OBJECTIVETo detect the single nucleotide polymorphisms of clopidogrel metabolism related genes (CYP2C19, ABCB1 and PON1) in Chinese patients with acute coronary syndrome (ACS) by genotype analysis.

METHODSGenetic analysis was performed in patients admitted to Fuwai Hospital from 2005 to 2008 with ACS within 4 weeks. The detection of polymorphisms was performed by TaqMan real-time PCR method. The alleles genotyped were CYP2C19 *2-*8, *17, ABCB1 C3435T, PON1 Q192R and PON1 L55M. Minor allele frequency (MAF) was calculated. Patients were classified as one of the 5 categories by clopidogrel metabolizer phenotypes as extensive [without any "loss-of-function" (LOF) allele *2-*8 or "gain-of-function" (GOF) allele *17], intermediate (with only one LOF allele), Poor (with two or more LOF alleles), ultra (with one or two GOF alleles) or unknown (with one LOF allele and one GOF allele).

RESULTSA total of 2800 ACS patients were enrolled [mean age (59.0 ± 12.3) years and 2236 males (79.9%)]. There were 74% patients with ST-segment elevation myocardial infarction (STEMI, n = 2072), 22.0% patients with non-ST-segment elevation myocardial infarction (NSTEMI, n = 617) and 4.0% patients with unstable angina (UA, n = 111). The minor allele frequency (MAF) for each genotype of CYP2C19 *2, *3, *4, *17 was 28.7%, 4.6%, 0.1% and 1.2%, respectively. There was no LOF allele *5-*8 in the study population. The MAF for ABCB1 C3435T, PON1 Q192R and PON1 L55M was 39.4%, 37.8% and 4.4%, respectively. Clopidogrel metabolizer groups were defined as extensive in 41.7%, intermediate in 45.6%, poor in 10.3%, ultra in 1.9% and unknown in 0.6% patients, respectively. There were no significant differences for all genotypes between males and females. Total LOF carriers of CYP2C19 were 56.4% and GOF carriers were 2.5%.

CONCLUSIONSOur study demonstrated a high distribution of the LOF allele of CYP2C19 in China ACS population.