2014 年 40 巻 7 号 p. 402-408
Warfarin is the most widely used oral anticoagulant for the prevention of thrombotic events and for the treatment of a confirmed episode of venous thrombosis. However, it has a narrow therapeutic range and there is large inter-individual variation in dose requirements. In particular, the anticipated side effects of warfarin could lead to serious problems. Therefore, warfarin is expected to be prescribed in response to the individual before drug administration. Recently, this variability has been accounted for by several single nucleotide polymorphisms (SNPs), including CYP2C9*3 and vitamin K epoxide reductase complex subunit 1 (VKORC1) -1639G>A. We established a new direct TaqMan PCR genotyping assay of the most common allelic variants of CYP2C9 and VKORC1 using saliva samples that are put on water-soluble paper without DNA extraction. A total of 186 healthy Japanese subjects participated in each genotype determination of the allele frequencies of CYP2C9 and VKORC1 by the TaqMan PCR and the duplex PCR-RFLP methods. Both methods yielded identical results. Therefore, our newly developed direct TaqMan PCR method has been shown to have sufficient accuracy. Furthermore, this method could reduce both the time and effort involved, as well as considerably reduce the risk of contamination, since the DNA extraction step is eliminated. We expect that this simple genotyping method will be useful in achieving personalized medication in the near future.