Variability of the S gene of hepatitis B virus in southeastern China

Abstract

In a study of 315 HBV specimens obtained from southern China, 240 (76. 9%) were assigned to genotype B, 72 (22. 9%) were genotype C, two (0. 6%) were genotype A and one (0. 3%) was genotype D. Statistical analysis revealed that variables such as age, gender, HBV vaccination rate, hepatitis anamnesis rate, anti-HBs and HBeAg prevalence and virus load were insignificant between genotype B (n = 240) and genotype C cases (n = 72) (P > 0. 05). However, the frequency of amino acid (aa) substitutions in the major hydrophilic region (MHR; aa 99-169) and the putative HLA class I-restricted cytotoxic T lymphocyte (CTL) epitope region of the S gene, as well as the overlapping polymerase/RT region (aa 32-212), were significantly higher in genotype C group than genotype B (P < 0. 001). These results suggest that the higher variability within genotype C carriers may account for the pathogenic potential. © 2010 Springer-Verlag.