Endothelial nitric oxide synthase Glu298Asp gene polymorphism in a multi-ethnical population with heart failure and controls

Abstract

Brazilian population has a multi-ethnical profile and the prevalence of endothelial nitric oxide synthase enzyme (eNOS) polymorphism in heart failure (HF) has not been previously studied. Therefore the present study assessed the association of eNOS Glu298Asp polymorphism in patients with HF and controls. In a crossover study, was analysed the distribution of the Glu298Asp in 100 outpatients with HF, and 103 healthy controls. Self-reported race were analyzed. Left atria and left ventricle diameters and ejection fraction were evaluated in patients group. Glu298Asp was analysed by polymerase chain reaction and restriction fragment length polymorphism. The patient’s average age was 59 years, 66% males, 49% Afro-descendants. The allelic frequency in patient group was Glu298 = 72%/Asp298 = 28% and the genotype frequency (GF) was Glu298Glu:49%; Glu298Asp:47%; Asp298Asp:4%. In control group, 60% Glu298 and 40% Asp298; 35% Glu298Glu, 49.5% Glu298Asp and 15.5% Asp298Asp. The prevalence of allele Glu298 was significantly higher in patients ( p = 0.009) as genotype Glu298Glu ( p = 0.03). The Glu298 in Afro-Brazilians (79%) and white patients (67%) were similar, although there was significant difference ( p = 0.03) in GF Glu298Glu between Afro-Brazilians and whites. There was an increased prevalence of hypertension and increased atria in Glu298Glu patients comparing with combined genotype Glu298Asp and Asp298Asp. This study suggests a regional variation in the distribution of Glu298Asp. The comparison of this distribution in African-Brazilian suggests a synergistic effect of African-descendent, Glu298Glu genotype and HF. Also demonstrated an increased frequency of Glu298 and Glu298Glu, suggesting interaction of them with HF. In HF patients, the clinical, echocardiograph and genotype analysis suggests an association of Glu298 allele and hypertension.