GTR Home > Conditions/Phenotypes > Dihydropyrimidine dehydrogenase deficiency


Dihyropyrimidine dehydrogenase deficiency shows large phenotypic variability, ranging from no symptoms to a convulsive disorder with motor and mental retardation in homozygous patients. In addition, homozygous and heterozygous mutation carriers can develop severe toxicity after the administration of the antineoplastic drug 5-fluorouracil (5FU), which is also catabolized by the DPYD enzyme. This is an example of a pharmacogenetic disorder (Van Kuilenburg et al., 1999). Since there is no correlation between genotype and phenotype in DPD deficiency, it appears that the deficiency is a necessary, but not sufficient, prerequisite for the development of clinical abnormalities (Van Kuilenburg et al., 1999; Enns et al., 2004). [from OMIM]

Associated genes

Clinical features

  • Hypertonia
  • Agenesis of corpus callosum
  • Intellectual disability
  • Microcephaly
  • Seizure
  • Nystagmus
  • Failure to thrive
  • Microphthalmos
  • Coloboma
  • Optic atrophy
  • Autism
  • Delayed speech and language development
  • Hyperactivity
  • Muscular hypotonia
  • Lethargy
  • Motor delay
  • Growth delay
  • Cerebral atrophy
  • Tetraplegia
  • Reduced dihydropyrimidine dehydrogenase activity
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Go to complete MedGen record for Dihydropyrimidine dehydrogenase deficiency

Clinical resources

Practice guidelines

  • CPIC, 2013
    Clinical pharmacogenetics implementation consortium guidelines for dihydropyrimidine dehydrogenase genotype and fluoropyrimidine dosing.
  • DailyMed Drug Label, 2012
    ADRUCIL (fluorouracil) injection HUMAN PRESCRIPTION DRUG LABEL

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