Polymorphisms of the endothelial nitric oxide synthase gene in preeclampsia in a Han Chinese population.

BACKGROUND/AIMS: The endothelial nitric oxide synthase (eNOS) gene has been enlisted by previous research as a candidate gene of preeclampsia predisposition. This study investigates the specific roles of 3 polymorphisms of the eNOS gene in a population of Chinese origin from mainland China.

METHODS

We studied the association of 3 commonly studied polymorphisms of the eNOS gene, namely 4b/a, T-786C and Glu298Asp, in a case-controlled sample of 220 patients diagnosed with preeclampsia and 200 healthy controls. The association between eNOS polymorphisms and preeclampsia was evaluated by performing genotyping for the eNOS variants and calculating odds ratios (OR) and 95% confidence intervals. The plasma nitrite concentration in participants was determined to examine how 3 eNOS polymorphisms affect plasma nitric oxide (NO) concentrations in pregnant women.

RESULTS

The frequencies of both the variant 298Asp allele and eNOS 4a allele were significantly lower in preeclamptic women than in the control group and had a significantly lower OR. The variant 298Asp allele and eNOS 4a are strongly associated with higher plasma NO concentrations in pregnant women.

CONCLUSIONS

Polymorphisms in the eNOS gene may be protective against preeclampsia in a Chinese population, and this protective effect may be associated with NO formation in plasma in pregnant women.