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ORPHA:3269

Isolated radio-ulnar synostosis

low confidenceDisorder

Also known as: Isolated congenital radioulnar fusion

Publications

1,182

Trials

1

Interventional, condition-specific

Researchers

1,033

Distinct authors in sample

Gene link

SMAD6, ZMAT2

Limited

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

radioulnar synostosis is a rare bone disorder that may be isolated or associated with other disorders and that is characterized by failure of segmentation of the radius and ulna during embryological development, causing limited rotational movements of the forearm, which may lead to difficulties with some activities of daily living.

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 (3)

radioulnar fusion · radioulnar synostosis · radioulnar synostosis (disease)

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

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

  1. Gene identifiedPresent

    Limited — SMAD6, ZMAT2

  2. LiteraturePresent

    1,182 matched papers (621 in last 10 years) Source

  3. Phenotype characterisedNot checked

    Not yet enriched from Monarch / HPO

  4. Animal modelNot checked

    Not yet enriched from Monarch / Alliance

  5. Orphan designationNot checked

    FDA/EMA orphan-drug designation not enriched yet

  6. Interventional trialPresent

    1 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?

Possibly — only limited evidence so far for SMAD6, ZMAT2.

GenCC classification: Limited.

Phenotypes (Monarch / HPO)

Not enriched in this build — Monarch phenotype joins were not run for this record.

Animal models (Monarch / Alliance)

Not enriched in this build.

Literature

Is anyone studying this?

1,182

1,182 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=5449) is 41.

1,182 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 41 (publications denominator n=5449).

621 in the last 10 years · low confidence

Phrase hits: 1,182 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,033

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
    Yang Y11 papers · 2026

    The Laboratory of Genetics and Metabolism, Institute of Pediatric Medicine of Hunan Province, Hunan Children's Hospital, Hengyang Medical School, University of South China, Changsha, China.

    Papers in Europe PMC
  2. 02
    Shen F8 papers · 2026

    The Laboratory of Genetics and Metabolism, Institute of Pediatric Medicine of Hunan Province, Hunan Children's Hospital, Hengyang Medical School, University of South China, Changsha, China.

    Papers in Europe PMC
  3. 03
    Chen S7 papers · 2024

    Department of Hand Surgery, Beijing Ji Shui Tan Hospital, Beijing, China.

    Papers in Europe PMC
  4. 04
    Zheng Y7 papers · 2026

    The Laboratory of Genetics and Metabolism, Institute of Pediatric Medicine of Hunan Province, Hunan Children's Hospital, Hengyang Medical School, University of South China, Changsha, China.

    Papers in Europe PMC
  5. 05
    Zhu G7 papers · 2026

    Department of orthopedics, Hunan Children's Hospital, Hengyang Meical School, University of South China, Changsha, China.

    Papers in Europe PMC
  6. 06
    Deng M5 papers · 2026

    Institute of Pediatrics, South China University, Department of Medical Genetics, Hunan Provincial Children's Hospital, Changsha, Hunan 410007, China. yongjia727@aliyun.com.

    Papers in Europe PMC
  7. 07
    Liu L5 papers · 2024

    Department of Hand Surgery, Beijing Ji Shui Tan Hospital, Beijing, China.

    Papers in Europe PMC
  8. 08
    Luo Z5 papers · 2026

    The Laboratory of Genetics and Metabolism, Institute of Pediatric Medicine of Hunan Province, Hunan Children's Hospital, Hengyang Medical School, University of South China, Changsha, China.

    Papers in Europe PMC
  9. 09
    Wang H5 papers · 2026

    Pediatrics Research Institute, the Affiliated Children's Hospital of Xiangya School of Medicine, Central South University (Hunan Children's Hospital), Changsha, China; Department of Medical Genetics, The Affiliated Children's Hospital of Xiangya School of Medicine (Hunan Children's Hospital), Central South University, Changsha, China.

    Papers in Europe PMC
  10. 10
    Xu J5 papers · 2026

    Department of Orthopedics, Shenzhen Children's Hospital, Shenzhen, China.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

1

interventional trials for this specific condition

1 interventional trial matched this specific condition name; 1 currently recruiting in our sample. 1 trial are registered for synostosis, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 27 July 2026

1 interventional trial — more than 73% of diseases in the trials denominator have none at all (5114 of 7003; this disease is at the 76.8th percentile).

low confidence · 76.8th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Broader category: synostosis

1

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

Worth raising with a clinician. How we count trials.

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

Where to find support

We do not yet link condition-specific patient organisations. These umbrella groups support undiagnosed and ultra-rare families:

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 radio-ulnar synostosis" OR "Isolated congenital radioulnar fusion" OR "radioulnar fusion" OR "radioulnar synostosis" OR "radioulnar synostosis (disease)"

Run this search on Europe PMC

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

"Isolated radio-ulnar synostosis" OR "Isolated congenital radioulnar fusion" OR "radioulnar fusion" OR "radioulnar synostosis" OR "radioulnar synostosis (disease)" OR "SMAD6" OR "ZMAT2"

Recall-expansion terms: SMAD6, ZMAT2

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: 1 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"synostosis"

Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion

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 (1182) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T22:42:43.904Z