Epidemiology of familial multiple sclerosis in Hungary.

The prevalence of familial aggregation of multiple sclerosis (MS) is estimated between 5 and 10%. Studies emphasize the effect of genetic factors over the environment of the patients in the development of the disease. We investigated familial accumulation of MS in the cases of 1500 patients in five Hungarian MS centers. According to our data, the risk of familial MS in Hungary is lower than in other countries for which literature data are accessible. The literature does not contain any data for the prevalence of familial MS in Hungary and middle-eastern Europe.