The anticoagulation DNA panel tests for genetic variants in the CYP2C9 and VKORC1 genes that account for >50% of variation in warfarin response. Genotyping may reduce the need for INR surveillance as genotype-based dosing regimens are established.
Variants tested by the anticoagulation panel include
CYP2C9 *1 (normal)
CYP2C9 *2 (c.430C>T; Arg144Cys)
CYP2C9 *3 (c.1075A>C; Ile359Leu)
VKORC1 *1 (normal)
VKORC1 *2 promoter variant (c. " “1639G>A)
Normal values:
CYP2C9 *1/*1
VKORC1 *1/*1
Use
Initiating warfarin (Coumadin) therapy
Optimizing dosing for warfarin
Limitations
The results of a genetic test may be affected by DNA rearrangements, blood transfusion, bone marrow transplantation, or rare sequence variations.