DNA obtained from the bones and teeth of ancient Europeans who lived up to 34,000 years ago is providing insight into the origin of the often-disabling neurological disease multiple sclerosis, finding that genetic variants that now increase its risk once served to protect people from animal-borne diseases.

The findings stemmed from research involving ancient DNA sequenced from 1,664 people from various sites across Western Europe and Asia. These ancient genomes were then compared with modern DNA from the UK Biobank, comprising about 410,000 self-identified "white-British" people, and more than 24,000 others born outside the United Kingdom, to discern changes over time.

One striking discovery related to MS, a chronic disease of the brain and spinal cord that is considered an autoimmune disorder in which the body mistakenly attacks itself.

The researchers identified a pivotal migration event about 5,000 years ago at the start of the Bronze Age when livestock herders called the Yamnaya people moved into Western Europe from an area that includes modern Ukraine and southern Russia.

They carried genetic traits that at the time were beneficial, protective against infections that could arise from their sheep and cattle. As sanitary conditions improved over the millennia, these same variants increased MS risk. This helps explain, the researchers said, why Northern Europeans have the world's highest MS prevalence, double that of Southern Europeans.

You can read more in an article by Will Dunham published in the Reuters web site at: http://tinyurl.com/myzkpuc3.