Spinal Muscular Atrophy (SMA) in the Therapeutic Era
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Purpose of Review
Spinal muscular atrophy (SMA) is an autosomal recessive disorder caused by a mutation in the SMN1 gene. It is relatively common worldwide, affecting approximately 1 in 11,000 live births, and about 1 in every 54 individuals is a carrier. The FDA-approved nusinersen (Spinraza) in December 2016 and onasmenogene abeparvovec (Zolgensma) in May 2019 for treatment of SMA after clinical trials showed slowed progression, improved motor function, and improved survival in treated infants and children. This review is aimed at educating medical professionals to facilitate a better understanding of SMA genetics, care recommendations, current and future therapies, and the avenues for early diagnosis.
With the advent of disease-modifying treatment for SMA, the prognosis and outcomes for patients are changing rapidly. Treatment response is time sensitive, and it is important to diagnose as early as possible and counsel families so prompt decisions regarding treatment can be made. An updated consensus statement on standards of care was published in 2018.
Understanding the historical phenotypes, genetics and treatment options are critical to provide comprehensive counseling to families, allowing them to make informed decisions. Improved education of providers and advances in screening recommendations and create the opportunity for earlier diagnosis and treatment, further improving the outlook for this disease.
KeywordsSpinal muscular atrophy SMA Gene therapy Genetic counseling
Compliance with Ethical Standards
Conflict of Interest
Anne Stratton reports membership on the Medical Advisory Board for Cure SMA (a nonpaid volunteer position) since 2015.
Julie Parsons reports serving as the principle investigator on clinical trials for Biogen, AveXis, Cytokinetics, Scholar Rock, and Genentech Roche, outside of the submitted work.
Melissa Gibbons reports membership on the Advisory Board for Sarepta and honoraria for speaking engagements at AveXis and France Foundation.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance
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