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ORPHA:3320

Thrombocytopenia-absent radius syndrome

low confidenceDisorder

Also known as: TAR syndrome

Publications

1,546

Trials

0

Interventional, condition-specific

Researchers

1,298

Distinct authors in sample

Gene link

RBM8A

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare syndrome characterized by bilateral absence/hypoplasia of the radii with presence of both thumbs, and thrombocytopenia. Additional manifestations can include cow's milk allergy, anomalies of the lower limbs, heart and genitourinary system.

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 (4)

1q21.1 susceptibility locus for Thrombocytopenia-Absent Radius (TAR) syndrome · Thrombocytopenia Absent Radius Syndrome · radial aplasia-thrombocytopenia syndrome · thrombocytopenia-absent radius 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

    Definitive — RBM8A

  2. LiteraturePresent

    1,546 matched papers (970 in last 10 years) Source

  3. Phenotype characterisedPresent

    115 HPO annotations (e.g. Anemia; Global developmental delay; Abnormal shoulder morphology) 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 (RBM8A).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

115

Associated phenotypes · MONDO:0010121

  • Anemia
  • Global developmental delay
  • Abnormal shoulder morphology
  • Fused cervical vertebrae
  • Finger syndactyly

Showing 5 of 115 — 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?

1,546

1,546 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.

1,546 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).

970 in the last 10 years · low confidence

Phrase hits: 697 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,298

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
    Zhang J7 papers · 2026

    Obstetrics and Gynecology Hospital, Institute of Reproduction and Development, Fudan University, Shanghai 200011, China.

    Papers in Europe PMC
  2. 02
    Wang Y5 papers · 2026

    International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China.

    Papers in Europe PMC
  3. 03
    Liu X4 papers · 2026

    Heart Center, The First Hospital of Tsinghua University, Beijing, 100016, China.

    Papers in Europe PMC
  4. 04
    Burger A3 papers · 2025

    University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA.

    Papers in Europe PMC
  5. 05
    Giordano P3 papers · 2016

    Department of Biomedicine in Childhood, University of Bari, Piazza Giulio Cesare, Bari, Italy.

    Papers in Europe PMC
  6. 06
    Klopocki E3 papers · 2023

    Institut für Medizinische Genetik, Charité Universitätsmedizin Berlin, Berlin, Germany.

    Papers in Europe PMC
  7. 07
    Kocere A3 papers · 2025

    University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA.

    Papers in Europe PMC
  8. 08
    Li S3 papers · 2024

    International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200030, China.

    Papers in Europe PMC
  9. 09
    Mao Y3 papers · 2026

    Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.

    Papers in Europe PMC
  10. 10
    Mosimann C3 papers · 2025

    University of Colorado School of Medicine, Anschutz Medical Campus, Department of Pediatrics, Section of Developmental Biology, Aurora, CO 80045, USA.

    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 7 · after dedupe 7 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 7 · 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 (7)

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 Thrombocytopenia-absent radius 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.

("Thrombocytopenia-absent radius syndrome" OR "TAR syndrome" OR "1q21.1 susceptibility locus for Thrombocytopenia-Absent Radius (TAR) syndrome" OR "Thrombocytopenia Absent Radius Syndrome" OR "radial aplasia-thrombocytopenia syndrome") OR ("RBM8A" OR "RBM8A syndrome" OR "RBM8A-related")

Run this search on Europe PMC

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

"Thrombocytopenia-absent radius syndrome" OR "TAR syndrome" OR "1q21.1 susceptibility locus for Thrombocytopenia-Absent Radius (TAR) syndrome" OR "Thrombocytopenia Absent Radius Syndrome" OR "radial aplasia-thrombocytopenia 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

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 (1546) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-26T22:51:59.127Z