Genetics

The remote Orkney and Shetland Islands of Scotland hold a medical mystery — they have the highest rates of multiple sclerosis (MS) anywhere on Earth. Scientists once suspected vitamin D deficiency or inbreeding might be to blame, but new research from the University of Edinburgh points elsewhere. By examining genetic data from thousands of islanders, researchers found that common MS risk genes, including the well-known HLA-DRB1*15:01 variant, explain only a tiny fraction of the disease’s excess cases. The study suggests that rare genetic variants, lifestyle factors, or environmental influences may hold the real clues behind this enduring mystery.