CYP2C19 genetic polymorphisms in Maltese patients on clopidogrel therapy

Abstract

Introduction and Aims: The prevalence of CYP2C19 genetic polymorphisms in the Maltese population is not reported. The aims were to determine CYP2C19 *2 and *17 allele frequencies and CYP2C19 genotype distribution in a cohort of Maltese patients on clopidogrel and to compare observed frequencies of the CYP2C19 *2 allele and *2/*2 genotype to other populations bordering the Mediterranean Sea.

Methods: Genotyping for the CYP2C19 *2 and *17 alleles in Maltese patients on clopidogrel was performed using TaqMan® drug metabolism assays. The frequency of both alleles and six genotypes (*1/*1, *1/*2, *2/*2, *1/*17, *17/*17, *2/*17) were determined. Observed frequencies of the CYP2C19 *2 allele and *2/*2 genotype were compared to fourteen populations bordering the Mediterranean Sea (p>0.05 indicated similar prevalence)

Results: Frequencies of the CYP2C19 *2 and *17 alleles in the 244 patients genotyped were 12.3% and 15.4% respectively. CYP2C19 genotype distribution was: *1/*1 (52.1%), *1/*17 (22.5%), *1/*2 (18.0%), 2/*17 (6.6%), *17/*17 (0.8%) and *2/*2 (0). Prevalence of the *2 allele in the Maltese cohort was similar to all fourteen populations bordering the Mediterranean Sea, while prevalence of *2/*2 was similar to Egyptian, Moroccan, Southern French, Slovenian, Turkish and Tunisian populations (p>0.05).

Conclusions: This study provides an indication of the prevalence of CYP2C19 polymorphisms in Maltese patients. The high percentage of patients with CYP2C19 IM or UM phenotype demonstrates that CYP2C19 genotyping could aid clinicians to individualise treatment with clopidogrel and other drugs metabolised by the CYP2C19 enzyme.