Is multiple sclerosis hereditary?

The cause of multiple sclerosis is unknown though it is considered an autoimmune disease, in which the body’s immune system attacks parts of the nervous system.

The disease may be hereditary. There are hundreds of genetic variants linked to the development of multiple sclerosis and in up to 20% of cases there is a family member with the disease. A sibling or a non-identical twin of a person with multiple sclerosis has a 3% to 5% risk of developing the disease (approximately 30 to 50 times higher than expected) while an identical twin has an even higher risk, in the range of 20% to 40% (approximately 200 to 400 times higher than expected).