Relationship between the different replication status of HBV and mutations in the core promoter in mothers and their children infected via mother-to-infant transmission

<正> OBJECTIVE: To study the relationship between the different replication status of hepatitis B virus(HBV) and mutations in the core promoter (CP) in mother and her child infected by mother-to-infanttransmission.METHODS: The core promoter was amplified by PCR and cloned into pGEM-T vector with the T-Achoning technique. The recombinant plasmid pGEM-CP was confirmed by digestion with restrictionenzyme Apa I and Sac I. Two clones were selected to be sequenced in each patient.RESULTS: Every pair of mother and child had same serotype and genotype and the homology ofnucleotides encoding "a" determinant was 98%-100%. The number of mutations in the core promoter ofpatients with a high replication status was less than that in those with a low replication status. Mutationswere mainly distributed in basia core promoter (BCP) and the inbibitor region of Kunitz-type serineprotease. This difference was not associated with mother or child.CONCLUSION: The different replication status of HBV is caused by mutations in the core promoter inmother and child infected hy mother-to-infant transmission and appears to be not associated with the statusof development of the infection.