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Drug Metabolism and Personalized Therapy

Official journal of the European Society of Pharmacogenomics and Personalised Therapy

Editor-in-Chief: Llerena, Adrián

Editorial Board: Benjeddou, Mongi / Chen, Bing / Dahl, Marja-Liisa / Devinsky, Ferdinand / Hirata, Rosario / Hubacek, Jaroslav A. / Ingelman-Sundberg, Magnus / Maitland-van der Zee, Anke-Hilse / Manolopoulos, Vangelis G. / Marc, Janja / Melichar, Bohuslav / Meyer, Urs A. / Nair, Sujit / Nofziger, Charity / Peiro, Ana / Sadee, Wolfgang / Salazar, Luis A. / Simmaco, Maurizio / Turpeinen, Miia / Schaik, Ron / Shin, Jae-Gook / Visvikis-Siest, Sophie / Zanger, Ulrich M.

4 Issues per year

CiteScore 2017: 1.46

SCImago Journal Rank (SJR) 2017: 0.531
Source Normalized Impact per Paper (SNIP) 2017: 0.645

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Volume 33, Issue 1


Accurate determination of the CYP2D6 (*1/*4)xN genotype by quantitative PCR

Kirsten M. Pondman / Ron H.N. van Schaik
  • Department of Clinical Chemistry, Erasmus MC – University Medical Center Rotterdam, Rotterdam, the Netherlands
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Jan van der Weide
Published Online: 2018-02-08 | DOI: https://doi.org/10.1515/dmpt-2017-0007



CYP2D6 is responsible for the metabolism of approximately 25% of all drugs. The expression of cytochrome P450 2D6 (CYP2D6) is influenced by a combination of factors including polymorphisms in the CYP2D6 gene. Analysis of the CYP2D6 genotype is used to personalize the medication to a patient’s metabolism. Although many genotypes can be determined using standard genotype analysis, in some cases, an incomplete analysis is performed. The CYP2D6 genotype *1/*4 often occurs in combination with a multiplication of the CYP2D6 gene, and is reported as (*1/*4)xN. Accurate determination of the multiplied gene is essential to provide a phenotype prediction for these patients. Duplication of the *1 gene leads to an extensive metabolizer genotype whereas multiplication of the *4 gene would not lead to extra functional enzyme and therefore provides an intermediate metabolizer phenotype.


Here, a technique is described in which the copy numbers of both the *4 and *1 genes are determined using quantitative PCR techniques.

Results and conclusions:

This technique provides a method to predict the patient’s CYP2D6 phenotype, and is therefore an important step toward personalized medicine.

Keywords: copy number variations (CNV); CYP2D6; pharmacogenetics; ultrarapid metabolizer


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About the article

Received: 2017-02-13

Accepted: 2017-12-18

Published Online: 2018-02-08

Published in Print: 2018-03-28

Author contributions All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

Research funding: None declared.

Employment or leadership: None declared.

Honorarium: None declared.

Competing interests: The funding organization(s) played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.

Citation Information: Drug Metabolism and Personalized Therapy, Volume 33, Issue 1, Pages 33–39, ISSN (Online) 2363-8915, ISSN (Print) 2363-8907, DOI: https://doi.org/10.1515/dmpt-2017-0007.

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