Is MS hereditary?

As of 2014, doctors don't have a clear understanding of what causes multiple sclerosis, but researchers hold the belief that MS is partially inherited, according to WebMD. First-, second- and third-degree relatives of people with the disease have a heightened risk of developing it.

For siblings of those with MS, the risk of developing the disease ranges from 2 to 5 percent, according to WebMD. Researchers believe that more than one gene plays a role in the likelihood of developing MS. Additionally, studies support that this disease occurs more frequently in particular parts of the world. It is especially prevalent in Scandinavia, Scotland and northern Europe.