New findings suggest that people of South Asian, African, and European ancestry share many of the same genetic risk factors for multiple sclerosis. This study is one of the most ancestrally diverse genetic analyses of MS conducted in the UK. 

MS affects around 150,000 people in the UK and more than two million people worldwide, yet most genetic research to date has focused on people of white European ancestry. The research team, led by Queen Mary University, of London, analyzed genetic data from more than 3,000 people with MS and more than 27,000 without MS. They looked at participants from the ADAMS Project, which specifically recruits people with MS from diverse backgrounds, and cases and controls from the UK Biobank. 

The researchers found genetic variants in the major histocompatibility complex region, a key component of the immune system and a long-established driver of MS risk, were strongly linked to MS in people of South Asian and African ancestry, as well as people of European ancestry.  

There was also evidence that some genetic patterns differed between ancestry groups. The researchers identified a genetic variant that may reduce the risk of MS and is relatively common in people of South Asian ancestry, but rare in people of European ancestry. Because this variant is uncommon in Europeans, it would likely not be detected in studies that only include European populations. This finding highlights how ancestry-specific genetic variants and effects can be missed when research lacks diversity.  

The study also found most genetic variants previously identified in European populations also appear to be present in people of South Asian and African ancestry. While the strength of these effects varied, the overall pattern suggests MS is driven by shared underlying immune and biological mechanisms across populations, rather than being a fundamentally different disease among different ancestry groups.  

Previous research has shown stark racial disparities in MS outcomes, with people from Black ethnic backgrounds often experiencing more severe disability and worse disease trajectories than their white counterparts. Differences in genetics alone do not explain these inequalities, but the historic lack of representation of South Asian and Black populations in genetic research means MS may be under-recognized, diagnosed later, or assessed less accurately in these groups. It also means there is less certainty genetic risk tools, and potentially treatments developed using European-focused data, perform equally well for everyone. This study shows how a more representative scientific approach can improve understanding of the disease and help close these gaps over time.  

The authors note this disparity reflects the European-dominant data used to develop these tools and highlights why broader representation is important for equitable predictive genetics.

The findings were published in the journal Neurology.