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ORPHA:1675

Dihydropyrimidine dehydrogenase deficiency

low confidenceDisorder

Also known as: Familial pyrimidinemia

Publications

4,118

Trials

2

Interventional, condition-specific

Researchers

1,307

Distinct authors in sample

Gene link

DPYD

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare disorder of pyrimidine metabolism characterized by a variable ranging from absence of symptoms to severe neurological involvement with , , and . Additional signs and symptoms may include , microcephaly, ocular abnormalities (such as microphthalmia, nystagmus, and strabismus), and autistic behavior, among others. Analysis of urine typically shows high levels of uracil and thymine. Patients are at risk of suffering from severe toxicity after the administration of the anti-neoplastic agent 5-fluorouracil.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (6)

DYPD deficiency · dihydropyrimidine dehydrogenase deficiency · dihydrouracil dehydrogenase deficiency · familial pyrimidinaemia · familial pyrimidinemia · thymine-uracilurea

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — DPYD

  2. LiteraturePresent

    4,118 matched papers (2,899 in last 10 years) Source

  3. Phenotype characterisedPresent

    77 HPO annotations (e.g. Reduced dihydropyrimidine dehydrogenase level; Uraciluria; Seizure) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPresent

    2 matched on ClinicalTrials.gov (1 recruiting in sample)

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Yes — we know a specific gene responsible (DPYD).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

77

Associated phenotypes · MONDO:0010130

  • Reduced dihydropyrimidine dehydrogenase level
  • Uraciluria
  • Seizure
  • Global developmental delay
  • High palate

Showing 5 of 77 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

4,118

4,118 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

4,118 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

2,899 in the last 10 years · low confidence

Phrase hits: 655 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,307

Distinct author names in 200 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Thomas F15 papers · 2025

    Department of Pharmacology. Institut Claudius-Regaud. CRCT, Université de Toulouse. Inserm. UPS, 20-24 Rue du Pont Saint-Pierre, 31300, Toulouse, France.

    Papers in Europe PMC
  2. 02
    Loriot MA11 papers · 2026

    Department of Clinical Chemistry, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, University of Paris, Paris, France.

    Papers in Europe PMC
  3. 03
    Ciccolini J10 papers · 2025

    SMARTc Unit, Inserm S-911 La Timone University Hospital of Marseille and Aix Marseille Universite, Marseille, France.

    Papers in Europe PMC
  4. 04
    Etienne-Grimaldi MC8 papers · 2024

    Oncopharmacology laboratory, Centre Antoine Lacassagne, Nice, France. Electronic address: marie-christine.etienne@nice.unicancer.fr.

    Papers in Europe PMC
  5. 05
    Narjoz C8 papers · 2026

    Department of Clinical Chemistry, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, University of Paris, Paris, France.

    Papers in Europe PMC
  6. 06
    Haufroid V7 papers · 2024

    Department of Toxicology and Applied Pharmacology, University Hospital St Luc/UCLouvain, Woluwe.

    Papers in Europe PMC
  7. 07
    Launay M7 papers · 2024

    Laboratory of Pharmacology and Toxicology, University Hospital Center of Saint-Etienne, Saint-Etienne Cedex 02, France.

    Papers in Europe PMC
  8. 08
    Royer B7 papers · 2024

    Department of Clinical Pharmacology, CHU Jean Minjoz, Besançon, France.

    Papers in Europe PMC
  9. 09
    Pallet N6 papers · 2024

    Department of Clinical Chemistry, Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, University of Paris, Paris, France. nicolas.pallet@aphp.fr.

    Papers in Europe PMC
  10. 10
    van Kuilenburg ABP6 papers · 2026

    Amsterdam UMC, University of Amsterdam, Departments of Clinical Chemistry, Genetics and Pediatrics, Amsterdam Gastroenterology & Metabolism, Amsterdam, The Netherlands. a.b.vankuilenburg@amc.uva.nl.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

2

interventional trials for this specific condition

2 interventional trials matched this specific condition name; 1 currently recruiting in our sample.

Data as of 11 September 2026 · last trial check 28 July 2026

2 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 84.5th percentile).

low confidence · 84.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

2 interventional trials matched after quoted-phrase search and title/condition post-filter.

Observational and natural-history studies

1 observational study matches this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 41 · after dedupe 41 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 41 · dropped 0 · fetched 2026-07-29

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Uncertain / not reviewed (41)

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for Dihydropyrimidine dehydrogenase deficiency — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

("Dihydropyrimidine dehydrogenase deficiency" OR "Familial pyrimidinemia" OR "DYPD deficiency" OR "dihydrouracil dehydrogenase deficiency" OR "familial pyrimidinaemia" OR "thymine-uracilurea") OR ("DPYD" OR "DPYD syndrome" OR "DPYD-related")

Run this search on Europe PMC

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"Dihydropyrimidine dehydrogenase deficiency" OR "Familial pyrimidinemia" OR "DYPD deficiency" OR "dihydrouracil dehydrogenase deficiency" OR "familial pyrimidinaemia" OR "thymine-uracilurea"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 2 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (4118) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T17:57:11.428Z