Endothelial nitric oxide synthase gene polymorphisms in preeclampsia with or without eclampsia in a Turkish population

Aim: To evaluate endothelial nitric oxide synthase (eNOS) gene polymorphisms in preeclampsia with or without eclampsia in a Turkish population. Material and Methods: Fifty-seven preeclamptic and 60 normotensive women were enrolled in the present study. The study focused on two functional variants: a variant in exon 7—G to T conversion at nucleotide position 894 resulting in the replacement of glutamic acid with aspartic acid at codon 298 (Glu298Asp) and a variant variable number of 27 bp tandem repeats in intron 4 (VNTR intron 4). Two polymorphisms in the maternal eNOS gene were characterized by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. Preeclamptic pregnant women were evaluated into two subgroups according to the presence of eclampsia. Results: We demonstrated a significant difference in patients with preeclampsia in terms of Glu298Asp/eNOS genotype frequency. G/G homozygotes of Glu298Asp among healthy pregnancies were significantly frequent when T/T homozygotes were significantly frequent among preeclamptic pregnancies. We showed that G/T heterozygotes of Glu298Asp/eNOS gene were significantly frequent among preeclamptic pregnant women who did not develop eclampsia than in preeclamptic pregnant women with eclampsia. Conclusion: Glu298Asp polymorphism in the eNOS gene could be an individual's risk factor and may modulate progression to an eclampsia complication of preeclampsia in the Turkish population.