The findings ultimately provide an explanation for the North-South MS disparity in Europe.
Ancient DNA helps explain why Northern Europeans have a higher risk of multiple sclerosis than other ancestry.
This is the genetic legacy of the horse-riding cattle herders who flocked to the area around 5,000 years ago.
The discovery comes from a large-scale project comparing modern DNA with DNA taken from ancient human teeth and bones, allowing scientists to identify genes associated with prehistoric migration and the diseases that accompanied it. Now you can track both.
When Bronze Age people called the Yamnaya migrated from the steppes of present-day Ukraine and Russia to northwestern Europe, they carried a genetic mutation now known to increase the risk of multiple sclerosis, a study shows. reported on Wednesday.
Yet the Yamnaya flourished and spread their subspecies widely. They concluded that these genes probably protected nomads from infectious diseases carried by cattle and sheep. journal nature.
“What we discovered surprised everyone,” said study co-author William Barry, a genetics researcher at the University of Cambridge. “These variants were giving these people some kind of advantage.”
This is one of several discoveries from the first-of-its-kind gene bank, which brings together thousands of samples from early humans in Europe and western Asia, and is based at Cambridge, a pioneer in ancient DNA research. The project is led by Eske Willerslev and the University of Copenhagen. . similar research We’ve even tracked down some of our earliest cousins, such as Neanderthals.
Exploring MS using the new gene bank was a logical first step. That’s because, although MS can affect anyone, it’s most common among people of white Scandinavian descent, and scientists can’t explain why.
What is MS and what causes it?
The potentially disabling disease occurs when immune system cells mistakenly attack and gradually erode the protective coating on nerve fibers. It causes a variety of symptoms, often increasing or decreasing, such as numbness or tingling in some people and difficulty walking or vision loss in others.
The cause of MS is not clear, but a leading theory is that certain infections can trigger MS in genetically susceptible people. More than 230 genetic mutations have been discovered that may increase someone’s risk.
The researchers first examined the DNA of about 1,600 ancient Eurasians and mapped some major changes in the population of northern Europe. First, farmers from the Middle East began to replace hunter-gatherers, and then, about 5,000 years ago, the Yamnaya people, who herded cattle and sheep and traveled by horse and cart, began to migrate.
The research team compared the ancient DNA of around 400,000 modern humans held in the UK gene bank and found that MS-related genetic variants remained in northern Europe, the direction the Yamnaya migrated, rather than in southern Europe. I confirmed that
In what is now Denmark, Willerslev said the Yamnaya people quickly replaced ancient farmers, making them the closest ancestors of modern Danes. The incidence of MS is particularly high in Scandinavian countries.
Why are genetic mutations that are presumed to have strengthened immunity in ancient times later implicated in autoimmune diseases?
Study co-author Dr Astrid Iversen from the University of Oxford said differences in how modern humans are exposed to animal bacteria may play a role in imbalances in the immune system.
The study’s findings ultimately provide an explanation for the North-South MS disparity in Europe, but further research is needed to confirm the link, said the New York-based Mt. Samira Asghari, a genetics expert at Sinai School of Medicine, warned. Attached commentary.