Allele and genotype frequencies of CYP2C19 in Sudanese patients undergoing percutaneous coronary intervention

Abstract

Genetic variations among different ethnic groups result in variation of drug response. Several studies reported association between these variants and reduction of enzymatic function. Cytochrome P450, specifically CYP2C19 represent a major contributor in this variability. The present study aimed to determine the prevalence of CYP2C19 variants in Sudanese patients undergoing percutaneous coronary intervention (PCI).This prospective observational cohort study recruited 197 Sudanese patients with PCI taking clopidogrel from Wad Medani Heart Diseases and Surgery Center. Patients were genotyped for CYP2C19*2 and CYP2C19*3 using ASP-PCR and PCR-CTPP respectively. The frequency of CYP2C19*2, and *3 was 15%, and 1% respectively. The wild type (*1/*1) was the most frequent CYP2C19 *2 alleles (71.6%), followed by heterozygous mutant (*1/*2) 25.9%, and the least frequent was homozygous mutant (*2/*2) 2.5%. For CYP2C19 * 3, the wild type allele was the most frequent (98.0%), followed by heterozygous mutant (*1/*3) 2% and 0% for homozygous mutant(*3/*3). The overall distribution of CYP2C19 genotype revealed that 69.0% of patients were carriers of homozygotes wild allele (*1/*1); 28.4% were carriers of heterozygotes mutants (1*/2*&1*/3*), and 2.5% were carriers homozygotes mutant (2*/2*). Thus, 69.0% were classified as extensive metabolizers (EMs), 28.4% intermediate metabolizers (IMs) and 2.5% poor metabolizers (PMs). The finding of the present study was comparable to that obtained from several studies conducted in Arabs and African population. The wild type allele was the most prevalent, followed by heterozygotes mutants, and the least was homozygotes mutant. Accordingly the most frequent predicted phenotype was EMs followed by IMs and the least frequent was PMs