Identification and Characterization of CYP2D6*56B, an Allele Associated with the Poor Metabolizer Phenotype

Abstract

A 5-year-old African-American girl presented with a CYP2D6*4xN/*10 genotype that was discordant with her poor metabolizer phenotype determined with the probe drug dextromethorphan. Both phenotype and genotype were confirmed in repeat assessments, suggesting that the CYP2D6*10 allele carried a novel debilitating sequence variation(s). The rationale for this study was to resolve the discordance and to describe the novel non-functional allelic variant of CYP2D6 and its frequency in populations of different ethnic backgrounds. Clinical Pharmacology & Therapeutics (2007) 81, 817–820. doi:10.1038/sj.clpt.6100125; published online 28 March 2007