Global Prevalence of Spinal Muscular Atrophy in 204 Countries and Territories, 1960-2024: A Systematic Review and...

Despite major therapeutic advances, the global epidemiology of spinal muscular atrophy (SMA) remains poorly characterized, with substantial geographic disparities in diagnostic capacity and data availability. Here, we aimed to estimate the global, regional, and national prevalence of SMA across all ages, newborns, and children.

We systematically searched PubMed/MEDLINE, Embase, CINAHL, and Google Scholar from database inception to October 13, 2025, for studies reporting SMA prevalence. We used a Bayesian hierarchical linear mixed-effects model to estimate SMA prevalence for newborns, children, and all ages across 204 countries and territories from 1960 to 2024. All estimates were derived from 4000 posterior draws with 95% credible intervals. We further assessed the associations between prevalence estimates and the Sociodemographic Index (SDI), the Healthcare Access and Quality Index, and gross domestic product per capita.

A total of 58 eligible studies reporting the prevalence of SMA were included. The global lifetime Bayesian prevalence of SMA across all ages was 0.010% (95% credible interval, 0.002-0.021). Prevalence was highest in high-income countries (0.027% [0.000-0.067]) and lowest in South Asia and sub-Saharan Africa (both 0.002% [0.002-0.003]). The global estimated prevalence among newborns was 0.020% (0.007-0.043) and among children was 0.008% (0.002-0.016). Western Europe showed the highest regional prevalence while South Asia and sub-Saharan Africa had the lowest. Higher national prevalence of SMA was positively associated with higher Sociodemographic Index, Healthcare Access and Quality, and gross domestic product per capita.

This study highlights the need to strengthen global surveillance, expand newborn and genetic screening, and improve diagnostic infrastructure, particularly in under-resourced settings.