Multiplex allele-specific detection of clinically important CYP2C19 variants associated with clopidogrel metabolism in a Bangladeshi population sample

Clopidogrel is an oral antiplatelet agent used in the treatment of acute coronary syndrome (ACS), myocardial infarction (MI), cerebrovascular disease and peripheral arterial disease. It is also indicated in combination with aspirin in patients undergoing percutaneous coronary intervention (PCI). Clopidogrel is a pro-drug which is converted into its active metabolite by several hepatic enzymes, especially CYP2C19. There is wide variability among patients in response to clopidogrel therapy, which is attributable to genetic variations at several locations of the CYP2C19 gene leading to either loss or gain of function of the enzyme. Here, we report a simple and fast multiplexed allele-specific PCR-based method to detect the clinically important variants of CYP2C19. CYP2C19*1 is the wild-type form of the gene that encodes an enzyme encodes with normal activity. Other variants such as, CYP2C19*2, CYP2C19*3, CYP2C19*4 result in loss of function, whereas CYP2C19*17 imparts gain of function. This multiplexed method does not call for high-end and expensive laboratory equipment, but can reliably detect clinically important CYP2C19 variants. This method was further validated by direct sequencing of the target variants. We applied this method to determine the genotypes of 673 Bangladeshi individuals. Our study showed that the CYP2C19*2 and CYP2C19*17 variants are present at high frequencies in Bangladeshi population. This method may be applied in routine genotyping of patients under clopidogrel regimen.