Μελέτη Κλινικά Σημαντικών Γενετικών Πολυμορφισμών Του Ανθρώπινου Γονιδιώματος Σε Σχέση Με Παθήσεις Του Καρδιαγγειακού Συστήματος

Abstract

AT1R gene polymorphisms lead to hyperactivity of renin-angiotensin-aldosterone system, eNOS gene polymorphisms are associated with reduced endothelial synthesis of NO, while ε2 and ε4 alleles of apoE affect cholesterol levels. All analyzed polymorphisms potentially affect the pathophysiology of coronary artery disease through altered physiology of the systems they are componets.Genotyping of AGT M235T and T174M, AT1R A1166C, eNOS-786T> C and G894T and apoE ε2 and ε3 alleles was performed by use of PCR-RFLP method. ACE I / D polymorphism was analyzed by use of PCR and Nested PCR methods. The cumulative effect of gene polymorphisms was assessed through gene score application. Gene score for each participant was calculated by adding a value of 0.5 for each variant allele. AGT T174M polymorphism was excluded from gene score application as it is in complete linkage with M235T polymorphism of the same gene, therefore the score for each individual varies from 0 (absence of variant alleles) to 6 (homozygotes for all variant alleles). The interaction of eNOS-786T> C and G894T polymorphisms and apoE ε2 and ε4 alleles with smoking was included in gene score by adding a value of 0.5 for all smokers carriers of these alleles in heterozygous or homozygous form. According to their gene score individuals were classified in three genetic risk groups: low risk (score 0-1.5), intermediate risk (score 2-3) and high risk (score 3.5-6).According to our results, the analyzed polymorphisms are not independently associated with coronary artery disease in Greek patients. We found, however, within coronary artery disease patients significant gene-environmental interactions with environmental factors such as hypertension and smoking. Specifically, the frequency of homozygous AGT 235TT genotype was significantly higher in hypertensive coronary artery disease patients compared to normotensive patients (p = 0.03), while the prevalence of eNOS 894T allele and 894TT homozygous genotype was significantly higher in smokers than nonsmokers coronary artery disease patients (p<0.01 and p=0.02, respectively). The composition of gene score risk groups did not differ between patients and controls before or after adaptation of gene-smoking interaction (p=0.41 and p=0.48, respectively).We conclude that, when investigating the genetic background of complex diseases such as coronary artery disease, it is of essential importance to take into account interactions between genetic polymorphisms and environmental factors. Therefore, association studies of gene polymorphisms with coronary artery disease in different ethnic groups can determine interactions of gene polymorphisms with environmental factor that could increase the risk of developing coronary artery disease. The approach of gene score that we performed can be XX applied in near future to assess the genetic burden of individuals candidates for coronary artery disease and may help not only identify high risk individuals, but also contribute to primary prevention of cardiovascular disease and to complete...