RISKS OF MULTIPLE-SCLEROSIS IN RELATIVES OF PATIENTS IN FLANDERS, BELGIUM

Objectives - To calculate age adjusted risks for multiple sclerosis in relatives of Flemish patients with multiple sclerosis. Methods - Life time risks were calculated using the maximum likelihood approach. Resu lts - Vital information was obtained on 674 probands with multiple scl erosis in Flanders and a total of their 26 225 first, second, and thir d degree relatives. Full medical information to allow documentation of multiple sclerosis status was available for 21 351 (81.4%) relatives. The age adjusted risk for parents was 1.61 (SEM 0.35)%, for siblings 2.10 (SE 0.36)%, and for children 1.71 (SEM 0.70)%. For aunts and uncl es, the risk was 0.66 (SEM 0.13)%. Conclusions - The risk for first de gree relatives of patients with multiple sclerosis in Flanders is incr eased 10-fold to 12-fold; for second degree relatives, it is increased threefold. This information can be used for risk counselling in famil ies and provides additional support for the role of more than one locu s contributing to the susceptibility of multiple sclerosis.