Aim: To explore the susceptibility of children to intrauterine HBV infection by studying the relationship between IFN-gamma gene polymorphism, including IFN-gamma+874A/T single nucleotide polymorphism (SNP) and CA repeat microsatellite polymorphism and intrauterine HBV infection.
Methods: A TaqMan fluorescence polymerase chain reaction in the IFN-gamma+874A/T single nucleotide polymorphism was tested in the intrauterine HBV infection group (group I) and the normal immune children group (group II). Capillary electrophoresis was performed in the above two groups to assay the IFN-gamma CA repeat microsatellite polymorphism.
Results: Frequencies of AA, AT and TT genotypes were 67.4%, 19.6% and 13.0% in the intrauterine HBV infection group, and 45.2%, 30.1% and 24.7% in the normal immune children group, respectively. A significant difference was found in the frequency distribution of IFN-gamma+874 genotype between the two groups (chi2 = 5.102, P = 0.02389). In the intrauterine HBV infection group the AA genotype was more common than in the normal immune group. Frequency of IFN-gamma+874A allele was 77.17% in the intrauterine HBV infection group, and 60.27% in the normal immune children group. In the intrauterine HBV infection group the IFN-gamma+874A allele was more common than in normal immune group. A significant difference was found in the frequency distribution between the two groups (chi2 = 7.238, P = 0.02389, OR = 2.228, 95% CI = 1.244-3.992). (CA12)+/(CA12)+ of IFN-gamma CA microsatellite polymorphism was 11.90% in the intrauterine HBV infection group and 26.47% in the normal immune children group. A significant difference was found in the frequency distribution between the two groups (chi2 = 5.64, P = 0.0176). Frequency of IFN-gamma CA repeat was 25% in the intrauterine HBV infection group and 43.38% in the normal immune children group. The frequency of IFN-gamma CA repeat was less in the intrauterine HBV infection group than in normal immune group. A significant difference was found in the frequency distribution between the two groups (chi2 = 7.548, P = 0.0060).
Conclusion: There is a relationship between IFN-gamma+874A/T SNP and intrauterine HBV infection as well as between IFN-gamma CA microsatellite polymorphism and intrauterine HBV infection. IFN-gamma gene polymorphism might be important in determining individual's susceptibility to intrauterine HBV infection.