Standardised interpretation of CYP2D6 genotypes and phenotypes : from lab reports to clinical recommendations

Abstract

Interpretation of CYP2D6 genotypes to assign phenotypes is critical since clinical recommendations are based on phenotypes. Inconsistencies in CYP2D6 classifications across laboratories have been identified over the years. Discussions include weather (i) an activity score of 1 should be considered as a genetic normal or intermediate metaboliser, and (ii) crude grouping of allelic variants, which may be particularly relevant for CYP2D6 (Gaedigk et all, 2018). The CYP2D6 Genotype to Phenotype Standarisation Project addressed concerns of discordant phenotype assignments reaching a consensus (Caudle et al, 2020).