Objective: To investigate whether the timing of secondary or primary progression is different between patients with familial and nonfamilial multiple sclerosis (MS).
Methods: Information on the family history of 313 patients with MS was taken from our prospective hospital-based database. We used Kaplan-Meier analyses and Cox regression models to evaluate differences between familial and nonfamilial MS in several endpoint measures. We investigated the risk of developing secondary progression in all patients with a relapsing-remitting disease onset, the length of the relapsing-remitting phase and age at onset of progression in patients with secondary progressive MS and the age at disease onset in patients with primary progressive MS (PPMS).
Results: Among the primary progressive patients, those with familial MS had a significantly younger age at disease onset than patients with nonfamilial MS (mean 33.04 years versus mean 37.73 years in nonfamilial MS, P = 0.02). There were no significant differences between familial and nonfamilial MS patients in any other investigated measure.
Conclusions: Familial MS appears related to the time of disease onset in PPMS. Patients with familial PPMS may be an important patient group for future genetic research in MS.