Fig. 1

Association plots for the extended major histocompatibility complex region. Significance levels of each marker (single-nucleotide polymorphisms, classic HLA alleles, and HLA amino-acid residues) and amino-acid positions were calculated by using logistic regression and log-likelihood tests, respectively, and plotted according to chromosomal locations (based on hg18). a Primary association was identified at HLA-B amino-acid positions 70, 97, and 114 in an unconditional analysis. b Secondary association was identified at HLA-C amino-acid position 116 when conditioned on the primary effect at the three HLA-B amino-acid positions. c, d Amino-acid positions 70 (yellow), 97 (red), and 114 (green) of HLA-B and 116 of HLA-C (blue) are located in epitope-binding sites. HLA human leukocyte antigen