The role of parental consanguinity and familial aggregation in development of multiple sclerosis: a case–control study.

Background: Several studies pointed out the importance of genetic risk factors such as parental consanguinity (PC) and familial multiple sclerosis (FMS) in the risk of MS. This study aimed to investigate the PC and FMS among people with MS (pwMS) in Isfahan, Iran. Methods: This case–control study was conducted on pwMS from the MS clinic of Kashani Hospital, Isfahan, Iran, in October 2023. A group of healthy controls (HC) were also recruited. Data on demographic and clinical characteristics and history of PC and FMS were collected from participants. The relationships between PC, FMS, and developing MS were assessed using multinomial logistic regression analysis. The odds ratio (OR) with a 95% confidence interval (CI) was computed. Results: A total number of 4264 pwMS and 400 HCs were included. The prevalence of PC and FMS among pwMS were 29.3% and 24%, respectively. Multinomial logistic regression adjusted for age and sex indicated that the odds of developing MS were significantly associated with a history of PC (OR = 3.03, 95% CI 2.23 to 4.13, p < 0.001) and FMS (OR = 5.42, 95% CI 3.51 to 8.38, p < 0.001). Conclusion: PC and FMS can increase the risk of developing MS. They should be considered along with other risk factors for developing MS. A comprehensive conclusion requires further research. [ABSTRACT FROM AUTHOR]