Familial Multiple Sclerosis Is Associated With Accelerated Progression to Secondary Progressive Phase: A Retrospective Single-Center Cohort Study

Abstract

Background Familial multiple sclerosis (MS), defined by the occurrence of MS in one or more relatives, is thought to represent a genetically influenced subtype of the disease. Objective To compare clinical progression, cerebrospinal fluid (CSF) parameters, and treatment responses between familial and sporadic MS patients. Methods We conducted a retrospective analysis of 1,035 patients diagnosed with MS according to the 2017 McDonald criteria (523 familial, 512 sporadic). Demographic variables, MS subtypes, expanded disability status scale (EDSS) scores, CSF oligoclonal band (OCB) status, IgG index, and treatment regimens were evaluated. Statistical tests included t tests, chi-square, and multivariable regression. Results Familial MS patients showed a higher incidence of secondary progressive MS (10.9%) compared to sporadic cases (7.0%, p = 0.030). Disease duration was significantly longer in familial MS (14.5 vs. 12.3 years, p < 0.01) though time to diagnosis did not differ. OCB positivity rates were comparable, but the IgG index was significantly elevated in familial MS (p < 0.01). Treatment responses did not differ between groups. Conclusion Familial MS is associated with more rapid disease progression and enhanced humoral immune activation, suggesting a distinct phenotype. These findings support the need for genetic and immunologic investigations to guide personalized treatment strategies.