Association of genetic variants within HLA-DR region with Parkinson's disease in Taiwan

Previous genome-wide association studies in Caucasians suggest genetic loci of human leukocyte antigen (HLA)-DR region may be associated with Parkinson's disease (PD). However, these gene-disease associations were limitedly reported in Asian populations. Herein, we investigated the effects of 5 top PD-associated genetic variants within HLA-DR region in Caucasians, including rs4248166, rs9268515, rs2395163, rs75855844, and rs660895, by genotyping 486 Taiwanese patients with PD and 473 age-matched control subjects. Although the association between rs2395163 C allele and patients with PD demonstrated marginal significance (odds ratio [OR] = 0.74, 95% CI: 0.55–0.99, p = 0.045). The frequency of rs2395163 C allele (8.65%) in male patients with PD was significantly lower than in male control subjects (14.02%; OR = 0.58, 95% CI: 0.39–0.88, p = 0.009). The genetic associations between patients with PD and other tested genetic variants were negative. Although strong linkage disequilibrium (rs4248166-rs9626515-s2395163 and rs9626515-rs660895) were observed, the haplotype analysis did not find any significant risk-associated allelic combinations. These results suggest a distinct genetic background within HLA-DR region between Taiwanese and Caucasian patients with PD.