Identifying common genetic markers for multiple sclerosis

A new study published in Neurology and led by Queen Mary University of London has revealed that people of South Asian, African , and European ancestry share many of the same genetic risk factors for multiple sclerosis (MS). 

This new 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 analysed genetic data from more than 3,000 people with MS and over 27,000 without MS (called controls). They looked at participantsfrom the ADAMS Project, which specifically recruits people with MS from diverse backgrounds, and cases and controls from the UK Biobank. The researchers found that genetic variants in the major histocompatibility complex (MHC) region, a key component of the immune system and a long-established driver of MS risk, were strongly associated with 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. Since 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 that 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 that 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 Asians and Black populations in genetic research means MS may be under-recognised, diagnosed later, or assessed less accurately in these groups. It also means there is less certainty that 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. 

MS genetics has, until now, been overwhelmingly based on people of European ancestry. This study shows that while many of the biological pathways driving MS are shared, leaving large parts of the global population out of research limits our understanding of the disease. Better representation is not only a fairness issue, but it also leads to better science."

Ruth Dobson, Study Lead Author and Professor, Clinical Neurology, Queen Mary University of London

Dr Benjamin Jacobs, Clinical Lecturer in Neurology at Queen Mary University of London and co-author on the study, said: "This work demonstrates why diversity matters in genetics. When studies only include one ancestral group, they miss important insights. By broadening participation, we can sharpen our understanding of MS, find risk factors that would otherwise stay hidden, and build prediction tools that work for everyone." 

Caitlin Astbury, Senior Research Communications Manager at the MS Society, said: "Over 150,000 people live with MS in the UK, and the condition can affect all communities, ages, ethnic backgrounds and genders. MS is likely to be caused by a combination of factors, including lifestyle, environment, and genetics. But almost everything we know about genes and MS comes from studies looking at people of White European descent. Making sure we include people from diverse backgrounds in research is key and the ADAMS study is leading the way. Research like this is vital to ensure that progress in MS treatments, diagnosis, and risk prediction benefits everyone." 

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