dihydropyrimidine dehydrogenase deficiency
Findings
No curated finding names dihydropyrimidine dehydrogenase deficiency yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
Dihydropyrimidine dehydrogenase (DPD) deficiency isaconditionin which the body cannot break down the nucleotides thymine and uracil. DPD deficiency can have a wide range of severity; some individuals may have various neurological problems, while others have no signsand symptoms. Signs and symptoms in severely affected individuals begin in infancy and may include seizures, intellectual disability, microcephaly, increased muscle tone (hypertonia), delayed motor skills, and autistic behavior. All individuals with the condition, regardless of the presence or severity of symptoms, are at risk for severe, toxic reactions to drugs called fluoropyrimidines which are used to treat cancer. Individuals with no symptoms may be diagnosed only by laboratory testing or after exposure to fluoropyrimidines. DPD deficiency is caused by mutations in the DPYD gene and is inherited in an autosomal recessive manner.
Definition from the Mondo Disease Ontology (MONDO:0010130), read 2026-09-29. CC BY 4.0.
- Onset and course
- Congenital onset · Infantile onset · Juvenile onset · Childhood onset
HPO, annotations 2026-09-02
Features
63 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Reduced dihydropyrimidine dehydrogenase levelHPOHP:0003654
- Very frequent (80% to 99% of cases)
- UraciluriaHPOHP:0012127
- Very frequent (80% to 99% of cases)
- EEG abnormalityHPOHP:0002353
- Frequent (30% to 79% of cases)
- Floppy infantHPOHP:0008947
- Frequent (30% to 79% of cases)
- Global developmental delayHPOHP:0001263
- Frequent (30% to 79% of cases)
- Multifocal epileptiform discharges
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- DPYDHGNC:3012
- Definitive · G2P · Autosomal recessive · 2018
- Strong · PanelApp Australia · Autosomal recessive · 2025
Where it sits
Other names
5 names
Resolves to: dihydropyrimidine dehydrogenase deficiency
- Also called
- dihydrouracil dehydrogenase deficiencyDYPD deficiencyfamilial pyrimidinaemiafamilial pyrimidinemiathymine-uracilurea