HLA fine mapping
Multiple signals were identified in the HLA region according to GWAS; therefore, we further discover the association between the HLA allele and IgE. The HLA star allele with FDR adjusted p values less than 0.05 were shown in Table 3. The most significant signal, HLA-DQB1*03:03 (beta=0.15, SE=0.05, p = 3.70×10-14) is associated with IgE under dominant genetic model. After stepwise conditional analysis under the dominant model, no other signals remained genome-wide significant (S Table 1 ). We further select two most significant HLA genes, HLA-DQB1 and HLA-DQA1 to conduct haplotype analysis. The haplotype HLA-DQA1*03:02 - HLA-DQB1*03:03 with frequency 0.15 became more significant positively associated with serum IgE (OR = 1.25, SE = 0.02, p-value = 8.88×10-16) compared with the most protective haplotype (S Table 2) .