HLA-DQA1 and Parkinson disease: Following these analyses, we found four HLA alleles that were associated with PD (Table 1, results for other HLA alleles are detailed in Supplementary Data 3): HLA-DQA1*03:01, HLA-DQB1*03:02, HLA-DRB1*04:01, and HLA-DRB1*04:04.