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Cheng S, Al-Kofahi M, Leeder JS, Brown JT. Population Pharmacokinetic Analysis of Atomoxetine and its Metabolites in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder. Clin Pharmacol Ther 2024; 115:1033-1043. [PMID: 38117180 DOI: 10.1002/cpt.3155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023]
Abstract
Atomoxetine (ATX) is a non-stimulant used to treat attention-deficit/hyperactivity disorder (ADHD) and systemic exposure is highly variable due to polymorphic cytochrome P450 2D6 (CYP2D6) activity. The objective of this study was to characterize the time course of ATX and metabolites (4-hydroxyatomoxetine (4-OH); N-desmethylatomoxetine (NDA); and 2-carboxymethylatomoxetine (2-COOH)) exposure following oral ATX dosing in children with ADHD to support individualized dosing. A nonlinear mixed-effect modeling approach was used to analyze ATX, 4-OH, and NDA plasma and urine, and 2-COOH urine profiles obtained over 24-72 hours from children with ADHD (n = 23) following a single oral ATX dose. Demographics and CYP2D6 activity score (AS) were evaluated as covariates. Simulations were performed to explore the ATX dosing in subjects with various CYP2D6 AS. A simultaneous pharmacokinetic modeling approach was used in which a model for ATX, 4-OH, and NDA in plasma and urine, and 2-COOH in urine was developed. Plasma ATX, 4-OH, and NDA were modeled using two-compartment models with first-order elimination. CYP2D6 AS was a significant determinant of ATX apparent oral clearance (CL/F), fraction metabolized to 4-OH, and systemic exposure of NDA. CL/F of ATX varied almost 7-fold across the CYP2D6 AS groups: AS 2: 20.02 L/hour; AS 1: 19.00 L/hour; AS 0.5: 7.47 L/hour; and AS 0: 3.10 L/hour. The developed model closely captures observed ATX, 4-OH, and NDA plasma and urine, and 2-COOH urine profiles. Application of the model shows the potential for AS-based dosing recommendations for improved individualized dosing.
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Affiliation(s)
- Shen Cheng
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, USA
| | - Mahmoud Al-Kofahi
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota, USA
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Jacob T Brown
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota College of Pharmacy, Duluth, Minnesota, USA
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Turner AJ, Nofziger C, Ramey BE, Ly RC, Bousman CA, Agúndez JAG, Sangkuhl K, Whirl-Carrillo M, Vanoni S, Dunnenberger HM, Ruano G, Kennedy MA, Phillips MS, Hachad H, Klein TE, Moyer AM, Gaedigk A. PharmVar Tutorial on CYP2D6 Structural Variation Testing and Recommendations on Reporting. Clin Pharmacol Ther 2023; 114:1220-1237. [PMID: 37669183 PMCID: PMC10840842 DOI: 10.1002/cpt.3044] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/23/2023] [Indexed: 09/07/2023]
Abstract
The Pharmacogene Variation Consortium (PharmVar) provides nomenclature for the highly polymorphic human CYP2D6 gene locus and a comprehensive summary of structural variation. CYP2D6 contributes to the metabolism of numerous drugs and, thus, genetic variation in its gene impacts drug efficacy and safety. To accurately predict a patient's CYP2D6 phenotype, testing must include structural variants including gene deletions, duplications, hybrid genes, and combinations thereof. This tutorial offers a comprehensive overview of CYP2D6 structural variation, terms, and definitions, a review of methods suitable for their detection and characterization, and practical examples to address the lack of standards to describe CYP2D6 structural variants or any other pharmacogene. This PharmVar tutorial offers practical guidance on how to detect the many, often complex, structural variants, as well as recommends terms and definitions for clinical and research reporting. Uniform reporting is not only essential for electronic health record-keeping but also for accurate translation of a patient's genotype into phenotype which is typically utilized to guide drug therapy.
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Affiliation(s)
- Amy J Turner
- Department of Pediatrics, Children’s Research Institute, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- RPRD Diagnostics LLC, Wauwatosa, Wisconsin, USA
| | | | | | - Reynold C Ly
- Department of Medical and Molecular Genetics, Division of Diagnostic Genomics, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Chad A Bousman
- Department of Medical Genetics, University of Calgary, Calgary, Alberta, Canada
| | - José AG Agúndez
- University of Extremadura, Cáceres, Spain
- Institute of Molecular Pathology Biomarkers, Cáceres, Spain
| | - Katrin Sangkuhl
- Department of Biomedical Data Science, Stanford University, Stanford, California, USA
| | | | | | - Henry M Dunnenberger
- Mark R. Neaman Center for Personalized Medicine, NorthShore University Health System, Evanston, Illinois, USA
| | - Gualberto Ruano
- Institute of Living, Hartford Hospital (Hartford CT) and Department of Psychiatry, University of Connecticut School of Medicine (Farmington CT), USA
| | - Martin A Kennedy
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | | | - Houda Hachad
- Houda Hachad, Department of Clinical Operations, AccessDx Laboratories, Houston, Texas, USA
| | - Teri E Klein
- Departments of Biomedical Data Science and Medicine (BMIR), Stanford University, Stanford, California, USA
| | - Ann M Moyer
- Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Andrea Gaedigk
- Children’s Mercy Research Institute (CMRI), Kansas City, Missouri, USA
- School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, USA
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Scantamburlo G, Nofziger C, Paulmichl M, Vanoni S. Genetic analysis of the equine orthologues for human CYP2D6: unraveling the complexity of the CYP2D family in horses. Front Vet Sci 2023; 10:1188633. [PMID: 37929279 PMCID: PMC10620600 DOI: 10.3389/fvets.2023.1188633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 09/25/2023] [Indexed: 11/07/2023] Open
Abstract
Introduction Because of their importance as companion animals or as racehorses, horses can be treated with various drugs. Although it is known that drug withdrawal times can vary for each horse, pharmacogenetics for these animals has not been adequately studied and requires further development. Since CYP2D6 is responsible for the metabolism of 25-30% of drugs in humans, including some used to treat horses, a study of the CYP2D family in horses was conducted to define its genetic structure as well as its expression pattern in the liver. Methods Genomic DNA extracted from venous blood and mRNA from fresh liver tissue were amplified and sequenced to analyze the genomic structure, genotype, and expression of the various enzymes that are part of the equine orthologous family for CYP2D6. Results Amplification and sequencing of the gDNA of CYP2D50, the major CYP2D6 orthologue identified in previous studies, revealed a novel putative genomic structure for this gene compared with that reported from the EquCab3.0 assembly, including the formation of a hybrid structure similar to what happens in human CYP2D6. At the mRNA level, transcripts from six different members of the equine CYP2D family were detected in horse liver. In addition, genotyping of CYP2D50 and CYP2D82 revealed the presence of several polymorphisms, six of which result in novel, nonsynonymous amino acid changes for each of the two genes. Discussion This study aimed to elucidate the pharmacogenetic analysis of the CYP2D family in horses and resulted in the identification of a novel gene structure for CYP2D50, the expression of six different members of the CYP2D family in horse liver, and several novel polymorphisms for CYP2D50 and CYP2D82.
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Biswas M, Jinda P, Sukasem C. Pharmacogenomics in Asians: Differences and similarities with other human populations. Expert Opin Drug Metab Toxicol 2023; 19:27-41. [PMID: 36755439 DOI: 10.1080/17425255.2023.2178895] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/07/2023] [Indexed: 02/10/2023]
Abstract
INTRODUCTION Various pharmacogenomic (PGx) variants differ widely in different ethnicities. and clinical outcomes associated with these variants may also be substantially varied. Literature was searched in different databases, i.e. PubMed, ScienceDirect, Web of Science, and PharmGKB, from inception to 30 June 2022 for this review. AREAS COVERED Certain PGx variants were distinctly varied in Asian populations compared to the other human populations, e.g. CYP2C19*2,*3,*17; CYP2C9*2,*3; CYP2D6*4,*5,*10,*41; UGT1A1*6,*28; HLA-B*15:02, HLA-B*15:21, HLA-B*58:01, and HLA-A*31:01. However, certain other variants do not vary greatly between Asian and other ethnicities, e.g. CYP3A5*3; ABCB1, and SLCO1B1*5. As evident in this review, the risk of major adverse cardiovascular events (MACE) was much stronger in Asian patients taking clopidogrel and who inherited the CYP2C19 loss-of-function alleles, e.g. CYP2C19*2 and*3, when compared to the western/Caucasian patients. Additionally, the risk of carbamazepine-induced severe cutaneous adverse drug reactions (SCARs) for the patients inheriting HLA-B*15:02 and HLA-B*15:21 alleles varied significantly between Asian and other ethnicities. In contrast, both Caucasian and Asian patients inheriting the SLCO1B1*5 variant possessed a similar magnitude of muscle toxicity, i.e. myopathy. EXPERT OPINION Asian countries should take measures toward expanding PGx research, as well as initiatives for the purposes of obtaining clinical benefits from this newly evolving and economically viable treatment model.
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Affiliation(s)
- Mohitosh Biswas
- Department of Pharmacy, University of Rajshahi, 6205, Rajshahi, Bangladesh
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 10400, Bangkok, Thailand
- Laboratory for Pharmacogenomics, Ramathibodi Hospital, Somdech Phra Debaratana Medical Center SDMC, 10400, Bangkok, Thailand
| | - Pimonpan Jinda
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 10400, Bangkok, Thailand
- Laboratory for Pharmacogenomics, Ramathibodi Hospital, Somdech Phra Debaratana Medical Center SDMC, 10400, Bangkok, Thailand
| | - Chonlaphat Sukasem
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 10400, Bangkok, Thailand
- Laboratory for Pharmacogenomics, Ramathibodi Hospital, Somdech Phra Debaratana Medical Center SDMC, 10400, Bangkok, Thailand
- Pharmacogenomics and Precision Medicine Clinic, Bumrungrad Genomic Medicine Institute (BGMI), Bumrungrad International Hospital, 10110, Bangkok, Thailand
- MRC Centre for Drug Safety Science, Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, L69 3GL, Liverpool, UK
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Leeder JS, Gaedigk A, Wright KJ, Staggs VS, Soden SE, Lin YS, Pearce RE. A longitudinal study of cytochrome P450 2D6 (CYP2D6) activity during adolescence. Clin Transl Sci 2022; 15:2514-2527. [PMID: 35997001 PMCID: PMC9579386 DOI: 10.1111/cts.13380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 07/07/2022] [Accepted: 07/09/2022] [Indexed: 01/25/2023] Open
Abstract
CYP2D6 substrates are among the most highly prescribed medications in teenagers and also commonly associated with serious adverse events. To investigate the relative contributions of genetic variation, growth, and development on CYP2D6 activity during puberty, healthy children and adolescents 7-15 years of age at enrollment participated in a longitudinal phenotyping study involving administration of 0.3 mg/kg dextromethorphan (DM) and 4-h urine collection every 6 months for 3 years (7 total visits). At each visit, height, weight, and sexual maturity were recorded, and CYP2D6 activity was determined as the urinary molar ratio of DM to its metabolite dextrorphan (DX). A total of 188 participants completed at least one visit, and 102 completed all seven study visits. Following univariate analysis, only CYP2D6 activity score (p < 0.001), urinary pH (p < 0.001), weight (p = 0.018), and attention-deficit/hyperactivity disorder (ADHD) diagnosis (p < 0.001) were significantly correlated with log(DM/DX). Results of linear mixed model analysis with random intercept, random slope covariance structure revealed that CYP2D6 activity score had the strongest effect on log(DM/DX), with model-estimated average log(DM/DX) being 3.8 SDs higher for poor metabolizers than for patients with activity score 3. A moderate effect on log(DM/DX) was observed for sex, and smaller effects were observed for ADHD diagnosis and urinary pH. The log(DM/DX) did not change meaningfully with age or pubertal development. CYP2D6 genotype remains the single, largest determinant of variability in CYP2D6 activity during puberty. Incorporation of genotype-based dosing guidelines should be considered for CYP2D6 substrates given the prevalent use of these agents in this pediatric age group.
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Affiliation(s)
- J. Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA,School of MedicineUniversity of Missouri‐Kansas CityKansas CityMissouriUSA
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA,School of MedicineUniversity of Missouri‐Kansas CityKansas CityMissouriUSA
| | - Krista J. Wright
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA
| | - Vincent S. Staggs
- School of MedicineUniversity of Missouri‐Kansas CityKansas CityMissouriUSA,Biostatistics & Epidemiology Core, Division of Health Services and Outcomes Research, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA,Division of Developmental and Behavioral Sciences, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA
| | - Sarah E. Soden
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA,School of MedicineUniversity of Missouri‐Kansas CityKansas CityMissouriUSA
| | - Yvonne S. Lin
- Department of PharmaceuticsUniversity of WashingtonSeattleWashingtonUSA
| | - Robin E. Pearce
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Department of PediatricsChildren's Mercy Kansas CityKansas CityMissouriUSA,School of MedicineUniversity of Missouri‐Kansas CityKansas CityMissouriUSA
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Wang WY, Twesigomwe D, Nofziger C, Turner AJ, Helmecke LS, Broeckel U, Derezinski AD, Hazelhurst S, Gaedigk A. Characterization of Novel CYP2D6 Alleles across Sub-Saharan African Populations. J Pers Med 2022; 12:1575. [PMID: 36294714 PMCID: PMC9605556 DOI: 10.3390/jpm12101575] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/11/2022] [Accepted: 09/19/2022] [Indexed: 07/16/2024] Open
Abstract
The CYP2D6 gene has been widely studied to characterize variants and/or star alleles, which account for a significant portion of variability in drug responses observed within and between populations. However, African populations remain under-represented in these studies. The increasing availability of high coverage genomes from African populations has provided the opportunity to fill this knowledge gap. In this study, we characterized computationally predicted novel CYP2D6 star alleles in 30 African subjects for whom DNA samples were available from the Coriell Institute. CYP2D6 genotyping and resequencing was performed using a variety of commercially available and laboratory-developed tests in a collaborative effort involving three laboratories. Fourteen novel CYP2D6 alleles and multiple novel suballeles were identified. This work adds to the growing catalogue of validated African ancestry CYP2D6 allelic variation in pharmacogenomic databases, thus laying the foundation for future functional studies and improving the accuracy of CYP2D6 genotyping, phenotype prediction, and the refinement of clinical pharmacogenomic implementation guidelines in African and global settings.
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Affiliation(s)
- Wendy Y. Wang
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
| | - David Twesigomwe
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- Division of Human Genetics, National Health Laboratory Service and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa
| | | | - Amy J. Turner
- Section of Genomic Pediatrics, Department of Pediatrics, Children’s Research Institute, The Medical College of Wisconsin, Milwaukee, WI 53226, USA
- RPRD Diagnostics LLC, Milwaukee, WI 53226, USA
| | - Lena-Sophie Helmecke
- PharmGenetix GmbH, A-5020 Niederalm, Austria
- Department of Biosciences, University of Salzburg, A-5020 Salzburg, Austria
| | - Ulrich Broeckel
- Section of Genomic Pediatrics, Department of Pediatrics, Children’s Research Institute, The Medical College of Wisconsin, Milwaukee, WI 53226, USA
- RPRD Diagnostics LLC, Milwaukee, WI 53226, USA
| | - Ashley D. Derezinski
- Section of Genomic Pediatrics, Department of Pediatrics, Children’s Research Institute, The Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Scott Hazelhurst
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa
- School of Electrical and Information Engineering, University of the Witwatersrand, Johannesburg 2001, South Africa
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children’s Mercy Research Institute, Kansas City, MO 64108, USA
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
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Dinh JC, Boone EC, Staggs VS, Pearce RE, Wang WY, Gaedigk R, Leeder JS, Gaedigk A. The Impact of the CYP2D6 "Enhancer" Single Nucleotide Polymorphism on CYP2D6 Activity. Clin Pharmacol Ther 2022; 111:646-654. [PMID: 34716917 PMCID: PMC8825689 DOI: 10.1002/cpt.2469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 10/21/2021] [Indexed: 11/10/2022]
Abstract
rs5758550 has been associated with enhanced transcription and suggested to be a useful marker of CYP2D6 activity. As there are limited and inconsistent data regarding the utility of this distant "enhancer" single nucleotide polymorphism (SNP), our goal was to further assess the impact of rs5758550 on CYP2D6 activity toward two probe substrates, atomoxetine (ATX) and dextromethorphan (DM), using in vivo urinary metabolite (DM; n = 188) and pharmacokinetic (ATX; n = 70) and in vitro metabolite formation (ATX and DM; n = 166) data. All subjects and tissues were extensively genotyped, the "enhancer" SNP phased with established CYP2D6 haplotypes either computationally or experimentally, and the impact on CYP2D6 activity investigated using several linear models of varying complexity to determine the proportion of variability in CYP2D6 activity captured by each model. For all datasets and models, the "enhancer" SNP had no or only a modest impact on CYP2D6 activity prediction. An increased effect, when present, was more pronounced for ATX than DM suggesting potential substate-dependency. In addition, CYP2D6*2 alleles with the "enhancer" SNP were associated with modestly higher metabolite formation rates in vitro, but not in vivo; no effect was detected for CYP2D6*1 alleles with "enhancer" SNP. In summary, it remains inconclusive whether the small effects detected in this investigation are indeed caused by the "enhancer" SNP or are rather due to its incomplete linkage with other variants within the gene. Taken together, there does not appear to be sufficient evidence to warrant the "enhancer" SNP be included in clinical CYP2D6 pharmacogenetic testing.
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Affiliation(s)
- Jean C Dinh
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - Erin C Boone
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - Vincent S Staggs
- Biostatistics and Epidemiology Core, Health Services and Outcomes Research, Children's Mercy Kansas City, Kansas City, Missouri, USA
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Robin E Pearce
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - Wendy Y Wang
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - Roger Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
| | - James Steven Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, USA
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri, USA
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Taylor C, Crosby I, Yip V, Maguire P, Pirmohamed M, Turner RM. A Review of the Important Role of CYP2D6 in Pharmacogenomics. Genes (Basel) 2020; 11:E1295. [PMID: 33143137 PMCID: PMC7692531 DOI: 10.3390/genes11111295] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/25/2020] [Accepted: 10/28/2020] [Indexed: 12/14/2022] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is a critical pharmacogene involved in the metabolism of ~20% of commonly used drugs across a broad spectrum of medical disciplines including psychiatry, pain management, oncology and cardiology. Nevertheless, CYP2D6 is highly polymorphic with single-nucleotide polymorphisms, small insertions/deletions and larger structural variants including multiplications, deletions, tandem arrangements, and hybridisations with non-functional CYP2D7 pseudogenes. The frequency of these variants differs across populations, and they significantly influence the drug-metabolising enzymatic function of CYP2D6. Importantly, altered CYP2D6 function has been associated with both adverse drug reactions and reduced drug efficacy, and there is growing recognition of the clinical and economic burdens associated with suboptimal drug utilisation. To date, pharmacogenomic clinical guidelines for at least 48 CYP2D6-substrate drugs have been developed by prominent pharmacogenomics societies, which contain therapeutic recommendations based on CYP2D6-predicted categories of metaboliser phenotype. Novel algorithms to interpret CYP2D6 function from sequencing data that consider structural variants, and machine learning approaches to characterise the functional impact of novel variants, are being developed. However, CYP2D6 genotyping is yet to be implemented broadly into clinical practice, and so further effort and initiatives are required to overcome the implementation challenges and deliver the potential benefits to the bedside.
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Affiliation(s)
- Christopher Taylor
- Wolfson Centre for Personalised Medicine, University of Liverpool, Liverpool L69 3BX, UK; (V.Y.); (M.P.); (R.M.T.)
- MC Diagnostics, St Asaph Business Park, Saint Asaph LL17 0LJ, UK; (I.C.); (P.M.)
| | - Ian Crosby
- MC Diagnostics, St Asaph Business Park, Saint Asaph LL17 0LJ, UK; (I.C.); (P.M.)
| | - Vincent Yip
- Wolfson Centre for Personalised Medicine, University of Liverpool, Liverpool L69 3BX, UK; (V.Y.); (M.P.); (R.M.T.)
| | - Peter Maguire
- MC Diagnostics, St Asaph Business Park, Saint Asaph LL17 0LJ, UK; (I.C.); (P.M.)
| | - Munir Pirmohamed
- Wolfson Centre for Personalised Medicine, University of Liverpool, Liverpool L69 3BX, UK; (V.Y.); (M.P.); (R.M.T.)
| | - Richard M. Turner
- Wolfson Centre for Personalised Medicine, University of Liverpool, Liverpool L69 3BX, UK; (V.Y.); (M.P.); (R.M.T.)
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Boone EC, Wang WY, Gaedigk R, Cherner M, Bérard A, Leeder JS, Miller NA, Gaedigk A. Long-Distance Phasing of a Tentative "Enhancer" Single-Nucleotide Polymorphism With CYP2D6 Star Allele Definitions. Front Pharmacol 2020; 11:486. [PMID: 32457600 PMCID: PMC7226225 DOI: 10.3389/fphar.2020.00486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 03/27/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The CYP2D6 gene locus has been extensively studied over decades, yet a portion of variability in CYP2D6 activity cannot be explained by known sequence variations within the gene, copy number variation, or structural rearrangements. It was proposed that rs5758550, located 116 kb downstream of the CYP2D6 gene locus, increases gene expression and thus contributes to variability in CYP2D6 activity. This finding has, however, not been validated. The purpose of the study was to address a major technological barrier, i.e., experimentally linking rs5758550, also referred to as the "enhancer" single-nucleotide polymorphism (SNP), to CYP2D6 haplotypes >100 kb away. To overcome this challenge is essential to ultimately determine the contribution of the "enhancer" SNP to interindividual variability in CYP2D6 activity. METHODS A large ethnically mixed population sample (n=3,162) was computationally phased to determine linkage between the "enhancer" SNP and CYP2D6 haplotypes (or star alleles). To experimentally validate predicted linkages, DropPhase2D6, a digital droplet PCR (ddPCR)-based method was developed. 10X Genomics Linked-Reads were utilized as a proof of concept. RESULTS Phasing predicted that the "enhancer" SNP can occur on numerous CYP2D6 haplotypes including CYP2D6*1, *2, *5, and *41 and suggested that linkage is incomplete, i.e., a portion of these alleles do not have the "enhancer" SNP. Phasing also revealed differences among the European and African ancestry data sets regarding the proportion of alleles with and without the "enhancer" SNP. DropPhase2D6 was utilized to confirm or refute the predicted "enhancer" SNP location for individual samples, e.g., of n=3 samples genotyped as *1/*41, rs5758550 was on the *41 allele of two samples and on the *1 allele of one sample. Our findings highlight that the location of the "enhancer" SNP must not be assigned by "default." Furthermore, linkage between the "enhancer" SNP and CYP2D6 star allele haplotypes was confirmed with 10X Genomics technology. CONCLUSIONS Since the "enhancer" SNP can be present on a portion of normal, decreased, or no function alleles, the phase of the "enhancer" SNP must be considered when investigating the impact of the "enhancer" SNP on CYP2D6 activity.
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Affiliation(s)
- Erin C. Boone
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Wendy Y. Wang
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Roger Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Mariana Cherner
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, United States
| | - Anick Bérard
- Faculty of Pharmacy, University of Montreal, Montreal, QC, Canada
- Research Center, CHU Sainte-Justine, Montreal, QC, Canada
| | - J. Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
| | - Neil A. Miller
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
- Center for Pediatric Genomic Medicine, Children's Mercy Kansas City, Kansas City, MO, United States
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO, United States
- School of Medicine, University of Missouri-Kansas City, Kansas City, MO, United States
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10
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Xin J, Yuan M, Peng Y, Wang J. Analysis of the Deleterious Single-Nucleotide Polymorphisms Associated With Antidepressant Efficacy in Major Depressive Disorder. Front Psychiatry 2020; 11:151. [PMID: 32256400 PMCID: PMC7093583 DOI: 10.3389/fpsyt.2020.00151] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/18/2020] [Indexed: 12/26/2022] Open
Abstract
Major depressive disorder (MDD) is a serious mental disease with negative effects on both mental and physical health of the patient. Currently, antidepressants are among the major ways to ease or treat MDD. However, the existing antidepressants have limited efficacy in treating MDD, with a large fraction of patients either responding inadequately or differently to antidepressants during the treatment. Pharmacogenetics studies have found that the genetic features of some genes are associated with the antidepressant efficacy. In order to obtain a better understanding on the relationship between the genetic factors and antidepressant treatment response, we compiled a list of 233 single-nucleotide polymorphisms (SNPs) significantly associated with the antidepressant efficacy in treating MDD. Of the 13 non-synonymous SNPs in the list, three (rs1065852, rs3810651, and rs117986340) may influence the structures and function of the corresponding proteins. Besides, the influence of rs1065852 on the structure of CYP2D6 was further investigated via molecular dynamics simulations. Our results showed that compared to the native CYP2D6 the flexibility of the F-G loop was reduced in the mutant. As a portion of the substrate access channel, the lower flexibility of F-G loop may reduce the ability of the substrates to enter the channel, which may be the reason for the lower enzyme activity of mutant. This study may help us to understand the impact of genetic variation on antidepressant efficacy and provide clues for developing new antidepressants.
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Affiliation(s)
- Juncai Xin
- School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Meng Yuan
- School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Yonglin Peng
- School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
| | - Ju Wang
- School of Biomedical Engineering, Tianjin Medical University, Tianjin, China
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11
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Nofziger C, Turner AJ, Sangkuhl K, Whirl-Carrillo M, Agúndez JAG, Black JL, Dunnenberger HM, Ruano G, Kennedy MA, Phillips MS, Hachad H, Klein TE, Gaedigk A. PharmVar GeneFocus: CYP2D6. Clin Pharmacol Ther 2020; 107:154-170. [PMID: 31544239 PMCID: PMC6925641 DOI: 10.1002/cpt.1643] [Citation(s) in RCA: 141] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 08/29/2019] [Indexed: 01/13/2023]
Abstract
The Pharmacogene Variation Consortium (PharmVar) provides nomenclature for the highly polymorphic human CYP2D6 gene locus. CYP2D6 genetic variation impacts the metabolism of numerous drugs and, thus, can impact drug efficacy and safety. This GeneFocus provides a comprehensive overview and summary of CYP2D6 genetic variation and describes how the information provided by PharmVar is utilized by the Pharmacogenomics Knowledgebase (PharmGKB) and the Clinical Pharmacogenetics Implementation Consortium (CPIC).
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Affiliation(s)
| | - Amy J. Turner
- Department of Pediatrics, Section of Genomic Pediatrics and Children’s Research Institute, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- RPRD Diagnostics LLC, Wauwatosa, Wisconsin, USA
| | - Katrin Sangkuhl
- Department of Biomedical Data Science, Stanford University, Stanford, CA, USA
| | | | - José A. G. Agúndez
- University Institute of Molecular Pathology Biomarkers, UEx, Cáceres; ARADyAL Instituto de Salud Carlos III. Spain
| | - John L. Black
- Personalized Genomics Laboratory, Division of Laboratory Genetics and Genomics, Mayo Clinic laboratories, Mayo Clinic, Rochester MN (200 1st Street SW, Rochester MN 55902)
| | - Henry M. Dunnenberger
- Mark R. Neaman Center for Personalized Medicine, NorthShore University HealthSystem, Evanton, IL, USA
| | - Gualberto Ruano
- Institute of Living at Hartford Hospital, Genomas Laboratory of Personalized Health, Hartford, Connecticut (67 Jefferson Street, Hartford, Connecticut 06106)
| | - Martin A. Kennedy
- Department of Pathology and Biomedical Science, University Otago, Christchurch, New Zealand
| | - Michael S. Phillips
- Sequence Bioinformatics Inc., 139 Water Street, 2 Floor, St. John’s NL, A1C 1B2, Canada
| | | | - Teri E. Klein
- Department of Biomedical Data Science, Stanford University, Stanford, CA, USA
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children’s Mercy Kansas City, Kansas City and School of Medicine, University of Missouri-Kansas City, Kansas City, MO, USA
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12
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Challenges to assess substrate-dependent allelic effects in CYP450 enzymes and the potential clinical implications. THE PHARMACOGENOMICS JOURNAL 2019; 19:501-515. [DOI: 10.1038/s41397-019-0105-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 09/09/2019] [Accepted: 10/02/2019] [Indexed: 12/12/2022]
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13
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Kumar S, Kundra P, Ramsamy K, Surendiran A. Pharmacogenetics of opioids: a narrative review. Anaesthesia 2019; 74:1456-1470. [DOI: 10.1111/anae.14813] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/30/2019] [Indexed: 10/26/2022]
Affiliation(s)
- S. Kumar
- Department of Pharmacology JIPMER Puducherry India
| | - P. Kundra
- Department of Anaesthesiology JIPMER Puducherry India
| | - K. Ramsamy
- Department of Pharmacology JIPMER Puducherry India
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14
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Gaedigk A, Turner A, Everts RE, Scott SA, Aggarwal P, Broeckel U, McMillin GA, Melis R, Boone EC, Pratt VM, Kalman LV. Characterization of Reference Materials for Genetic Testing of CYP2D6 Alleles: A GeT-RM Collaborative Project. J Mol Diagn 2019; 21:1034-1052. [PMID: 31401124 DOI: 10.1016/j.jmoldx.2019.06.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/10/2019] [Accepted: 06/13/2019] [Indexed: 11/25/2022] Open
Abstract
Pharmacogenetic testing increasingly is available from clinical and research laboratories. However, only a limited number of quality control and other reference materials currently are available for the complex rearrangements and rare variants that occur in the CYP2D6 gene. To address this need, the Division of Laboratory Systems, CDC-based Genetic Testing Reference Material Coordination Program, in collaboration with members of the pharmacogenetic testing and research communities and the Coriell Cell Repositories (Camden, NJ), has characterized 179 DNA samples derived from Coriell cell lines. Testing included the recharacterization of 137 genomic DNAs that were genotyped in previous Genetic Testing Reference Material Coordination Program studies and 42 additional samples that had not been characterized previously. DNA samples were distributed to volunteer testing laboratories for genotyping using a variety of commercially available and laboratory-developed tests. These publicly available samples will support the quality-assurance and quality-control programs of clinical laboratories performing CYP2D6 testing.
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Affiliation(s)
- Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri
| | - Amy Turner
- Medical College of Wisconsin, Milwaukee, Wisconsin; RPRD (Right Patient Right Drug) Diagnostics, LLC, Wauwatosa, Wisconsin
| | | | - Stuart A Scott
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York; Sema4, Stamford, Connecticut
| | - Praful Aggarwal
- Medical College of Wisconsin, Milwaukee, Wisconsin; RPRD (Right Patient Right Drug) Diagnostics, LLC, Wauwatosa, Wisconsin
| | - Ulrich Broeckel
- Medical College of Wisconsin, Milwaukee, Wisconsin; RPRD (Right Patient Right Drug) Diagnostics, LLC, Wauwatosa, Wisconsin
| | | | | | - Erin C Boone
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, University of Missouri-Kansas City School of Medicine, Kansas City, Missouri
| | - Victoria M Pratt
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| | - Lisa V Kalman
- Informatics and Data Science Branch, Division of Laboratory Systems, Office of Surveillance, Epidemiology, and Laboratory Services, Centers for Disease Control and Prevention, Atlanta, Georgia.
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15
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Salyakina D, Roy S, Wang W, Oliva M, Akhouri R, Sotto I, Mulas N, Solano R, Fernández JR, Sanchez S, Shamshad U, Perlyn C, McCafferty-Fernandez J. Results and challenges of Cytochrome P450 2D6 (CYP2D6) testing in an ethnically diverse South Florida population. Mol Genet Genomic Med 2019; 7:e922. [PMID: 31389673 PMCID: PMC6732280 DOI: 10.1002/mgg3.922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 12/20/2022] Open
Abstract
Background This study focuses on the implementation of CYP2D6 genetic test profiling and the challenges associated with using standard pharmacogenetics panels in a diverse South Florida population. Methods A total of 413 participants were recruited to participate in this study through Nicklaus Children's Hospital. Buccal swabs were collected and tested using an extended CYP2D6 panel including 22 alleles. Phenotype, genotype, and allelic frequencies were compared among different racial and ethnic groups. Results The majority of participants (75.0%) self‐identified as Hispanics. Four alleles, CYP2D6*4, *17, *41, and *2A, showed a statistically significant difference between White Hispanics and Black Non‐Hispanics. Aggregate frequency of all alleles with decreased function varied between 2.8% and 50.0% in different racial and ethnic groups. Additionally, rare allele combinations were observed in this South Florida cohort. Conclusions The heterogeneity among Hispanic groups demonstrated in previous literature and by this study reflects the complexity of ethnicity and suggests that a more granular categorization is needed, one based on ancestry and migration history rather than primary language. Overall, we have determined that there are statistically significant differences in CYP2D6 allele frequencies in the distinct racial and ethnic populations of South Florida, demonstrating a unique genetic makeup within South Florida. However, overall, the frequencies of Poor Metabolizer, Normal Metabolizer, Intermediate Metabolizer, and Ultrarapid Metabolizer did not differ between racial and ethnic groups at a statistically significant level.
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Affiliation(s)
- Daria Salyakina
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Sharmeen Roy
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Weize Wang
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Mailin Oliva
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Rohan Akhouri
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Ileana Sotto
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Nicole Mulas
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Rafaela Solano
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - José R Fernández
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama
| | | | - Uzma Shamshad
- Research Institute, Nicklaus Children's Hospital, Miami, Florida
| | - Chad Perlyn
- Research Institute, Nicklaus Children's Hospital, Miami, Florida.,Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
| | - Jennifer McCafferty-Fernandez
- Research Institute, Nicklaus Children's Hospital, Miami, Florida.,Herbert Wertheim College of Medicine, Florida International University, Miami, Florida
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16
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Supervised Classification of CYP2D6 Genotype and Metabolizer Phenotype With Postmortem Tramadol-Exposed Finns. Am J Forensic Med Pathol 2019; 40:8-18. [DOI: 10.1097/paf.0000000000000447] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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17
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Jarvis JP, Peter AP, Shaman JA. Consequences of CYP2D6 Copy-Number Variation for Pharmacogenomics in Psychiatry. Front Psychiatry 2019; 10:432. [PMID: 31281270 PMCID: PMC6595891 DOI: 10.3389/fpsyt.2019.00432] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/03/2019] [Indexed: 12/20/2022] Open
Abstract
Pharmacogenomics represents a potentially powerful enhancement to the current standard of care for psychiatric patients. However, a variety of biological and technical challenges must be addressed in order to provide adequate clinical decision support for personalized prescribing and dosing based on genomic data. This is particularly true in the case of CYP2D6, a key drug-metabolizing gene, which not only harbors multiple genetic variants known to affect enzyme function but also shows a broad range of copy-number and hybrid alleles in various patient populations. Here, we describe several challenges in the accurate measurement and interpretation of data from the CYP2D6 locus including the clinical consequences of increased copy number. We discuss best practices for overcoming these challenges and then explore various current and future applications of pharmacogenomic analysis of CYP2D6 in psychiatry.
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18
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Qiao W, Martis S, Mendiratta G, Shi L, Botton MR, Yang Y, Gaedigk A, Vijzelaar R, Edelmann L, Kornreich R, Desnick RJ, Scott SA. Integrated CYP2D6 interrogation for multiethnic copy number and tandem allele detection. Pharmacogenomics 2018; 20:9-20. [PMID: 30730286 DOI: 10.2217/pgs-2018-0135] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
AIM To comprehensively interrogate CYP2D6 by integrating genotyping, copy number analysis and novel strategies to identify CYP2D6*36 and characterize CYP2D6 duplications. METHODS Genotyping of 16 CYP2D6 alleles, multiplex ligation-dependent probe amplification (MLPA) and CYP2D6*36 and duplication allele-specific genotyping were performed on 427 African-American, Asian, Caucasian, Hispanic, and Ashkenazi Jewish individuals. RESULTS A novel PCR strategy determined that almost half of all CYP2D6*10 (100C>T) alleles are actually *36 (isolated or in tandem with *10) and all identified duplication alleles were characterized. Integrated results from all testing platforms enabled the refinement of genotype frequencies across all studied populations. CONCLUSION The polymorphic CYP2D6 gene requires comprehensive interrogation to characterize allelic variation across ethnicities, which was enabled in this study by integrating multiplexed genotyping, MLPA copy number analysis, novel PCR strategies and duplication allele-specific genotyping.
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Affiliation(s)
- Wanqiong Qiao
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Suparna Martis
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Geetu Mendiratta
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Lisong Shi
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Mariana R Botton
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Yao Yang
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, MO 64108, USA
| | - Raymon Vijzelaar
- MRC-Holland, Willem Schoutenstraat 6, Amsterdam, The Netherlands
| | - Lisa Edelmann
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Ruth Kornreich
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
| | - Robert J Desnick
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Stuart A Scott
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Sema4, a Mount Sinai venture, Stamford, CT 06902, USA
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19
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Puaprasert K, Chu C, Saralamba N, Day NPJ, Nosten F, White NJ, Dondorp AM, Imwong M. Real time PCR detection of common CYP2D6 genetic variants and its application in a Karen population study. Malar J 2018; 17:427. [PMID: 30442143 PMCID: PMC6238304 DOI: 10.1186/s12936-018-2579-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 11/09/2018] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Plasmodium vivax malaria is characterized by relapses arising from the hypnozoite stages in the liver. The only currently registered drug for radical treatment to prevent relapse is primaquine. Primaquine, a prodrug, requires metabolism through the liver cytochrome CYP2D6 isoenzyme to its active metabolite. Mutations in the CYP2D6 gene may thus affect primaquine efficacy. A SNPs genotyping technique was developed to characterize the CYP2D6 genetic variants and tested this in the patients with Plasmodium vivax infection collected in a Karen population on the Thailand-Myanmar border, where P. vivax malaria is endemic. METHODS Direct sequencing of PCR-reamplified products (DSP) was used to uncover exonic CYP2D6 sequence variations. Subsequently, an allele-specific oligonucleotide probe real-time SNPs genotyping (ASO) assay was developed for rapid detection of the four clinically relevant CYP2D6 variants occurring in this population. These two in-house developed assays were used to genotype CYP2D6 mutations in blood samples obtained from 70 Karen adults. RESULTS Results showed a high degree of concordance between the DSP and ASO methods. Six CYP2D6 point mutations were identified within the Karen population: C100T, C1039T, G1661C, G1846A, C2850T and G4180C, at frequencies of 0.43, 0.43, 0.76, 0.02, 0.32 and 0.76, respectively. The CYP2D6*2, *4, *5, *10 and *36 allelic frequencies were 0.33, 0.02, 0.03, 0.40 and 0.01, respectively. Alleles conferring an intermediate CYP2D6 metabolizer phenotype comprised 46% of the total number of alleles. CONCLUSION The newly developed ASO assay is a reliable and rapid tool for large-scale CYP2D6 genotyping. The high frequency of the CYP2D6*10 allele in the Karen population warrants further assessment of its association with the radical curative efficacy of primaquine.
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Affiliation(s)
- Kanokpich Puaprasert
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Cindy Chu
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Naowarat Saralamba
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Francois Nosten
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicholas J White
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Arjen M Dondorp
- Mahidol Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Mallika Imwong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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Chamnanphon M, Gaedigk A, Vanwong N, Nuntamool N, Hongkaew Y, Puangpetch A, Sukasem C. CYP2D6 genotype analysis of a Thai population: platform comparison. Pharmacogenomics 2018; 19:947-960. [DOI: 10.2217/pgs-2018-0075] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The highly polymorphic CYP2D6 gene locus leads to a wide range of enzyme activity. Since there are limited data for Thai, the major aim was to investigate CYP2D6 genetic variation in a large Thai population (n = 920). CYP2D6 genotyping was performed using four different platforms. Genotype call rates of the Luminex xTAG® and AmpliChip CYP450 test were 96.5% and 87.4%, respectively. Based on Luminex xTAG® data, the most common alleles and genotypes were *1 0 (49.6%), *1 (24.6%), *2 (10.8%), *5 (6.7%), *41 (6.5%) and *1/*10 (23.9%), *10/*10 (21.5%), *2/*10 (9.4%), *5/*10 (6.9%), *10/*41 (5.7%), respectively. Challenges and limitations of the platforms evaluated are discussed. These data add to our knowledge regarding interethnic variability in CYP2D6 activity and contribute to improving drug therapy in the Thai.
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Affiliation(s)
- Monpat Chamnanphon
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
- Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok 10400, Thailand
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy Kansas City and School of Medicine, University of Missouri – Kansas City, Kansas City, Missouri, MO 64108, USA
| | - Natchaya Vanwong
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok 10332, Thailand
| | - Nopphadol Nuntamool
- Department of Pharmaceutical Care, Faculty of Pharmacy, Payap University, Chiangmai 50000, Thailand
| | - Yaowaluck Hongkaew
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
- Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok 10400, Thailand
| | - Apichaya Puangpetch
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
- Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok 10400, Thailand
| | - Chonlaphat Sukasem
- Division of Pharmacogenomics and Personalized Medicine, Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand
- Laboratory for Pharmacogenomics, Somdech Phra Debaratana Medical Center (SDMC), Ramathibodi Hospital, Bangkok 10400, Thailand
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Stargazer: a software tool for calling star alleles from next-generation sequencing data using CYP2D6 as a model. Genet Med 2018; 21:361-372. [PMID: 29875422 PMCID: PMC6281872 DOI: 10.1038/s41436-018-0054-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/23/2018] [Indexed: 01/13/2023] Open
Abstract
Purpose Genotyping CYP2D6 is important for precision drug therapy because it metabolizes approximately 25% of drugs and its activity varies considerably among individuals. Genotype analysis of CYP2D6 is challenging due to its highly polymorphic nature. Over 100 haplotypes (star alleles) have been defined for CYP2D6, some involving a gene conversion with its nearby non-functional but highly homologous paralog CYP2D7. We present Stargazer, a new bioinformatics tool that uses next-generation sequencing (NGS) data to call star alleles for CYP2D6 (https://stargazer.gs.washington.edu/stargazerweb/). Stargazer is currently being extended for other pharmacogenes. Methods Stargazer identifies star alleles from NGS data by detecting single nucleotide variants, insertion-deletion variants, and structural variants. Stargazer detects structural variation including gene deletions, duplications, and conversions by calculating paralog-specific copy number from read depth. Results We applied Stargazer to NGS data of 32 ethnically diverse HapMap trios that were genotyped by TaqMan assays, long-range PCR, quantitative multiplex PCR, High Resolution Melt analysis, and/or Sanger sequencing. CYP2D6 genotyping by Stargazer was 99.0% concordant with data obtained by these methods and showed 28.1% of the samples had structural variation including CYP2D6/CYP2D7 hybrids. Conclusion Accurate genotyping of pharmacogenes with NGS and subsequent allele calling with Stargazer will aid the implementation of precision drug therapy.
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22
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Matsusue A, Ikeda T, Tani N, Waters B, Hara K, Kashiwagi M, Takayama M, Ikematsu N, Kubo SI, Ishikawa T. Association between cytochrome P450 2D6 polymorphisms and body fluid methamphetamine concentrations in Japanese forensic autopsy cases. Forensic Sci Int 2018; 289:33-39. [PMID: 29843110 DOI: 10.1016/j.forsciint.2018.05.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/03/2018] [Accepted: 05/10/2018] [Indexed: 12/14/2022]
Abstract
Methamphetamine (MA) is an illicit stimulant that affects the central nervous system. Cytochrome P450 2D6 (CYP2D6) plays an important role in MA metabolism. Numerous allelic variants confer substantial variation in CYP2D6 activity among individuals. In the present study, we examined the frequencies of CYP2D6 alleles, including CYP2D6*1, *2, *4, *5, *10, *14A, *14B, *18, and *36, and multiplication, in 82 forensic autopsy cases of MA abusers and 567 autopsy cases in which MA was not detected (controls). Ultrarapid metabolizer (UM), extensive metabolizer (EM), intermediate metabolizer (IM), and poor metabolizer (PM) phenotypes were predicted from CYP2D6 genotypes. Of MA abusers, 64 subjects were predicted to be EM, 17 were IM, and 1 was UM. No MA abuser had the predicted PM phenotype. No significant differences in CYP2D6 phenotype frequencies were found between MA abusers and controls. MA and amphetamine (AMP) concentrations were measured in the right heart blood, left heart blood, peripheral external iliac blood, urine, pericardial fluid, and bone marrow of MA abusers. MA concentrations in urine and bone marrow were significantly higher in IM than in EM. AMP concentration was not associated with CYP2D6 phenotype in any body fluid. These results suggest that the MA concentration in body fluids is influenced by CYP2D6 phenotypes in the Japanese population.
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Affiliation(s)
- Aya Matsusue
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
| | - Tomoya Ikeda
- Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
| | - Naoto Tani
- Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
| | - Brian Waters
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Kenji Hara
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Masayuki Kashiwagi
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Mio Takayama
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Natsuki Ikematsu
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Shin-Ichi Kubo
- Department of Forensic Medicine, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Takaki Ishikawa
- Department of Legal Medicine, Osaka City University Medical School, Asahi-machi 1-4-3, Abeno, Osaka 545-8585, Japan
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23
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Del Tredici AL, Malhotra A, Dedek M, Espin F, Roach D, Zhu GD, Voland J, Moreno TA. Frequency of CYP2D6 Alleles Including Structural Variants in the United States. Front Pharmacol 2018; 9:305. [PMID: 29674966 PMCID: PMC5895772 DOI: 10.3389/fphar.2018.00305] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 03/15/2018] [Indexed: 01/01/2023] Open
Abstract
The CYP2D6 gene encodes an enzyme important in the metabolism of many commonly used medications. Variation in CYP2D6 is associated with inter-individual differences in medication response, and genetic testing is used to optimize medication therapy. This report describes a retrospective study of CYP2D6 allele frequencies in a large population of 104,509 de-identified patient samples across all regions of the United States (US). Thirty-seven unique CYP2D6 alleles including structural variants were identified. A majority of these alleles had frequencies which matched published frequency data from smaller studies, while eight had no previously published frequencies. Importantly, CYP2D6 structural variants were observed in 13.1% of individuals and accounted for 7% of the total variants observed. The majority of structural variants detected (73%) were decreased-function or no-function alleles. As such, structural variants were found in approximately one-third (30%) of CYP2D6 poor metabolizers in this study. This is the first CYP2D6 study to evaluate, with a consistent methodology, both structural variants and single copy alleles in a large US population, and the results suggest that structural variants have a substantial impact on CYP2D6 function.
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Affiliation(s)
| | - Alka Malhotra
- Millennium Health, LLC, San Diego, CA, United States
| | - Matthew Dedek
- Millennium Health, LLC, San Diego, CA, United States
| | - Frank Espin
- Millennium Health, LLC, San Diego, CA, United States
| | - Dan Roach
- Millennium Health, LLC, San Diego, CA, United States
| | - Guang-Dan Zhu
- Millennium Health, LLC, San Diego, CA, United States
| | - Joseph Voland
- Millennium Health, LLC, San Diego, CA, United States
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24
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Bank PCD, Caudle KE, Swen JJ, Gammal RS, Whirl-Carrillo M, Klein TE, Relling MV, Guchelaar HJ. Comparison of the Guidelines of the Clinical Pharmacogenetics Implementation Consortium and the Dutch Pharmacogenetics Working Group. Clin Pharmacol Ther 2017; 103:599-618. [PMID: 28994452 DOI: 10.1002/cpt.762] [Citation(s) in RCA: 156] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/24/2017] [Accepted: 06/01/2017] [Indexed: 12/16/2022]
Abstract
Both the Clinical Pharmacogenetics Implementation Consortium (CPIC) and Dutch Pharmacogenetics Working Group provide therapeutic recommendations for well-known gene-drug pairs. Published recommendations show a high rate of concordance. However, as a result of different guideline development methods used by these two consortia, differences between the published guidelines exist. The aim of this paper is to compare both initiatives and explore these differences, with the objective to achieve harmonization.
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Affiliation(s)
- P C D Bank
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Centre, Leiden, The Netherlands
| | - K E Caudle
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - J J Swen
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Centre, Leiden, The Netherlands
| | - R S Gammal
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee, USA.,Department of Pharmacy Practice, MCPHS University, Boston, Massachusetts, USA
| | - M Whirl-Carrillo
- Pharmacogenomics Knowledgebase (PharmGKB), Stanford University School of Medicine, Palo Alto, California, USA
| | - T E Klein
- Pharmacogenomics Knowledgebase (PharmGKB), Stanford University School of Medicine, Palo Alto, California, USA
| | - M V Relling
- Department of Pharmaceutical Sciences, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - H-J Guchelaar
- Department of Clinical Pharmacy and Toxicology, Leiden University Medical Centre, Leiden, The Netherlands
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25
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Yang Y, Botton MR, Scott ER, Scott SA. Sequencing the CYP2D6 gene: from variant allele discovery to clinical pharmacogenetic testing. Pharmacogenomics 2017; 18:673-685. [PMID: 28470112 DOI: 10.2217/pgs-2017-0033] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
CYP2D6 is one of the most studied enzymes in the field of pharmacogenetics. The CYP2D6 gene is highly polymorphic with over 100 catalogued star (*) alleles, and clinical CYP2D6 testing is increasingly accessible and supported by practice guidelines. However, the degree of variation at the CYP2D6 locus and homology with its pseudogenes make interrogating CYP2D6 by short-read sequencing challenging. Moreover, accurate prediction of CYP2D6 metabolizer status necessitates analysis of duplicated alleles when an increased copy number is detected. These challenges have recently been overcome by long-read CYP2D6 sequencing; however, such platforms are not widely available. This review highlights the genomic complexities of CYP2D6, current sequencing methods and the evolution of CYP2D6 from allele discovery to clinical pharmacogenetic testing.
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Affiliation(s)
- Yao Yang
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Genomics & Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mariana R Botton
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Erick R Scott
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.,Icahn Institute for Genomics & Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Stuart A Scott
- Department of Genetics & Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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26
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Dinh JC, Pearce RE, Van Haandel L, Gaedigk A, Leeder JS. Characterization of Atomoxetine Biotransformation and Implications for Development of PBPK Models for Dose Individualization in Children. Drug Metab Dispos 2016; 44:1070-9. [PMID: 27052878 PMCID: PMC4931890 DOI: 10.1124/dmd.116.069518] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 04/04/2016] [Indexed: 11/22/2022] Open
Abstract
Atomoxetine (ATX) is a second-line nonstimulant medication used to control symptoms of attention deficit hyperactivity disorder (ADHD). Inconsistent therapeutic efficacy has been reported with ATX, which may be related to variable CYP2D6-mediated drug clearance. We characterized ATX metabolism in a panel of human liver samples as a basis for a bottom-up PBPK model to aid in ATX exposure prediction and control. Km, Vmax, and Clint values in pooled human liver microsomes (HLMs) were 2.4 µM, 479 pmol/min/mg protein, and 202 µl/min/mg protein, respectively. Mean population values of kinetic parameters are not adequate to describe variability in a population, given that Km, Vmax, and Clint values from single-donor HLMs ranged from 0.93 to 79.2 µM, 20.0 to 1600 pmol/min/mg protein, and 0.3 to 936 µl/min/mg protein. All kinetic parameters were calculated from 4-hydroxyatomoxetine (4-OH-ATX) formation. CYP2E1 and CYP3A contributed to 4-OH-ATX formation in livers with CYP2D6 intermediate and poor metabolizer status. In HLMs with lower CYP2D6 activity levels, 2-hydroxymethylatomoxetine (2-CH2OH-ATX) formation became a more predominant pathway of metabolism, which appeared to be catalyzed by CYP2B6. ATX biotransformation at clinically relevant plasma concentrations was characterized in a panel of pediatric HLM (n = 116) samples by evaluating primary metabolites. Competing pathways of ATX metabolism [N-desmethylatomoxetine (NDM-ATX) and 2-CH2OH-ATX formation] had increasing importance in livers with lesser CYP2D6 activity, but, overall ATX clearance was still compromised. Modeling ATX exposure to individualize therapy would require comprehensive knowledge of factors that affect CYP2D6 activity as well as an understanding of competing pathways, particularly for individuals with lower CYP2D6 activity.
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Affiliation(s)
- Jean C Dinh
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation (J.C.D., L.V.H., R.E.P., A.G., J.S.L.), Department of Pediatrics, Children's Mercy Hospital (L.V.H., R.E.P., A.G., J.S.L.), University of Kansas Medical Center (J.S.L.), and Department of Pharmacology (A.G., R.E.P., J.S.L.), University of Missouri-Kansas City, Kansas City, Missouri
| | - Robin E Pearce
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation (J.C.D., L.V.H., R.E.P., A.G., J.S.L.), Department of Pediatrics, Children's Mercy Hospital (L.V.H., R.E.P., A.G., J.S.L.), University of Kansas Medical Center (J.S.L.), and Department of Pharmacology (A.G., R.E.P., J.S.L.), University of Missouri-Kansas City, Kansas City, Missouri
| | - Leon Van Haandel
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation (J.C.D., L.V.H., R.E.P., A.G., J.S.L.), Department of Pediatrics, Children's Mercy Hospital (L.V.H., R.E.P., A.G., J.S.L.), University of Kansas Medical Center (J.S.L.), and Department of Pharmacology (A.G., R.E.P., J.S.L.), University of Missouri-Kansas City, Kansas City, Missouri
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation (J.C.D., L.V.H., R.E.P., A.G., J.S.L.), Department of Pediatrics, Children's Mercy Hospital (L.V.H., R.E.P., A.G., J.S.L.), University of Kansas Medical Center (J.S.L.), and Department of Pharmacology (A.G., R.E.P., J.S.L.), University of Missouri-Kansas City, Kansas City, Missouri
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation (J.C.D., L.V.H., R.E.P., A.G., J.S.L.), Department of Pediatrics, Children's Mercy Hospital (L.V.H., R.E.P., A.G., J.S.L.), University of Kansas Medical Center (J.S.L.), and Department of Pharmacology (A.G., R.E.P., J.S.L.), University of Missouri-Kansas City, Kansas City, Missouri
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27
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Constellation: a tool for rapid, automated phenotype assignment of a highly polymorphic pharmacogene, CYP2D6, from whole-genome sequences. NPJ Genom Med 2016; 1:15007. [PMID: 29263805 PMCID: PMC5685293 DOI: 10.1038/npjgenmed.2015.7] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/10/2015] [Accepted: 11/10/2015] [Indexed: 12/30/2022] Open
Abstract
An important component of precision medicine-the use of whole-genome sequencing (WGS) to guide lifelong healthcare-is electronic decision support to inform drug choice and dosing. To achieve this, automated identification of genetic variation in genes involved in drug absorption, distribution, metabolism, excretion and response (ADMER) is required. CYP2D6 is a major enzyme for drug bioactivation and elimination. CYP2D6 activity is predominantly governed by genetic variation; however, it is technically arduous to haplotype. Not only is the nucleotide sequence of CYP2D6 highly polymorphic, but the locus also features diverse structural variations, including gene deletion, duplication, multiplication events and rearrangements with the nonfunctional, neighbouring CYP2D7 and CYP2D8 genes. We developed Constellation, a probabilistic scoring system, enabling automated ascertainment of CYP2D6 activity scores from 2×100 paired-end WGS. The consensus reference method included TaqMan genotyping assays, quantitative copy-number variation determination and Sanger sequencing. When compared with the consensus reference Constellation had an analytic sensitivity of 97% (59 of 61 diplotypes) and analytic specificity of 95% (116 of 122 haplotypes). All extreme phenotypes, i.e., poor and ultrarapid metabolisers were accurately identified by Constellation. Constellation is anticipated to be extensible to functional variation in all ADMER genes, and to be performed at marginal incremental financial and computational costs in the setting of diagnostic WGS.
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28
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Brown JT, Abdel-Rahman SM, van Haandel L, Gaedigk A, Lin YS, Leeder JS. Single dose, CYP2D6 genotype-stratified pharmacokinetic study of atomoxetine in children with ADHD. Clin Pharmacol Ther 2016; 99:642-50. [PMID: 26660002 DOI: 10.1002/cpt.319] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/30/2015] [Accepted: 12/02/2015] [Indexed: 01/22/2023]
Abstract
The effect of CYP2D6 genotype on the dose-exposure relationship for atomoxetine has not been well characterized in children. Children 6-17 years of age diagnosed with attention-deficit hyperactivity disorder (ADHD) were stratified by CYP2D6 genotype into groups with 0 (poor metabolizers [PMs], n = 4), 0.5 (intermediate metabolizers [IMs], n = 3), one (extensive metabolizer [EM]1, n = 8) or two (EM2, n = 8) functional alleles and administered a single 0.5 mg/kg oral dose of atomoxetine (ATX). Plasma and urine samples were collected for 24 (IM, EM1, and EM2) or 72 hours (PMs). Dose-corrected ATX systemic exposure (area under the curve [AUC]0-∞ ) varied 29.6-fold across the study cohort, ranging from 4.4 ± 2.7 μM*h in EM2s to 5.8 ± 1.7 μM*h, 16.3 ± 2.9 μM*h, and 50.2 ± 7.3 μM*h in EM1s, IMs, and PMs, respectively (P < 0.0001). Simulated steady state profiles at the maximum US Food and Drug Administration (FDA)-recommended dose suggest that most patients are unlikely to attain adequate ATX exposures. These data support the need for individualized dosing strategies for more effective use of the medication.
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Affiliation(s)
- J T Brown
- Department of Pharmacy Practice and Pharmaceutical Sciences, University of Minnesota College of Pharmacy, Duluth, Minnesota, USA
| | - S M Abdel-Rahman
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - L van Haandel
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - A Gaedigk
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
| | - Y S Lin
- Department of Pharmaceutics, University of Washington School of Pharmacy, Seattle, Washington, USA
| | - J S Leeder
- Division of Clinical Pharmacology, Toxicology, and Therapeutic Innovation, Department of Pediatrics, Children's Mercy Kansas City and University of Missouri-Kansas City, Kansas City, Missouri, USA
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29
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Qiao W, Yang Y, Sebra R, Mendiratta G, Gaedigk A, Desnick RJ, Scott SA. Long-Read Single Molecule Real-Time Full Gene Sequencing of Cytochrome P450-2D6. Hum Mutat 2015; 37:315-23. [PMID: 26602992 DOI: 10.1002/humu.22936] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 11/13/2015] [Indexed: 12/30/2022]
Abstract
The cytochrome P450-2D6 (CYP2D6) enzyme metabolizes ∼25% of common medications, yet homologous pseudogenes and copy number variants (CNVs) make interrogating the polymorphic CYP2D6 gene with short-read sequencing challenging. Therefore, we developed a novel long-read, full gene CYP2D6 single molecule real-time (SMRT) sequencing method using the Pacific Biosciences platform. Long-range PCR and CYP2D6 SMRT sequencing of 10 previously genotyped controls identified expected star (*) alleles, but also enabled suballele resolution, diplotype refinement, and discovery of novel alleles. Coupled with an optimized variant-calling pipeline, CYP2D6 SMRT sequencing was highly reproducible as triplicate intra- and inter-run nonreference genotype results were completely concordant. Importantly, targeted SMRT sequencing of upstream and downstream CYP2D6 gene copies characterized the duplicated allele in 15 control samples with CYP2D6 CNVs. The utility of CYP2D6 SMRT sequencing was further underscored by identifying the diplotypes of 14 samples with discordant or unclear CYP2D6 configurations from previous targeted genotyping, which again included suballele resolution, duplicated allele characterization, and discovery of a novel allele and tandem arrangement. Taken together, long-read CYP2D6 SMRT sequencing is an innovative, reproducible, and validated method for full-gene characterization, duplication allele-specific analysis, and novel allele discovery, which will likely improve CYP2D6 metabolizer phenotype prediction for both research and clinical testing applications.
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Affiliation(s)
- Wanqiong Qiao
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Yao Yang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Robert Sebra
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029.,Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Geetu Mendiratta
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri, 64108.,School of Medicine, University of Missouri-Kansas City, Kansas City, Missouri, 64108
| | - Robert J Desnick
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
| | - Stuart A Scott
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, 10029
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30
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Gaedigk A, Riffel AK, Leeder JS. CYP2D6 Haplotype Determination Using Long Range Allele-Specific Amplification: Resolution of a Complex Genotype and a Discordant Genotype Involving the CYP2D6*59 Allele. J Mol Diagn 2015; 17:740-8. [PMID: 26335396 DOI: 10.1016/j.jmoldx.2015.06.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/14/2015] [Accepted: 06/22/2015] [Indexed: 01/08/2023] Open
Abstract
Cytochrome P450 (CYP) 2D6, a major contributor to the metabolism and bioactivation of many clinically used drugs, is encoded by a complex, highly polymorphic gene locus. To aid in the characterization of CYP2D6 allelic variation, we developed allele-specific long-range PCR (ASXL-PCR) to amplify only the allele of interest for further characterization by PCR. This development was achieved utilizing single-nucleotide polymorphisms in the upstream region of CYP2D6 and a universal CYP2D6-specific reverse primer. This approach was assessed and optimized on samples with known genotypes. The application of ASXL-PCR clarified a case with a complex genotype (CYP2D6*2x2/*4N+*4) by amplifying the duplicated gene units separately for subsequent analysis. Furthermore, ASXL-PCR and subsequent sequence analysis also resolved genotype discord in a mother/daughter relationship by revealing the presence of the CYP2D6*59 allelic variant in both individuals. Finally, we demonstrated that the 2939G>A single-nucleotide polymorphism present on CYP2D6*59 interfered with the TaqMan genotype assay that detected 2850C>T, causing false genotype assignments. Assay interference was resolved using an alternative TaqMan genotype assay currently available as a custom-made assay. These examples demonstrate the utility of ASXL-PCR for improved CYP2D6 allele/haplotype characterization. This fast, easy-to-perform method is not limited to CYP2D6 but can be adapted to any gene locus for which polymorphic sites are known.
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Affiliation(s)
- Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri; Department of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri.
| | - Amanda K Riffel
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri
| | - J Steven Leeder
- Division of Clinical Pharmacology, Toxicology and Therapeutic Innovation, Children's Mercy Kansas City, Kansas City, Missouri; Department of Pediatrics, University of Missouri-Kansas City, Kansas City, Missouri
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31
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Gaedigk A, Garcia-Ribera C, Jeong HE, Shin JG, Hernandez-Sanchez J, Hernandez-Sanchez JT. Resolution of a clinical AmpliChip CYP450 Test™ no call: discovery and characterization of novel CYP2D6*1 haplotypes. Pharmacogenomics 2015; 15:1175-84. [PMID: 25141893 DOI: 10.2217/pgs.14.94] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A Han Chinese patient failed CYP2D6 genotype analysis with the AmpliChip CYP450 Test™. The CYP2D6 gene locus of the patient and her son were extensively genotyped including copy number variation and gene resequencing. Two SNPs were discovered on the patient's CYP2D6*1 allele, -498C>A and 1661G>C, while the son's CYP2D6*1 allele had -498C>A only. AmpliChip failure was attributed to the presence of a CYP2D6*1 allele carrying the 1661G>C SNP. Functional analyses of -498C>A did not reveal altered activity in vitro or in vivo suggesting that both novel CYP2D6*1 subvariants are functional. The implementation of pharmacogenetics-guided drug therapy relies on accurate clinical-grade genotype analysis. Although the AmpliChip is a reliable platform, numerous allelic (sub)variants and gene arrangements are not detected or may trigger no calls. While such cases may be rare, the clinical/genetic testing community must be aware of the challenges of CYP2D6 testing on the AmpliChip platform and implications regarding accuracy of test results.
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Affiliation(s)
- Andrea Gaedigk
- Division of Clinical Pharmacology, Toxicology & Therapeutic Innovation, Children's Mercy Hospital, 2401 Gilham Road, Kansas City, MO 64108, USA
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32
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Saladores P, Mürdter T, Eccles D, Chowbay B, Zgheib NK, Winter S, Ganchev B, Eccles B, Gerty S, Tfayli A, Lim JSL, Yap YS, Ng RCH, Wong NS, Dent R, Habbal MZ, Schaeffeler E, Eichelbaum M, Schroth W, Schwab M, Brauch H. Tamoxifen metabolism predicts drug concentrations and outcome in premenopausal patients with early breast cancer. THE PHARMACOGENOMICS JOURNAL 2015; 15:84-94. [PMID: 25091503 PMCID: PMC4308646 DOI: 10.1038/tpj.2014.34] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 04/30/2014] [Accepted: 06/04/2014] [Indexed: 12/11/2022]
Abstract
Tamoxifen is the standard-of-care treatment for estrogen receptor-positive premenopausal breast cancer. We examined tamoxifen metabolism via blood metabolite concentrations and germline variations of CYP3A5, CYP2C9, CYP2C19 and CYP2D6 in 587 premenopausal patients (Asians, Middle Eastern Arabs, Caucasian-UK; median age 39 years) and clinical outcome in 306 patients. N-desmethyltamoxifen (DM-Tam)/(Z)-endoxifen and CYP2D6 phenotype significantly correlated across ethnicities (R(2): 53%, P<10(-77)). CYP2C19 and CYP2C9 correlated with norendoxifen and (Z)-4-hydroxytamoxifen concentrations, respectively (P<0.001). DM-Tam was influenced by body mass index (P<0.001). Improved distant relapse-free survival (DRFS) was associated with decreasing DM-Tam/(Z)-endoxifen (P=0.036) and increasing CYP2D6 activity score (hazard ratio (HR)=0.62; 95% confidence interval (CI), 0.43-0.91; P=0.013). Low (<14 nM) compared with high (>35 nM) endoxifen concentrations were associated with shorter DRFS (univariate P=0.03; multivariate HR=1.94; 95% CI, 1.04-4.14; P=0.064). Our data indicate that endoxifen formation in premenopausal women depends on CYP2D6 irrespective of ethnicity. Low endoxifen concentration/formation and decreased CYP2D6 activity predict shorter DRFS.
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Affiliation(s)
- P Saladores
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - T Mürdter
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - D Eccles
- Faculty of Medicine, Cancer Sciences Academic Unit and University of Southampton Clinical Trials Unit, University of Southampton, Southampton, UK
- University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - B Chowbay
- Clinical Pharmacology Laboratory, Division of Medical Sciences, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
- Academic Medicine Research Institute, Office of Clinical Sciences, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore
- SingHealth Clinical Pharmacology Core, Academia, Singapore Health Services, Singapore, Singapore
| | - N K Zgheib
- Faculty of Medicine, Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon
| | - S Winter
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - B Ganchev
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - B Eccles
- Faculty of Medicine, Cancer Sciences Academic Unit and University of Southampton Clinical Trials Unit, University of Southampton, Southampton, UK
- University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - S Gerty
- Faculty of Medicine, Cancer Sciences Academic Unit and University of Southampton Clinical Trials Unit, University of Southampton, Southampton, UK
- University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - A Tfayli
- Hematology-Oncology Division, Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - J S L Lim
- Clinical Pharmacology Laboratory, Division of Medical Sciences, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
| | - Y S Yap
- Department of Medical Oncology, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
| | - R C H Ng
- Department of Medical Oncology, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
| | - N S Wong
- Department of Medical Oncology, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
| | - R Dent
- Department of Medical Oncology, Humphrey Oei Institute of Cancer Research, National Cancer Centre Singapore, Singapore, Singapore
| | - M Z Habbal
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - E Schaeffeler
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - M Eichelbaum
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - W Schroth
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
| | - M Schwab
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- Department of Clinical Pharmacology, University Hospital Tübingen, Tübingen, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - H Brauch
- Dr Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, Germany
- University of Tübingen, Tübingen, Germany
- German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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Fang H, Liu X, Ramírez J, Choudhury N, Kubo M, Im HK, Konkashbaev A, Cox NJ, Ratain MJ, Nakamura Y, O’Donnell PH. Establishment of CYP2D6 reference samples by multiple validated genotyping platforms. THE PHARMACOGENOMICS JOURNAL 2014; 14:564-72. [PMID: 24980783 PMCID: PMC4237721 DOI: 10.1038/tpj.2014.27] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 04/30/2014] [Accepted: 05/22/2014] [Indexed: 11/30/2022]
Abstract
Cytochrome P450 2D6 (cytochrome P450, family 2, subfamily D, polypeptide 6 (CYP2D6)), a highly polymorphic drug-metabolizing enzyme, is involved in the metabolism of one-quarter of the most commonly prescribed medications. Here we have applied multiple genotyping methods and Sanger sequencing to assign precise and reproducible CYP2D6 genotypes, including copy numbers, for 48 HapMap samples. Furthermore, by analyzing a set of 50 human liver microsomes using endoxifen formation from N-desmethyl-tamoxifen as the phenotype of interest, we observed a significant positive correlation between CYP2D6 genotype-assigned activity score and endoxifen formation rate (rs = 0.68 by rank correlation test, P = 5.3 × 10(-8)), which corroborated the genotype-phenotype prediction derived from our genotyping methodologies. In the future, these 48 publicly available HapMap samples characterized by multiple substantiated CYP2D6 genotyping platforms could serve as a reference resource for assay development, validation, quality control and proficiency testing for other CYP2D6 genotyping projects and for programs pursuing clinical pharmacogenomic testing implementation.
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Affiliation(s)
- Hua Fang
- Committee on Clinical Pharmacology and Pharmacogenomics, The University of Chicago, Chicago, IL 60637, USA
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
| | - Xiao Liu
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
| | - Jacqueline Ramírez
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
| | - Noura Choudhury
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
| | | | - Hae Kyung Im
- Department of Health Studies, The University of Chicago, Chicago, IL 60637, USA
| | - Anuar Konkashbaev
- Section of Genetic Medicine, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
| | - Nancy J. Cox
- Committee on Clinical Pharmacology and Pharmacogenomics, The University of Chicago, Chicago, IL 60637, USA
- Section of Genetic Medicine, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA
- Center for Personalized Therapeutics, The University of Chicago, Chicago, IL 60637, USA
| | - Mark J. Ratain
- Committee on Clinical Pharmacology and Pharmacogenomics, The University of Chicago, Chicago, IL 60637, USA
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
- Center for Personalized Therapeutics, The University of Chicago, Chicago, IL 60637, USA
| | - Yusuke Nakamura
- Committee on Clinical Pharmacology and Pharmacogenomics, The University of Chicago, Chicago, IL 60637, USA
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
- Department of Surgery, The University of Chicago, Chicago, IL 60637, USA
- Center for Personalized Therapeutics, The University of Chicago, Chicago, IL 60637, USA
| | - Peter H. O’Donnell
- Committee on Clinical Pharmacology and Pharmacogenomics, The University of Chicago, Chicago, IL 60637, USA
- Section of Hematology/Oncology, The University of Chicago, Chicago, IL 60637, USA
- Center for Personalized Therapeutics, The University of Chicago, Chicago, IL 60637, USA
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Muroi Y, Saito T, Takahashi M, Sakuyama K, Niinuma Y, Ito M, Tsukada C, Ohta K, Endo Y, Oda A, Hirasawa N, Hiratsuka M. Functional characterization of wild-type and 49 CYP2D6 allelic variants for N-desmethyltamoxifen 4-hydroxylation activity. Drug Metab Pharmacokinet 2014; 29:360-6. [PMID: 24647041 DOI: 10.2133/dmpk.dmpk-14-rg-014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic variations in cytochrome P450 2D6 (CYP2D6) contribute to interindividual variability in the metabolism of clinically used drugs, e.g., tamoxifen. CYP2D6 is genetically polymorphic and is associated with large interindividual variations in therapeutic efficacy and drug toxicity. In this study, we performed an in vitro analysis of 50 allelic variants of CYP2D6 proteins. Wild-type CYP2D6.1 and 49 variants were transiently expressed in COS-7 cells, and the enzymatic activities of the CYP2D6 variants were characterized using N-desmethyltamoxifen as a substrate. The kinetic parameters K(m), V(max), and intrinsic clearance (V(max)/K(m)) of N-desmethyltamoxifen 4-hydroxylation were determined. Among the 50 CYP2D6 variants, the kinetic parameters for N-desmethyltamoxifen 4-hydroxylation were determined for 20 CYP2D6 variants. On the other hand, the kinetic parameters of 30 CYP2D6 variants could not be determined because the amount of metabolite produced was at or below the detection limit at the lower substrate concentrations. Among them, 8 variants, i.e., CYP2D6.2, .9, .26, .28, .32, .43, .45, and .70, showed decreased intrinsic clearance at <50% of CYP2D6.1. The comprehensive in vitro assessment of CYP2D6 variants provides novel insights into allele-specific activity towards tamoxifen and may be valuable when interpreting in vivo studies.
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Affiliation(s)
- Yuka Muroi
- Laboratory of Pharmacotherapy of Life-Style Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University
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Abstract
The US FDA has granted market approval for the first pharmacogenetic test using a DNA microarray, the AmpliChip CYP450, which genotypes cytochrome P450 (CYP)2D6 and CYP2C19. The test uses software to predict phenotypes and tests for 27 CYP2D6 alleles, including the deletions and duplications, and three CYP2C19 alleles. Other DNA microarray platforms are being developed for CYP testing, but none have been completely developed or approved by the FDA to date. The differences between an implementation of pharmacogenetic tests centered on the individual and implementation using a public health approach are discussed. In this review, the major obstacles to the wide implementation of pharmacogenetic testing in the clinical environment are summarized.
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Affiliation(s)
- Jose de Leon
- University of Kentucky, Mental Health Research Center at Eastern State Hospital, 627 West Fourth St., Lexington, KY 40508, USA.
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36
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Abstract
Cytochrome P450 2D6 (CYP2D6) plays an important role in the metabolism and bioactivation of about 25% of clinically used drugs including many antidepressants, antipsychotics and opioids. CYP2D6 activity is highly variably ranging from no activity in so-called poor metabolizers to ultrarapid metabolism at the other end of the extreme of the activity distribution. A large portion of this variability can be explained by the highly polymorphic nature of the CYP2D6 gene locus for which > 100 variants and subvariants identified to date. Allele frequencies vary markedly between ethnic groups; some have exclusively or predominantly only been observed in certain populations. Pharmacogenetic testing holds the promise of individualizing drug therapy by identifying patients with CYP2D6 diplotypes that puts them at an increased risk of experiencing dose-related adverse events or therapeutic failure. Inferring a patient's CYP2D6 metabolic capacity, or phenotype, however, is a challenging task due to the complexity of the CYP2D6 gene locus. Allelic variation includes SNPs, small insertions and deletions, gene copy number variation and rearrangements with CYP2D7, a highly related non-functional gene. This review provides a summary of the intricacies of CYP2D6 variation and genotype analysis, knowledge that is invaluable for the translation of genotype into clinically useful information.
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Affiliation(s)
- Andrea Gaedigk
- Children's Mercy Hospital and Clinics, Division of Clinical Pharmacology and Innovative Therapeutics , Kansas City, Missouri , USA
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Montané Jaime LK, Lalla A, Steimer W, Gaedigk A. Characterization of the CYP2D6 gene locus and metabolic activity in Indo- and Afro-Trinidadians: discovery of novel allelic variants. Pharmacogenomics 2013; 14:261-76. [PMID: 23394389 DOI: 10.2217/pgs.12.207] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The highly polymorphic CYP2D6 gene has extensively been studied in many populations, but there is a void of knowledge regarding CYP2D6 pharmacogenetics and activity in populations with unique ancestries and admixture, such as those residing in Trinidad and Tobago. MATERIALS & METHODS 167 healthy Indo- and 103 Afro-Trinidadians were phenotyped with dextromethorphan and extensively genotyped. Gene resequencing was performed to resolve cases with genotype/phenotype discordance. RESULTS CYP2D6 activity did not differ between the Indo-Trinidadians and Afro-Trinidadians. Poor metabolizers were, however, more frequent in the Indo-Trinidadians (4.19 vs 1.94%), and unique allele frequency patterns were observed. Two novel nonfunctional allelic variants were found among the Indo-Trinidadians in two discordant cases. CYP2D6*100 is characterized by a single nucleotide deletion and CYP2D6*101 by a 19-bp deletion; both cause frameshifts. CONCLUSION Our study underscores the importance of thoroughly characterizing the genetic make up of unique populations when considering pharmacogenetic testing for individualized therapy.
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Affiliation(s)
- Lazara Karelia Montané Jaime
- Pharmacology Unit, Department of Paraclinical Sciences, Faculty of Medical Sciences, The University of The West Indies, St Augustine, Trinidad & Tobago.
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Kim J, Lim YR, Han S, Han JS, Chun YJ, Yun CH, Lee CH, Kim D. Functional influence of human CYP2D6 allelic variations: P34S, E418K, S486T, and R296C. Arch Pharm Res 2013; 36:1500-6. [PMID: 23897164 DOI: 10.1007/s12272-013-0212-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 07/09/2013] [Indexed: 11/29/2022]
Abstract
CYP2D6 is responsible for the oxidative metabolism of 20-25 % of clinical drugs and its genetic polymorphisms can significantly influence the drug metabolism. In this study, we analyzed the functional activities of four nonsynonymous single nucleotide polymorphisms from CYP2D6*52 allele, which were recently found, and one found frequently in CYP2D6 alleles. Recombinant variant enzymes of E418K, S486T, and R296C were successfully expressed in Escherichia coli and purified. However, a CYP holoenzyme spectrum of P34S variant was not detected in E. coli whole cell level. Structural analysis indicated that P34S mutation seemed to perturb a highly conserved proline-rich N-terminus of CYP2D6. Steady state kinetic analyses showed the significant reductions of enzymatic activities in E418K and R296C variants. In the case of bufuralol 1'-hydroxylation, a novel mutant, E418K, showed 32 % decrease in catalytic efficiency (k cat/K m) mainly due to the decrease of k cat value. R296C showed much greater reduction in the catalytic efficiency (9 % of wild-type) due to both of a decrease of k cat value and an increase of K m value. In the case of dextromethorphan O-demethylation, E418K showed both of a decrease of k cat value and an increase K m value to result in ~43 % reduction of catalytic efficiency. A highly decreased catalytic efficiency (~6 % of wild-type) in the mutant of R296C also was observed mainly due to the dramatic change of k cat value of dextromethorphan O-demethylation. These results suggested that individuals carrying these allelic variants are likely to have the altered metabolic abilities of many clinical drugs therefore, these polymorphisms of CYP2D6 should be much concerned for reliable drug treatment.
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Affiliation(s)
- Joohwan Kim
- Department of Biological Sciences, Konkuk University, 120 Neungdong-ro, Gwangjjn-gu, Seoul, 143-701, Korea
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Sutter ME, Gaedigk A, Albertson TE, Southard J, Owen KP, Mills LD, Diercks DB. Polymorphisms in CYP2D6 may predict methamphetamine related heart failure. Clin Toxicol (Phila) 2013; 51:540-4. [PMID: 23855716 DOI: 10.3109/15563650.2013.818684] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Methamphetamine (METH) has been associated with a dilated cardiomyopathy. The first and rate-limiting step of metabolism is dependent on the polymorphic enzyme CYP2D6. OBJECTIVES To evaluate if polymorphisms in CYP2D6 can be associated with the development of a methamphetamine-induced cardiomyopathy. METHODS We performed a prospective case-control pilot study. Cases were defined by a urinary drug screen positive for amphetamine and evidence of heart failure by beta natriuretic peptide (BNP) greater than 300 pg/ml and symptoms of heart failure. Controls were defined with urinary drug screens positive for amphetamines but without evidence of heart failure defined by a BNP lesser than 300 pg/ml or symptoms of heart failure. Exclusion criteria were less than 18 years or greater than 60 years of age, urinary toxicology screen positive for additional stimulants, known coronary artery disease (CAD) defined by greater than 50% stenosis on catheterization or previous myocardial infarction, known cardiomyopathy of alternative etiology or inability to provide consent. Patients underwent gas chromatography confirmation-mass spectroscopy for methamphetamine, genotyping of CYP2D6, limited echocardiography, and participated in a modified 2007 National Survey of Drug Use and Health Stimulant Survey. Genotype results were analyzed with traditional classifications and "Activity Scores". RESULTS Fifty-six patients completed the study with 19 cases and 37 controls. There was no statistically significant difference in days of use in a month, age, gender, or ethnicity between cases and controls. While not statistically significant, age and days of use did trend higher in cases. CYP2D6 genotype demonstrated that the lower the activity score/poor metabolizer group had less heart failure than extensive metabolizers/higher activity score. However, it did not reach statistical significance. When adjusting for higher days of use, extensive metabolizers had the highest odds of developing a dilated cardiomyopathy. (OR: 2.33, 95% CI: 0.54-10.13). Echo findings in all cases showed reduced ejection fractions with a mean of 18.6% (range: 10-35%) and 70% had a dilated cardiomyopathy. No cardiomyopathies were seen in the controls. Mean ejection fraction was 56.75% (range: 45-70%). The odds ratio of having a dilated cardiomyopathy in extensive metabolizers was 1.62 (95% CI: 0.47-5.5). CONCLUSION Our study demonstrates a trend that individuals with decreased metabolic activity were less likely to develop heart failure. While not statistically significant, a signal is present that extensive metabolizers may be at increased risk for the development of a cardiomyopathy.
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Affiliation(s)
- M E Sutter
- Department of Emergency Medicine, University of California, Davis Medical Center, Sacramento, CA, USA.
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Dodgen TM, Hochfeld WE, Fickl H, Asfaha SM, Durandt C, Rheeder P, Drögemöller BI, Wright GEB, Warnich L, Labuschagne CDJ, van Schalkwyk A, Gaedigk A, Pepper MS. Introduction of the AmpliChip CYP450 Test to a South African cohort: a platform comparative prospective cohort study. BMC MEDICAL GENETICS 2013; 14:20. [PMID: 23356658 PMCID: PMC3605304 DOI: 10.1186/1471-2350-14-20] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/18/2013] [Indexed: 02/02/2023]
Abstract
Background Adverse drug reactions and lack of therapeutic efficacy associated with currently prescribed pharmacotherapeutics may be attributed, in part, to inter-individual variability in drug metabolism. Studies on the pharmacogenetics of Cytochrome P450 (CYP) enzymes offer insight into this variability. The objective of this study was to compare the AmpliChip CYP450 Test® (AmpliChip) to alternative genotyping platforms for phenotype prediction of CYP2C19 and CYP2D6 in a representative cohort of the South African population. Methods AmpliChip was used to screen for thirty-three CYP2D6 and three CYP2C19 alleles in two different cohorts. As a comparison cohort 2 was then genotyped using a CYP2D6 specific long range PCR with sequencing (CYP2D6 XL-PCR + Sequencing) platform and a PCR-RFLP platform for seven CYP2C19 alleles. Results Even though there was a low success rate for the AmpliChip, allele frequencies for both CYP2D6 and CYP2C19 were very similar between the two different cohorts. The CYP2D6 XL-PCR + Sequencing platform detected CYP2D6*5 more reliably and could correctly distinguish between CYP2D6*2 and *41 in the Black African individuals. Alleles not covered by the AmpliChip were identified and four novel CYP2D6 alleles were also detected. CYP2C19 PCR-RFLP identified CYP2C19*9,*15, *17 and *27 in the Black African individuals, with *2, *17 and *27 being relatively frequent in the cohort. Eliminating mismatches and identifying additional alleles will contribute to improving phenotype prediction for both enzymes. Phenotype prediction differed between platforms for both genes. Conclusion Comprehensive genotyping of CYP2D6 and CYP2C19 with the platforms used in this study, would be more appropriate than AmpliChip for phenotypic prediction in the South African population. Pharmacogenetically important novel alleles may remain undiscovered when using assays that are designed according to Caucasian specific variation, unless alternate strategies are utilised.
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Affiliation(s)
- Tyren M Dodgen
- Department of Pharmacology, University of Pretoria, Pretoria, South Africa
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41
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Kim J, Lee SY, Lee KA. Copy number variation and gene rearrangements in CYP2D6 genotyping using multiplex ligation-dependent probe amplification in Koreans. Pharmacogenomics 2012; 13:963-73. [PMID: 22676200 DOI: 10.2217/pgs.12.58] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM The present study introduces a simple method for CYP2D6 genotyping that not only determines the heterozygous or homozygous deletions and duplications, but also distinguishes tandem hybrids. MATERIALS & METHODS Using two commercially available methods, 49 Korean male subjects were genotyped for CYP2D6. The Affymetrix(®) Targeted Human Drug Metabolizing Enzymes and Transporter 1.0 Assay was used for SNP genotyping and multiplex ligation-dependent probe amplification (MLPA) assay (SALSA(®) MLPA(®) Kit P128-A1 CYP450) was used for copy number analysis. Long range PCR was used to confirm the MLPA results. Fifty Caucasian samples obtained from the Coriell Institute were used to confirm the accuracy of the MLPA assay. RESULTS Using two commercially available methods, we found seven different allele types with CYP2D6*1 (34.7%), *2 (12.2%), *10 (17.4%) and *36-*10 (22.5%) being the most common alleles in the Korean population. The MLPA results showed 100% agreement with long-range-PCR results and were able to distinguish deletions and duplications among 50 Caucasian reference samples. CONCLUSION The application of MLPA-based genotyping to routine clinical analysis will enable patients to be assigned to more accurate genotypes at a reasonable cost in a large number of individuals at the majority of locations.
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Affiliation(s)
- Juwon Kim
- Department of Laboratory Medicine, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 135-720, Korea
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42
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Serin A, Canan H, Alper B, Gulmen. M. The frequencies of mutated alleles of CYP2D6 gene in a Turkish population. Forensic Sci Int 2012; 222:332-4. [DOI: 10.1016/j.forsciint.2012.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 07/15/2012] [Accepted: 07/26/2012] [Indexed: 10/28/2022]
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The neuroprotective enzyme CYP2D6 increases in the brain with age and is lower in Parkinson's disease patients. Neurobiol Aging 2012; 33:2160-71. [DOI: 10.1016/j.neurobiolaging.2011.08.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 07/18/2011] [Accepted: 08/21/2011] [Indexed: 11/22/2022]
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Gaedigk A, Twist GP, Leeder JS. CYP2D6, SULT1A1 and UGT2B17 copy number variation: quantitative detection by multiplex PCR. Pharmacogenomics 2012; 13:91-111. [DOI: 10.2217/pgs.11.135] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: Among the genes of drug-metabolizing enzymes, CYP2D6 is notoriously difficult to characterize owing to the complexity of gene deletions, duplications, multiplications and the presence of hybrid genes composed of CYP2D6 and CYP2D7. For SULT1A1 up to five gene copies have been reported, while UGT2B17 is known for gene deletions only. Different platforms exist for copy number variation (CNV) detection; however, there are no gold standards. Robust methods are required that address specific challenges to accurately determine gene CNVs in complex gene loci. Materials & methods: Quantitative multiplex PCR amplification (MPA) was performed on a diverse set of genomic DNA samples. Resulting PCR fragments were separated on an ABI 3730 instrument and analyzed with GeneMapper. CYP2D6 was targeted at four different gene regions and either normalized against CYP2D8 or UGT2B15 and SULT1A2. Inconsistent observations and CNVs contrasting genotype data were further characterized by long-range PCR and/or DNA sequence analysis. UGT2B17 and SULT1A1 were normalized against UGT2B15 and SULT1A2, respectively. Results: MPA detected 0–5, 1–5 and 0–2 copies for CYP2D6, SULT1A1 and UGT2B17, respectively. The interrogation of four CYP2D6 regions resulted in robust copy number assignments that were in agreement with genotype, sequencing and extra long PCR-based data. Gene deletions, duplication, and multiplications among known and novel hybrid genes were reliably identified. Novel findings regarding allelic variation include nonfunctional CYP2D6/2D7 hybrids such as CYP2D6*4N and *68, which were consistently identified on a subset of CYP2D6*4 alleles. In addition, a novel variant, designated CYP2D6*83, was discovered. For SULT1A1, we report the first six-copy case and for UGT2B15 and UGT2B17 we have evidence for rare deletion and duplication events, respectively. Conclusion: This MPA-based copy number platform not only allowed us to determine CNVs, but also served as a tool for allele discovery and characterization in a diverse panel of samples in a fast and reliable manner. Original submitted 6 July 2011; Revision submitted 24 August 2011
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Affiliation(s)
| | - Greyson P Twist
- Division of Pediatric Pharmacology & Medical Toxicology, The Children’s Mercy Hospital & Clinics, 2401 Gillham Rd, Kansas City, MO 64108, USA
| | - J Steven Leeder
- Division of Pediatric Pharmacology & Medical Toxicology, The Children’s Mercy Hospital & Clinics, 2401 Gillham Rd, Kansas City, MO 64108, USA
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Teh LK, Bertilsson L. Pharmacogenomics of CYP2D6: molecular genetics, interethnic differences and clinical importance. Drug Metab Pharmacokinet 2011; 27:55-67. [PMID: 22185816 DOI: 10.2133/dmpk.dmpk-11-rv-121] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
CYP2D6 has received intense attention since the beginning of the pharmacogenetic era in the 1970s. This is because of its involvement in the metabolism of more than 25% of the marketed drugs, the large geographical and inter-ethnic differences in the genetic polymorphism and possible drug-induced toxicity. Many interesting reviews have been published on CYP2D6 and this review aims to reinstate the importance of the genetic polymorphism of CYP2D6 in different populations as well as some clinical implications and important drug interactions.
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Affiliation(s)
- Lay Kek Teh
- Pharmacogenomics Centre PROMISE, Faculty of Pharmacy, Universiti Teknologi MARA, Selangor DE, Malaysia.
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Black JL, Walker DL, O'Kane DJ, Harmandayan M. Frequency of undetected CYP2D6 hybrid genes in clinical samples: impact on phenotype prediction. Drug Metab Dispos 2011; 40:111-9. [PMID: 22004686 DOI: 10.1124/dmd.111.040832] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 2D6 (CYP2D6) is highly polymorphic. CYP2D6-2D7 hybrid genes can be present in samples containing CYP2D6*4 and CYP2D6*10 alleles. CYP2D7-2D6 hybrid genes can be present in samples with duplication signals and in samples with homozygous genotyping results. The frequency of hybrid genes in clinical samples is unknown. We evaluated 1390 samples for undetected hybrid genes by polymerase chain reaction (PCR) amplification, PCR fragment analysis, TaqMan copy number assays, DNA sequencing, and allele-specific primer extension assay. Of 508 CYP2D6*4-containing samples, 109 (21.5%) harbored CYP2D6*68 + *4-like, whereas 9 (1.8%) harbored CYP2D6*4N + *4-like. Of 209 CYP2D6*10-containing samples, 44 (21.1%) were found to have CYP2D6*36 + *10. Of 332 homozygous samples, 4 (1.2%) harbored a single CYP2D7-2D6 hybrid, and of 341 samples with duplication signals, 25 (7.3%) harbored an undetected CYP2D7-2D6 hybrid. Phenotype before and after accurate genotyping was predicted using a method in clinical use. The presence of hybrid genes had no effect on the phenotype prediction of CYP2D6*4- and CYP2D6*10-containing samples. Four of four (100%) homozygous samples containing a CYP2D7-2D6 gene had a change in predicted phenotype, and 23 of 25 (92%) samples with a duplication signal and a CYP2D7-2D6 gene had a change in predicted phenotype. Four novel genes were identified (CYP2D6*13A1 variants 1 and 2, CYP2D6*13G1, and CYP2D6*13G2), and two novel hybrid tandem structures consisting of CYP2D6*13B + *68×2 + *4-like and CYP2D6*13A1 variant 2 + *1×N were observed.
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Affiliation(s)
- John Logan Black
- Department of Laboratory Medicine and Pathology, Mayo Clinic 200 1st Street SW, Rochester, Minnesota, NM 55902, USA.
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Scheer N, Kapelyukh Y, McEwan J, Beuger V, Stanley LA, Rode A, Wolf CR. Modeling human cytochrome P450 2D6 metabolism and drug-drug interaction by a novel panel of knockout and humanized mouse lines. Mol Pharmacol 2011; 81:63-72. [PMID: 21989258 DOI: 10.1124/mol.111.075192] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The highly polymorphic human cytochrome P450 2D6 enzyme is involved in the metabolism of up to 25% of all marketed drugs and accounts for significant individual differences in response to CYP2D6 substrates. Because of the differences in the multiplicity and substrate specificity of CYP2D family members among species, it is difficult to predict pathways of human CYP2D6-dependent drug metabolism on the basis of animal studies. To create animal models that reflect the human situation more closely and that allow an in vivo assessment of the consequences of differential CYP2D6 drug metabolism, we have developed a novel straightforward approach to delete the entire murine Cyp2d gene cluster and replace it with allelic variants of human CYP2D6. By using this approach, we have generated mouse lines expressing the two frequent human protein isoforms CYP2D6.1 and CYP2D6.2 and an as yet undescribed variant of this enzyme, as well as a Cyp2d cluster knockout mouse. We demonstrate that the various transgenic mouse lines cover a wide spectrum of different human CYP2D6 metabolizer phenotypes. The novel humanization strategy described here provides a robust approach for the expression of different CYP2D6 allelic variants in transgenic mice and thus can help to evaluate potential CYP2D6-dependent interindividual differences in drug response in the context of personalized medicine.
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Suwannasri P, Thongnoppakhun W, Pramyothin P, Assawamakin A, Limwongse C. Combination of multiplex PCR and DHPLC-based strategy for CYP2D6 genotyping scheme in Thais. Clin Biochem 2011; 44:1144-1152. [DOI: 10.1016/j.clinbiochem.2011.06.985] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/01/2011] [Accepted: 06/26/2011] [Indexed: 10/18/2022]
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Contreras AV, Monge-Cazares T, Alfaro-Ruiz L, Hernandez-Morales S, Miranda-Ortiz H, Carrillo-Sanchez K, Jimenez-Sanchez G, Silva-Zolezzi I. Resequencing, haplotype construction and identification of novel variants of CYP2D6 in Mexican Mestizos. Pharmacogenomics 2011; 12:745-56. [PMID: 21391885 DOI: 10.2217/pgs.11.8] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
AIM The CYP2D6 enzyme participates in the metabolism of commonly prescribed drugs: antidepressants, antipsychotics and antihypertensives. The CYP2D6 gene shows a high degree of interindividual and interethnic variability that influences its expression and function. Mexican Mestizos are a recently admixed population resulting from the combination of Amerindian, European and, to a lesser extent, African populations. This study aimed to comprehensively characterize the CYP2D6 gene in Mexican Mestizos. MATERIALS & METHODS We performed linkage disequilibrium and network analyses in resequencing data of 96 individuals from two regions within Mexico with a different history of admixture and particular population dynamics, the Northwestern state of Sonora and the Central-Pacific state of Guerrero. RESULTS & CONCLUSION We identified 64 polymorphisms, including 14 novel variants: 13 SNPs and a CYP2D7 exon 2 conversion, that was assigned CYP2D6*82 by the Human Cytochrome P450 (CYP) Allele Nomenclature Committee. Three novel SNPs were predicted to have functional effects. For CYP2D6*82 we hypothesize an Amerindian origin that is supported by its identification in three Mexican Amerindian groups (Mayas, Tepehuanos and Mixtecos). Frequencies of CYP2D6*1, *2, *4, *5, *10, *29, *53, *82 and its duplications were 50.0, 25.5, 14.1, 2.0, 2.6, 1.0, 0.5, 2.1 and 3.6%, respectively. We found significant frequency differences in CYP2D6*1 and *2 between Mexican Mestizos and in CYP2D6*1, *2, *4, *5, *10 and *29 between Mexicans and at least one other population. We observed strong linkage disequilibrium and phylogenetic relationships between haplotypes. To our knowledge, this study is the first comprehensive resequencing analysis of CYP2D6 in Mexicans or any other Latin American population, providing information about genetic diversity relevant in the development of pharmacogenomics in this region.
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Affiliation(s)
- Alejandra V Contreras
- National Institute of Genomic Medicine (MEXICO), Periférico Sur 4124 Torre Zafiro II Piso 6, Col. Ex-Rancho de Anzaldo, Mexico DF 01900, Mexico
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Copy number variants in pharmacogenetic genes. Trends Mol Med 2011; 17:244-51. [PMID: 21388883 DOI: 10.1016/j.molmed.2011.01.007] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Revised: 01/14/2011] [Accepted: 01/14/2011] [Indexed: 01/07/2023]
Abstract
Variation in drug efficacy and toxicity remains an important clinical concern. Presently, single nucleotide polymorphisms (SNPs) only explain a portion of this problem, even in situations where the pharmacological trait is clearly heritable. The Human CNV Project identified copy number variations (CNVs) across approximately 12% of the human genome, and these CNVs were considered causes of diseases. Although the contribution of CNVs to the pathogenesis of many common diseases is questionable, CNVs play a clear role in drug-related genes by altering drug metabolizing and drug response. In this review, we provide a comprehensive evaluation of the clinical relevance of CNVs to drug efficacy, toxicity, and disease prevalence in world populations, and discuss the implication of using CNVs as a diagnostic tool in clinical intervention.
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