Genetic association of PON2 polymorphisms with susceptibility to preterm birth

Target: The objective of this study was to investigate the association of paraoxonase 2 (PON2) Ala148Gly (A148G) and Ser311Cys (S311C) polymorphisms with the susceptibility to preterm birth. Methods: In this casecontrol study, we genotyped PON2 A148G and S311C polymorphisms of 110 premature infants and 121 normal infants using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The control group was matched with the case group by maternal gestational age. The distribution differences of genotypes and alleles between the two groups were checked by χ2 test which was also used to evaluate the Hardy-Weinberg equilibrium (HWE). Odds ratio (OR) and 95% confidence interval (CI) were used to represent the relative risk of preterm birth. Results: The genotypes distributions of PON2 A148G and S311C polymorphisms in the control group accorded with HWE. The genotype frequency of AA in A148G polymorphism was significantly higher in cases, compared with AG/GG (P=0.011); CC genotype of S311C polymorphism in infant obviously increased the risk of preterm birth and its genotype frequency was 2.169 times higher than the common genotype SS (OR=2.169, 95% CI=1.016-4.630). What’s more, birth weight was associated with preterm birth and A148G polymorphism had an influence on birth weight obviously (P<0.05). Conclusions: In PON2 gene, AA common genotype of A148G polymorphism and CC mutant genotype of S311C were associated with the risk of preterm birth development. In addition, A148G polymorphism plays an important in infant birth weight, but not S311C.