Effects of CYP2C9 and VKORC1 genetic polymorphisms in Chinese Han population on maintenance dosage of warfarin

Abstract

Objective To analyze CYP2C9 and VKORC1 gene polymorphisms in Chinese Han population and their correlation with the maintenance dosage of warfarin. Methods From October 2017 to April 2018, 458 Chinese Han patients (213 males and 245 females, aged from 26 to 94 years old) who underwent coagulation analysis in Peking University People′s Hospital were included in this retrospective study. PCR-Fluorescent probe method was applied to detect CYP2C9*3 and VKORC1-1639A>G gene polymorphisms in 458 patients, and among them, 130 patients who took warfarin for anticoagulant therapy and reached the international standard ratio of prothrombin time (INR) within the range of 2.0-3.0 were recorded. The basic information, dosage of warfarin and INR were also recorded. The statistical analysis data were compared with the reference table of recommended dosage of warfarin for different genotypes of patients recommended by FDA and the formula of predicted dosage of warfarin was simply verified by SPSS. Results Among the 458 patients who took anticoagulant therapy, the genotype frequencies of CYP2C9*1/*1(AA), CYP2C9*1/*3(AC) and CYP2C9*3/*3(CC) were 90.8%, 8.5%, and 0.7%; the genotype frequencies of VKORC1-1639GG and VKORC1-1639AG were 0.9% and 14.2%; the genotype frequencies of VKORC1-1639AA was 84.9%. After INR was reached, the results showed that the variant CYP2C9*1/*3 and CYP2C9*3/*3 required lower daily maintain dosage [(2.92±1.29) mg] than wild-type CYP2C9*1/*1 patients did [(3.91±1.63) mg], with statistically significant difference (P=0.018). And variant VKORC1-AA required lower daily maintain dosage [(3.68±1.64) mg] than variant VKORC1-AG patients did [(4.54±1.29) mg], with statistically significant difference (P=0.001). The application dosage of warfarin in patients with different VKORC1+CYP2C9 genotypes was consistent with the recommended dosage of the FDA reference table. The prediction accuracy of miao 2007 formula was lower than that of IWPC formula, and 94.1% of patients′ dosages of warfarin were underestimated. Conclusion Patients with CYP2C9*3 or VKORC1-AA genotype required lower warfarin dosage. The CYP2C9 and VKORC1 gene polymorphisms had a certain correlation with maintenance dosage of warfarin. Key words: Warfarin; Polymorphism, genetic; Cytochrome P-450 CYP2C9; Vitamin K epoxide reductases; Dose-respanse relationship,drug