Ancient DNA Unravels Multiple Sclerosis Mystery in Europeans
Recent research spearheaded by teams from the University of Copenhagen and the University of Cambridge has uncovered fascinating insights into why multiple sclerosis (MS) is more prevalent in certain populations, particularly white Europeans. By analyzing ancient DNA and comparing it with the genetic data of contemporary individuals, researchers have begun to piece together a compelling narrative.
MS, a progressive disease affecting the brain and spinal cord, leads to symptoms like paralysis. While it's not directly hereditary, susceptibility to MS is influenced by certain gene variants. Researchers focused on understanding why MS rates are notably higher in northwest Europe, particularly Scandinavia, compared to southern Europe.
The study, which included the analysis of teeth and bones from Europe and Western Asia and involved a database of 1,600 ancient genomes, drew comparisons with over 400,000 modern individuals from the UK Biobank. The findings, published in Nature, suggest a connection between genetic risk for MS and the legacy of ancient Eurasian herders.
These herders, specifically the Yamnaya people from the Eurasian steppe who migrated to Europe around 5,000 years ago, are believed to have had genes that helped them combat infections from close contact with livestock. However, the same genes that offered protection in the past may now predispose individuals to autoimmune diseases like MS.
Rasmus Nielsen, a professor involved in the research, explained that the genes passed on for their protective traits against infectious diseases might now render people more susceptible to autoimmune conditions due to environmental changes.
The study highlights the complex interplay between genetics and environment over millennia. Northern Europeans, particularly those with Yamnayan ancestry, show a higher susceptibility to MS. This genetic predisposition is less common in southern Europe, where Yamnayan influence is less prevalent.
As lifestyles and environments have evolved, with changes in diet, distance from livestock, and improved hygiene, the human immune system has not fully adapted. This mismatch results in an imbalanced immune response, potentially leading to autoimmune diseases.
The research opens new avenues for understanding and treating MS. Current treatments focus on suppressing the immune system, but with these new insights, researchers, including Dr. Astrid Iversen and Oxford expert Lars Fugger, hope to develop more targeted approaches to recalibrate the immune response.
This groundbreaking study sheds light on the historical and genetic factors influencing MS prevalence and offers hope for more effective treatments in the future.