Title: Origin of Multiple Sclerosis Genetic Variant Traced to Ancient Migration of Yamnaya Pastoralists
Multiple sclerosis (MS), a debilitating autoimmune disease, is more prevalent among white, northern Europeans compared to their southern counterparts. Approximately one-fifth of northern Europeans possess a genetic variant known as HLA-DRB1*15:01, which increases the risk of developing MS. The origin and spread of this genetic variant have remained a mystery until now.
A team of researchers from the University of Cambridge has made a significant breakthrough in unraveling the prevalence of MS-associated gene variants by studying newly sequenced Medieval and post-Medieval Danish genomes, as well as ancient human sequences. Their findings suggest that these gene variants have their roots in the Pontic Steppe region of eastern Europe, which currently includes parts of Ukraine, South-West Russia, and West Kazakhstan.
Around 5,000 years ago, a nomadic group of pastoralists called the Yamnaya migrated westward into northern Europe, bringing with them the MS-associated genes. This migration is believed to be responsible for the high prevalence of the HLA-DRB1*15:01 variant in modern populations from Finland, Sweden, Iceland, and ancient populations with steppe ancestry.
What is intriguing is that the MS-associated gene variants seem to have undergone positive selection, indicating that they might have provided a survival advantage in the past, despite being connected to neurocognitive decline in modern times. The research team suggests that an overactive immune system, which is the cause of MS, could have offered protection against pathogens and plagues that were prevalent during that era.
By comparing the data with contemporary human genomes, the researchers found that the frequency of the HLA-DRB1*15:01 variant was highest in populations with steppe ancestry and modern populations from Finland, Sweden, and Iceland.
This groundbreaking study sheds light on the evolution of MS and other autoimmune diseases, showcasing how the lifestyle and genetic makeup of our ancestors impact our susceptibility to modern diseases. Though more concrete evidence is needed to validate the hypotheses presented, the findings also indicate a potential association between infectious diseases and MS risk.
The study, published in the prestigious journal Nature, serves as a small step forward in understanding the complex mechanisms behind MS development and paves the way for further research into effective preventive measures and treatments for this debilitating disease.
As we unravel the secrets of our ancestors, the genetic and historical complexities continue to shape our modern health challenges.
