[Preliminary study on NS5 region gene sequencing and variants of hepatitis G virus in China]

To study the genomic specificity and variation of Hepatitis G virus(HGV) in China.

The 141nt cDNA fragments locating at nonstructural region 5 (NS5) of HGV were obtained from the sera of 16 HGV infected patients by RT-nested-PCR using NS5 primers, then purified and directly sequenced by dideoxynucleotide chain termination method.

The sequence diversity near the N-terminus of the region between nt 7,820 and 7,960 was more marked than that near the C-terminus. Compared with the HGV-US isolate, the nt alterations of NS5 in Chinese isolates usually took place at nt 7,824, 7,892, 7,914, 7,917, 7,935 and in region nt 7,845-7,860, the rate of variability at one nt position was 0-89.5%. The nucleotide homology was 83.6%-95.7% (89.6% in average) and the homology of deduced amino acid sequence was 83.0-100%(91.2% in average).

The nucleotide and deduced amino acid sequences of NS5 of Chinese HGV are relatively conserved but are obviously different from the HGV and GBV-C reported in USA in this study.