A Case-Control Study of Relevance Between NOS2 rs2297518 Polymorphism with Preeclampsia Risk in the Chinese Han women

Backgroud: Inducible Nitric Oxide Synthase (iNOS) acts on the contraction and expansion of blood vessels by mediating the synthesis of Nitric Oxide (NO), which is implicated in the pathophysiology of preeclampsia (PE) associated with systemic vasoconstriction. The polymorphism of NOS2, the gene of coding iNOS, can affect the function of protein. Therefore, we aimed to explore whether the polymorphism site rs2297518 in NOS2 is associated with susceptibility of PE in a Chinese Han population. Methods and Results:Genotyping the NOS2 rs2297518 polymorphism through TaqMan real-time fluorescence quantitative polymerase chain reaction (PCR) after DNA extraction from blood samples in this case-control study including 979 PE patients and 1187 healthy pregnant women. Using independent sample t-test and chi-square test to analyse clinical data and experimental results. We performed the odds ratios (ORs) and 95% confidence intervals (CIs) to estimate the degree of the association.There was no statistical significance in the genetic distributions for the polymorphism of rs2297518 between the PE and control groups (c2=1.43, p=0.49 by genotype frequency, c2=0.85, p=0.36, odds ratio=1.07, 95% confidence interval 0.92-1.25 by allele frequency), and no differences among early/late-onset or mild/severe PE and controls was seen. Conclusion: Our results indicated that the NOS2 rs2297518 polymorphism may be not play a major role in the susceptibility to PE in the Chinese Han population. Therefore, it is essential to test other polymorphisms of this gene to validate a potential relationship for susceptibility to PE.