RESUMO
Primers were synthesized according to DNA sequence of HBV found in China, and the reverse transcriptase (RT) region in polymerase gene, HBV preC/C region and the whole genome were amplified by PCR method from the serum of 8 patients with chronic HBV infection. Then the PCR products were ligated into pGEM Teasy vectors. 27 clones were sequenced. Deduced amino acid sequences were compared, and the results showed that mutations were widely distributed in structural and non structural viral proteins. The substitution mutations occur in clones isolated from specific patients, which led to a characteristic mutation in the quasispecies group. The results indicated that the diversity of HBV gene might play an important role in the pathogenesis of chronic HBV infection.