Polymorphisms of MDR1, CYP2C19 and P2Y12 genes in Indian population: effects on clopidogrel response

Abstract

Aims/objective: Influence of genetic variations on the response of clopidogrel, an antiplatelet drug is implicated. In the present study, the prevalence of single nucleotide polymorphisms of MDR1 (C3435T), CYP2C19 [CYP2C19*2 CYP2C19*3, CYP2C19*17] and P2Y12 (i-T744C) in Indian population and their effects on clopidogrel response was analyzed.

Methods and results: To analyze the prevalence of polymorphisms, 102 healthy individuals were recruited. Clopidogrel response was assessed by ADP induced platelet aggregation in clopidogrel naïve acute myocardial infarction (AMI) patients (n = 26) screened from 100 AMI cases, before loading dose of 300 mg, at 24 h before next dose and 6 days after on 75 mg per day and platelet aggregation inhibition (PAI) was calculated between these time intervals. Genotyping was carried out by PCR-based restriction enzyme digestion method for C3435T of MDR1 and i-T744C of P2Y12, by multiplex PCR for CYP2C19*2 (G681A) and CYP2C19*3 (G636A) and by nested PCR for CYP2C19*17 (C806T). The effect of the above mentioned genetic variations on PAI was analyzed. Variant allele of CYP2C19*3 was not observed while the prevalence of 3435T of MDR1 (0.524), CYP2C19*2 (681A, 0.352); i-744C of P2Y12 (0.088), as well as wild type allele CYP2C19*17 (C806, 0.897) associated with decrease clopidogrel response were observed. Trend toward poor response to clopidogrel was observed at 24 h with the variant genotypes of CYP2C19*2 and i-T744C of P2Y12 as compared to wild type.

Conclusion: The present study did show a trend toward impaired response of clopidogrel to inhibit platelet aggregation with variant genotypes of CYP2C19*2 and iT744C of P2Y12 compared to respective wild type genotype at 24 h.

Fig. 1

The restriction digestion pattern of MDR1 [C3435T] on 10% polyacrylamide gel electrophoresis. Lane 1: PCR product of 197 bp. Lane 2 and 4: heterozygous genotype (C3435T) showing two bands of 197 bp and 158 bp. Lane 3: O′ Range Ruler, 20 bp, ready to use DNA Ladder from MBI Fermentas. Lane 4: homozygous mutant genotype (T3435T) showing one band of 158 bp. Lane 6: wild type genotype (C3435C) showing one band of 197 bp.

Fig. 2

The restriction digestion pattern of CYP2C19*2 and CYP2C19*3 on 10% polyacrylamide gel electrophoresis. Lane 1: PCR products of 321 bp and 271 bp for CYP2C19*2 and CYP2C19*3 respectively. Lane 2–Lane 4: wild type genotype (*1 × *1) of CYP2C19*2 showing two bands 212 bp and 109 bp and wild type genotype (*1 × *1) of CYP2C19*3 showing two bands 175 bp and 196 bp. Lane 3: Heterozygous genotype (*1 × *2) of CYP2C19*2 showing three bands 321 bp, 212 bp and 109 bp  and wild type genotype (*1 × *1) of CYP2C19*3 showing two bands 175 bp and 196 bp. Lane 4: homozygous mutant genotype (*2 × *2) showing one band of 321 bp and wild type genotype (*1 × *1) of CYP2C19*3 showing two bands 175 bp and 196 bp. Lane 5: O′ Range Ruler, 20 bp, ready to use DNA Ladder from MBI Fermentas.

Fig. 3

The restriction digestion pattern of CYP2C19*17 on 10% polyacrylamide gel electrophoresis. Lane 1: PCR products of 143 bp. Lane 2: wild type genotype (*1 × *1) showing one band of 116 bp. Lane 3: Heterozygous genotype (*1 × *17) showing two bands 143 bp and 116 bp. Lane 4 to 6: homozygous mutant genotype (*17 × *17) showing one band of 143 bp. Lane 7: O′ Range Ruler, 20 bp, ready to use DNA Ladder from MBI Fermentas.

Fig. 4

The restriction digestion pattern of P2Y₁₂ [i-T744C] on 10% polyacrylamide gel electrophoresis. Lane 1: PCR products of 220 bp. Lane 2: wild type genotype (i-T744T) showing one band of 220 bp. Lane 3: heterozygous genotype (i-T744C) showing two bands 220 bp and 196 bp. Lane 4: Homozygous mutant genotype (i-C744C) showing one band of 196 bp. Lane 5: O′ Range Ruler, 20 bp, ready to use DNA Ladder from MBI Fermentas.