[Sequence analysis of 5' non-coding region of hepatitis G viruses and preliminary classification of genotypes].

For analyzing the structural characteristics of hepatitis G virus (HGV or GBV-C), 277 nucleic acids of 5' non-coding region of HGV were amplified using PCR from the sera of 2 paid donors, 2 chronic hepatitis patients and 2 patients with liver cirrohsis. The products were cloned and sequenced. The data were analyzed with the computer programs. The results indicated that the gene sequence homologies among 6 HGV isolates (G001-G006) obtained in this study were above 96.2%. The comparison of these 6 isolates and 3 foreign isolates reported previously showed that the sequence homologies were in the range from 86.9% to 91.6%. According to the variability of gene sequences, the preliminary division of genotypes of 6 Chinese HGV isolates (G001-G006) and 3 isolates reported abroad were classified into three distinct groups. The results suggest that the gene sequences of Chinese HGV isolates are highly homologous but have an obvious divergence with the foreign isolates. The 5' untranslated regions of all isolates analyzed probably contain a stable and similar secondary structure.