By LAURAN NEERGAARD
Updated [hour]:[minute] [AMPM] [timezone], [monthFull] [day], [year]
WASHINGTON (AP) — It turns out that ancient DNA has an important role in explaining why Northern Europeans are more at risk of getting multiple sclerosis than a lot of other ancestries. The researchers have linked this risk to a genetic legacy from about 5,000 years ago. This genetic influence stems from horseback-riding cattle herders who made their way into the region, as concluded by a huge project. The project allowed scientists to trace prehistoric migration and disease-linked genes while comparing modern DNA with that of ancient humans’ teeth and bones.
The research published in the journal Nature revealed that a Bronze Age group called the Yamnaya moved from the steppes of what is now Ukraine and Russia to northwestern Europe. These Yamnaya carried gene variants that today are known to increase people’s risk of multiple sclerosis. Surprisingly, these gene variants not only found their way into the local inhabitants but also gave the herders a competitive advantage. In conclusion, the genes probably protected the nomadic herders from infections carried by their cattle and sheep.
It’s surprising news like this that has come from the first-of-its-kind gene bank with thousands of early human samples in Europe and western Asia. Using the new gene bank, researchers were able to explore MS and did so for a good reason. MS is most common among white descendants of northern Europeans and while researchers have been unable to explain that, they have found more than 230 genetic variants that may increase the risk.
The researchers first examined DNA from about 1,600 ancient Eurasians, mapping some key shifts in northern Europe’s population. From these findings, it was determined that the MS-linked genetic variations persist in the north, where the Yamnaya moved. In what is now Denmark, the Yamnaya rapidly replaced the ancient farmers, making them the closest ancestors of the modern Danes among whom MS rates are particularly high.
As to why gene variants that provided ancient immunity later came to play a role in an autoimmune disease, well, that is a question that hasn’t been fully answered yet. To learn more about this subject, read more.