CYP3A4 and CYP3A5 Genotyping Recommendations: A Joint Consensus Recommendation of the Association for Molecular Pathology, Clinical Pharmacogenetics Implementation Consortium, College of American Pathologists, Dutch Pharmacogenetics Working Group of the Royal Dutch Pharmacists Association, European Society for Pharmacogenomics and Personalized Therapy, and Pharmacogenomics Knowledgebase.

The goals of the Association for Molecular Pathology (AMP) Clinical Practice Committee's Pharmacogenomics (PGx) Working Group are to define the key attributes of pharmacogenetic alleles recommended for clinical testing and a minimum set of variants that should be included in clinical PGx genotyping assays. This document series provide recommendations for a minimum panel of variant alleles ("Tier 1") and an extended panel of variant alleles ("Tier 2") that will aid clinical laboratories when designing assays for PGx testing. The AMP PGx Working Group considered functional impact of the variant alleles, allele frequencies in multiethnic populations, the availability of reference materials, as well as other technical considerations for PGx testing when developing these recommendations. The goal of this Working Group is to promote standardization of PGx genes/alleles testing across clinical laboratories. This document will focus on clinical CYP3A4 and CYP3A5 PGx testing that may be applied to all CYP3A4 and CYP3A5-related medications. These recommendations are not to be interpreted as prescriptive but to provide a reference guide.