NEW VARIANT GROUPS IDENTIFIED FROM HGV ISOLATES

We have determined the primary sequence of the 5' noncoding region (5' /NCR) and putative helicase regions (NS-3) of hepatitis G virus (HGV) and GB virus C (GBV-C) that were isolated in Japan from suspected case s of nonA-nonB and/or nonA-nonB-nonC viral hepatitis by using RT-PCR, and we compared the newly isolated sequences with three established is olates. The addition of a ''G'' residue was found at the 5' terminus o f all 8 Japanese isolates. These isolates were more clearly distinguis hed from the prototype viruses by comparison with the 5' NCR sequence than by comparison with the NS-3 region. Our results suggested that at least three distinct genomic variants of HGV exist. Genotyping of HGV by using RT-PCR based on the sequence of the 5' NCR seems highly feas ible.