Putative association of DNA methyltransferase 1 (DNMT1) polymorphisms with clearance of HBV infection.

DNA methyltransferase (DNMT) 1 is the key enzyme responsible for DNA methylation, which often occurs in CpG islands located near the regulatory regions of genes and affects transcription of specific genes. In this study, we examined the possible association of DNMT1 polymorphisms with HBV clearance and the risk of hepatocellular carcinoma (HCC). Seven common polymorphic sites were selected by considering their allele frequencies, haplotype-tagging status and LDs for genotyping in larger-scale subjects (n = 1,100). Statistical analysis demonstrated that two intron polymorphisms of DNMT1, +34542G > C and +38565G > T, showed significant association with HBV clearance in a co-dominant model (OR = 1.30, P(corr) = 0.03) and co- dominant/recessive model (OR = 1.34-1.74, P(corr) = 0.01-0.03), respectively. These results suggest that two intron polymorphisms of DNMT1,+34542G > C and +38565G > T, might affect HBV clearance.