Spinal muscular atrophy

Spinal muscular atrophy (SMA) affects the motor neurons – the nerve cells responsible for controlling movement of the skeletal muscles. Damage to or complete loss of motor neurons causes muscle wasting or atrophy and weakness. The weakness is usually more severe in the proximal muscles (close to the centre of the body) and usually worsens with age.

SMA is caused by defects in the SMN1 gene, which is responsible for making a protein called the survival motor neuron (SMN) protein. Various factors can affect the amount of SMN protein available and this in turn affects the severity of the disease, which has been classified into different types depending on the maximum functional ability the affected person reaches: individuals with type I never manage to sit independently; those with type II achieve the ability to sit up on their own but never manage to walk independently; type III patients achieve the ability to walk but may lose this ability later or require a wheelchair for longer distances.

Read more about SMA at the NIH Genetics Home Reference site here

Our research in SMA focuses on the epidemiology of the disease, as well as standards of care, data sharing and patient registries. SMA is at the forefront of therapy development in neuromuscular disease, and with new treatments being developed and approved, this background data is becoming essential for providing evidence to payers about the numbers of people benefiting from new therapies as well as determining long-term outcomes and access to therapies.



*Photo with the kind permission of Vitaliy Matyushenko, Children with Spinal Muscular Atrophy, Ukraine


Girl with SMA takes selfie with her brother

Relevant publications

Pechmann, A, König, K, Bernert, G, Schachtrup, K, Schara, U, Schorling, D et al.. SMArtCARE - A platform to collect real-life outcome data of patients with spinal muscular atrophy. Orphanet J Rare Dis. 2019.14 (1)18 PMID:30665421

Kletzl, H, Marquet, A, Günther, A, Tang, W, Heuberger, J, Groeneveld, GJ et al.. The oral splicing modifier RG7800 increases full length survival of motor neuron 2 mRNA and survival of motor neuron protein: Results from trials in healthy adults and patients with spinal muscular atrophy. Neuromuscul. Disord. 2019.29 (1)21-29 PMID:30553700

Lochmüller, H, Evans, D, Farwell, W, Finkel, R, Goemans, N, de Lemus, M et al.. Position Statement: Sharing of Clinical Research Data in Spinal Muscular Atrophy to Accelerate Research and Improve Outcomes for Patients. J Neuromuscul Dis. 2018.5 (2)131-133 PMID:29865093

Boczonadi, V, King, MS, Smith, AC, Olahova, M, Bansagi, B, Roos, A et al.. Mitochondrial oxodicarboxylate carrier deficiency is associated with mitochondrial DNA depletion and spinal muscular atrophy-like disease. Genet. Med. 2018.20 (10)1224-1235 PMID:29517768

Verhaart, IEC, Robertson, A, Wilson, IJ, Aartsma-Rus, A, Cameron, S, Jones, CC et al.. Prevalence, incidence and carrier frequency of 5q-linked spinal muscular atrophy - a literature review. Orphanet J Rare Dis. 2017.12 (1)124 PMID:28676062

Verhaart, IEC, Robertson, A, Leary, R, McMacken, G, König, K, Kirschner, J et al.. A multi-source approach to determine SMA incidence and research ready population. J. Neurol. 2017.264 (7)1465-1473 PMID:28634652

Bertini, E, Dessaud, E, Mercuri, E, Muntoni, F, Kirschner, J, Reid, C et al.. 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. Lancet Neurol. 2017.16 (7)513-522 PMID:28460889

Evangelista, T, Bansagi, B, Pyle, A, Griffin, H, Douroudis, K, Polvikoski, T et al.. Phenotypic variability of TRPV4 related neuropathies. Neuromuscul. Disord. 2015.25 (6)516-21 PMID:25900305

Boczonadi, V, Müller, JS, Pyle, A, Munkley, J, Dor, T, Quartararo, J et al.. EXOSC8 mutations alter mRNA metabolism and cause hypomyelination with spinal muscular atrophy and cerebellar hypoplasia. Nat Commun. 2014.5 4287 PMID:24989451

Bladen, CL, Thompson, R, Jackson, JM, Garland, C, Wegel, C, Ambrosini, A et al.. Mapping the differences in care for 5,000 spinal muscular atrophy patients, a survey of 24 national registries in North America, Australasia and Europe. J. Neurol. 2014.261 (1)152-63 PMID:24162038

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