sub-optimally dosed ?7 mice. Taken together, we have developed a new murine model of symptomatic SMA in adolescents and adult mice that is induced pharmacologically from a more severe model, and demonstrated efficacy of both SMN2 splicing modifiers as well as a myostatin inhibitor in mice at later disease stages.

The neuromuscular impact of symptomatic SMN restoration in a mouse model of spinal muscular atrophy.Publié le 07 01 2016

BACKGROUND: Significant advances in the development of SMN-restoring therapeutics have occurred since 2010 when very effective biological treatments were reported in mouse models of spinal muscular atrophy. As these treatments are applied in human clinical trials, there is pressing need to define quantitative assessments of disease progression, treatment stratification, and therapeutic efficacy. The electrophysiological measures Compound Muscle Action Potential and Motor Unit Number Estimation are reliable measures of nerve function. In both the SMN?7 mouse and a pig model of spinal muscular atrophy, early SMN restoration results in preservation of electrophysiological measures. Currently, clinical trials are underway in patients at post-symptomatic stages of disease progression. In this study, we present results from both early and delayed SMN restoration using clinically-relevant measures including electrical impedance myography, compound muscle action potential, and motor unit number estimation to quantify the efficacy and time-sensitivity of SMN-restoring therapy.
METHODS: SMA?7 mice were treated via intracerebroventricular injection with antisense oligonucleotides targeting ISS-N1 to increase SMN protein from the SMN2 gene on postnatal day 2, 4, or 6 and compared with sham-treated spinal muscular atrophy and control mice. Compound muscle action potential and motor unit number estimation of the triceps surae muscles were performed at day 12, 21, and 30 by a single evaluator blinded to genotype and treatment. Similarly, electrical impedance myography was measured on the biceps femoris muscle at 12 days for comparison.
RESULTS: Electrophysiological measures and electrical impedance myography detected significant differences at 12 days between control and late-treated (4 or 6 days) and sham-treated spinal muscular atrophy mice, but not in mice treated at 2 days(p<0.01). EIM findings paralleled and correlated with compound muscle action potential and motor unit number estimation (r=0.61 and r=0.50, respectively, p<0.01). Longitudinal measures at 21 and 30 days show that symptomatic therapy results in reduced motor unit number estimation associated with delayed normalization of compound muscle action potential.
CONCLUSIONS: The incomplete effect of symptomatic treatment is accurately identified by both electrophysiological measures and electrical impedance myography. There is strong correlation between these measures and with weight and righting reflex. This study predicts that measures of compound muscle action potential, motor unit number estimation, and electrical impedance myography are promising biomarkers of treatment stratification and effect for future spinal muscular atrophy trials. The ease of application and simplicity of electrical impedance myography compared with standard electrophysiological measures may be particularly valuable in future pediatric clinical trials.

Established Stem Cell Model of Spinal Muscular Atrophy Is Applicable in the Evaluation of the Efficacy of Thyrotropin-Releasing Hormone Analog.Publié le 20 12 2015

: Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder characterized by the degeneration of spinal motor neurons. This disease is mainly caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Currently, no effective treatment is available, and only symptomatic treatment can be provided. Our purpose in the present study was to establish a human SMA-derived induced pluripotent stem cell (SMA-iPSC) disease model and assay a therapeutic drug in preparation for the development of a novel treatment of SMA. We generated iPSCs from the skin fibroblasts of a patient with SMA and confirmed that they were pluripotent and undifferentiated. The neural differentiation of SMA-iPSCs shortened the dendrite and axon length and increased the apoptosis of the spinal motor neurons. In addition, we found activated astrocytes in differentiated SMA-iPSCs. Using this model, we confirmed that treatment with the thyrotropin-releasing hormone (TRH) analog, 5-oxo-l-prolyl-l-histidyl-l-prolinamide, which had marginal effects in clinical trials, increases the SMN protein level. This increase was mediated through the transcriptional activation of the SMN2 gene and inhibition of glycogen synthase kinase-3? activity. Finally, the TRH analog treatment resulted in dendrite and axon development of spinal motor neurons in differentiated SMA-iPSCs. These results suggest that this human in vitro disease model stimulates SMA pathology and reveal the potential efficacy of TRH analog treatment for SMA. Therefore, we can screen novel therapeutic drugs such as TRH for SMA easily and effectively using the human SMA-iPSC model.
SIGNIFICANCE: Platelet-derived growth factor (PDGF) has recently been reported to produce the greatest increase in survival motor neuron protein levels by inhibiting glycogen synthase kinase (GSK)-3?; however, motor neurons lack PDGF receptors. A human in vitro spinal muscular atrophy-derived induced pluripotent stem cell model was established, which showed that the thyrotropin releasing hormone (TRH) analog promoted transcriptional activation of the SMN2 gene and inhibition of GSK-3? activity, resulting in the increase and stabilization of the SMN protein and axon elongation of spinal motor neurons. These results reveal the potential efficacy of TRH analog treatment for SMA.

Is spinal muscular atrophy a disease of the motor neurons only: pathogenesis and therapeutic implications?Publié le 19 12 2015

Spinal muscular atrophy (SMA) is a genetic neurological disease that causes infant mortality; no effective therapies are currently available. SMA is due to homozygous mutations and/or deletions in the survival motor neuron 1 gene and subsequent reduction of the SMN protein, leading to the death of motor neurons. However, there is increasing evidence that in addition to motor neurons, other cell types are contributing to SMA pathology. In this review, we will discuss the involvement of non-motor neuronal cells, located both inside and outside the central nervous system, in disease onset and progression. Even if SMN restoration in motor neurons is needed, it has been shown that optimal phenotypic amelioration in animal models of SMA requires a more widespread SMN correction. It has been demonstrated that non-motor neuronal cells are also involved in disease pathogenesis and could have important therapeutic implications. For these reasons it will be crucial to take this evidence into account for the clinical translation of the novel therapeutic approaches.

Peptide nanoparticle delivery of charge-neutral splice-switching morpholino oligonucleotides.Publié le 19 12 2015

Oligonucleotide analogs have provided novel therapeutics targeting various disorders. However, their poor cellular uptake remains a major obstacle for their clinical development. Negatively charged oligonucleotides, such as 2'-O-Methyl RNA and locked nucleic acids have in recent years been delivered successfully into cells through complex formation with cationic polymers, peptides, liposomes, or similar nanoparticle delivery systems. However, due to the lack of electrostatic interactions, this promising delivery method has been unsuccessful to date using charge-neutral oligonucleotide analogs. We show here that lipid-functionalized cell-penetrating peptides can be efficiently exploited for cellular transfection of the charge-neutral oligonucleotide analog phosphorodiamidate morpholino. The lipopeptides form complexes with splice-switching phosphorodiamidate morpholino oligonucleotide and can be delivered into clinically relevant cell lines that are otherwise difficult to transfect while retaining biological activity. To our knowledge, this is the first study to show delivery through complex formation of biologically active charge-neutral oligonucleotides by cationic peptides.

Radiation-induced camptocormia and dropped head syndrome: Review and case report of radiation-induced movement disorders.Publié le 18 12 2015

BACKGROUND: In recent years, camptocormia and dropped head syndrome (DHS) have gained attention as particular forms of movement disorders. Camptocormia presents with involuntary forward flexion of the thoracolumbar spine that typically increases during walking or standing and may severely impede walking ability. DHS is characterized by weakness of the neck extensors and a consecutive inability to extend the neck; in severe cases the head is fixed in a "chin to chest position." Many diseases may underlie these conditions, and there have been some reports about radiation-induced camptocormia and DHS.
METHODS: A PubMed search with the keywords "camptocormia," "dropped head syndrome," "radiation-induced myopathy," "radiation-induced neuropathy," and "radiation-induced movement disorder" was carried out to better characterize radiation-induced movement disorders and the radiation techniques involved. In addition, the case of a patient developing camptocormia 23 years after radiation therapy of a non-Hodgkin's lymphoma of the abdomen is described.
RESULTS: In total, nine case series of radiation-induced DHS (n?=?45 patients) and-including our case-three case reports (n?=?3 patients) about radiogenic camptocormia were retrieved. Most cases (40/45 patients) occurred less than 15 years after radiotherapy involving extended fields for Hodgkin's disease.
CONCLUSION: The use of wide radiation fields including many spinal segments with paraspinal muscles may lead to radiation-induced movement disorders. If paraspinal muscles and the thoracolumbar spine are involved, the clinical presentation can be that of camptocormia. DHS may result if there is involvement of the cervical spine. To prevent these disorders, sparing of the spine and paraspinal muscles is desirable.

Clinical Characteristics and Genotype-Phenotype Correlation of Korean Patients with Spinal and Bulbar Muscular Atrophy.Publié le 15 12 2015

PURPOSE: Spinal and bulbar muscular atrophy (SBMA) is an X-linked motor neuron disease characterized by proximal muscle weakness, muscle atrophy, and fas-ciculation. Although SBMA is not uncommon in Korea, there is only one study reporting clinical characteristics and genotype-phenotype correlation in Korean patients.
MATERIALS AND METHODS: In this study, age at the onset of symptoms, the score of severity assessed by impairment of activities of daily living milestones, and rate of disease progression, and their correlations with the number of CAG repeats in the androgen receptor (AR) gene, as well as possible correlations among clinical characteristics, were analyzed in 40 SBMA patients.
RESULTS: The median ages at onset and at diagnosis were 44.5 and 52.5 years, respectively, and median interval between onset and diagnosis and median rate of disease progression were 5.0 years and 0.23 score/year, respectively. The median number of CAG repeats in the AR gene was 44 and the number of CAG repeats showed a significant inverse correlation with the age at onset of symptoms (r=-0.407, p=0.009). In addition, patients with early symptom onset had slower rate of disease progression.
CONCLUSION: As a report with the largest and recent Korean cohort, this study demonstrates clinical features of Korean patients with SBMA and reaffirms the inverse correlation between the age at disease onset and the number of CAG repeats. Interestingly, this study shows a possibility that the rate of disease progression may be influenced by the age at onset of symptoms.

Effect of neurostimulation on camptocormia in Parkinson's disease depends on symptom duration.Publié le 15 12 2015

Although some reports on neurostimulation are positive, no effective treatment method for camptocormia in Parkinson's disease (PD) is known to date. We aim to identify prognostic factors for a beneficial DBS effect on camptocormia. In an observational cohort study, we investigated 25 idiopathic PD patients, who suffered additionally from camptocormia, and underwent bilateral neurostimulation of the subthalamic nucleus (STN) to improve classical PD symptoms. Using an established questionnaire, we examined deep brain stimulation (DBS) effects on camptocormia in addition to general neurostimulation effects. A beneficial neurostimulation effect on camptocormia was defined as an improvement in the bending angle of a least 50%. In 13 patients, the bending angle of camptocormia improved, in 12 patients it did not. A multifactorial analysis revealed a short duration between onset of camptocormia and start of neurostimulation to be the relevant factor for outcome. All patients with duration of camptocormia up to 1.5 years showed a beneficial effect; patients between 1.5 and ?3 years showed mixed results, but none with a duration of more than 40 months improved except for 1 patient whose camptocormia was levodopa responsive. The bending angle was not a prognostic factor. Our data indicate that the main prognostic factor for a beneficial DBS effect on camptocormia is its short duration. As an explanation, we suggest that neurostimulation may improve camptocormia only as long as muscle pathology is limited. Our findings may help to elucidate the mode of action of neurostimulation. A prospective study is necessary.

Resistance strength training exercise in children with spinal muscular atrophy.Publié le 15 12 2015

INTRODUCTION: Preliminary evidence in adults with spinal muscular atrophy (SMA) and in SMA animal models suggests exercise has potential benefits in improving or stabilizing muscle strength and motor function.
METHODS: We evaluated feasibility, safety, and effects on strength and motor function of a home-based, supervised progressive resistance strength training exercise program in children with SMA types II and III. Up to 14 bilateral proximal muscles were exercised 3 times weekly for 12 weeks.
RESULTS: Nine children with SMA, aged 10.4 ± 3.8 years, completed the resistance training exercise program. Ninety percent of visits occurred per protocol. Training sessions were pain-free (99.8%), and no study-related adverse events occurred. Trends in improved strength and motor function were observed.
CONCLUSIONS: A 12-week supervised, home-based, 3-day/week progressive resistance training exercise program is feasible, safe, and well tolerated in children with SMA. These findings can inform future studies of exercise in SMA.

Hypothermia improves disease manifestations in SMA mice via SMN augmentation.Publié le 10 12 2015

Spinal muscular atrophy (SMA) is a progressive motor neuron disease caused by a deficiency of survival motor neuron protein (SMN). In this study, we evaluated the efficacy of intermittent transient hypothermia in a mouse model of SMA. SMA mice were exposed to ice for 50 seconds to achieve transient hypothermia (below 25°C) daily beginning on post-natal day 1. Neonatal SMA mice (Smn(-/-)SMN2(+/-)) who received daily transient hypothermia exhibited reduced motor neuron degeneration and muscle atrophy and preserved the architecture of neuromuscular junction when compared to untreated controls at day 8 post-treatment. Daily hypothermia also prolonged the lifespan, increased body weight and improved motor coordination in SMA mice. Quantitative polymerase chain reaction (PCR) and Western blot analyses showed that transient hypothermia led to an increase in SMN transcript and protein levels in the spinal cord and brain. In in vitro studies using an SMN knockdown motor neuron-like cell-line, transient hypothermia increased intracellular SMN protein expression and length of neurites, confirming the direct effect of hypothermia on motor neurons. These data indicate that the efficacy of intermittent transient hypothermia in improving outcome in an SMA mouse model may be mediated, in part, via an up regulation of SMN levels in the motor neurons.

Gene-targeting pharmaceuticals for single gene disorders.Publié le 03 12 2015

The concept of orphan drugs for treatment of orphan genetic diseases is perceived enthusiastically at present, and this is leading to research investment on the part of governments, disease-specific foundations, and industry. This review attempts to survey the potential to use traditional pharmaceuticals as opposed to biopharmaceuticals to treat single gene disorders. The available strategies include the use of antisense oligonucleotides to alter splicing or knock-down expression of a transcript, siRNAs to knock-down gene expression, and drugs for nonsense mutation read-through. There is an approved drug for biallelic knock-down of the APOB gene as treatment for familial hypercholesterolemia. Both ASOs and siRNAs are being explored to knock-down the TTR gene to prevent the related form of amyloidosis. The use of ASOs to alter gene-splicing to treat spinal muscular atrophy is in phase 3 clinical trials. Work is progressing on the use of ASOs to activate the normally silent paternal copy of the imprinted UBE3A gene in neurons as a treatment for Angelman syndrome. A gene activation or gene-specific ramp-up strategy would be generally helpful if such could be developed. There is exciting theoretical potential for converting biopharmaceutical strategies such gene correction and CRISPR-cas9 editing to a synthetic pharmaceutical approach.

Large-Scale Production of Adeno-Associated Viral Vector Serotype-9 Carrying the Human Survival Motor Neuron Gene.Publié le 27 11 2015

Recombinant AAV (rAAV) vectors are a suitable vector for gene therapy studies because of desired characteristics such as low immunogenicity, transfection of non-dividing and dividing cells, and long-term expression of the transgene. In this study, the large-scale production of single stranded (ss) and self-complementary (sc) AAV9 carrying the human survival motor neuron (SMN) gene (AAV9-SMN) suitable for in vivo gene therapy studies of SMA was described. SMN cDNA has been cloned into pAAV-CB6-PI and pAAVsc-CB6-PI with and without its specific UTRs, respectively. Both plasmids bear CMV enhancer/beta-actin (CB) promoter, CMV IE enhancer, and polyadenylation signal sequences. 2.5 ?g of constructed pAAV-CB6-PI-SMN and pAAVsc-CB6-PI-SMN cause to, respectively, 4.853- and 2.321-fold increases in SMN protein levels in transfected cells compared to untransfected cells. Ss and scAAV9-SMN vectors were also produced from these plasmids by transient transfection of HEK293 cells using CaCl2 solution. The silver staining and electron microscopy analysis demonstrated good quality of both isolated vectors, ssAAV9-SMN and scAAV9-SMN, with the titers of 2.00E+13 and 1.00E+13 GC/ml. The results of this study show that, the plasmid containing UTR elements causes to twice more SMN gene expression in transfected cells. The quality control results show that both produced ss and scAAV9-SMN are suitable for in vivo studies.

Gene therapy rescues disease phenotype in a spinal muscular atrophy with respiratory distress type 1 (SMARD1) mouse model.Publié le 25 11 2015

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is an autosomal recessive motor neuron disease affecting children. It is caused by mutations in the IGHMBP2 gene (11q13) and presently has no cure. Recently, adeno-associated virus serotype 9 (AAV9)-mediated gene therapy has been shown to rescue the phenotype of animal models of another lower motor neuron disorder, spinal muscular atrophy 5q, and a clinical trial with this strategy is ongoing. We report rescue of the disease phenotype in a SMARD1 mouse model after therapeutic delivery via systemic injection of an AAV9 construct encoding the wild-type IGHMBP2 to replace the defective gene. AAV9-IGHMBP2 administration restored protein levels and rescued motor function, neuromuscular physiology, and life span (450% increase), ameliorating pathological features in the central nervous system, muscles, and heart. To test this strategy in a human model, we transferred wild-type IGHMBP2 into human SMARD1-induced pluripotent stem cell-derived motor neurons; these cells exhibited increased survival and axonal length in long-term culture. Our data support the translational potential of AAV-mediated gene therapies for SMARD1, opening the door for AAV9-mediated therapy in human clinical trials.

Chronic Treatment with the AMPK Agonist AICAR Prevents Skeletal Muscle Pathology but Fails to Improve Clinical Outcome in a Mouse Model of Severe Spinal Muscular Atrophy.Publié le 20 11 2015

Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder characterized by spinal and brainstem motor neuron (MN) loss and skeletal muscle paralysis. Currently, there is no effective treatment other than supportive care to ameliorate the quality of life of patients with SMA. Some studies have reported that physical exercise, by improving muscle strength and motor function, is potentially beneficial in SMA. The adenosine monophosphate-activated protein kinase agonist 5-aminoimidazole-4-carboxamide-1-?-D-ribofuranoside (AICAR) has been reported to be an exercise mimetic agent that is able to regulate muscle metabolism and increase endurance both at rest and during exercise. Chronic AICAR administration has been shown to ameliorate the dystrophic muscle phenotype and motor behavior in the mdx mouse, a model of Duchenne muscular dystrophy. Here, we investigated whether chronic AICAR treatment was able to elicit beneficial effects on motor abilities and neuromuscular histopathology in a mouse model of severe SMA (the SMN?7 mouse). We report that AICAR improved skeletal muscle atrophy and structural changes found in neuromuscular junctions of SMN?7 animals. However, although AICAR prevented the loss of glutamatergic excitatory synapses on MNs, this compound was not able to mitigate MN loss or the microglial and astroglial reaction occurring in the spinal cord of diseased mice. Moreover, no improvement in survival or motor performance was seen in SMN?7 animals treated with AICAR. The beneficial effects of AICAR in SMA found in our study are SMN-independent, as no changes in the expression of this protein were seen in the spinal cord and skeletal muscle of diseased animals treated with this compound.

Glycosphingolipids are modulators of disease pathogenesis in amyotrophic lateral sclerosis.Publié le 18 11 2015

Recent genetic evidence suggests that aberrant glycosphingolipid metabolism plays an important role in several neuromuscular diseases including hereditary spastic paraplegia, hereditary sensory neuropathy type 1, and non-5q spinal muscular atrophy. Here, we investigated whether altered glycosphingolipid metabolism is a modulator of disease course in amyotrophic lateral sclerosis (ALS). Levels of ceramide, glucosylceramide, galactocerebroside, lactosylceramide, globotriaosylceramide, and the gangliosides GM3 and GM1 were significantly elevated in spinal cords of ALS patients. Moreover, enzyme activities (glucocerebrosidase-1, glucocerebrosidase-2, hexosaminidase, galactosylceramidase, ?-galactosidase, and ?-galactosidase) mediating glycosphingolipid hydrolysis were also elevated up to threefold. Increased ceramide, glucosylceramide, GM3, and hexosaminidase activity were also found in SOD1(G93A) mice, a familial model of ALS. Inhibition of glucosylceramide synthesis accelerated disease course in SOD1(G93A) mice, whereas infusion of exogenous GM3 significantly slowed the onset of paralysis and increased survival. Our results suggest that glycosphingolipids are likely important participants in pathogenesis of ALS and merit further analysis as potential drug targets.

Old measures and new scores in spinal muscular atrophy patients.Publié le 03 11 2015

INTRODUCTION: A recent Rasch analysis performed on the Hammersmith Functional Motor Scale-Expanded (HFMSE) in patients with spinal muscular atrophy (SMA) identified issues impacting scale validity, redundant items, and disordered thresholds on some items.
METHODS: We modified the HMFSE scoring based on the Rasch analysis and on expert consensus to establish whether the traditional scoring overestimated the number of patients with changes within 2 points from baseline. Data were collected retrospectively from multicenter data sets in 255 type 2 and 3 SMA patients.
RESULTS: The mean 12-month changes using the new and the traditional scoring system did not differ significantly (P?>?0.05). The numbers of patients who improved or decreased by >2 points were also similar.
CONCLUSIONS: The presence of outliers using the traditional scoring system was not due to overestimation of changes in activities that were tested bilaterally or to discrepancies in the scoring hierarchy of individual items.

Spinal Muscular Atrophy.Publié le 31 10 2015

Spinal muscular atrophy is an autosomal-recessive disorder characterized by degeneration of motor neurons in the spinal cord and caused by mutations in the survival motor neuron 1 gene, SMN1. The severity of SMA is variable. The SMN2 gene produces a fraction of the SMN messenger RNA (mRNA) transcript produced by the SMN1 gene. There is an inverse correlation between SMN2 gene copy number and clinical severity. Clinical management focuses on multidisciplinary care. Preclinical models of SMA have led to an explosion of SMA clinical trials that hold great promise of effective therapy in the future.

Understanding the experiences and needs of individuals with Spinal Muscular Atrophy and their parents: a qualitative study.Publié le 27 10 2015

BACKGROUND: The clinical features of SMA, which range along a spectrum of severity, are relatively well described. In contrast, the literature on how individuals with SMA and their families experience this condition is limited. To address this gap, we undertook a qualitative study with individuals affected by SMA Types I, II and III, parents of those affected, and clinicians.
METHODS: We completed 16 focus group sessions and 37 interviews in the US with 96 participants including: 21 with individuals with SMA; 64 parents of individuals affected by SMA; and 11 clinicians who specialize in the care of SMA patients.
RESULTS: The Diagnostic Journey: Families reported substantial diagnostic delays owing to: 1) lack of awareness and knowledge about SMA; 2) the difficulty of distinguishing normal from abnormal development; and 3) the challenge of differential diagnosis. Lack of sensitivity in how clinicians communicated this potentially devastating diagnosis compounded parents' negative impressions. Newborn Screening: Parents generally held positive views about adding SMA to newborn screening panels. For example, it would: 1) enable earlier access to care; 2) shorten the diagnostic journey; and 3) give families more time to prepare to care for a disabled child. Some noted negative outcomes such as prematurely affecting a parent's relationship with a child before symptoms are evident. The Psychosocial Impact of Living with SMA: Ten thematic areas characterized the impact: 1) confronting premature death; 2) making difficult treatment choices; 3) fearing the loss of functional ability; 4) coming to terms with lost expectations; 5) loss of sleep and stress; 6) stigma; 7) limitations on social activities; 8) independence; 9) uncertainty and helplessness; and 10) family finances.
CONCLUSIONS: The results of this study suggest high levels of burden experienced by individuals with SMA and their families. The difficulties of living with SMA begin with the long and often arduous process of finding a diagnosis for their child. Newborn screening for SMA is seen as an important step toward shortening this journey. The psychosocial effects of coping with SMA are substantial and wide ranging both for the individual living with this condition and family members of affected individuals.

Pluripotent stem cell-based models of spinal muscular atrophy.Publié le 27 10 2015

Motor neuron diseases, as the vast majority of neurodegenerative disorders in humans, are incurable conditions that are challenging to study in vitro, owing to the obstacles in obtaining the cell types majorly involved in the pathogenesis. Recent advances in stem cell research, especially in the development of induced pluripotent stem cell (iPSC) technology, have opened up the possibility of generating a substantial amount of disease-specific neuronal cells, including motor neurons and glial cells. The present review analyzes the practical implications of iPSCs, generated from fibroblasts of patients affected by spinal muscular atrophy (SMA), and discusses the challenges in the development and optimization of in vitro disease models. Research on patient-derived disease-specific cells may shed light on the pathological processes behind neuronal dysfunction and death in SMA, thus providing new insights for the development of novel effective therapies.

Generation of Human Induced Pluripotent Stem Cells from Extraembryonic Tissues of Fetuses Affected by Monogenic Diseases.Publié le 17 10 2015

The generation of human induced pluripotent stem cells (hiPSCs) derived from an autologous extraembryonic fetal source is an innovative personalized regenerative technology that can transform own-self cells into embryonic stem-like ones. These cells are regarded as a promising candidate for cell-based therapy, as well as an ideal target for disease modeling and drug discovery. Thus, hiPSCs enable researchers to undertake studies for treating diseases or for future applications of in utero therapy. We used a polycistronic lentiviral vector (hSTEMCCA-loxP) encoding OCT4, SOX2, KLF4, and cMYC genes and containing loxP sites, excisible by Cre recombinase, to reprogram patient-specific fetal cells derived from prenatal diagnosis for several genetic disorders, such as myotonic dystrophy type 1 (DM1), ?-thalassemia (?-Thal), lymphedema-distichiasis syndrome (LDS), spinal muscular atrophy (SMA), cystic fibrosis (CF), as well as from wild-type (WT) fetal cells. Because cell types tested to create hiPSCs influence both the reprogramming process efficiency and the kinetics, we used chorionic villus (CV) and amniotic fluid (AF) cells, demonstrating how they represent an ideal cell resource for a more efficient generation of hiPSCs. The successful reprogramming of both CV and AF cells into hiPSCs was confirmed by specific morphological, molecular, and immunocytochemical markers and also by their teratogenic potential when inoculated in vivo. We further demonstrated the stability of reprogrammed cells over 10 and more passages and their capability to differentiate into the three embryonic germ layers, as well as into neural cells. These data suggest that hiPSCs-CV/AF can be considered a valid cellular model to accomplish pathogenesis studies and therapeutic applications.

Training improves oxidative capacity, but not function, in spinal muscular atrophy type III.Publié le 17 10 2015

INTRODUCTION: In this study we investigated the effect of 12 weeks of cycle ergometer training in patients with spinal muscular atrophy type III (SMA III), a hereditary motor neuron disease with progressive muscle weakness and atrophy.
METHODS: Six SMA III patients and 9 healthy subjects completed a 12-week training program, performing 42 30-minute sessions exercising at 65-70% of maximal oxygen uptake (VO2max ). VO2max , muscle strength, functional tests, and self-reported activities of daily living were assessed before and after the training.
RESULTS: Training induced a 27?±?3% increase in VO2max (17?±?2 to 21?±?2 ml/kg/min, P < 0.001) in patients. However, fatigue was a major complaint and caused 1 patient to drop out, increased the need for sleep in 3 patients, and led to training modifications in 2 patients.
CONCLUSIONS: Cycle exercise improves VO2max in SMA III without causing muscle damage, but it also induces significant fatigue. This warrants study into alternative training methods to improve exercise capacity in SMA III patients.

[Evolution of functional capacity, assessed with the Egen Klassifikation scale, in the Spanish population with spinal muscular atrophy or Duchenne muscular dystrophy. A three year longitudinal study].Publié le 16 10 2015

INTRODUCTION: Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are two neuromuscular diseases which evolve with a progressive loss of muscle strength and, therefore, the loss of functional capacity. The valuation measurement scales are used to understand better and to quantify this involution as well as making treatment to anticipate problems and improve the quality of life of people suffering from these diseases.
AIM: To study the changes in the functional capacity of a group of patients with SMA and DMD, over a period of three years.
PATIENTS AND METHODS: Nineteen individuals of the Spanish population affected with SMA and DMD, which were assessed with the Egen Klassifikation scale twice, with a time interval of three years.
RESULTS: The results show a decrease in the functional capacity of these persons during this time period, with a significant difference in the total amount of the scale (p = 0.003). All scale items showed lower valuations after three years, reaching statistical significance during the assessment, containing the ability to move his hands and coughing.
CONCLUSION: The functional capacity of patients with SMA and DMD decreases significantly within three years.

Systemic, postsymptomatic antisense oligonucleotide rescues motor unit maturation delay in a new mouse model for type II/III spinal muscular atrophy.Publié le 16 10 2015

Clinical presentation of spinal muscular atrophy (SMA) ranges from a neonatal-onset, very severe disease to an adult-onset, milder form. SMA is caused by the mutation of the Survival Motor Neuron 1 (SMN1) gene, and prognosis inversely correlates with the number of copies of the SMN2 gene, a human-specific homolog of SMN1. Despite progress in identifying potential therapies for the treatment of SMA, many questions remain including how late after onset treatments can still be effective and what the target tissues should be. These questions can be addressed in part with preclinical animal models; however, modeling the array of SMA severities in the mouse, which lacks SMN2, has proven challenging. We created a new mouse model for the intermediate forms of SMA presenting with a delay in neuromuscular junction maturation and a decrease in the number of functional motor units, all relevant to the clinical presentation of the disease. Using this new model, in combination with clinical electrophysiology methods, we found that administering systemically SMN-restoring antisense oligonucleotides (ASOs) at the age of onset can extend survival and rescue the neurological phenotypes. Furthermore, these effects were also achieved by administration of the ASOs late after onset, independent of the restoration of SMN in the spinal cord. Thus, by adding to the limited repertoire of existing mouse models for type II/III SMA, we demonstrate that ASO therapy can be effective even when administered after onset of the neurological symptoms, in young adult mice, and without being delivered into the central nervous system.

Nutritional practices at a glance: spinal muscular atrophy type I nutrition survey findings.Publié le 16 10 2015

Proactive nutritional management for children with spinal muscular atrophy type I can provide insight into improved spinal muscular atrophy care. This observational study consisted of a nutritional and medical history survey of children with spinal muscular atrophy type I collected in 2009-2011. Forty-four caregiver survey responses were evaluated using descriptive statistics. Average age of spinal muscular atrophy type I subjects was 5 years (5 mo-16 y). The subject cohort was composed of 22 males, 21 females, and 1 unreported. Nutrition support via feeding tube was utilized by 43 of 44 subjects. A majority of respondents reported using elemental or semi-elemental formula for subjects' essential caloric intake (34 of 44). Formula intolerance issues were reported by many caregivers (27 of 44). Half of caregivers implemented dietary changes on their own or with guidance from other families; 15 caregivers consulted a registered dietitian. Survey responses and comments indicate need for evidence-based nutritional guidelines for spinal muscular atrophy.

Bilateral rib-to-pelvis Eiffel Tower VEPTR construct for children with neuromuscular scoliosis: a preliminary report.Publié le 13 10 2015

BACKGROUND CONTEXT: Neuromuscular scoliosis could develop at a young age and progress beyond skeletal maturity. An early spinal fusion arrests growth of the spine and thorax, risking the development of secondary thoracic insufficiency syndrome. Vertical expandable prosthetic titanium rib (VEPTR) is a fusionless technique aiming at correction of the deformity with preservation of growth potential.
PURPOSE: To demonstrate the preliminary results of the use of VEPTR in an Eiffel Tower construct in children with neuromuscular scoliosis in regard to coronal and sagittal profiles, space available for the lungs (SAL), and spinal growth. The report lists the complications we faced during the follow-up of 1.33 years after the index procedure.
STUDY DESIGN: A retrospective analysis of prospectively collected data of a case series.
PATIENT SAMPLE: Twenty nonambulatory children (mean 8.9 years) with neuromuscular scoliosis. Their primary diagnoses were myelomeningocele in seven, cerebral palsy in three, spinal muscular atrophy in two, myopathies in three, arthrogryposis in one, and syndromic scoliosis in four patients.
METHODS: All 20 patients received percutaneous rib-to-pelvis VEPTR implantation. Mean operative time was 2 hours, and mean hospital stay was 12 days. None of them needed blood transfusion. They underwent 20 primary implantations and 39 lengthenings.
OUTCOME MEASURES: The patients were assessed based on physiologic measures, that is, the radiographic improvement of their scoliosis, SAL, pelvic tilt, spinal height, and sagittal and coronal decompensation.
RESULTS: At the latest follow-up, thoracolumbar curvature improved significantly (65.7°±20.5° to 49.9°±15.7°), as did lumbar curvature (61.6°±19.5° to 35°±21.2°), thoracic (17.2±2.3 to 20±2.3 cm) and lumbar spinal height (9.9±1.7 to 11.9±1.8 cm), SAL (86.5±8.9 to 97±10), pelvic obliquity (12.5°±8° to 5.2°± 5.2°), and the iliolumbar angle (15°±8° to 10.06°±7.1°). Nine patients suffered complications in the form of proximal cradle migration (five), implant breakage (five), deep wound infection (three), and dislodged iliac hooks (two).
CONCLUSIONS: Early results of VEPTR for neuromuscular scoliosis are encouraging. Follow-up till skeletal maturity will best determine future indications.

Genetically Modified Pig Models for Neurodegenerative Disorders.Publié le 09 10 2015

Increasing incidence of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease has become one of the most challenging health issues in aging humans. One approach to combat this is to generate genetically modified animal models of neurodegenerative disorders for studying pathogenesis, prognosis, diagnosis, treatment, and prevention. Owing to the genetic, anatomic, physiologic, pathologic, and neurologic similarities between pigs and humans, genetically modified pig models of neurodegenerative disorders have been attractive large animal models to bridge the gap of preclinical investigations between rodents and humans. In this review, we provide a neuroanatomical overview in pigs; summarize and discuss the generation of genetically modified pig models of neurodegenerative disorders including Alzheimer's diseases, Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis, spinal muscular atrophy, and ataxia-telangiectasia. We also highlight how noninvasive bioimaging technologies like Positron Emission Tomography (PET), Computer Tomography (CT), and Magnetic Resonance Imaging (MRI) and behavioural testing have been applied to characterize neurodegenerative pig models. We further propose a multiplex genome editing and preterm recloning (MAP) approach by using the fast growing of the ground-breaking precision genome editing technology CRISPR/Cas9 and somatic cell nuclear transfer (SCNT). With this approach, we hope to shorten the temporal requirement in generating multiple transgenic pigs, increase the survival rate of founder pigs, and generate genetically modified pigs that will more closely resemble the disease causing mutations and recapitulate pathologic features of human conditions.

Reconstruction of shoulder and elbow function using multiple muscle transfers for cervical spondylotic amyotrophy.Publié le 09 10 2015

STUDY DESIGN: This was a retrospective study of 8 patients with cervical spondylotic amyotrophy who underwent multiple muscle transfers.
OBJECTIVE: The purpose of this study was to evaluate results of multiple muscle transfers about the shoulder and elbow in patients with cervical spondylotic amyotrophy.
SUMMARY OF BACKGROUND DATA: Cervical spondylotic amyotrophy is characterized by severe muscle atrophy of the shoulder girdle and elbow. Even after cervical spine surgery, many patients have poor shoulder and elbow function.
METHODS: Multiple muscle transfer procedures including the transfer of trapezius, pectoralis major, latissimus dorsi muscles, and the Steindler procedure for reconstruction of shoulder and elbow function were performed in 8 patients with cervical spondylotic amyotrophy. Patients were evaluated at a mean of 18.2 months (range, 5-75 mo).
RESULTS: All 8 patients obtained satisfactory functional recovery with improvement of active range of motion without any systemic and local complications within 3 to 6 months postoperatively. Patients at the last follow-up had obtained a mean of 91° of shoulder abduction, 111° of shoulder flexion, 23° of external rotation and 110° of elbow flexion. Disability scores (Japanese version) of the arm, shoulder, and hand improved by a mean of 28 points.
CONCLUSION: Multiple muscle transfers can improve shoulder and elbow function in cervical spondylotic amyotrophy, in cases of not only poor outcome after cervical surgery, but also in advanced paralysis. It is a useful set of procedures even in old patients, and provides definitive functional improvement of shoulder and elbow function from 3 to 6 months.

Instruments for the evaluation of motor abilities for children with severe multiple disabilities: A systematic review of the literature.Publié le 06 10 2015

Based on a systematic review, psychometric characteristics of currently available instruments on motor abilities of children with disabilities were evaluated, with the aim to identify candidates for use in children with severe multiple (intellectual and motor) disabilities. In addition, motor abilities are essential for independent functioning, but are severely compromised in these children. The methodological quality of all studies was evaluated with the Consensus Based Standards for the Selection of Health Status Measurement Instruments (COSMIN) Checklist; overall levels of evidence per instrument were based on the Cochrane Back Review Group strategy. As a result, 18 studies with a total of eight instruments, developed for children with cerebral palsy (CLA, GMFM-88 and LE85), spinal muscular atrophy (MHFMS), neuromuscular diseases (MFM), disabilities 0-6 years (VAB, WeeFIM), and one developed specifically for children with severe multiple disabilities (TDMMT) were found. Strong levels of evidence were found for construct validity of LE85 and MFM and for responsiveness of WeeFIM, but reliability studies of these instruments had a limited methodological quality. Up to now studies of the TDMMT resulted in limited and unknown evidence for structural validity due to the poor methodological quality of reliability studies. In a next step, the clinical suitability of the instruments for children with severe multiple disabilities will be evaluate.

Genetic Inhibition of JNK3 Ameliorates Spinal Muscular Atrophy.Publié le 02 10 2015

Mutation of the Survival Motor Neuron 1 (SMN1) gene causes spinal muscular atrophy (SMA), an autosomal recessive neurodegenerative disorder that occurs in early childhood. Degeneration of spinal motor neurons caused by SMN deficiency results in progressive muscle atrophy and death in SMA. The molecular mechanism underlying neurodegeneration in SMA is unknown. No treatment is available to prevent neurodegeneration and reduce the burden of illness in SMA. We report that the c-Jun NH2-terminal kinase (JNK) signaling pathway mediates neurodegeneration in SMA. The neuron-specific isoform JNK3 is required for neuron degeneration caused by SMN deficiency. JNK3-deficiency reduces degeneration of cultured neurons caused by low levels of SMN. Genetic inhibition of JNK pathway in vivo by Jnk3 knockout results in amelioration of SMA phenotype. JNK3-deficiency prevents the loss of spinal cord motor neurons, reduces muscle degeneration, improves muscle fiber thickness and muscle growth, improves motor function and overall growth and increases lifespan of mice with SMA that shows a systemic rescue of phenotype by a SMN-independent mechanism. JNK3 represents a potential (non-SMN) therapeutic target for the treatment of SMA.

Mechanical insufflation/exsufflation improves vital capacity in neuromuscular disorders.Publié le 24 09 2015

Inherited neuromuscular disorders inevitably result in severe lung volume restriction associated with high morbidity and mortality. The aim of this retrospective study was to evaluate the long-term effects of the regular use of mechanical insufflation/exsufflation on the course of the vital capacity. This retrospective data analysis included 21 patients (16.1 ± 6.5 years) with neuromuscular disorders and severe lung volume restriction using nocturnal noninvasive ventilation. The patients were advised to regularly use the mechanical insufflation/exsufflation twice a day for 10 minutes applying sets of three insufflation/exsufflation breath via face mask irrespective of respiratory tract infection. Data on the course of vital capacity were collected 2 years prior and 2 years after the introduction of regular use of mechanical insufflation/exsufflation. Before the introduction of mechanical insufflation/exsufflation vital capacity decreased from 0.71 ± 0.38 L to 0.50 ± 0.24 L in the last year and from 0.88 ± 0.45 L to 0.71 ± 0.38 L in the next to last year. In the first year, after regular use of mechanical insufflation/exsufflation vital capacity significantly increased by 28% (from 0.50 L to 0.64 L)-after the second year the vital capacity increase remained stable (0.64 vs. 0.65 L). These data suggest that the regular use of mechanical insufflation/exsufflation improves vital capacity in patients with neuromuscular disorders and severe lung volume restriction.

Mechanistic principles of antisense targets for the treatment of spinal muscular atrophy.Publié le 20 09 2015

Spinal muscular atrophy (SMA) is a major neurodegenerative disorder of children and infants. SMA is primarily caused by low levels of SMN protein owing to deletions or mutations of the SMN1 gene. SMN2, a nearly identical copy of SMN1, fails to compensate for the loss of the production of the functional SMN protein due to predominant skipping of exon 7. Several compounds, including antisense oligonucleotides (ASOs) that elevate SMN protein from SMN2 hold the promise for treatment. An ASO-based drug currently under Phase III clinical trial employs intronic splicing silencer N1 (ISS-N1) as its target. Cumulative studies on ISS-N1 reveal a wealth of information with significance to the overall therapeutic development for SMA. Here, the authors summarize the mechanistic principles behind various antisense targets currently available for SMA therapy.

[The causes of physical disability in municipalities of the northeast of Brazil and an estimate of costs of specialized services].Publié le 18 09 2015

The population of the northeast of Brazil is characterized by high rates of endogamy and disabilities. An epidemiological cross-sectional study using the informant method was conducted in eight communities in the hinterlands of Paraiba to describe genetic and acquired diseases that cause disabilities and to estimate the costs of specialized services such as physiotherapy and the acquisition of technological assistential equipment. From a population of 48,499 inhabitants, 338 individuals were screened and 123 (0.34%) were clinically, genetically and functionally assessed by a multidisciplinary team of specialists. Genetic factors were responsible for 58.5% of the disabilities, with some clusters of prevalent diseases being found within the sampled communities, namely progressive spinal muscular atrophy, spinocerebellar ataxia, muscular dystrophy and Spoan syndrome. The socioeconomic profile and the demand for rehabilitation services and technological assistance highlight the need to introduce and implement specific public health policies in these communities.

Motor Neuron Diseases in Sub-Saharan Africa: The Need for More Population-Based Studies.Publié le 09 09 2015

Motor neuron diseases (MNDs) are devastating neurological diseases that are characterised by gradual degeneration and death of motor neurons. Major types of MNDs include amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). These diseases are incurable, with limited disease-modifying treatment options. In order to improve MND-based biomedical research, drug development, and clinical care, population-based studies will be important. These studies, especially among less-studied populations, might identify novel factors controlling disease susceptibility and resistance. To evaluate progress in MND research in Africa, we examined the published literature on MNDs in Sub-Saharan Africa to identify disease prevalence, genetic factors, and other risk factors. Our findings indicate that the amount of research evidence on MNDs in Sub-Saharan Africa is scanty; molecular and genetics-based studies are particularly lacking. While only a few genetic studies were identified, these studies strongly suggest that there appear to be population-specific causes of MNDs among Africans. MND genetic underpinnings vary among different African populations and also between African and non-African populations. Further studies, especially molecular, genetic and genomic studies, will be required to advance our understanding of MND biology among African populations. Insights from these studies would help to improve the timeliness and accuracy of clinical diagnosis and treatment.

Modeling motor neuron disease: the matter of time.Publié le 05 09 2015

Stem cell technologies have created new opportunities to generate unlimited numbers of human neurons in the lab and study neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Although some disease hallmarks have been reported in patient-derived stem cell models, it is proving more difficult to recapitulate the full phenotypic extent of these disorders. The problem with these stem cell models lies in the disparity between the advanced age of onset of neurodegenerative disorders and the embryonic nature of the in vitro derived cell types. In this review we discuss experimental methods of in vitro aging of neural cell types as a means to elicit late-onset symptoms in induced pluripotent stem cell (iPSC) models of neurodegenerative disease.

In vitro gene manipulation of spinal muscular atrophy fibroblast cell line using gene targeting fragment for restoration of SMN protein expression.Publié le 04 09 2015

The reduced level of survival motor neuron (SMN) protein, caused by homozygous deletions in the SMN gene, led to a common neurodegenerative disorder known as Spinal muscular atrophy (SMA). In spite of extensive efforts to find a cure for SMA, there is currently no effective treatment available for this devastating disease. In this study, restoration of SMN expression through 'gene targeting' method in SMA fibroblast cells was attempted. We designed a 2697 bp Gene targeting cassette; it consisted of an SMN1 open reading frame (ORF) expressing 38 kD SMN protein, and the upstream and downstream regions of exon 1 of SMN1 gene at the ends as the homology arms. SMA fibroblast cells were transfected by gene targeting cassette using Lipofectamine LTX-PLUS reagent. Occurrence of homologous recombination in selected cells was investigated by PCR analysis. Increased expression of SMN protein was shown by Real Time-PCR and western blot analysis. The immunofluorescence analysis results demonstrated that the number of SMN nuclear structures, gems, was the same as or greater than the number of gems found in normal fibroblasts. The results of this study indicate that gene targeting methods do, in fact, present as an alternative for restoration of SMN expression in SMA patients-derived cells in vitro.Gene Therapy accepted article preview online, 02 September 2015. doi:10.1038/gt.2015.92.

Postoperative quality of life in patients with progressive neuromuscular scoliosis and their parents.Publié le 01 09 2015

BACKGROUND CONTEXT: The functional level of children with progressive neuromuscular disease is a major factor that affects the quality of life (QOL) of parents. However, only a few publications have reported changes in the QOL of parents after correctional spinal surgery.
PURPOSE: The purpose was to compare changes in QOL for both patients and parents after spinal correctional surgery for better sitting balance and to analyze correlation among radiographic parameters, functional outcome, and QOL questionnaires. Finally, the QOL of patients and parents was compared with the population norm.
STUDY DESIGN: This study is a retrospective analysis of prospectively gathered data.
PATIENT SAMPLE: From 2008 to 2011, 58 patients who underwent correctional surgery for progressive neuromuscular scoliosis and their parents were enrolled.
OUTCOME MEASURES: A Muscular Dystrophy Spine Questionnaire (MDSQ) and short-form questionnaire 36 (SF-36) were used.
METHODS: The gathered functional outcome and QOL data using MDSQ and SF-36 for both enrolled patients and parents were compared preoperatively, postoperatively at 3 months, and at 1-year follow-up.
RESULTS: Mean age was 15.0±4.1 years. Forty male and 18 female patients were enrolled. Mean follow-up was 38.4±13.7 months. Cobb angle was 61.5°±23.5° preoperatively, 39.0°±20.1° immediately postoperative, and 40.0°±20.2° at the final follow-up. Cobb angle, pelvic obliquity, and lumbar lordosis were significantly improved after surgery (p<.001). Among sitting-related questions, answers to questions 15 (sitting comfortably), 16 (change weight in wheelchair), 22 (sit all day), 24 (sit at table for meal), 26 (keep balance while sitting in wheelchair), and 27 (look good while sitting in wheelchair) were significantly improved after correctional surgery (p<.001). Regarding the SF-36 scales for patients, bodily pain and social functioning significantly improved postoperatively (p<.001).
CONCLUSIONS: Muscular Dystrophy Spine Questionnaire results indicated that patients had significantly improved sitting balance-related outcomes, whereas the SF-36 indicated improvements only in bodily pain and social functioning scales. For parents, no SF-36 scales improved significantly postoperatively. Accordingly, improved sitting balance and QOL for neuromuscular scoliosis patients after surgery do not necessarily increase parent QOL.

IGF-1R Reduction Triggers Neuroprotective Signaling Pathways in Spinal Muscular Atrophy Mice.Publié le 29 08 2015

Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by the selective loss of spinal motor neurons due to the depletion of the survival of motor neuron (SMN) protein. No therapy is currently available for SMA, which represents the leading genetic cause of death in childhood. In the present study, we report that insulin-like growth factor-1 receptor (Igf-1r) gene expression is enhanced in the spinal cords of SMA-like mice. The reduction of expression, either at the physiological (through physical exercise) or genetic level, resulted in the following: (1) a significant improvement in lifespan and motor behavior, (2) a significant motor neuron protection, and (3) an increase in SMN expression in spinal cord and skeletal muscles through both transcriptional and posttranscriptional mechanisms. Furthermore, we have found that reducing IGF-1R expression is sufficient to restore intracellular signaling pathway activation profile lying downstream of IGF-1R, resulting in both the powerful activation of the neuroprotective AKT/CREB pathway and the inhibition of the ERK and JAK pathways. Therefore, reducing rather than enhancing the IGF-1 pathway could constitute a useful strategy to limit neurodegeneration in SMA.
SIGNIFICANCE STATEMENT: Recent evidence of IGF-1 axis alteration in spinal muscular atrophy (SMA), a very severe neurodegenerative disease affecting specifically the motor neurons, have triggered a renewed interest in insulin-like growth factor-1 (IGF-1) pathway activation as a potential therapeutic approach for motor neuron diseases. The present study challenges this point of view and brings the alternative hypothesis that reducing rather than enhancing the IGF-1 signaling pathway exerts a neuroprotective effect in SMA. Furthermore, the present data substantiate a newly emerging concept that the modulation of IGF-1 receptor expression is a key event selectively determining the activation level of intracellular pathways that lie downstream of the receptor. This aspect should be considered when designing IGF-1-based treatments for neurodegenerative diseases.

mRNA regulation: A patch for a splice.Publié le 29 08 2015

PMID: 26083069 [PubMed - indexed for MEDLINE]

SMN2 splice modulators enhance U1-pre-mRNA association and rescue SMA mice.Publié le 27 08 2015

Spinal muscular atrophy (SMA), which results from the loss of expression of the survival of motor neuron-1 (SMN1) gene, represents the most common genetic cause of pediatric mortality. A duplicate copy (SMN2) is inefficiently spliced, producing a truncated and unstable protein. We describe herein a potent, orally active, small-molecule enhancer of SMN2 splicing that elevates full-length SMN protein and extends survival in a severe SMA mouse model. We demonstrate that the molecular mechanism of action is via stabilization of the transient double-strand RNA structure formed by the SMN2 pre-mRNA and U1 small nuclear ribonucleic protein (snRNP) complex. The binding affinity of U1 snRNP to the 5' splice site is increased in a sequence-selective manner, discrete from constitutive recognition. This new mechanism demonstrates the feasibility of small molecule-mediated, sequence-selective splice modulation and the potential for leveraging this strategy in other splicing diseases.

A SIGMAR1 splice-site mutation causes distal hereditary motor neuropathy.Publié le 25 08 2015

OBJECTIVE: To identify the underlying genetic cause in a consanguineous Chinese family segregating distal hereditary motor neuropathy (dHMN) in an autosomal recessive pattern.
METHODS: We used whole-exome sequencing and homozygosity mapping to detect the genetic variant in 2 affected individuals of the consanguineous Chinese family with dHMN. RNA analysis of peripheral blood leukocytes and immunofluorescence and immunoblotting of stable cell lines were performed to support the pathogenicity of the identified mutation.
RESULTS: We identified 3 shared novel homozygous variants in 3 shared homozygous regions of the affected individuals. Sequencing of these 3 variants in family members revealed the c.151+1G>T mutation in SIGMAR1 gene, which located in homozygous region spanning approximately 5.3 Mb at chromosome 9p13.1-p13.3, segregated with the dHMN phenotype. The mutation causes an alternative splicing event and generates a transcript variant with an in-frame deletion of 60 base pairs in exon 1 (c.92_151del), and results in an internally shortened protein ?1R(31_50del). The proteasomal inhibitor treatment increased the intracellular amount of ?1R(31_50del) and led to the formation of nuclear aggregates. Stable expressing ?1R(31_50del) induced endoplasmic reticulum stress and enhanced apoptosis.
CONCLUSION: The homozygous c.151+1G>T mutation in SIGMAR1 caused a novel form of autosomal recessive dHMN in a Chinese consanguineous family. Endoplasmic reticulum stress may have a role in the pathogenesis of dHMN.

An update on RNA-targeting therapies for neuromuscular disorders.Publié le 19 08 2015

PURPOSE OF REVIEW: Antisense-mediated modulation of transcripts is a dynamic therapeutic field, especially for neuromuscular disorders.
RECENT FINDINGS: For three diseases, this approach has advanced to the clinical trial phase, that is Duchenne muscular dystrophy, spinal muscular atrophy and myotonic dystrophy. In parallel, numerous proof-of-concept studies in cell and animal models have been reported for additional neuromuscular disorders.
SUMMARY: This review discusses the most notable advances in preclinical and clinical studies in the past year. For Duchenne muscular dystrophy, spinal muscular atrophy and myotonic dystrophy trials are ongoing to assess safety and efficacy, while in parallel preclinical studies are being conducted to identify ways to improve efficiency and delivery. For other neuromuscular diseases, progress is made as well warranting future clinical trials. However, towards clinical trial readiness, it is important not only to optimize the therapy preclinically but to also develop the infrastructure that is needed to conduct trials.

Spinal muscular atrophy associated with progressive myoclonic epilepsy: A rare condition caused by mutations in ASAH1.Publié le 24 07 2015

OBJECTIVE: To present the clinical features and the results of laboratory investigations in three patients with spinal muscular atrophy associated with progressive myoclonic epilepsy (SMA-PME), a rare condition caused by mutations in the N-acylsphingosine amidohydrosilase 1 (ASAH1) gene.
METHODS: The patients were submitted to clinical evaluation, neurophysiologic investigations (that included wakefulness and sleep electroencephalography [EEG], video-polygraphic recording with jerk-locked back-averaging, multimodal evoked potentials, and electromyography), brain magnetic resonance imaging (MRI), biochemical screening, muscle and skin biopsies, and molecular genetic analysis.
RESULTS: The main clinical features were onset in childhood with proximal muscular weakness, generalized epilepsy with absences and myoclonic seizures, cognitive impairment of variable degree; the course was progressive with muscle wasting and uncontrolled epileptic seizures. In one patient, earlier onset before the age of 2 years was associated with a more complex clinical picture, with abnormal eye movements, progressive cognitive impairment, and a more rapid and severe course. EEG/polygraphic data were consistent with PME, demonstrating generalized spike-and-wave discharges, evidence of positive and negative myoclonia, and prominent photosensitivity. In one patient, transcranial magnetic stimulation showed a hyperexcitable motor cortex, whereas somatosensory evoked potentials were unaffected. Possible involvement of the central acoustic and visual pathways was suggested by abnormal auditory and visual evoked potentials. Muscle biopsies showed typical signs of neurogenic damage. Molecular genetic analysis showed mutations of the ASAH1 gene.
SIGNIFICANCE: Our data indicate that SMA-PME associated with ASAH1 mutations is a genetically distinct condition with specific clinical and neurophysiologic features. Further studies are warranted to explore the role of the ASAH1 gene in muscle and brain function.

Advances and challenges in developing a therapy for spinal muscular atrophy.Publié le 24 07 2015

Spinal muscular atrophy (SMA) is a debilitating and incurable childhood onset disease characterized by the degeneration of motor neurons in the spinal cord resulting in muscular atrophy and paralysis. Over the past 20 years, there has been significant progress in understanding the molecular basis of the disease, allowing researchers to identify the main causative gene and successfully model SMA in various animals. Despite an improved understanding of the disease, there is still no effective treatment for SMA patients. Here, we discuss the current knowledge surrounding the pathogenesis of SMA, and outline recent advances toward the development of a successful therapy for this devastating disease.

An examination of camptocormia assessment by dynamic quantification of sagittal posture.Publié le 24 07 2015

OBJECTIVE: Camptocormia is a disabling pathology of the axial system that debilitates patients in their daily life. To date, there have been no studies evaluating the impact of camptocormia on walking performance. This study presents a new method for assessing sagittal posture under walking conditions in patients with camptocormia.
DESIGN: The severity of camptocormia was evaluated by measuring sagittal inclination, represented indirectly by the horizontal distance between the C7 and S1 markers (C7 sagittal arrow; C7-SAR). Sagittal inclination was measured under various behavioural conditions using clinical, radiological and kinematic approaches.
PATIENTS: Forty-three patients were included in the study (17 with Parkinson's disease and 26 with idiopathic camptocormia).
RESULTS: Under static conditions, C7-SAR could be assessed using different methods. During walking, there was a dramatic increase in C7-SAR values. Correlation analysis revealed a relationship between functional impairment and dynamic C7-SAR values, but not with radiological C7-SAR values. PATIENTS with Parkinson's disease behaved differently from idiopathic patients, suggesting the involvement of different underlying physiopathological mechanisms.
CONCLUSION: Monitoring sagittal inclination during walking is more accurate than radiological measurements to determinine the detrimental effects of camptocormia and its consequences for quality of life.

How far away is spinal muscular atrophy gene therapy?Publié le 21 07 2015

Spinal muscular atrophy (SMA) is a devastating motor neuron disease primarily affecting children, for which there is currently no known disease-modifying therapy or cure. The identification of the disease gene, survival motor neuron, led to an expansion in SMA research and allowed the creation of numerous animal and cellular models. This led to a significant increase in our understanding of the pathophysiology of SMA, culminating in the development of multiple SMN-dependent and -independent therapies. Among the most exciting options, viral gene therapy has emerged as one leading candidate. A growing body of pre-clinical evidence suggests that administration of scAAV9 carrying an SMN transgene can be both efficacious and translationally viable. In this article, we briefly review the progress which has been made in the field, and provide a commentary on some of the challenges which remain.

Report of an unusual complication of radiofrequency neurotomy of medial branches of dorsal rami.Publié le 18 07 2015

PMID: 25247917 [PubMed - indexed for MEDLINE]

Developing therapies for spinal muscular atrophy.Publié le 16 07 2015

Spinal muscular atrophy is an autosomal-recessive pediatric neurodegenerative disease characterized by loss of spinal motor neurons. It is caused by mutation in the gene survival of motor neuron 1 (SMN1), leading to loss of function of the full-length SMN protein. SMN has a number of functions in neurons, including RNA splicing and snRNP biogenesis in the nucleus, and RNA trafficking in neurites. The expression level of full-length SMN protein from the SMN2 locus modifies disease severity. Increasing full-length SMN protein by a small amount can lead to significant improvements in the neurological phenotype. Currently available interventions for spinal muscular atrophy patients are physical therapy and orthopedic, nutritional, and pulmonary interventions; these are palliative or supportive measures and do not address the etiology of the disease. In the past decade, there has been a push for developing therapeutics to improve motor phenotypes and increase life span of spinal muscular atrophy patients. These therapies are aimed primarily at restoration of full-length SMN protein levels, but other neuroprotective treatments have been investigated as well. Here, we discuss recent advances in basic and clinical studies toward finding safe and effective treatments of spinal muscular atrophy using gene therapy, antisense oligonucleotides, and other small molecule modulators of SMN expression.

[The conference, "rare diseases not only in the curriculum" in Szczecin].Publié le 08 07 2015

The conference 'Rare diseases not only in the curriculum', organised on 12th May, 2014 in Pomeranian Medical University in Szczecin, had a scientific and educational character. Representatives of patient organizations, medical students, junior doctors and physiotherapist were active participants of the meeting. There were rare diseases presented--from the medical curriculum, e.g., Wilson disease, Noonan syndrome and Diamond Blackfan anemia--and diseases that are not discussed in the course of medical studies in Poland, as Costello syndrome, Rabson-Mendenhall syndrome and cholestasis familiaris groenlandica--Byler-like disease.The importance of physiotherapy of children with spinal muscular atrophy was discussed.The place ofthe issue of rare diseases in the idea of personalized medicine was specified and difficulties in the care of patients with rare diseases, including muscle and metabolic diseases, in Poland were explained.

Spinal muscular atrophy: journeying from bench to bedside.Publié le 07 07 2015

Spinal muscular atrophy (SMA) is a frequently fatal neuromuscular disorder and the most common inherited cause of infant mortality. SMA results from reduced levels of the survival of motor neuron (SMN) protein. Although the disease was first described more than a century ago, a precise understanding of its genetics was not obtained until the SMA genes were cloned in 1995. This was followed in rapid succession by experiments that assigned a role to the SMN protein in the proper splicing of genes, novel animal models of the disease, and the eventual use of the models in the pre clinical development of rational therapies for SMA. These successes have led the scientific and clinical communities to the cusp of what are expected to be the first truly promising treatments for the human disorder. Yet, important questions remain, not the least of which is how SMN paucity triggers a predominantly neuromuscular phenotype. Here we review how our understanding of the disease has evolved since the SMA genes were identified. We begin with a brief description of the genetics of SMA and the proposed roles of the SMN protein. We follow with an examination of how the genetics of the disease was exploited to develop genetically faithful animal models, and highlight the insights gained from their analysis. We end with a discussion of ongoing debates, future challenges, and the most promising treatments to have emerged from our current knowledge of the disease.

Gene therapy for neurodegenerative diseases.Publié le 01 07 2015

Gene therapy is, potentially, a powerful tool for treating neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy, Parkinson's disease (PD) and Alzheimer's disease (AD). To date, clinical trials have failed to show any improvement in outcome beyond the placebo effect. Efforts to improve outcomes are focusing on three main areas: vector design and the identification of new vector serotypes, mode of delivery of gene therapies, and identification of new therapeutic targets. These advances are being tested both individually and together to improve efficacy. These improvements may finally make gene therapy successful for these disorders.

Reliability and validity of outcome measures of in-hospital and at-home visits in a randomized, double-blind, placebo-controlled trial for spinal muscular atrophy.Publié le 30 06 2015

We used at-home assessments in a clinical trial to relieve the visit burden for participants. A total of 57 patients with type II or III spinal muscular atrophy were enrolled and 10 of them (7 type II and 3 type III) received at-home assessments. The primary end points were Gross Motor Function Measure, Manual Muscle Test, and serum biomarker. The secondary endpoints were Modified Hammersmith Functional Motor Scale and forced vital capacity. The correlation coefficients and analysis of covariance showed good reliability and validity of all outcome measures. Except for Gross Motor Function Measure and Modified Hammersmith Functional Motor Scale, there were no significant differences in measures between in-hospital and at-home groups (intersubject) or among 3 patients who received both at-home and in-hospital visits (intrasubject). We concluded that at-home assessments could provide sufficient reliability in a controlled trial. This modification could help design a successful clinical trial for spinal muscular atrophy.

Decay in survival motor neuron and plastin 3 levels during differentiation of iPSC-derived human motor neurons.Publié le 28 06 2015

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by mutations in Survival Motor Neuron 1 (SMN1), leading to degeneration of alpha motor neurons (MNs) but also affecting other cell types. Induced pluripotent stem cell (iPSC)-derived human MN models from severe SMA patients have shown relevant phenotypes. We have produced and fully characterized iPSCs from members of a discordant consanguineous family with chronic SMA. We differentiated the iPSC clones into ISL-1+/ChAT+ MNs and performed a comparative study during the differentiation process, observing significant differences in neurite length and number between family members. Analyses of samples from wild-type, severe SMA type I and the type IIIa/IV family showed a progressive decay in SMN protein levels during iPSC-MN differentiation, recapitulating previous observations in developmental studies. PLS3 underwent parallel reductions at both the transcriptional and translational levels. The underlying, progressive developmental decay in SMN and PLS3 levels may lead to the increased vulnerability of MNs in SMA disease. Measurements of SMN and PLS3 transcript and protein levels in iPSC-derived MNs show limited value as SMA biomarkers.

Old measures and new scores in SMA patients.Publié le 28 06 2015

INTRODUCTION: A recent Rasch analysis performed on the Hammersmith Functional Motor Scale Expanded (HFMSE) in patients with spinal muscular atrophy (SMA) identified issues impacting scale validity, redundant items, and disordered thresholds on some items.
METHODS: We modified the HMFSE scoring based on the Rasch analysis and on expert consensus in order to establish whether the traditional scoring overestimated the number of patients with changes within 2 points from baseline. Data were collected retrospectively from multicenter datasets in 255 type 2 and 3 SMA patients Results: The mean 12-month-changes using the new and the traditional scoring system did not differ significantly (P>0.05). The number of patients who improved or decreased more than 2 points was also similar.
DISCUSSION: The presence of outliers using the traditional scoring system was not due to overestimation of changes in activities that were tested bilaterally or to discrepancies in the scoring hierarchy of individual items. This article is protected by copyright. All rights reserved.

Splicing regulation in spinal muscular atrophy by an RNA structure formed by long-distance interactions.Publié le 24 06 2015

Humans carry two copies of the survival motor neuron gene: SMN1 and SMN2. Loss of SMN1 coupled with skipping of SMN2 exon 7 causes spinal muscular atrophy (SMA), a leading genetic disease associated with infant mortality. Our discovery of intronic splicing silencer N1 (ISS-N1) is a promising target, currently in a phase III clinical trial, for an antisense oligonucleotide-mediated splicing correction in SMA. We have recently shown that the first residue of ISS-N1 is locked in a unique RNA structure that we term ISTL1 (internal stem through long-distance interaction-1). Complementary strands of ISTL1 are separated from each other by 279 nucleotides. Using site-specific mutations and chemical structure probing, we confirmed the formation and functional significance of ISTL1. Located in the middle of intron 7, the 3' strand of ISTL1 falls within an inhibitory region that we term ISS-N2. We demonstrate that an antisense oligonucleotide-mediated sequestration of ISS-N2 fully corrects SMN2 exon 7 splicing and restores high levels of SMN in SMA patient cells. These results underscore the therapeutic potential of the regulatory information present in a secondary and high-order RNA structure of a human intron.

Clinical and molecular features and therapeutic perspectives of spinal muscular atrophy with respiratory distress type 1.Publié le 23 06 2015

Spinal muscular atrophy with respiratory distress (SMARD1) is an autosomal recessive neuromuscular disease caused by mutations in the IGHMBP2 gene, encoding the immunoglobulin ?-binding protein 2, leading to motor neuron degeneration. It is a rare and fatal disease with an early onset in infancy in the majority of the cases. The main clinical features are muscular atrophy and diaphragmatic palsy, which requires prompt and permanent supportive ventilation. The human disease is recapitulated in the neuromuscular degeneration (nmd) mouse. No effective treatment is available yet, but novel therapeutical approaches tested on the nmd mouse, such as the use of neurotrophic factors and stem cell therapy, have shown positive effects. Gene therapy demonstrated effectiveness in SMA, being now at the stage of clinical trial in patients and therefore representing a possible treatment for SMARD1 as well. The significant advancement in understanding of both SMARD1 clinical spectrum and molecular mechanisms makes ground for a rapid translation of pre-clinical therapeutic strategies in humans.

Chatting with the neighbors: crosstalk between Rho-kinase (ROCK) and other signaling pathways for treatment of neurological disorders.Publié le 18 06 2015

ROCK inhibition has been largely applied as a strategy to treat neurodegenerative diseases (NDDs) and promising results have been obtained in the recent years. However, the underlying molecular and cellular mechanisms are not fully understood and different models have been proposed for neurodegenerative disorders. Here, we aim to review the current knowledge obtained for NDDs identifying common mechanisms as well as disease-specific models. In addition to the role of ROCK in different cell types such as neurons and microglia, we focus on the molecular signaling-pathways which mediate the beneficial effects of ROCK. Besides canonical ROCK signaling, modulation of neighboring pathways by non-canonical ROCK-crosstalk is a recurrent pattern in many NDD-model systems and has been suggested to mediate beneficial effects of ROCK-inhibition.

Disease Mechanisms and Therapeutic Approaches in Spinal Muscular Atrophy.Publié le 14 06 2015

Motor neuron diseases are neurological disorders characterized primarily by the degeneration of spinal motor neurons, skeletal muscle atrophy, and debilitating and often fatal motor dysfunction. Spinal muscular atrophy (SMA) is an autosomal-recessive motor neuron disease of high incidence and severity and the most common genetic cause of infant mortality. SMA is caused by homozygous mutations in the survival motor neuron 1 (SMN1) gene and retention of at least one copy of the hypomorphic gene paralog SMN2. Early studies established a loss-of-function disease mechanism involving ubiquitous SMN deficiency and suggested SMN upregulation as a possible therapeutic approach. In recent years, greater knowledge of the central role of SMN in RNA processing combined with deep characterization of animal models of SMA has significantly advanced our understanding of the cellular and molecular basis of the disease. SMA is emerging as an RNA disease not limited to motor neurons, but one that involves dysfunction of motor circuits that comprise multiple neuronal subpopulations and possibly other cell types. Advances in SMA research have also led to the development of several potential therapeutics shown to be effective in animal models of SMA that are now in clinical trials. These agents offer unprecedented promise for the treatment of this still incurable neurodegenerative disease.

iPSC-Derived neural stem cells act via kinase inhibition to exert neuroprotective effects in spinal muscular atrophy with respiratory distress type 1.Publié le 14 06 2015

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) is a motor neuron disease caused by mutations in the IGHMBP2 gene, without a cure. Here, we demonstrate that neural stem cells (NSCs) from human-induced pluripotent stem cells (iPSCs) have therapeutic potential in the context of SMARD1. We show that upon transplantation NSCs can appropriately engraft and differentiate in the spinal cord of SMARD1 animals, ameliorating their phenotype, by protecting their endogenous motor neurons. To evaluate the effect of NSCs in the context of human disease, we generated human SMARD1-iPSCs motor neurons that had a significantly reduced survival and axon length. Notably, the coculture with NSCs ameliorate these disease features, an effect attributable to the production of neurotrophic factors and their dual inhibition of GSK-3 and HGK kinases. Our data support the role of iPSC as SMARD1 disease model and their translational potential for therapies in motor neuron disorders.

The effect of the DcpS inhibitor D156844 on the protective action of follistatin in mice with spinal muscular atrophy.Publié le 10 06 2015

Spinal muscular atrophy (SMA), a leading genetic cause of pediatric death in the world, is an early-onset disease affecting the motor neurons in the anterior horn of the spinal cord. This degeneration of motor neurons leads to loss of muscle function. At the molecular level, SMA results from the loss of or mutation in the survival motor neuron 1 (SMN1) gene. The number of copies of the nearly duplicated gene SMN2 modulates the disease severity in humans as well as in transgenic mouse models for SMA. Most preclinical therapeutic trials focus on identifying ways to increase SMN2 expression and to alter its splicing. Other therapeutic strategies have investigated compounds which protect affected motor neurons and their target muscles in an SMN-independent manner. In the present study, the effect of a combination regimen of the SMN2 inducer D156844 and the protectant follistatin on the disease progression and survival was measured in the SMN?7 SMA mouse model. The D156844/follistatin combination treatment improved the survival of, delayed the end stage of disease in and ameliorated the growth rate of SMN?7 SMA mice better than follistatin treatment alone. The D156844/follistatin combination treatment, however, did not provide additional benefit over D156844 alone with respect to survival and disease end stage even though it provided some additional therapeutic benefit over D156844 alone with respect to motor phenotype.

Comparison of three cough-augmentation techniques in neuromuscular patients: mechanical insufflation combined with manually assisted cough, insufflation-exsufflation alone and insufflation-exsufflation combined with manuPublié le 10 06 2015

BACKGROUND: Mechanical insufflation-exsufflation (MI-E), more commonly known as 'cough assist therapy', is a method which produces inspiratory and expiratory assistance to improve cough performances. However, other alternatives or combinations are possible.
OBJECTIVE: The objective was to compare the effects of mechanical insufflation combined with manually assisted coughing (MAC), insufflation-exsufflation alone and insufflation-exsufflation combined with MAC in neuromuscular patients requiring cough assistance.
METHODS: Eighteen neuromuscular patients with severe respiratory muscle dysfunction and peak cough flow (PCF) lower than 3 liters/s or maximal expiratory pressure (MEP) lower than +45 cm H2O were studied. Patients were studied under three cough-assisted conditions, which were used in random order: insufflation by intermittent positive-pressure breathing (IPPB) combined with MAC, MI-E and MI-E + MAC.
RESULTS: Overall, PCF was higher with IPPB + MAC than with MI-E + MAC or MI-E alone. Among the 12 patients who had higher PCF values with IPPB + MAC than with the two other techniques, 9 exhibited mask pressure swings during MI-E exsufflation, with a transient positive-pressure value due to the expiratory flow produced by the combined patient cough effort and MAC. Each of these 9 patients had higher PCF values (>5 liters/s) than did the other 9 patients when using IPPB + MAC.
CONCLUSION: Our results indicate that adding the MI-E device to MAC is unhelpful in patients whose PCF with an insufflation technique and MAC exceeds 5 liters/s. This is because the expiratory flow produced by the patient's effort and MAC transitorily exceeds the vacuum capacity of the MI-E device, which therefore becomes a transient load against the PCF.

Comparison of three cough-augmentation techniques in neuromuscular patients: mechanical insufflation combined with manually assisted cough, insufflation-exsufflation alone and insufflation-exsufflation combined with manuPublié le 10 06 2015

BACKGROUND: Mechanical insufflation-exsufflation (MI-E), more commonly known as 'cough assist therapy', is a method which produces inspiratory and expiratory assistance to improve cough performances. However, other alternatives or combinations are possible.
OBJECTIVE: The objective was to compare the effects of mechanical insufflation combined with manually assisted coughing (MAC), insufflation-exsufflation alone and insufflation-exsufflation combined with MAC in neuromuscular patients requiring cough assistance.
METHODS: Eighteen neuromuscular patients with severe respiratory muscle dysfunction and peak cough flow (PCF) lower than 3 liters/s or maximal expiratory pressure (MEP) lower than +45 cm H2O were studied. Patients were studied under three cough-assisted conditions, which were used in random order: insufflation by intermittent positive-pressure breathing (IPPB) combined with MAC, MI-E and MI-E + MAC.
RESULTS: Overall, PCF was higher with IPPB + MAC than with MI-E + MAC or MI-E alone. Among the 12 patients who had higher PCF values with IPPB + MAC than with the two other techniques, 9 exhibited mask pressure swings during MI-E exsufflation, with a transient positive-pressure value due to the expiratory flow produced by the combined patient cough effort and MAC. Each of these 9 patients had higher PCF values (>5 liters/s) than did the other 9 patients when using IPPB + MAC.
CONCLUSION: Our results indicate that adding the MI-E device to MAC is unhelpful in patients whose PCF with an insufflation technique and MAC exceeds 5 liters/s. This is because the expiratory flow produced by the patient's effort and MAC transitorily exceeds the vacuum capacity of the MI-E device, which therefore becomes a transient load against the PCF.

Comparison of three cough-augmentation techniques in neuromuscular patients: mechanical insufflation combined with manually assisted cough, insufflation-exsufflation alone and insufflation-exsufflation combined with manuPublié le 10 06 2015

BACKGROUND: Mechanical insufflation-exsufflation (MI-E), more commonly known as 'cough assist therapy', is a method which produces inspiratory a