Association between VKORC1 gene polymorphism and warfarin dose requirement and frequency of VKORC1 gene polymorphism in patients from Kerman province.

Warfarin is an anticoagulant prescribed in the treatment and prevention of thrombosis. Variation in dose requirements is different for everyone, and genetic factors have an effect on dose variation. Polymorphism of vitamin K epoxide reductase complex 1 (VKORC1) gene is identified as the main genetic factor involved in warfarin dosage requirement variations. This study aims to determine the frequency of VKORC1 polymorphism in patients using warfarin from Kerman city and investigated association between VKORC1 gene polymorphism and patient characteristics with warfarin dose requirement. A total of 112 patients taking warfarin with stable dose requirements enrolled in the study. DNA samples from these patients were genotyped for VKORC1 gene polymorphism by using the polymerase chain reaction restriction fragment length polymorphism method (PCR-RFLP) and examined associations between demographic characteristics (e.g. age, sex, smoking, etc.) and genetic factors with maintenance dose of warfarin. The most common genotype was VKORC1 GA (48.2%). genotype frequency subjects carried VKORC1 GG and AA were 39.3% and 12.5%, respectively. In addition, a significant relationship was found between VKORC1-1639G>A and the daily dose of warfarin (P = 0.011, R2 = 0.080). The frequencies of the VKORC1-1639 A alleles were significantly lower than VKORC1-1639 G alleles and required fewer warfarin dose.