HLA-DRA and Parkinson disease: Although the expressed HLA-DRA*01:01:01 and -DQA1*03:01:01 are protective alleles in the PD-HC comparison at Pc<0.1 (Table 3), HLA-DQA1*03:01:01 is significant only at the p<0.05 level and HLA-DRA*01:01:01 is not significant (p>0.05) in the SWEDD-HC comparison (Table 4).