Severe fluoropyrimidine toxicity due to novel and rare DPYD missense mutations, deletion and genomic amplification affecting DPD activity and mRNA splicing

Andre B. P. van Kuilenburg*, Judith Meijer, Dirk Maurer, Doreen Dobritzsch, Rutger Meinsma, Maartje Los, Lia C. Knegt, Lida Zoetekouw, Rob L. H. Jansen, Vincent Dezentje, Lieke H. van Huis-Tanja, Roel J. W. van Kampen, Jens Michael Hertz, Raoul C. M. Hennekam

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

26 Citations (Web of Science)

Abstract

Dihydropyrimidine dehydrogenase (DPD) is the initial and rate-limiting enzyme in the catabolism of 5-fluorouracil (5FU). Genetic variations in DPD have emerged as predictive risk factors for severe fluoropyrimidine toxicity. Here, we report novel and rare genetic variants underlying DPD deficiency in 9 cancer patients presenting with severe fluoropyrimidine-associated toxicity. All patients possessed a strongly reduced DPD activity, ranging from 9 to 53% of controls. Analysis of the DPD gene (DPYD) showed the presence of 21 variable sites including 4 novel and 4 very rare aberrations: 3 missense mutations, 2 splice-site mutations, 1 intronic mutation, a deletion of 21 nucleotides and a genomic amplification of exons 9-12. Two novel/rare variants (c.2843T > C, c.321 + I G > A) were present in multiple, unrelated patients. Functional analysis of recombinantly-expressed DPD mutants carrying the p.1948T and p.G284V mutation showed residual DPD activities of 30% and 0.5%, respectively. Analysis of a DPD homology model indicated that the p.I948T and p.G284V mutations may affect electron transfer and the binding of FAD, respectively. cDNA analysis showed that the c321 + 1G > A mutation in DPYD leads to skipping of exon 4 immediately upstream of the mutated splice-donor site in the process of DPD premRNA splicing. A lethal toxicity in two DPD patients suggests that fluoropyrimidines combined with other therapies such as radiotherapy might be particularly toxic for DPD deficient patients. Our study advocates a more comprehensive genotyping approach combined with phenotyping strategies for upfront screening for DPD deficiency to ensure the safe administration of fluoropyrimidines. (C) 2016 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)721-730
Number of pages10
JournalBiochimica et Biophysica Acta-Molecular Basis of Disease
Volume1863
Issue number3
DOIs
Publication statusPublished - Mar 2017

Keywords

  • Dihydropyrimidine dehydrogenase
  • DPYD
  • 5-Fluorouracil
  • Capecitabine
  • Pharmacogenetics
  • Toxicity
  • DIHYDROPYRIMIDINE DEHYDROGENASE-DEFICIENCY
  • SINGLE NUCLEOTIDE POLYMORPHISMS
  • III COLON-CANCER
  • CLINICAL-RELEVANCE
  • ADJUVANT TREATMENT
  • INTRAGENIC REARRANGEMENTS
  • 5-FLUOROURACIL TOXICITY
  • COLORECTAL-CANCER
  • ENZYME-ACTIVITY
  • GENE

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