Browsing by Subject "Cytochrome P-450 CYP3A"

Now showing 1 - 6 of 6
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    Characterization of Reference Materials for CYP3A4 and CYP3A5: A GeT-RM Collaborative Project
    (Elsevier, 2023) Gaedigk, Andrea; Boone, Erin C.; Turner, Amy J.; van Schaik, Ron H.N.; Cheranova, Dilyara; Wang, Wendy Y.; Broeckel, Ulrich; Granfield, Caitlin A.; Hodge, Jennelle C.; Ly, Reynold C.; Lynnes, Ty C.; Mitchell, Matthew W.; Moyer, Ann M.; Oliva, Jason; Kalman, Lisa V.; Medical and Molecular Genetics, School of Medicine
    Pharmacogenetic testing for CYP3A4 is increasingly provided by clinical and research laboratories; however, only a limited number of quality control and reference materials are currently available for many of the CYP3A4 variants included in clinical tests. To address this need, the Division of Laboratory Systems, CDC-based Genetic Testing Reference Material Coordination Program (GeT-RM), in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Institute for Medical Research, has characterized 30 DNA samples derived from Coriell cell lines for CYP3A4. Samples were distributed to five volunteer laboratories for genotyping using a variety of commercially available and laboratory-developed tests. Sanger and next-generation sequencing were also utilized by some of the laboratories. Whole-genome sequencing data from the 1000 Genomes Projects were utilized to inform genotype. Twenty CYP3A4 alleles were identified in the 30 samples characterized for CYP3A4: CYP3A4∗4, ∗5, ∗6, ∗7, ∗8, ∗9, ∗10, ∗11, ∗12, ∗15, ∗16, ∗18, ∗19, ∗20, ∗21, ∗22, ∗23, ∗24, ∗35, and a novel allele, CYP3A4∗38. Nineteen additional samples with preexisting data for CYP3A4 or CYP3A5 were re-analyzed to generate comprehensive reference material panels for these genes. These publicly available and well-characterized materials can be used to support the quality assurance and quality control programs of clinical laboratories performing clinical pharmacogenetic testing.
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    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
    (Elsevier, 2023) Pratt, Victoria M.; Cavallari, Larisa H.; Fulmer, Makenzie L.; Gaedigk, Andrea; Hachad, Houda; Ji, Yuan; Kalman, Lisa V.; Ly, Reynold C.; Moyer, Ann M.; Scott, Stuart A.; van Schaik, Ron H. N.; Whirl-Carrillo, Michelle; Weck, Karen E.; Medical and Molecular Genetics, School of Medicine
    The goals of the Association for Molecular Pathology 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 provides 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 Association for Molecular Pathology PGx Working Group considered functional impact of the variant alleles, allele frequencies in multiethnic populations, the availability of reference materials, and other technical considerations for PGx testing when developing these recommendations. The goal of this Working Group is to promote standardization of PGx gene/allele 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.
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    The CYP3A5 genotypes of both liver transplant recipients and donors influence the time-dependent recovery of tacrolimus clearance during the early stage following transplantation
    (Wiley, 2021-10) Huang, Li; Assiri, Abdullah A.; Wen, Peihao; Zhang, Kun; Fan, Junwei; Xing, Tonghai; Liu, Yuan; Zhang, Jinyan; Wang, Zhaowen; Su, Zhaojie; Chen, Jiajia; Xiao, Yi; Wang, Rui; Na, Risi; Yuan, Liyun; Liu, Dehua; Xia, Junjie; Zhong, Lin; Liu, Wanqing; Guo, Wenzhi; Overholser, Brian R.; Peng, Zhihai; Medicine, School of Medicine
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    PharmVar GeneFocus: CYP3A5
    (Wiley, 2022) Rodriguez-Antona, Cristina; Savieo, Jessica L.; Lauschke, Volker M.; Sangkuhl, Katrin; Drögemöller, Britt I.; Wang, Danxin; van Schaik, Ron H. N.; Gilep, Andrei A.; Prakasam Peter, Arul; Boone, Erin C.; Ramey, Bronwyn E.; Klein, Teri E.; Whirl-Carrillo, Michelle; Pratt, Victoria M.; Gaedigk, Andrea; Medicine, School of Medicine
    The Pharmacogene Variation Consortium (PharmVar) catalogs star (*) allele nomenclature for the polymorphic human CYP3A5 gene. Genetic variation within the CYP3A5 gene locus impacts the metabolism of several clinically important drugs, including the immunosuppressants tacrolimus, sirolimus, cyclosporine, and the benzodiazepine midazolam. Variable CYP3A5 activity is of clinical importance regarding tacrolimus metabolism. This GeneFocus provides a CYP3A5 gene summary with a focus on aspects regarding standardized nomenclature. In addition, this review also summarizes recent changes and updates, including the retirement of several allelic variants and provides an overview of how PharmVar CYP3A5 star allele nomenclature is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).
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    Physiologically-Based Pharmacokinetic Modeling Characterizes the CYP3A-Mediated Drug-Drug Interaction Between Fluconazole and Sildenafil in Infants
    (Wiley, 2021) Salerno, Sara N.; Edginton, Andrea; Gerhart, Jacqueline G.; Laughon, Matthew M.; Ambalavanan, Namasivayam; Sokol, Gregory M.; Hornik, Chi D.; Stewart, Dan; Mills, Mary; Martz, Karen; Gonzalez, Daniel; Pediatrics, School of Medicine
    Physiologically-based pharmacokinetic (PBPK) modeling can potentially predict pediatric drug-drug interactions (DDIs) when clinical DDI data are limited. In infants for whom treatment of pulmonary hypertension and prevention or treatment of invasive candidiasis are indicated, sildenafil with fluconazole may be given concurrently. To account for developmental changes in cytochrome P450 (CYP) 3A, we determined and incorporated fluconazole inhibition constants (KI ) for CYP3A4, CYP3A5, and CYP3A7 into a PBPK model developed for sildenafil and its active metabolite, N-desmethylsildenafil. Pharmacokinetic (PK) data in preterm infants receiving sildenafil with and without fluconazole were used for model development and evaluation. The simulated PK parameters were comparable to observed values. Following fluconazole co-administration, differences in the fold change for simulated steady-state area under the plasma concentration vs. time curve from 0 to 24 hours (AUCss,0-24 ) were observed between virtual adults and infants (2.11-fold vs. 2.82-fold change). When given in combination with treatment doses of fluconazole (12 mg/kg i.v. daily), reducing the sildenafil dose by ~ 60% resulted in a geometric mean ratio of 1.01 for simulated AUCss,0-24 relative to virtual infants receiving sildenafil alone. This study highlights the feasibility of PBPK modeling to predict DDIs in infants and the need to include CYP3A7 parameters.