How come i have multiple sclerosis, but nobody else in the family has it?

Genes only one part: While there are some genetic susceptibilities to ms, the true reasons while one person develops the disease and another does not remain unclear. Family history is only a risk factor, and not a definite predictor, with other factors such as nutrition, infection, and so forth likely playing a role.

Various causes of MS: Both genetic and non-genetic factors are thought to contribute to ms. A person may have had different environmental exposures than their family, or their genetic risk may reflect a combination of risks from the parents. Other family members may not have gotten that same exact combination of risks.

Combination of event: You have a genetic susceptibility, and have encountered environmental triggers which have caused your outcomes. However, usually does not run in families as is not a genetic disorder.