'Decoding' the origin of multiple sclerosis

New research shows that the migration of ancient people in Eurasia may have influenced the risk of many diseases of modern Europeans.

Common disease

The results were published in the journal Nature. Along with two other papers by study co-authors, the papers include DNA analysis from the bones and teeth of hundreds of ancient individuals, the oldest of whom date to the Neolithic period, or Mesolithic period. Scientists compared the DNA of these people with the genomes of Europeans today.

The research sheds light on the genetic legacy of three ancient human migrations to different regions in Europe. These include: The appearance of hunter-gatherers about 45 thousand years ago; Neolithic farmers in the Middle East about 11 thousand years ago; Sheep and cattle herders from the Pontic steppes - an area stretching across Eastern Europe and Central Asia, about 5 thousand years ago.

A risk variant called ApoE4 increases the risk of developing Alzheimer's disease, but may increase fertility in women.

The project also received cooperation from museums across Europe and West Asia. This collaboration has helped the research team create a gene bank, opening up new opportunities in analyzing and understanding diseases based on ancient DNA, and expanding to neurological and psychiatric diseases. others such as Parkinson's, Alzheimer's, attention deficit hyperactivity disorder (ADHD) and schizophrenia. In total, the researchers compared the genomes of 1,750 ancient humans with the genomes of about 410,000 people who contributed data to the UK Biobank.

The authors estimate that these participants inherited ancient DNA. One of the new papers identified gene variants associated with the autoimmune disease MS . This was a disease carried by the farmers of the Pontic steppes when they migrated mainly to Northern Europe.

This may help explain why MS is most common in people of Northern European descent. The researchers concluded that these risk variants have been 'positively selected'. That means they provide some benefit to migrants and are therefore under evolutionary pressure to emerge.

Specific gene variations related to immune function are known to increase people's susceptibility to MS. These include HLA gene variations , which help the body detect pathogens. However, like a double-edged sword, certain HLA variants are also strongly associated with autoimmune diseases. In it, the body attacks its own cells.

The study authors hypothesize that, in the past, these variations likely helped ancient farmers fight zoonotic diseases. However, as people's lifestyles changed over time, in terms of hygiene, diet and medicine, these variations took on new meanings.

The study authors also hypothesize that understanding the evolutionary forces driving the selection of these genes may have implications for treating MS.

Dr. Lars Fugger - senior study co-author and Professor of neuroimmunology at Oxford University (UK) said: 'Thinking about the double-edged sword, what we need to aim for is trying downregulates the immune response, rather than completely eliminating it'.

People who carry more DNA from hunter-gatherer groups may have a higher genetic risk of type 2 diabetes.

Risk variation

In another paper, the authors explored the inheritance of genetic risk variants for 35 complex traits. That means traits are caused by the combination of multiple genes and their interaction with the environment.

They discovered that genes related to lactose tolerance in adults appeared in Europe about 6 thousand years ago. This phenomenon may appear in Northern Europeans today with a higher tendency than Southern Europeans. The reason is partly because Northern Europeans inherited genes from farmers in the Pontic steppes.

The study authors also found that people who carry more DNA from the hunter-gatherer groups they studied may have a higher genetic risk of type 2 diabetes and Alzheimer's disease than people who carry fewer gene variants. that's more.

Modern populations with this hunter-gatherer DNA mostly live in Eastern Europe. Alzheimer's disease risk variants may have been actively selected. For example, a risk variant called ApoE4 increases the risk of developing Alzheimer's disease, but may increase fertility in women.

Senior study co-author Dr. Astrid Iversen, Professor of virology and immunology at Oxford University, said increased fertility may have given our ancestors an ' advantage. big'.

Meanwhile, Mr. Omer Gokcumen - Professor of evolutionary anthropology at the University at Buffalo in New York, who was not involved in the study said: 'These articles add further evidence that changes Diet and lifestyle, often accompanied by migration, may have created preferential alleles that were maintained in the context of evolutionary trade-offs '.

These two studies looked for correlations between specific gene variants and the incidence of different diseases. Because of this, the study authors cannot prove that inheriting those ancient gene variants inevitably causes such diseases in Europeans today.

Eske Willerslev - Project director and evolutionary geneticist at the University of Cambridge (UK) and the University of Copenhagen (Denmark), said: 'What these studies are doing is establishing a framework for how you can use those ancient human genomes to understand the origin and spread of disease risk'.

The ancient DNA research project led by scientists from the University of Cambridge and Oxford University has opened up new insights into human genetic history, as well as being closely related to current pathology. grand. International collaboration and support from museums and research organizations have made this project not only a scientific achievement, but also an outstanding example of international research collaboration. international.