Table 1.

Clinical Allele Function Assignment from CPIC of Selected CYP2D6 Alleles

Allele typeCYP2D6 allelesValue for activity score calculation
Normal function *1, *2, *35 1
Decreased function *9, *17, *29, *41 0.5
“Severely” decreased function# *10 0.25
No function *3, *4, *5, *6, *40 0
Increased function *1x2, *2x2 2

For a comprehensive list of CYP2D6 alleles, please See PharmVar. Table updated on 13 October 2021, see the allele functionality table from CPIC for the most recent function assignments.

#

CPIC does not use the term “severely decreased function” to describe the CYP2D6*10 allele, this designation has been provided for clarity in this document.

From: CYP2D6 Overview: Allele and Phenotype Frequencies

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Pratt VM, Scott SA, Pirmohamed M, et al., editors.
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