Classification of hepatitis C virus into major types and subtypes based on molecular evolutionary analysis

Molecular evolutionary analysis was applied to determine the number of hepatitis C virus (HCV) types and subtyoes based on all the HCV nucleotide sequences available from the DNA data banks (DDBJ, GenBank (NCBI), EMBL) and the literature. There was an excellent concordance among the types and subtypes assigned based on diffeent HCV genomic regions. Only one HCV isolate was assigned to different HCV types based on the 5′ non-coding (NC) and envelope 1 (E1) regions. The 5′ NC region was well conserved and could be used to assign only types and not subtypes. From the sequence data available there were 13 suhtypes based on the core region and 14 subtypes based on the E1 and non-structural proteins 5 (NS5) regions.