Genome-wide association study identified new susceptible genetic variants in HLA class I region for hepatitis B virus-related hepatocellular carcinoma

We have performed a genome-wide association study (GWAS) including 473 Japanese HBV (hepatitis B virus)-positive HCC (hepatocellular carcinoma) patients and 516 HBV carriers including chronic hepatitis and asymptomatic carrier individuals to identify new host genetic factors associated with HBV-derived HCC in Japanese and other East Asian populations. We identified 65 SNPs with P values < 10(-4) located within the HLA class I region and three SNPs were genotyped in three independent population-based replication sets. Meta-analysis confirmed the association of the three SNPs (rs2523961: OR = 1.73, P = 7.50 x 10(-12); rs1110446: OR = 1.79, P = 1.66 x 10(-13); and rs3094137: OR = 1.73, P = 7.09 x 10(-9)). We then performed two-field HLA genotype imputation for six HLA loci using genotyping data to investigate the association between HLA alleles and HCC. HLA allele association testing revealed that HLA-A*33:03 (OR = 1.97, P = 4.58 x 10(-4)) was significantly associated with disease progression to HCC. Conditioning analysis of each of the three SNPs on the HLA class I region abolished the association of HLA-A*33:03 with disease progression to HCC. However, conditioning the HLA allele could not eliminate the association of the three SNPs, suggesting that additional genetic factors may exist in the HLA class I region.