Association between NOS3 G894T, T-786C and 4a/4b Variants and Coronary Artery Diseases in Iranian Population

BACKGROUND: Endothelial nitric oxide synthase, encoded by NOS3, produces an atheroprotective metabolite. The G894T, T-786C and 4a/4b variants of this gene associated with increased risk for coronary artery diseases (CAD) have been evaluated in different populations worldwide, and inconsistent results have been obtained. We investigated the association between these three polymorphisms and presence of CAD in Iranian individuals. METHODS: Overall, 234 people including angiography-positive patients from Amir-Almomenin Hospital (Heart Center), Kordkoy City, Golestan Province, northern Iran in 2016, angiography-negative subjects and healthy individuals from north of Iran were genotyped for the G894T and T-786C variations by PCR-RFLP, and 4a/4b VNTR only by PCR. RESULTS: The genotype distribution and allelic frequencies for the three variants tested were not dramatically different between CAD and control subjects and also between CAD patients and people with pains and symptoms very similar to CAD but no stenosis (P>0.05). Moreover, the odds ratio for CAD related to the G894T (OR=1.09, 95% CI=(0.60–2.00), T-786C (OR=1.04, 95% CI=(0.57–1.89) and 4a/4b (OR=1.75, 95% CI=(0.92–3.32) variants did not show statistical significance. Similarly, the odds ratio for stenosis confirmed by angiography related to the 894T (OR=1.03, 95% CI= (0.61–1.74), −786C (OR=0.90, 95% CI=(0.54–1.50) and 4b (OR=1.64, 95% CI=(0.92 –2.93) alleles were not significant. CONCLUSION: G894T, T-786C and 4a/4b variants were not associated with risk for CAD and occurrence of angiography-assessed stenosis in Northern Iranian population (P>0.05). These alleles might be population-specific and not to be associated with their corresponding gene pool. However, further analysis is required to clarify other CAD-correlated markers in our community.