Genetic Study Offers Hint to the Origin of an Autoimmune Disorder

PERTH, AUSTRALIA—Science News reports that an analysis of the genomes of more than 1,600 Europeans and western Asians by evolutionary biologist Morten Allentoft of Curtin University and his colleagues suggests that Yamnaya herders originated with hunter-gatherers who lived near western Russia’s Don River some 7,300 years ago. Yamnaya people then migrated from southwest Asia and mixed with populations in Eastern Europe before moving into Northern Europe, where they again produced a hybrid population. Computational biologist William Barrie of the University of Cambridge then compared ancient Eurasian DNA to a database of DNA from more than 400,000 modern British individuals, and determined that a specific gene change now linked to a higher risk for multiple sclerosis, or MS, developed in Yamnaya herders some 5,000 years ago. These gene variants, which perhaps boosted Yamnaya herders’ immune defenses against diseases carried by their livestock, were therefore introduced into northern European populations. How genes, environmental factors, and viruses bring about the disease is not well understood, but today’s northwestern Europeans are diagnosed with MS at about twice the rate of southern Europeans. “This is the first evidence of this [evolutionary process] in an autoimmune disorder,” Barrie explained. Read the original scholarly article about this research in Nature. For more on the Yamnaya, go to "Around the World: Bulgaria."