Abstract
Background: Coronary artery disease is a complex trait caused by a number of genetic and environmental factors. Genes involved in hemostasis and coagulation are excellent candidate genes for CAD and its thrombotic complications, ie, myocardial infarction (MI) and unstable angina. Methods: We determined the frequency of -fibrinogen genotypes in a homogenous patient population with CAD undergoing coronary angioplasty and in a comparable group in the general population. DNA was extracted from the blood and genotypes were determined by polymerase chain reaction, restriction mapping with Hha-l and gel electrophoresis. Cases and controls were also genotyped for a Q17382J polymorphism in the (-Myosin heavy chain) (MyHC) gene, which is not a candidate gene for CAD. Results: The distribution of -MyHC G/T genotypes and the frequency of alleles were similar in cases and controls. However, the β-fibrinogen G/G genotype was present in 71% of patients with CAD as compared to 54% in the general population (p = 0.0001, OR: 2.1, 95% CI: 1.7-2.8). Seventy-one percent of patients with MI and 72% of patients with unstable angina had GIG genotype (p = 0.003, OR: 2.0, 95% CI: 1.33.3, andp = 0.005, OR: 2.1, 95% CI: 1.3-3.7, respectively). Sixty-nine percent of male and 82% of female patients with CAD had the G/G genotype as compared to 56% and 53% in the general population, respectively (p = 0.0381, and 0.0003, respectively). Multivariate regression analysis showed that the allele G was an independent predictor of case-control status or risk of MI in a codominant manner (F = 86.8,p<0.0001). Conclusions: β-fibrinogen G/G genotype is a genetic risk factor for predisposition to CAD and its thrombotic compli-cations.