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ORPHA:99731

Isolated sulfite oxidase deficiency

low confidenceSubtype of disorder

Also known as: ISOD · Sulfocysteinuria

Publications

1,655

Trials

0

Interventional, condition-specific

Researchers

1,086

Distinct authors in sample

Gene link

SUOX

Definitive

Readiness

3/6

Stages with a signal

How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (4)

isolated sulfite oxidase deficiency · sulfite oxidase deficiency · sulfite oxidase deficiency, isolated · sulfocysteinuria

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.”

3/6 stages with a signal

No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.

  1. Gene identifiedPresent

    Definitive — SUOX

  2. LiteraturePresent

    1,655 matched papers (1,075 in last 10 years) Source

  3. Phenotype characterisedPresent

    34 HPO annotations (e.g. Floppy infant; Hemiplegia; Ataxia) 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 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 (SUOX).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

34

Associated phenotypes · MONDO:0010089

  • Floppy infant
  • Hemiplegia
  • Ataxia
  • Generalized hypotonia
  • Multifocal epileptiform discharges

Showing 5 of 34 — 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?

1,655

1,655 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.

1,655 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).

1,075 in the last 10 years · low confidence

Phrase hits: 416 · MeSH hits: 7

Open Europe PMC search

Who's working on it?

1,086

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, Center for Molecular Medicine Cologne (CMMC) and Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Zuelpicher Straße 47, 50674 Cologne, Germany gschwarz@uni-koeln.de.

    Papers in Europe PMC
  2. 02
    Johnson JL6 papers · 2003

    Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA. jean_johnson@biochem.duke.edu

    Papers in Europe PMC
  3. 03
    Rajagopalan KV6 papers · 2006
    Papers in Europe PMC
  4. 04
    Wang Y6 papers · 2024

    State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China.

    Papers in Europe PMC
  5. 05
    Johnson TK5 papers · 2026

    Department of Biochemistry and Chemistry and La Trobe Institute for Molecular Science, La Trobe University, Bundoora, VIC 3086, Australia. Electronic address: t.johnson@latrobe.edu.au.

    Papers in Europe PMC
  6. 06
    Leipnitz G5 papers · 2023

    Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, RS, Brazil; Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, RS, Brazil. Electronic address: guilhian@ufrgs.br.

    Papers in Europe PMC
  7. 07
    Mele S5 papers · 2026

    School of Biological Sciences, Monash University, Clayton, VIC 3800, Australia.

    Papers in Europe PMC
  8. 08
    Schwahn BC5 papers · 2025

    Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Health Innovation Manchester, Manchester, UK.

    Papers in Europe PMC
  9. 09
    Chen D4 papers · 2026

    Division of Neurology Rady Children's Hospital San Diego California.

    Papers in Europe PMC
  10. 10
    Grings M4 papers · 2023

    Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Ramiro Barcelos, 2600-Anexo, CEP 90035-003 Porto Alegre, RS, Brazil.

    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. 1 observational study did — shown below because natural-history and cohort work can be an important step toward a trial.

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.

low 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.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

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.

None of the matched observational studies is currently listed as 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 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 Isolated sulfite oxidase 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.

("Isolated sulfite oxidase deficiency" OR "Sulfocysteinuria" OR "sulfite oxidase deficiency" OR "sulfite oxidase deficiency, isolated") OR (MESH:"Sulfite oxidase deficiency") OR ("SUOX" OR "SUOX syndrome" OR "SUOX-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Sulfite oxidase deficiency

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

"Isolated sulfite oxidase deficiency" OR "Sulfocysteinuria" OR "sulfite oxidase deficiency" OR "sulfite oxidase deficiency, isolated"

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

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: ISOD

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
  • Publication count (1655) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T06:13:59.376Z