Effects of rare CYP2C9 alleles on stable warfarin doses in Chinese Han patients with atrial fibrillation

Aim:Gene polymorphisms are critical in warfarin dosing variation. Here, the role of rareCYP2C9alleles on warfarin doses in Chinese Han patients was investigated.Methods:A retrospective study recruited 681 warfarin treated atrial fibrillation patients. The genetic and clinical data were collected. Dose-related variables were selected by univariate analyses and the warfarin-dosing algorithm was derived by multivariate regression analysis.Results:Three rareCYP2C9alleles (CYP2C9*13, *16 and *60) were associated with lower stable doses. Inclusion of the rareCYP2C9alleles in the prediction model added an extra 3.7% warfarin dose predictive power.Conclusion:CYP2C9*13, *16 and *60 was associated with lower stable warfarin doses in Chinese patients. The algorithm including rareCYP2C9alleles tends to more accurately predict stable warfarin doses.