First report of genotype e of hepatitis B virus in an Indian population

Twenty-one hepatitis B virus (HBV) isolates from the state of Haryana (North India) were studied for genotype, subgenotype, serotype distribution and precore mutations. Assays of alanine aminotransminase (ALT) and HBeAg were performed on all samples. Genotypes, subgenotypes and serotypes were determined by amplification of pre-S1/S2 regions followed by RFLP and also by phylogenetic analysis of amplified products. Mutations were studied by amplification and sequencing of the precore region. Twenty-four percent of the samples had high ALT levels and 90% were HBeAg negative. It was observed that 90% of the samples were HBV D genotype, (subgenotype D1, serotype ayw2), 5% HBV A genotype (subgenotype A1, serotype adw2), and the remaining 5% were HBV E genotype (serotype ayw4). The subgenotype A1 was quite similar to the South African isolates. Phylogenetic analysis of the HBV isolates, based on the pre-S1/S2 gene sequences, confirmed genotype E. Amplification and sequencing of the precore region showed 1762(A-T) and 1764(G-A) mutations in 38 and 15% of the samples, respectively. 1809(T) was observed in 5% of the cases under study. This is the first report of the genotype E of hepatitis B virus in the Indian population. Efforts are underway to amplify and sequence the full length of this genotype E isolate.