Nitric oxide levels and endothelial nitric oxide synthase gene polymorphisms in Turkish women with idiopathic recurrent miscarriage

Abstract

To determine whether endothelial nitric oxide synthase (eNOS) gene polymorphisms are associated with an increased risk for Idiopathic Recurrent Miscarriage (IRM) in the Turkish population and to evaluate the association between Nitric Oxide (NO) levels and eNOS gene polymorphisms in women with IRM. A total of 120 Turkish women were enrolled in this study in four groups. Of these, 30 women were first trimester pregnant who had IRM (Group I). Thirty healthy multipara women were in the first trimester of pregnancy with no history of abortion (Group II). Thirty women were non pregnant with a history of IRM (Group III). The remaining 30 subjects were healthy multipara non-pregnant women with no history of abortion (Group IV). DNA analysis of four groups were performed for the two polymorphisms using the PCR and/or PCR-RFLPs method and NO levels were measured spectrophotometrically. We observed statistically significant decreased NO levels in the pregnant patient group (p=0.001) while elevated NO levels were measured in the non pregnant patient group (p=0.004). We demonstrated that, while there was no significant difference in terms of VNTR 4/eNOS genotype, there was a marginally significant difference in terms of Glu298Asp/eNOS genotype frequency (p=0.055) in patients with IRM in the Turkish population. We observed no association between NO levels and Glu298Asp/eNOS or VNTR 4/eNOS genotypes in any of the groups. The Glu298Asp polymorphism of eNOS could be an intriguing susceptibility factor that modulates an individual's risk of IRM in Turkish population. Further studies to explain the role of the NO pathway in the pathophysiology of IRM are needed.