With KUOW Public Radio
Multiple Sclerosis has long been known as an autoimmune disorder that affects more people living in the Pacific Northwest than in most other parts of the country, and the world. Scientists still don't have a firm answer why that is.
But researchers have begun unraveling some new theories about the disease from a set of intriguing clues. They know, for example, that the farther you live from the equator, the higher your risk. The map below is based on data collected by the National MS Society.