The T(1858) variant predisposing to the precore stop mutation correlates with one of two major genotype F hepatitis B virus clades.
The precore mutation G(1896)-->A occurs frequently in anti-HBe-positive carriers of HBsAg with T(1858) in the stem of the encapsidation signal. Hepatitis B virus (HBV) genotype F, considered an Amerindian genotype, subdivides into two clades and the precore mutation occurs in Central American F strains. To investigate the relationship between substitutions at position 1858 and these clades, the precore and small S genes of 48 strains of HBV genotype F were subjected to phylogenetic analyses. Isolates of one clade, formed mainly of Central American strains, all had T(1858) and Thr(45) in the S gene, whereas in the other clade, formed mainly of South American strains and one strain from Polynesia, all had C(1858) and Leu(45). The latter strain was related to strains from Venezuela and Colombia, supporting an Amerindian contribution to the Polynesian population. The position of the Polynesian strain in the phylogenetic tree indicates that the two clades have resulted from an early split, showing a high degree of genetic stability of the stem of the HBsAg encapsidation signal.
Norder
Heléne
H
Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden.
Arauz-Ruiz
Patricia
P
Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden.
Blitz
Linda
L
Laboratorio Regional de Referencia Virologica, Instituto de Investigaciones Clinicas, LUZ, Maracaibo, Venezuela.
Pujol
Flor H
FH
Laboratorio de Virologia Molecular, CMBC, IVIC, Caracas, Venezuela.
Echevarria
José M
JM
Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
Magnius
Lars O
LO
Virological Department, Swedish Institute for Infectious Disease Control, S-171 82 Solna, Sweden.
D002489:Central America; D014644:Genetic Variation; D005838:Genotype; D006512:Hepatitis B Core Antigens / Q000235:genetics* / Q000378:metabolism; D006514:Hepatitis B Surface Antigens / Q000235:genetics; D006515:Hepatitis B virus / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010802:Phylogeny; D011114:Polynesia; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013020:South America
D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D011498:Protein Precursors