Scal Polymorphism of the Atrial Natriuretic Peptide Gene in Patients with Coronary Heart Disease below 50 Years of Age with and without Arterial Hypertension

Abstract

Background It has been suggested that A1 allele of single twoallele ScaI restriction fragment length polymorphism at exon three within the atrial natriuretic peptide (ANP) gene is associated with the arterial hypertension in the salt-sensitive populations. We examined the possible relationship between the ScaI ANP gene polymorphism and an increased risk for coronary atherosclerosis, arterial hypertension, survived myocardial infarction (MI) and familial coronary heart disease (CHD) history among youngerpatients with angiographically proven CHD.
Methods The study was performed in 92 consecutive patients with proven CHD aged below 50 years old (females - 5, males - 87, mean age 44 ± 4 years, 33% were hypertensive, 75% survived MI and 63% had familial CHD history). The ScaI ANP polymorphism was assessed using the polymerase chain reaction and subsequent ScaI enzyme digestion, resulting in three possible genotypes, either AlAl, A1A2 or A2A2.
Results: ScaI ANP genotype frequencies in our study group (A1A1-3%, AlA2 -33% and A2A2 -64%) were in agreement with Hardy-Weinberg equilibrium. There was much more frequent positive history of myocardial infarction in the A2A2 patients than AlA2 + A1A1 (86 vs. 56%, p < 0.003) in the whole study group and in the subgroups with and without hypertension. There was not significant difference in the incidence of arterial hypertension between genotypes (AlA2 -ł-AIAI - 29%, A2A2 -36%, p = 0,5). The ScaI ANP genotype did not influence the incidence of the positive familial CHD history (A2A2 - 61% vs. A1A1+AlA2 - 70%). Also the severity of coronary atherosclerosis was independent from the ANP genotype ( multiple vessel disease A2A2 - 81% vs. A1A1 + AlA2 - 71%).
Conclusion Observed distribution of the ScaI ANP genotypes suggests that the A2A2 genotype of the ScaI ANP polymorphism is associated with survived myocardial infarction in younger subjects with confirmed coronary atherosclerosis with and without arterial hypertension.