Association between SNPs in miRNA-machinery genes and chronic hepatitis B in the Chinese Han population.

Single nucleotide polymorphisms (SNPs) in miRNA-machinery genes can influence their generation and maturation, then expression and structure. To explore the relationship between three SNPs (rs3757 in DGCR8, rs636832 in AGO1, rs7813 in GEMIN4) in miRNA-machinery genes and chronic hepatitis B, we genotyped the SNPs by high resolution melting method (HRM) in a case-control study of 332 unrelated chronic hepatitis B patients and 352 unrelated healthy controls in Western China. Interestingly, the rs636832 was significantly associated with the susceptibility of CHB (genotype: AA/GA/GG: p=0.010; allele: A/G: OR=0.727, 95% CI=0.575-0.920, p=0.008). The minor allele A of rs636832 was significantly associated with a decreased risk of CHB. Additionally, the dominant model AG+GG vs. AA showed a risk of 1.442-fold (p=0.018) with CHB. Further exploration for the association between rs636832 and HBV-DNA load in 329 cases showed no significant difference (genotype: p=0.321; allele: p=0.148). Neither did the association between rs636832 and the status of HBsAg and HbeAg (HBsAg: genotype p=0.337, allele p=0.436; HBeAg: genotype p=0.861, allele p=0.822). Our study first provided the evidence that rs636832 in AGO1 was associated with chronic HBV infection susceptibility in Chinese Han population. Further epidemiological and functional studies in larger populations are warranted to verify our results.