Genomic characterization of HBV genotype F in Bolivia: genotype F subgenotypes correlate with geographic distribution and T(1858) variant.

Hepatitis B virus (HBV) strains were classified into eight genotypes from A to H. Genotype F, an indigenous genotype in Central and South America, has been classified into subgenotypes. An in-depth phylogenetic analysis was performed using two full-length Bolivian HBV sequences and other genotype F strains from the database. A novel nomenclature of subgenotypes of genotype F was proposed, in which Bolivia strains belonged to subgenotype F4. This subgenotype had both Leu(45) and Ile(110) in the S gene, and linked to the T(1858) in the precore. This novel nomenclature demonstrated the relation between variability of the HBV genome and the restricted geographical distribution of the virus in some parts of Central and South America.