Scientists Solve Genetic Mystery of 'MS' Disease

DNA obtained from the bones and teeth of ancient Europeans who lived 34,000 years ago provides information about the origins of 'multiple sclerosis' or 'MS'. This study has determined that genetic variants that increase the risk of this disease were once used to protect people against infections transmitted from animals. These findings emerged after examining ancient DNA from 1,664 individuals from various locations across Western Europe and Asia. Scientists compared ancient genomes with modern DNA from the UK Biobank, which includes about 410,000 'white English' individuals and over 24,000 others born outside the UK, to identify changes over time. A significant discovery related to 'MS', which is considered an autoimmune disorder, was made. Researchers identified an important migratory event around 5,000 years ago when herders known as 'Yamnaya' migrated from an area that includes present-day Ukraine and southern Russia to Western Europe. They possessed genetic traits that were considered beneficial at the time and protected them against infections that could be transmitted through sheep and cattle. With improved sanitary conditions, these same traits increased the risk of 'MS'. Researchers say this helps explain why Northern Europeans have the highest prevalence of 'MS' in the world. Rasmus Nielsen, a population geneticist from the University of California, Berkeley, told Reuters, 'We are an evolutionary product that occurred in past environments and, in many ways, we are not well adapted to the environment we have created for ourselves today.' The results of this research were published in the scientific journal 'Nature'. The study explained that about 11,000 years ago, farmers from the region that is now modern Turkey moved to Western Europe, replacing hunter-gatherers who primarily obtained their food through gathering, and it was these farmers who were later replaced by the Yamnaya. Nielsen noted that many of the replacements that occurred were related to war. These findings show how genetic traits can shift from 'beneficial' to 'harmful' as conditions evolve. Ivan Irving Pease, a computational evolutionary biologist from the University of Copenhagen and one of the study's authors, told Reuters that pathogenic infections during the Bronze Age became prevalent due to the proximity of people and domesticated animals, as well as increased population density. He added, 'In the modern era, when healthcare and medical care became widespread, these genetic variants no longer fit human immune needs, thus increasing the risk of MS and other autoimmune diseases.' These findings could aid further research and treatment of 'MS'. The research also illuminated other characteristics of Europeans. Since the Yamnaya were genetically tall, modern Northern Europeans are taller than those in Southern Europe. Researchers found that Eastern Europeans have a high genetic risk for Alzheimer's and type 2 diabetes. They also discovered that lactose tolerance, the ability to digest sugar found in milk and other dairy products, emerged in Europe about 6,000 years ago.