RARE DISEASERESEARCH ATLAS
Open navigation menu

ORPHA:93602

Xanthinuria type II

medium confidenceSubtype of disorder

Also known as: XDH and AOX dual deficiency · Xanthine dehydrogenase and xanthine aldehyde oxidase dual deficiency

Publications

747

83.1th percentile

Trials

0

Interventional, condition-specific

Researchers

1,255

Distinct authors in sample

Gene link

MOCOS

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

Type II xanthinuria, a type of classical xanthinuria, is a rare disorder of purine metabolism characterized by the deficiency of both xanthine dehydrogenase and aldehyde oxidase, leading to the formation of urinary xanthine urolithiasis and leading, in some patients, to kidney failure. Other less common manifestations include arthropathy, and duodenal ulcer, while some patients remain asymptomatic.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (3)

XAN2 · xanthine dehydrogenase and aldehyde oxidase, combined deficiency of · xanthine dehydrogenase and xanthine aldehyde oxidase dual deficiency

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

No matched interventional trial, but a gene association and an animal model are on record — often described as translation-ready / stalled at the clinical step.

  1. Gene identifiedPresent

    Definitive — MOCOS

  2. LiteraturePresent

    747 matched papers (486 in last 10 years) Source

  3. Phenotype characterisedPresent

    8 HPO annotations (e.g. Increased urinary hypoxanthine level; Kidney stone; Hypouricemia) Source

  4. Animal modelPresent

    1 genotype model (Mus musculus) Source

  5. Orphan designationNot found

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

  6. Interventional trialNot found

    No matched interventional trial under our ClinicalTrials.gov rules

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 (MOCOS).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

8

Associated phenotypes · MONDO:0011346

  • Increased urinary hypoxanthine level
  • Kidney stone
  • Hypouricemia
  • Renal insufficiency
  • Xanthinuria

Showing 5 of 8 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

Model associations linked to this Mondo ID

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?

747

747 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.

747 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).

486 in the last 10 years · medium confidence · 83.1th percentile (publications denominator)

Phrase hits: 397 · MeSH hits: 1

Open Europe PMC search

Who's working on it?

1,255

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

Who's working on it?

No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.

  1. 01
    Schwarz G12 papers · 2025

    Institute of Biochemistry, Department of Chemistry, University of Cologne, Cologne, Germany.

    Papers in Europe PMC
  2. 02
    Ichida K9 papers · 2022

    Department of Pathophysiology, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan.

    Papers in Europe PMC
  3. 03
    Santamaria-Araujo JA6 papers · 2024

    Orphatec/Colbourne Pharmaceuticals, Niederkassel, Germany.

    Papers in Europe PMC
  4. 04
    Schwahn BC6 papers · 2025

    Royal Hospital for Sick Children, NHS Greater Glasgow and Clyde, Glasgow, UK; Willink Biochemical Genetics Unit, Saint Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, UK. Electronic address: bernd.schwahn@cmft.nhs.uk.

    Papers in Europe PMC
  5. 05
    Reiss J5 papers · 2019

    Institut für Humangenetik, Universitätsmedizin Göttingen, Germany. jreiss@gwdg.de

    Papers in Europe PMC
  6. 06
    Wang X5 papers · 2026

    Case Western Reserve University School of Medicine, Cleveland, Ohio, USA.

    Papers in Europe PMC
  7. 07
    Clayton PT3 papers · 2025

    Genetics and Genomic Medicine, University College London Great Ormond Street Institute of Child Health, London, UK.

    Papers in Europe PMC
  8. 08
    Ding Y3 papers · 2025

    Rady Children's Institute for Genomic Medicine, San Diego, California 92123, USA.

    Papers in Europe PMC
  9. 09
    Feigenbaum A3 papers · 2024

    Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA; Rady Children's Hospital, San Diego, CA 92123, USA; Department of Pediatrics, University of California, San Diego, San Diego, CA 92093, USA.

    Papers in Europe PMC
  10. 10
    Hoffmann GF3 papers · 2026

    Pediatric Neurology and Center for Rare Disorders, Center for Pediatric and Adolescent Medicine, Heidelberg University Hospital, Heidelberg, Germany.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

0

interventional trials for this specific condition

No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).

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

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

medium confidence · 38.6th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.

Broader category xanthinuria also has no matched interventional trial. See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

Broader category: xanthinuria

0

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Parent-category matching found a broader label but no interventional trials under it. How we count trials.

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 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-30

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).

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 Xanthinuria type II — 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.

("Xanthinuria type II" OR "XDH and AOX dual deficiency" OR "Xanthine dehydrogenase and xanthine aldehyde oxidase dual deficiency" OR "xanthine dehydrogenase and aldehyde oxidase, combined deficiency of") OR (MESH:"Xanthinuria, Type II") OR ("MOCOS" OR "MOCOS syndrome" OR "MOCOS-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Xanthinuria, Type II

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

"Xanthinuria type II" OR "XDH and AOX dual deficiency" OR "Xanthine dehydrogenase and xanthine aldehyde oxidase dual deficiency" OR "xanthine dehydrogenase and aldehyde oxidase, combined deficiency of" OR "Xanthinuria, Type II"

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

Parent-category trials query:

"xanthinuria"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: XAN2

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-27T04:27:37.182Z