Epidemiology of familial multiple sclerosis and its comparison to sporadic form in Markazi Province, Iran

Abstract

BackgroundLimited data have been published about the epidemiology of familial multiple sclerosis (FMS) and its comparison to the sporadic form. Additionally, the epidemiology of FMS varies significantly in numerous provinces of Iran. ObjectivesThe current study aimed to establish the epidemiology and clinical presentations of FMS and compare this form of the disease to sporadic multiple sclerosis (SMS) in Markazi province, Iran. MethodsIn this cross-sectional registry-based study, the data were collected by the Multiple Sclerosis (MS) Society of Markazi province within 2012-2021. The demographic and clinical characteristics, diagnosis, and treatment of the MS patients living in the province were registered in this system. ResultsA total of 924 MS cases who completed the data about the familial history of MS participated in this study. Based on the results, the female/male ratios were equal to 3.11 and 3.96 in FMS and SMS groups, respectively. Furthermore, 29.4% of the individuals had a history of the disease in their first- to third-degree relatives. The prevalence of primary-progressive multiple sclerosis was higher among the FMS patients (8.5%) than in the SMS patients (4.6%). Along with motor, sphincter, cognitive, and brain stem signs as the onset symptoms, the FMS group experienced a higher rate of polysymptomatic onset (P = 0.000). Moreover, significantly more autoimmune diseases and consanguineous marriages (P = 0.000) were observed in the FMS group than in the SMS group. The individuals with FMS reported a higher mean number of recurrences and higher Expanded Disability Status Scale (EDSS) scores (P = 0.000). ConclusionThe results showed a significant prevalence of FMS in Markazi province. The FMS and SMS patients were significantly different regarding first presentations, onset symptoms, MS clinical characteristics, and EDSS scores. Finally, consanguineous marriage was significantly more common in the FMS group than in the SMS group.