[Familial multiple sclerosis in Canary Islands]

Multiple sclerosis (MS) is an autoimmune disease that occurs in genetically predisposed individuals. Its inheritance is polygenic. Genetic epidemiology studies have shown an increased familial aggregation. AIM. To determine the prevalence of familial MS (fMS) in a series of patients from the Canary Islands.

From a cohort of 266 patients with defined MS, during a 6-year period, we investigated prospectively by personal interviews the presence of MS on first and second degree relatives. We analysed as well the presence of HLA DRB1 in affected families, and also clinical and demographic characteristics in fMS and compared them with sporadic MS (sMS).

fMS prevalence was 13.9% (27 non-related families with 50 affected individuals). The HLA DRB01*1501 allele were present in 51,8% of familial cases. We could not found either intrafamilial concordance in clinically affected regions and age of onset or clinical evolution. We have not found any phenotypic differences between familial and sMS.

The prevalence of fMS in our series is comparable to that in other Mediterranean populations. Our results do not support that fMS was a different clinical entity of sMS and intrafamilial concordance in its clinical expression.