The 27-bp Tandem Repeat Polymorphism in Intron 4 of the Endothelial Nitric Oxide Synthase Gene Is Not Associated with Coronary Artery Disease in a Hospital-Based Taiwanese Population

Abstract

We studied whether the 27 base pair (bp) tandem repeat polymorphism in intron 4 of the endothelial nitric oxide synthase (eNOS) gene was associated with coronary artery disease (CAD) in a hospital-based Taiwanese population. We included 219 consecutive patients who underwent coronary angiography at our institution. Two alleles, containing 4 (eNOS4a) and 5 repeats (eNOS4b), were identified after polymerase chain reaction amplifying intron 4 of the eNOS gene. The genotype frequencies for eNOS4b/b, eNOS4a/b and eNOS4a/a were 77.9, 21.5 and 0.6% in CAD subjects, and 80, 20 and 0% in control subjects (Fisher’s exact test, p = 0.90), respectively. The odds ratio (OR) for CAD in patients with at least one eNOSa allele was 1.2 (0.5–2.9) after adjustment for classical CAD risk factors. The eNOS4a allele was not associated with the severity of CAD (Fisher’s exact test, p = 0.90) and the occurrence of acute myocardial infarction (AMI) or unstable angina (adjusted OR 0.6, 0.3–1.6) in patients with CAD. In conclusion, the 27-bp repeat polymorphism of the eNOS gene was not associated with CAD and the occurrence of AMI or unstable angina in a hospital-based Taiwanese population.