HLA-DRA/HLA-DRB5 polymorphism affects risk of sporadic ALS and survival in a southwest Chinese cohort

Frontotemporal dementia (FTD), amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD) are neurodegenerative diseases that share common genetic risk factors. A recent genome-wide association study has linked risk of FTD with polymorphisms in the HLA-DRA/HLA-DRB5 gene (rs9268877, rs9268856), BTNL2 gene (rs1980493), and RAB38/CTSC gene (rs302668). We used the SNPscan™ Kit to genotype these variants in 400 Chinese patients with sporadic ALS, 554 with sporadic PD and 634 healthy controls. The AA genotype at rs9268856 increased risk of ALS (P=0.005). Mean survival time was significantly shorter in patients with the AA genotype (24.8±16.2months) than in patients with other genotypes (36.9±19.9months; P