Complete genomes of hepatitis C virus (HCV) subtypes 6c, 6l, 6o, 6p and 6q: completion of a full panel of genomes for HCV genotype 6.

Five hepatitis C virus (HCV) complete genome sequences (Th846, 537796, QC227, QC216 and QC99) from a blood donor in Thailand and three Asian immigrants and one Caucasian in North America were determined. Phylogenetically, they represent the first complete genomes for subtypes 6c, 6l, 6o, 6p and 6q, respectively. Similarity analysis showed no evidence of inter- or intrasubtype recombination. Further analysis in conjunction with partial sequences from the Los Alamos HCV database led to the identification of other closely related isolates from south-eastern Asia or immigrants from that region. However, Th846 did not cluster with any reference sequence and is the sole isolate of subtype 6c reported so far. This study completes the full genome sequencing of all 17 assigned HCV genotype 6 subtypes (6a-6q). The utility of this panel of complete sequences for accurate detection and classification of infection, and for estimating the origin of this genotype of HCV, is discussed.