[Identification of vertical transmission of hepatitis B virus from mother to children by direct sequencing a segment of surface gene of hepatitis B virus].
To explore the reason for the failure to interrupt vertical transmission of hepatitis B virus (HBV) from mother to children in Chinese subjects by vaccination.


METHODS
HBV nucleotide sequences isolated from three sets of mother/children pairs were analyzed. HBV DNA from the surface antigen region encoding the amino acids 101 to 160 of hepatitis B surface antigen (HBsAg) was amplified and sequenced from HBsAg positive mother and their children.


RESULTS
Nucleotide and deduced amino acid sequences were absolutely identical in the mother and children in family one and two respectively. However, there were five nucleotides different in family one's isolates compared with the family two's isolates. All of them were a subtype. In one child of family three, with coexisted HBsAg and anti-HBs, sequencing result revealed a point mutation which predicted a change from glycine to arginine at residue 145 in the second loop of the determinant. The mother and another child had a glycine at this position.


CONCLUSIONS
This study revealed the vertical transmission linkage of HBV between the mother and children in a molecular level, and also first described a codon 145 immune escape mutant in Chinese vaccinated children.
Zhong
M
M
Department of Infectious Diseases, Nanfang Hospital, First Medical College of PLA, Guangzhou.
Hou
J
J
Luo
K
K
D000328:Adult; D001483:Base Sequence; D004279:DNA, Viral / Q000235:genetics*; D005260:Female; D006509:Hepatitis B / Q000635:transmission*; D017325:Hepatitis B Vaccines / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D008969:Molecular Sequence Data; D017354:Point Mutation; D017422:Sequence Analysis, DNA; D014611:Vaccination
D004279:DNA, Viral; D017325:Hepatitis B Vaccines