We observed a marked enrichment for SNPs within the MHC among the cis- and trans-acting trait-associated SNPs: 65 of 472 cis-acting SNPs (13.8%, EVD p<1.0×10−16) and 32 of 67 trans-acting SNPs (47.8%, EVD p<1.0×10−16) mapped within the MHC (Figure 3). These SNPs all map to the Human Leukocyte Antigens (HLA) locus: SNPs within the HLA class I region, class II region and class III region affect 20, 7 and 2 different genes in trans, respectively.
