ANGIOTENSIN-I CONVERTING-ENZYME GENOTYPE DD IS A RISK FACTOR FOR CORONARY-ARTERY DISEASE

Background: Coronary artery disease (CAD) is a polygenic disease whose phenotypic manifestation is due to interaction of a number of environ mental factors with an underlying genetic background, A number of gene s, including the angiotensin-I converting enzyme (ACE) gene, have been implicated in the pathogenesis of CAD, ACE can affect oxidation of LD L, endothelial cell function, and smooth muscle cell migration and pro liferation: all important components of atherosclerosis. A variant of ACE gene, genotype DD is associated with a higher plasma level of ACE and an increased risk of myocardial infarction, and cardiomyopathies, In this study, we sought to determine the distribution of ACE genotype s and the frequency of allele D in patients with CAD undergoing corona ry angioplasty. Methods: DNA from 182 white patients undergoing corona ry angioplasty and 338 apparently healthy white individuals was amplif ied by polymerase chain reaction (PCR) in the region of the polymorphi sm using the previously published protocol. Results: PCR amplification of alleles I and D resulted in 490 bp and 190 bp products, respective ly, ACE genotype DD was present in 47% of patients with CAD as compare d to 30% in the general population (p = 0.0002, Odds ratio 2.7), The f requency of allele D was 0.68 in patients with CAD and 0.55 in general population, respectively (p < (0.0001). Genotype DD was associated wi th CAD only in males (54% vs. 30%,p = 0.0001, Odds ratio 2.0), but not in female patients, There was no association between the frequency of ACE genotype DD and the prior history of myocardial infarction, or th e extent of CAD, The frequency of ACE genotype DD was the highest amon g patients with restenosis following angioplasty (55%), however, the d ifference was not significantly changed as compared to those without r estenosis (40%). Conclusions: ACE genotype DD is more common in patien ts with CAD as compared to the general population, indicating that gen otype DD is a genetic risk factor for CAD.