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ORPHA:1308

C syndrome

low confidenceDisorder

Also known as: OTCS · Opitz C trigonocephaly · Opitz trigonocephaly C syndrome · Opitz trigonocephaly syndrome · Trigonocephaly C syndrome

Publications

5,686

Trials

0

Interventional, condition-specific

Researchers

1,448

Distinct authors in sample

Gene link

CD96

Limited

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

C syndrome is a rare multiple anomaly/ syndrome characterized by trigonocephaly and metopic suture synostosis, facial features, short neck, skeletal anomalies, and variable .

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (1)

trigonocephaly C syndrome

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

    Limited — CD96

  2. LiteraturePresent

    5,686 matched papers (3,859 in last 10 years) Source

  3. Phenotype characterisedPresent

    96 HPO annotations (e.g. Long philtrum; Micrognathia; Anteverted nares) 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?

Possibly — only limited evidence so far for CD96.

GenCC classification: Limited.

Phenotypes (Monarch / HPO)

96

Associated phenotypes · MONDO:0008893

  • Long philtrum
  • Micrognathia
  • Anteverted nares
  • Short neck
  • Upslanted palpebral fissure

Showing 5 of 96 — 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?

5,686

5,686 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

5,686 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).

3,859 in the last 10 years · low confidence

Phrase hits: 385 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,448

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
    Grinberg D8 papers · 2020

    Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Institut de Biomedicina de la Universitat de Barcelona, 08028 Barcelona, Spain. Electronic address: dgrinberg@ub.edu.

    Papers in Europe PMC
  2. 02
    Opitz JM8 papers · 2018

    Pediatrics (Medical Genetics), Pathology, Obstetrics & Gynecology, and Human Genetics, University of Utah School of Medicine, Salt Lake City, Utah 84132, USA. john.opitz@hsc.utah.edu

    Papers in Europe PMC
  3. 03
    Vilageliu L8 papers · 2020

    Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Institut de Biomedicina de la Universitat de Barcelona, 08028 Barcelona, Spain.

    Papers in Europe PMC
  4. 04
    Canals I5 papers · 2020

    Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras, 28029 Madrid, Spain; Institut de Biomedicina de la Universitat de Barcelona, 08028 Barcelona, Spain.

    Papers in Europe PMC
  5. 05
    Moore C5 papers · 2022

    Wales Specialist Virology Centre, Public Health Wales Microbiology Cardiff, University Hospital of Wales, Cardiff, UK

    Papers in Europe PMC
  6. 06
    Benetó N4 papers · 2020

    Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, CIBERER, IBUB, IRSJD, E-08028 Barcelona, Spain.

    Papers in Europe PMC
  7. 07
    Neri G4 papers · 2018

    Istituto Genetica Medica, Università Cattolica Sacro Cuore, Policlínico A Gemelli, Roma, Italy.

    Papers in Europe PMC
  8. 08
    Atkinson S3 papers · 2013

    Biomedical Sciences, University of Ulster, Coleraine, BT52 1SA

    Papers in Europe PMC
  9. 09
    Balcells S3 papers · 2018

    Department of Genetics, Faculty of Biology, Universitat de Barcelona, CIBERER, IBUB, Barcelona, Spain.

    Papers in Europe PMC
  10. 10
    Breuer J3 papers · 2022

    Infection, Immunity and Inflammation Department, GOS Institute of Child Health, University College London, London, UK

    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.

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.

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 40 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 40 · 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 (40)

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 C syndrome — 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.

("C syndrome" OR "Opitz C trigonocephaly" OR "Opitz trigonocephaly C syndrome" OR "Opitz trigonocephaly syndrome" OR "Trigonocephaly C syndrome") OR ("CD96" OR "CD96 syndrome" OR "CD96-related")

Run this search on Europe PMC

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

"C syndrome" OR "Opitz C trigonocephaly" OR "Opitz trigonocephaly C syndrome" OR "Opitz trigonocephaly syndrome" OR "Trigonocephaly C syndrome"

Study-type breakdown: 0 interventional · 0 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

Synonyms dropped by stoplist: OTCS

Confidence reasoning

  • Preferred label is short or not clearly distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T16:59:48.581Z