The new study has found the genes that significantly increase a person’s risk of developing multiple sclerosis were introduced into north-western Europe around 5,000 years ago by sheep and cattle herders migrating from the east. Credit: SayoStudio
The world’s first ancient human gene bank, with genome data from an individual that lived 34,000 years ago, has revealed the startling origins of neurodegenerative diseases, especially multiple sclerosis. Future analysis of the unique bank is hoped to reveal more about the genetic markers of autism, ADHD, schizophrenia, bipolar disorder and depression.
Today, Northern Europe has the highest prevalence of multiple sclerosis in the world. Interestingly, there are about twice as many cases of MS in Northan Europe compared to Southern Europe—something that has always been a mystery to researchers.
Now, research published across four papers by a combined 175 international scientists explains the “North-South Gradient” by mapping the geographic spread of MS from its origins to now.
Researchers involved in the study analyzed the bones and teeth of 5,000 ancient humans, held in museum collections across Europe and Western Asia. They generated DNA profiles ranging across the Mesolithic and Neolithic through the Bronze Age, Iron Age and Viking period into the Middle Ages. The team then compared the ancient DNA data with modern DNA from 400,000 people living in Britain today.
The study traced the geographical spread of MS from its origins on the Pontic Steppe—a region spanning parts of what are now Ukraine, Southwest Russia and the West Kazakhstan region—through its introduction into Northwest Europe by the Yamnaya people, who were migrating livestock herders that lived around 5,000 years ago.
The research shows that the genes that significantly increase a person’s risk of developing MS actually provided a survival advantage to the Yamnaya people, most likely by protecting them from catching infections from their sheep and cattle. While beneficial, the variants, however, still increased the risk of developing MS.
“These results astounded us all,” said William Barrie, co-author of the paper and postdoc in the University of Cambridge’s Department of Zoology. “They provide a huge leap forward in our understanding of the evolution of MS and other autoimmune diseases. Showing how the lifestyles of our ancestors impacted modern disease risk just highlights how much we are the recipients of ancient immune systems in a modern world.”
Co-author Lars Fugger from the University of Oxford agrees with Barrie.
“This means we can now understand and seek to treat MS for what it actually is: the result of a genetic adaptation to certain environmental conditions that occurred back in our prehistory,” said Fugger.
The unique gene bank of ancient DNA was created by the researchers over the past five years. It is the first of its kind in the world, already enabling new insights into the genes that drive neurodegenerative diseases.
“We’ve demonstrated that our gene bank works as a precision tool that can give us new insights into human diseases, when combined with analyses of present-day human DNA data and inputs from several other research fields. That in itself is amazing, and there’s no doubt it has many applications beyond MS research,” said Eske Willerslev, an expert in ancient DNA and director of the project.
The team now plans to investigate other neurological conditions, including Parkinson’s and Alzheimer’s diseases, as well as psychiatric disorders like ADHD and schizophrenia.
While the gene bank is not freely available right now, the researchers do hope to make it accessible for other scientists working around the world in the near future.