Genetics

This post unpacks a new study that followed nearly everyone born in the Netherlands in 1966 to ask a simple but powerful question: how much do your genes really change your chances of developing multiple sclerosis (MS)? Using polygenic risk scores—basically a summary of hundreds of tiny genetic risk factors—the researchers show that people in the highest genetic risk group can have over 20 times the lifetime risk of MS compared with those in the lowest group. But there’s an important twist: even in the highest-risk group, most people never get MS, and a high genetic score doesn’t seem to predict how severe the disease will be. We walk through what this means in human terms for patients, families, and clinicians, and why genes are only one part of the MS story.