Earlier this month, an article was published in the Journal of Neuromuscular Diseases titled, “Spinal Muscular Atrophy (SMA) Subtype Concordance in Siblings: Findings from the Cure SMA Cohort.” This paper examined the concordance and discordance of SMA sub-type among siblings in order to learn about the family experience of SMA, support the identification of genetic modifiers and aid in creating and implementing treatment plans for individuals with SMA.

This paper represents how the Cure SMA membership database can be utilized to better understand SMA.  Since 1996 Cure SMA has maintained the largest global membership database of patient reported information. At the time of the data analysis, over 7,000 individuals with SMA were recorded in the Cure SMA database. The database tracks personal information such as birthdate, gender, SMA type, and diagnosis date. After applying exclusion criteria, a total of 627 siblings from 303 families (sibships) that had initially contacted Cure SMA from 1996-2016 were available for this analysis. Concordant sibships were defined as those where all siblings with SMA had the same subtype, while discordant sibships were those with two or more siblings with SMA having different subtypes.

Among the 303 sibships, 84.8% had concordant SMA subtypes. Type I SMA was the most common SMA subtype seen among the concordant suptypes, followed by SMA type II. Among the discordant subtypes, the combination of SMA types II and III was the most common.

In summary, the study of subtype concordance supports the prediction of disease trajectory and enables a better understanding of the burden of illness within families. Cure SMA would like to thank the entire SMA community for their contribution to this study. Providing patient reported data enables the research community to help better understand SMA which may lead to the development of new novel SMA therapies.