Diversity of hepatitis g virus within a single infected individual

The extent of population diversity among GB virus C (GBV-C)/hepatitis G vir us (HGV) within a persistently infected individual (Iw) was investigated by sequence analysis of multiple clones generated from polymerase chain react ion (PCR)-amplified products of cDNA analogous to fragments of 5' non-codin g region (5'NC), envelope region 1/2 (E1/E2) and non-structural region 3 (N S3) of viral genome. Although nucleotide substitutions were more common in coding regions than in the 5'NC region, there was no region corresponding t o the hypervariable region of hepatitis C virus in the E1/E2 region. Transi tion substitution exceeded transversion by 7 to 12-fold, and 79.4% of subst itutions were synonymous. This bias against substitutions producing amino a cid replacements and the use of Pfu DNA polymerase with an error rate 10 ti mes lower than the observed frequency of substitution, suggests that most s ubstitutions were not artefactual. This data suggests that individual genom es of HGV within an infected individual may differ from each other at 0.23- 0.84% nucleotide position and at 0.42-0.61% amino acid position.