Mutations in Hepatitis B Virus Precore and Core Promotor in Children with Chronic Hepatitis B Infection - Comparison Between Vertical and Non-vertical Transmission

ABSTRACT

PURPOSE: The aims of this study were to investigate the frequencies and role of hepatitis B virus(HBV) precore and core promotor mutations in children with chronic hepatitis B infection. METHODS: Sera from 46 children with chronic hepatitis B infection were analyzed by direct sequencing of polymerase chain reaction product of HBV DNA. In this study, the patients were divided into vertical and non-vertical groups according to the mode of HBV transmission. Statistical analysis was performed by using Fisher's exact test. RESULTS: Forty-six adr type of HBV DNA were analyzed. The mutations in HBV precore region were observed in 12(26.1Yo) of 46 cases. The GA mutation of nucletide(nt) 1896 was observed in 5 cases(10.9Yo). The frequency of mutations in HBV precore region of the non-vertical group (6/16; 37.5Fo) was higher than that of the vertical group(6/30; 20M), but there was no statistical significance. The mutation in HBV core promotor region was observed in 40(87.0%) of 46 cases. The A-->T mutation of nt 1762 or G-->A mutation of nt 1764 were observed in 24(52.2%) of 46 cases, and 23 cases revealed combined mutation at both positions 1762 and 1764. The frequency of mutations in HBV core promotor region of the vertical group(28/30; 93.3Yo) was higher than that of the non-vertical group(12/16; 75.0M), but there was no statistical significance. The frequencies of mutations in HBV precore and core promotor regions of the HBeAg negative patients was higher than that of HBeAg positive patients, but there was no statistical significance. Also there were no significant correlations between the frequencies of mutations in HBV precore and core promotor regions and AST, ALT level or the level of HBV DNA. CONCLUSION: These observations suggest that mutations in HBV precore and core promotor regions were frequently detected in children with chronic hepatitis B infection. There were no statistical significant differences in the frequencies of mutations in HBV precore and core promotor regions between vertical and non-vertical transmission groups. (J Korean Pediatr Soc 2000; 43779-791)