Table 3.

The CPIC Assignment of Likely CYP2C9 Phenotype based on Genotype (2020)

Likely phenotypea,bActivity scoreGenotypeExamples of diplotype
Normal metabolizer2An individual who has 2 normal function alleles*1/*1
Intermediate metabolizer1.5
1		An individual who has one normal function allele plus one decreased function allele; OR
one normal function allele plus one no function allele
OR
2 decreased function alleles		*1/*2
*1/*3
*2/*2
Poor metabolizer0.5
0		An individual who has one no function allele plus one decreased function allele; OR
2 no function alleles		*2/*3
*3/*3
Indeterminaten/aAn individual who has allele combinations with uncertainc or unknown function alleles*1/*7
*1/*10
*7/*10
*1/*58

Note: There are no known cases of CYP2C9 ultrarapid metabolizers .

a

Assignment of allele function and associated citations can be found at the CPIC website, also see CYP2C9 Allele Definition Table and CYP2C9 Allele Functionality Table in (2).

b

See the CYP2C9 Frequency Table for population-specific allele and phenotype frequencies. (19)

c

Alleles with moderate to limited evidence on their effect on CYP2C9 function.

This CPIC table has been adapted from (2).

From: Celecoxib Therapy and CYP2C9 Genotype

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