Detection of pre－C region mutants of hepatitis B virus from HBeAg negative patients in Xi＇an area of China

Ｄｅｔｅｃｔｉｏｎｏｆｐｒｅ－ＣｒｅｇｉｏｎｍｕｔａｎｔｓｏｆｈｅｐａｔｉｔｉｓＢｖｉｒｕｓｆｒｏｍＨＢｅＡｇｎｅｇａｔｉｖｅｐａｔｉｅｎｔｓｉｎＸｉ＇ａｎａｒｅａｏｆＣｈｉｎａＨａｎＪｉｅ（韩捷）；ＹａｎＹａｎ（阎岩）；ＤｉｎｇＺｈｅｎｒｕｏ（丁振...

Detection of pre-C region mutants of hepatitis B virus from HBeAg negative patients in Xi'an area of China

HBV-DNA extracted from forty-seven sera of HBeAg negative and anti-HBe positive hepatitis B patients was used as template for polymerase chain reaction(PCR) with pre-C region primer. Amplified products of hepatitis B virus DNA were digested with EcoRI and the resultant gene fragment of 312 base pairs(bp) containing the precore region was cloned into PUC18 plasmid and then transformed into E. coli JM109. After being identified by PCR and digested with restriction endonuclease, the nucleotide sequence of the precore region was determined by the dideoxy-chain termination method. The results demonstrated that hepatitis B virus (HBV) mutation was present in the precore region in the clones of two patients. A point mutation from G to A at 1896 site of HBV precore region might convert Trp 28(TGG) to a stop codon(TAG), which is the commonest mutation observed so far.The discovery of mutants of HBV precore region in Xi'an area of China could be of value for further investigation of the pathogenesis of hepatitis B.