Most of the people with MS are of European descent. MS is less common in African Americans (about half as common) and appears to be even less common among Asians living in the United States. These observations are in agreement with the finding that MS is rare in Africa and in Asia.
However, in Australia, a country that is populated predominantly by people of European descent, MS is less common than in the United States, Canada, and Europe. Also, a so-called “North–South gradient” is apparently seen in Australia.