The main cause of multiple sclerosis had yet to be established. The risk of contracting multiple sclerosis in a person is elevated in the event that a corresponding family member is afflicted by it as well, foreshadowing one of the reasons for the development multiple sclerosis to be possibly hereditary. A sibling, parent or child of the afflicted will contract multiple sclerosis by a three percent chance. in the case of identical twins where one twin develops multiple sclerosis, the chances of the other twin contracting it is approximately thirty percent, whereas for non-identical twins, where one is afflicted by multiple sclerosis, the likelihood of the other developing it is about 4%.

Studies show that those migrating from an area displaying a higher rate of multiple sclerosis to an area where the disease’s incidence rate is lower are noted with a decline in risk of contracting multiple sclerosis, as opposed by migration in the opposite direction, where the migrant population is observed to retain the lower risk of the disorder from their place of origin, though chances of younger migrants in developing it are notably elevated to the country’s incidence rate of multiple sclerosis here.

It is also observed that multiple sclerosis occurs in 1 out of 2000 people from countries of a temperate climate, contrasted by 1 out of 10, 000 people who had lived their lives in a tropical climate. Multiple sclerosis is claimed to occur almost rarely among those dwelling near the equator, probably due to a high exposure to sunlight, a natural purveyor of vitamin D. it is as yet unknown how vitamin D plays a hand in reducing chances of developing multiple sclerosis.

There is also speculation that a virus may be responsible for multiple sclerosis. Still, its role in triggering the disease till now had yet to be established. one such virus is known as Epstein-Barr, the popular belief concerning it is that approximately 95% of the worldwide population is infected by it at a certain point, and ensuing infection, the virus will dwell in dormancy on the body’s B lymphocytes, cells playing major roles in the immune system such as the production of antibodies against antigens. Several studies have also shown that those infected by the Epstein-Barr virus with higher antibody levels are more predisposed to develop multiple sclerosis than those with lower antibody levels, though it did not suffice to justify that the virus is directly associated to the disease, as claimed by a news report on April 15, 2010.