Prevalence and types of genetic polymorphisms of CYP2C19 and their effects on platelet aggregation inhibition by clopidogrel.

Abstract

The current study was conducted to determine the distribution of genetic polymorphisms in CYP2C19 in Iraqi patients and their role in inter-individual variability of clopidogrel efficacy. A prospective controlled study was done on 100 patients under high risk of cardiovascular diseases who started clopidogrel prophylactic therapy. Polymerase chain reaction-restriction fragment length polymorphism method was used to determine the existence of the CYP2C19 gene mutation. Vasodilator-stimulated phosphoprotein (VASP) index baseline besides one-month post-therapy was analyzed by dual-color flow cytometry analysis. Eight gene mutations of CYP2C19 werefound(*1/*1), (*1/*2), (*1/*3), (*1/*8), (*1/*17), (*2/*2), (*2/*4), and (*3/*3) with higher prevalent CYP2C19*1 gene. Homozygous CYP2C19*1 allele was shown to be the rapid metabolizer comparing to the heterozygous CYP2C19*1 allele, whereas, CYP2C19*2 and CYP2C19*3 were resistant alleles and were present in 28% of patients. The analysis of VASP phosphorylation produces accurate inter-individual response variability in platelets inhibition by antiplatelet drugs. In vitro gene analysis and VASP index improve the clinical outcome of a patient candidate to clopidogrel as prophylaxisin cardiovascular events.