A study of correlation between CYP2C9 gene polymorphism and Warfarin maintenance dose in anticoagulant therapy among Han people in Yunnan of China

In this study, we investigated the correlation between CYP2C9 gene polymorphism and maintenance dose of Warfarin in 300 patients who were the Han population derived from the Affiliated Yan An Hospital of Kunming Medical University in Yunnan Province of China, subjected to the operation of cardiac valve replacement and Warfarin oral administration post operation from 2008 to 2009 by detecting the genotypes and Allele Frequency at the three candidate loci (CYP2C9*2CYP2C9*3 and CYP2C9*c_65) of CYP2C9 gene from the blood samples. Polymerase chain reaction -restriction fragment length polymorphism (PCR-RFLP) assay and DNA sequencing were used to ascertain the genotypes and their corresponding distribution rate. The maintenance dose of Warfarin administered in anticoagulant therapy among the CYP2C9*3 genetypes found in our experiment showed: A/A wild type > A/C heterozygote>C/C homozygote, suggesting that patients with C mutation need the lowest maintenance dose of Warfarin among the three genotypes found in this study. Our results will shed a new light on the personalized medicine of Warfarin and provide basic and genetic experimental data and foundation for future studies with regard to multiple genes’ effect on Warfarin dorsage in anticogulantant therapy. Key words: Warfarin, maitenance dosage, CYP2C9, gene polymorphism, single nucleotide polymorphism (SNP), restriction fragment length polymorphism (RFLP), correlation.