Evidence of association of a common variant of the endothelial nitric oxide synthase gene (Glu298 Asp polymorphism) to coronary artery disease in South Indian population

Genetic variants of endothelial nitric oxide synthase (eNOS) could influence individual susceptibility to coronary artery disease (CAD) with or without association with demographic factors. This study was designed to assess the Glu298 /Asp variant of the eNOS gene in 79 patients with CAD as compared to equal number (79) of controls. The genotype frequencies for eNOS gene polymorphism were determined by PCR and RFLP, and the results analyzed statistically. Demographic factors were recorded using structured questionnaire. The genotype frequencies for Glu298/Asp (Glu/Glu, Glu/Asp and Asp/Asp) genotypes were 46.83%, 30.37% and 22.78% in CAD subjects and 60.75%, 31.64% and 7.59% in control subjects, respectively. The genotype frequencies differed significantly (p<0.05) between the controls and cases. From our Regression analysis we found that Glu/Asp variant in association with other factors such as hypertension, smoking, were independent risk factors of CAD, whereas other factors were not CAD independent risk factors. The individuals with eNOS Glu298/Asp variant were at greater risk of CAD, and this might indicate genetic susceptibility to CAD and that eNOS gene (Glu298/Asp) polymorphism could represent a useful genetic marker in identifying individuals at greater risk of developing atherosclerotic disease.