title: Phylogenetic origin of hepatitis B virus strains with precore C-1858 variant.
abstract: Mutations that prevent the expression of the hepatitis B e antigen frequently emerge in the immunoreactive phase of infection. The predominant mutation, the precore G-->A-1896 mutation, is restricted by the variability at position 1858 and is rare in strains with cytosine at nucleotide 1858. The C-1858 variant is characteristic of genotype A. It also occurs in genotypes C and F, but not in B, D, or E, explaining the geographical variation in the prevalence of precore mutants. C-1858 strains have been frequently observed in southeast Asia, but have not been phylogenetically characterized. By sequencing eight complete hepatitis B virus genomes, C-1858 variants of east Asian origin were found to constitute a phylogenetic entity within genotype C that probably diverged several hundred years ago. Further study of the distribution of this variant is warranted.
authors.affiliation: Department of Clinical Virology, Göteborg University, Göteborg, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Alestig
authors.forename: C
authors.initials: C
authors.lastname: Hannoun
authors.forename: P
authors.initials: P
authors.lastname: Horal
authors.forename: M
authors.initials: M
authors.lastname: Lindh
mesh_terms: D014644:Genetic Variation; D005838:Genotype; D006509:Hepatitis B / Q000821:virology; D006513:Hepatitis B e Antigens / Q000097:blood / Q000235:genetics*; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011498:Protein Precursors / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D006513:Hepatitis B e Antigens; D011498:Protein Precursors