CYP2D6 phenotype, tamoxifen, and risk of contralateral breast cancer in the WECARE Study

Breast Cancer Research

Table 2 Summary of genotyped CYP2D6 variants and associated phenotype

Allele	SNP (RefSeq)^a	Variant	CYP2D6 activity	Activity score value^b	Phenotype
CYP2D6*1	NA	Wild type	Normal	1	EM
CYP2D6*2	rs16947, rs1135840	2850C > T, 4180G > C	Normal	1	EM
CYP2D6*3	rs35742686	2549delA	Inactive	0	EM
CYP2D6*4	rs3892097	1846G > A,	Inactive	0	PM
CYP2D6*5	NA	Full gene deletion	Inactive	0	PM
CYP2D6*6	rs5030655	1707delT	Inactive	0	PM
CYP2D6*9	rs5030656	2615_2617del AAG	Reduced	0.5	IM
CYP2D6*10	rs1065852, rs1135840	100C > T, 4180G > C	Reduced	0.5	IM
CYP2D6*41	rs28371725	2988G > A	Reduced	0.5	IM

SNP single nucleotide polymorphism, RefSeq reference sequence, NA not applicable, EM extensive metabolizer, PM poor metabolizer, IM intermediate metabolizer
^aWhere more than one SNP is listed for a given allele, a variant at only one loci needed to be present to classify an individual as having that allele
^bActivity score (AS) calculated as the sum of the activity score value for each allele held by an individual for a range of values from 0 to 2. One exception to this is the instance of individuals carrying two IM (reduced activity) alleles, where we provided a distinction between individuals classified as EM/PM (AS = 1), IM/IM (AS = 0.75), and IM/PM (AS = 0.5)

ISSN: 1465-542X