Three type 6 hepatitis C virus subgroups among blood donors in the Yangon area of Myanmar are identified as subtypes 6m and 6n, and a novel subtype by sequence analysis of the core region.

Previously, using phylogenetic analysis of NS5b sequences, we found that three type 6 variant subgroups (M6-1, M6-2 and M6-3) exist in Myanmar. According to the new nomenclature of hepatitis C, M6-1 and M6-2 belong to subtypes 6m and 6n, respectively, but M6-3 is unassigned. In this study, we sequenced and phylogenetically analyzed the core region of these type 6 variant subgroups. Serum samples assigned as 6m or 6n by NS5b sequence were also identified as 6 m or 6n by core region analysis. The M6-3 (sample name MYAN-3E-3) remained unassigned to a subgroup based on its core region analysis. The findings of this study suggest that either the core region or the NS5b region can be analyzed for HCV subtype classification.