Allele frequency distribution of CYP2C19*2 allelic variants associated with clopidogrel resistance in cardiac patients

Rehman,Kashif  Ur; Akhtar,Tanveer; Sabar,Muhammad  Farooq; Tariq,Muhammad  Akram

doi:10.3892/etm.2015.2493

Allele frequency distribution of CYP2C19*2 allelic variants associated with clopidogrel resistance in cardiac patients

Authors:
- Kashif Ur Rehman
- Tanveer Akhtar
- Muhammad Farooq Sabar
- Muhammad Akram Tariq
View Affiliations

Affiliations: Molecular Biology and Parasitology Laboratory, Department of Zoology, University of the Punjab, Lahore 54590, Pakistan, Center for Applied Molecular Biology (CAMB), Thokar Niaz Baig, Lahore 53700, Pakistan, Department of Biosciences, COMSATS Institute of Information Technology, Sahiwal 57000, Pakistan
Published online on: May 14, 2015 https://doi.org/10.3892/etm.2015.2493
Pages: 309-315

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )

Metrics: Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )

Cited By (CrossRef): 0 citations Loading Articles...

Abstract

Drug resistance is a phenomenon that has become a critical issue in medical practice. Such is the case in the response to clopidogrel treatment, which is variable inter‑individually and inter‑ethnically due to genetic polymorphisms in the cytochrome P40 (CYP) gene. Clopidogrel is an anti‑platelet agent administered to cardiac patients in the form of a prodrug, which is further metabolized into an active form by CYP enzymes. There are many allelic variants of the CYP gene that are involved in clopidogrel resistance, of which CYP2C19*2 has been demonstrated to be one of the most significant loss‑of‑function alleles. In the present study, 100 cardiac patients with percutaneous coronary intervention (PCI) or acute coronary syndrome (ACS) who were undergoing treatment with clopidogrel were selected and the patients were analyzed for CYP2C19*2 allelic variants using an allele‑specific primer extension polymerase chain reaction method. The variant amplicons were visualized on gel and validated by Sanger sequencing. The observed allelic frequency distribution of CYP2C19*2 variants was 18% heterozygous for CYP2C19*2 A/C/G variants, 35% heterozygous for A/G variants, 13% heterozygous for C/G variants, 6% heterozygous for A/C variants, 7% homozygous for A variant, 5% homozygous for C variant and 16% homozygous for G wild‑type. Furthermore, tri‑allelic single nucleotide polymorphisms (SNPs) were identified in the CYP2C19*2 allele in cardiac patients for the first time, to the best of our knowledge; these were CYP2C19*2 A/C/G SNPs (18%). The overall frequency observed for new allelic variant C of CYP2C19*2 was 42%. These results suggested that there are significant inter‑ethnic variations in the allelic frequencies of CYP2C19*2, which may be responsible for the variable clopidogrel response in cardiac patients.

View Figures

View References

1	Ding Z, Kim S, Dorsam RT, Jin J and Kunapuli SP: Inactivation of the human P2Y12 receptor by thiol reagents requires interaction with both extracellular cysteine residues, Cys17 and Cys270. Blood. 101:3908–3914. 2003. View Article : Google Scholar : PubMed/NCBI
2	Alwan A: Global status report on noncommunicable diseases 2010. World Health Organization; Geneva: 2010
3	Mendis S, Puska P and Norrving B: Global Atlas on cardiovascular disease prevention and control. World Health Organization in collaboration with the World Heart Federation and the World Stroke Organization; Geneva: 2011
4	Angiolillo DJ, Fernandez-Ortiz A, Bernardo E, et al: Identification of low responders to a 300-mg clopidogrel loading dose in patients undergoing coronary stenting. Thrombosis Res. 115:101–108. 2005. View Article : Google Scholar
5	Antman EM, Hand M, Armstrong PW, et al: 2007 focused update of the ACC/AHA 2004 guidelines for the management of patients with ST-elevation myocardial infarction: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the Canadian Cardiovascular Society endorsed by the American Academy of Family Physicians: 2007 Writing Group to review new evidence and update the ACC/AHA 2004 guidelines for the management of patients with ST-elevation myocardial infarction, writing on behalf of the 2004 Writing Committee. Circulation. 117:296–329. 2008. View Article : Google Scholar : PubMed/NCBI
6	Hulot JS, Bura A, Villard E, et al: Cytochrome P450 2C19 loss-of-function polymorphism is a major determinant of clopidogrel responsiveness in healthy subjects. Blood. 108:2244–2247. 2006. View Article : Google Scholar : PubMed/NCBI
7	Sibbing D, Stegherr J, Latz W, et al: Cytochrome P450 2C19 loss-of-function polymorphism and stent thrombosis following percutaneous coronary intervention. Eur Heart J. 30:916–922. 2009. View Article : Google Scholar : PubMed/NCBI
8	Brandt JT, Close SL, Iturria SJ, et al: Common polymorphisms of CYP2C19 and CYP2C9 affect the pharmacokinetic and pharmacodynamic response to clopidogrel but not prasugrel. J Throm Haemost. 5:2429–2436. 2007. View Article : Google Scholar
9	Giusti B, Gori AM, Marcucci R, et al: Cytochrome P450 2C19 loss-of-function polymorphism, but not CYP3A4 IVS10 + 12 G/A and P2Y12 T744C polymorphisms, is associated with response variability to dual antiplatelet treatment in high-risk vascular patients. Pharmacogenet Genom. 17:1057–1064. 2007. View Article : Google Scholar
10	Trenk D, Hochholzer W, Fromm MF, et al: Cytochrome P450 2C19 681G>A polymorphism and high on-clopidogrel platelet reactivity associated with adverse 1-year clinical outcome of elective percutaneous coronary intervention with drug-eluting or bare-metal stents. J Am Coll Cardiol. 51:1925–1934. 2008. View Article : Google Scholar : PubMed/NCBI
11	Fontana P, Senouf D and Mach F: Biological effect of increased maintenance dose of clopidogrel in cardiovascular outpatients and influence of the cytochrome P450 2C19*2 allele on clopidogrel responsiveness. Thromb Res. 121:463–468. 2008. View Article : Google Scholar : PubMed/NCBI
12	Ferreiro JL and Angiolillo DJ: Clopidogrel response variability: current status and future directions. Thromb Haemost. 102:7–14. 2009.PubMed/NCBI
13	Chan MY: Clopidogrel pharmacogenetics of east, south and other Asian populations. Euro Heart J Suppl. 14:A41–A42. 2012. View Article : Google Scholar
14	Rehman K, Tariq MA and Akhtar T: Clopidogrel resistance and its genetics. Pak Heart J. 46:151–158. 2013.
15	Abid L, Laroussi L, Bahloul A, Siala A, Abdelhédi R, Kharrat N, Hentati M and Kammoun S: Impact of cytochrome P450 2C19*2 polymorphism on the clinical cardiovascular events after stent implantation in patients receiving clopidogrel of a southern Tunisian region. World J Cardiovasc Dis. 3:4–10. 2013. View Article : Google Scholar
16	Hirotsu N, Murakami N, Kashiwagi T, Ujiie K and Ishimaru K: Protocol: a simple gel-free method for SNP genotyping using allele-specific primers in rice and other plant species. Plant Methods. 6:122010. View Article : Google Scholar : PubMed/NCBI
17	Aynacioglu AS, Sachsc C, Bozkurt A, et al: Low frequency of defective alleles of cytochrome P450 enzymes 2C19 and 2D6 in the Turkish population. Clin Pharmacol Ther. 66:185–192. 1999. View Article : Google Scholar : PubMed/NCBI
18	Lamba JK, Dhiman RK and Kohli KK: Genetic polymorphism of the hepatic cytochrome P450 2C19 in north Indian subjects. Clin Pharmacol Ther. 63:422–427. 1998. View Article : Google Scholar : PubMed/NCBI
19	Ozawa S, Soyama A, Saeki M, et al: Ethnic differences in genetic polymorphisms of CYP2D6, CYP2C19, CYP3As and MDR1/ABCB1. Drug Metabol Pharmacokinet. 19:83–95. 2004. View Article : Google Scholar
20	Zand N, Tajik N, Moghaddam AS and Milanian I: Genetic polymorphisms of cytochrome P450 enzymes 2C9 and 2C19 in a healthy Iranian population. Clin Exp Pharmacol Physiol. 34:102–105. 2007. View Article : Google Scholar : PubMed/NCBI
21	Sukasem C, Tunthong R, Chamnanphon M, et al: CYP2C19 polymorphisms in the Thai population and the clinical response to clopidogrel in patients with atherothrombotic-risk factors. Pharmgenomics Pers Med. 6:85–91. 2013.PubMed/NCBI
22	Hodgkinson A and Eyre-Walker A: Human triallelic sites: evidence for a new mutational mechanism? Genetics. 184:233–241. 2010. View Article : Google Scholar : PubMed/NCBI
23	Coulondre C, Miller JH, Farabaugh PJ and Gilbert W: Molecular-basis of base substitution hotspots in Escherichia coli. Nature. 274:775–780. 1978. View Article : Google Scholar : PubMed/NCBI
24	Blake RD, Hess ST and Nicholson-Tuell J: The influence of nearest neighbors on the rate and pattern of spontaneous point mutations. J Mol Evol. 34:189–200. 1992. View Article : Google Scholar : PubMed/NCBI
25	Zhao Z, Fu YX, Hewett-Emmett D and Boerwinkle E: Investigating single nucleotide polymorphism (SNP) density in the human genome and its implications for molecular evolution. Gene. 312:207–213. 2003. View Article : Google Scholar : PubMed/NCBI
26	Hwang DG and Green P: Bayesian Markov chain Monte Carlo sequence analysis reveals varying neutral substitution patterns in mammalian evolution. Proc Natl Acad Sci USA. 101:13994–14001. 2004. View Article : Google Scholar : PubMed/NCBI
27	Bird AP: DNA methylation and the frequency of CpG in animal DNA. Nucleic Acids Res. 8:1499–1504. 1980. View Article : Google Scholar : PubMed/NCBI
28	Mega JL, Close SL, Wiviott SD, et al: Cytochrome P-450 polymorphisms and response to clopidogrel. New Engl J Med. 360:354–362. 2009. View Article : Google Scholar : PubMed/NCBI
29	Jinnai T, Horiuchi H, Makiyama T, et al: Impact of CYP2C19 polymorphisms on the antiplatelet effect of clopidogrel in an actual clinical setting in Japan. Circ J. 73:1498–1503. 2009. View Article : Google Scholar : PubMed/NCBI