Relationship between HBV/C subgenotypes and gene mutation of core promoter, precore/core region

Objective To study the core promoter, precore/core region mutation of HBV/C subgenotypes and to analyze the virological features. Methods A total of 79 sera of HBV/C genotype were chosen by the enzyme-linked immunosobent assay (ELISA). Then HBV/C strains were subtyped by polymerase chain reactioin and restricion fragment length polymporphism (PCR-RFLP), and their HBV DNA sequences bearing the core promoter, precore/core region were amplified by hemi-nested PCR, products thereof were directly sequenced. Results (1) Among 79 sera of HBV/C, 33 (41.8%) of subtype HBV/C1 and 46 (58.2%) of subtype HBV/C2 were detected. (2)The HBV/C1 was found only in patients from Southern China. (3) Prevalence of V1753 was higher in HBV/C1 strains (P0.04), A1898 was only found among HBV/C1. HBV/C2 distinguished by frequently found T1858 (90%) and A1896 (40%). T1762/A1764 was frequent in both subgenotypes. (3) Mutations associated with HCC in the present study were V1753 and T1762/A1764. Conclusions HBV/C1 and HBV/C2 have distinct geographic distribution in China. V1753 in addition to T1762/A1764 double mutation would be associated with HCC development, especially among patients with HBV/C1.