ABSTRACT
OBJECTIVE To discover diversity of X gene sequences of hepatitis B virus isolates in hepatitis B induced liver cirrhosis patients and HBV carriers.METHODS DNA fragment including X gene sequences of hepatitis B virus was amplified,sequencing PCR products was preformed.The PCR products of three liver cirrhosis patients and three HBV symptomless carriers were cloned into pGEMT Easy vectors.Positive clones with target sequences were selected out for sequencing.Sequence comparison was made to find the identity.RESULTS A comparison of T1762/A1764,G1719T,T1727G/A,G1730C and T1753C mutations in a core promoter between the liver cirrhosis patients and the HBV carriers showed that the HBV isolates from the former had higher frequencies of mutation than the latter.The X promoter region of the HBV isolates from the liver cirrhosis patients showed higher frequencies of mutation than the isolates from the HBV carriers.Additionally,the homology between clones of X gene from one individual with liver cirrhosis averages 91.3-99.7%,that of HBV carriers averages 96-100%.CONCLUSIONS The core and X promoter region of the HBV isolates from the liver cirrhosis patients show the higher frequencies of mutation than the isolates from the HBV carriers.There are HBV quasispecies which possess great variation in the liver cirrhosis patients.