The ancient origins of MS

11 January 2024

Teams from the Universities of Cambridge and Copenhagen have published new research this week linking the origins of MS to prehistoric migration.

Herding peoples spread out from the steppes of Western Asia over 5000 years ago. They brought with them genes that increase the risk of getting MS. People from north-western Europe and Scandinavia are more likely to carry these genes than other Europeans. This may explain why MS is more common in countries like the UK, Ireland, Sweden and Iceland.

Researchers from Cambridge and Copenhagen compared modern genetic variation with a database of ancient DNA samples. They were able to link the genes known to increase MS risk to the ancient herding peoples that colonised Europe from the steppe region around modern Ukraine and southern Russia. 

You can read media reports on this research here.

How did this happen?

As generations of people live, reproduce and die, genes that give protection from the dangers of that time will become more common. However, these genes may come with unwanted side effects. A gene that protects you from a deadly parasite or fatal disease may make you more susceptible to another illness like cancer or MS. But if the infectious disease is very dangerous, it could be worth the trade-off. 

Animal diseases first became a significant risk for humans when they developed lifestyles based around cattle, sheep and other herd animals. Living with their herds, the herding peoples of the steppe were exposed to new diseases. They developed genetic protection against them over 5000 years ago, and these are the same genes that are linked to MS risk. The herding lifestyle was successful and the herders spread out into new territories across Scandinavia and Northern Europe, and mixed with the hunter-gather and farming peoples already there.

For hunter-gathering people, getting a reliable supply of food could have been difficult, so they developed genetic protection against famine. In modern times, those genes are linked to diabetes risk. Early farmers lived in towns and cities, so infectious diseases were a danger for them. The researchers found that steppe herder genes may also contribute to north-western Europeans being taller than southern Europeans, having a lower risk of getting Alzheimer's disease and the ability to digest milk products as adults. 

Fast forward to modern times, where famine and infectious diseases are no longer a significant cause of death and disease in Europe. We still have the prehistoric genes that protected our ancestors, but now it's the trade-offs that came with them that affect our health.

What does this mean?

  • Does this mean that there are genes for MS? The genes mentioned in this research are linked to increased risk of MS. Having them does not mean you will definitely develop MS, in fact most people with these gene variants will not. Scientists think that an additional trigger may be needed for MS to develop, such as exposure to smoking or a viral infection.

    Read more about the causes of MS.

  • Does this mean that only white Europeans get MS? No. Genetic heritage is not the same race or skin colour. The steppe people mentioned in the studies lived in Western Asia over 5000 years ago. They are not the same as the people who live in that area now, and people with this genetic ancestry are likely to have migrated far beyond Europe and Western Asia as well. People with non-European ancestry can and do get MS.

    Read more about who gets MS.

  • What about the Vikings? The steppe herders mentioned in this research reached modern Denmark around 5000 years ago, well before the Viking era 1200 years ago. Vikings went on to colonise much of Scandinavia and Northern Europe, and therefore contributed to the genetic heritage of people living in Canada, USA, New Zealand or Australia through more recent colonisation and migration.

    Read more about the prevalence and incidence of MS.

  • What does this mean for me? This research is not necessarily going to lead to new treatments for MS immediately. There is no suggestion that you should change your diet and lifestyle to be more like a steppe pastoralist! This research helps us to understand how our immune system evolved over time to tackle threats, and how we can be left with conditions like MS as a relic of our prehistoric past.

    Read more about living well with MS.

Barrie, W., Yang, Y., Irving-Pease, E.K. et al.
Elevated genetic risk for multiple sclerosis emerged in steppe pastoralist populations.
Nature 625, 321–328 (2024).
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