Brain Atrophy Associated With Risk Variant rs10191329 Extends Beyond Multiple Sclerosis

The risk allele rs10191329*A is associated with disease severity and brain atrophy in people with multiple sclerosis (MS). We investigated the association of rs10191329 with age-related brain atrophy in a population-based cohort using 10,308 magnetic resonance imaging (MRI) scans of 4,815 participants aged ≥ 45 years without MS in cross-sectional and longitudinal analyses. We observed associations between the rs10191329*A allele and lower total brain volume and gray matter volume in middle-aged (< 55 years of age), but not in older participants. These data suggest that rs10191329*A contributes to earlier onset of atrophy in the general population, and that mediating mechanisms of accelerated neurodegeneration extend beyond MS. ANN NEUROL 2026;99:1083-1089.