Table 4.

CYP2D6 phenotype inference based on genotype information

CYP2D6
Ultrarapid metabolizers
AS > 2.25	*1/*1xN, *1/*2xN, *2/*2xN *1x2/*9	Duplicated normal function alleles in combination with (1) a decreased function allele other than CYP2D6*10 or (2) another normal function allele
Normal metabolizers
AS = 2.25	*1x2/*10, *2x2/*10	Duplicated normal function alleles in combination with CYP2D6*10
AS = 2.0	*1/*1, *1/*2	2 normal function alleles
AS = 1.5	*1/*41, *1/*9	A normal function allele plus a decreased function allele other than CYP2D6*10
AS = 1.25	*1/*10	CYP2D6*10 plus a normal function allele
Intermediate metabolizers
AS = 1.0	*41/*41, *1/*5	2 decreased function alleles other than CYP2D6*10
AS = 0.75	*9/*10, *10/*41	CYP2D6*10 plus another decreased function allele
AS = 0.5	*4/*41, *10/*10	CYP2D6*10/*10
AS = 0.25	*4/*10	CYP2D6*10 plus a no function allele
Poor metabolizers
AS = 0	*3/*4, *4/*4, *5/*5, *5/*6	2 no function alleles

Information obtained from Clinical Pharmacogenetics Implementation Consortium (CPIC) and Dutch Pharmacogenetics Working Group standardizing consensus on CYP2D6 genotype to phenotype translation. ¹¹¹

AS, activity score; CYP2D6, cytochrome P450 2D6.