Table 1.

Selected gene alleles, their causative variations, and associated phenotypes

Gene and AlleleCausative Variation(s)Phenotype
CYP2C9
 *2rs1799853 (T)Decreased function
 *3rs1057910 (C)Decreased function
CYP4F2
 *3rs2108622 (T)Decreased function
CYP3A5
 *3rs776746 (C)Decreased function
CYP2C19
 *2rs4244285 (A)Decreased function
 *3rs4986893 (A)Decreased function
 *17rs12248560 (T)Increased function
TPMT
 *2rs1800462 (G)Decreased function
 *3Ars1800460 (T); rs1142345 (C)Decreased function
 *3Brs1800460 (T)Decreased function
 *3Crs1142345 (C)Decreased function
 *4rs1800584 (T)Decreased function
VKORC1
 −1639G>Ars9923231 (T)Increased sensitivity to warfarin
SLCO1B1
 *5rs4149056 (C)Decreased function
HLA-B
 *58:01N/AIncreased SCAR risk
  • TPMT, thiopurine methyltransferase; N/A, not applicable; SCAR, severe cutaneous adverse reaction.