ORPHA:3169
Sirenomelia
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
717
Trials
0
Interventional, condition-specific
Researchers
973
Distinct authors in sample
Gene link
—
Readiness
1/6
Stages with a signal
Clinical definition (Orphanet)
A rare, lethal, anomaly that may represent the most severe form of caudal dysgenesia and characterized by fusion of the lower limbs (mermaid-like) always associated with severe genitourinary and gastrointestinal anomalies. Furthermore, there is wide phenotipical variability in the musculoskeletal, central nervous system, cardiopulmonary, anomalies present. Pelvic, sacral and spinal defects , internal and external genitalia defects, renal agenesis, absent bladder, rectal/anal atresia are commonly described. Most cases are stillborn or die during, or shortly after, birth. Sirenomelia can be classified on the basis of limb malformations phenotypes. Due to the similarity, the distinction between sirenomelia and caudal regression syndrome, familial caudal dysgenesis and VACTERL is debated.
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.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0017850
- UMLS:C0037205
- NCIT:C118455
Additional Mondo synonyms (1)
symmelia
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.”
1/6 stages with a signal
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
717 matched papers (245 in last 10 years) Source
- Phenotype characterisedNot checked
Not yet enriched from Monarch / HPO
- Animal modelNot checked
Not yet enriched from Monarch / Alliance
- Orphan designationNot checked
FDA/EMA orphan-drug designation not enriched yet
- 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?
Not yet — the cause hasn't been pinned down in GenCC.
No strong gene–disease assertion joined for this Orphanet entity.
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?
717
717 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.
717 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).
245 in the last 10 years · low confidence
Phrase hits: 717 · MeSH hits: 0
Who's working on it?
973
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.
- 01Wang Y7 papers · 2026
Department of Neurology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Papers in Europe PMC - 02Boer LL4 papers · 2023
Department of Anatomy and Museum for Anatomy and Pathology, Radboud University Medical Centre, Geert Grooteplein Noord 21, 6525 EZ, Nijmegen, The Netherlands. Lucas.boer@radboudumc.nl.
Papers in Europe PMC - 03Oostra RJ4 papers · 2023
Department of Anatomy, Embryology and Physiology, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
Papers in Europe PMC - 04
- 05Ma B3 papers · 2026
Ultrasound Medicine Center, Lanzhou University Second Hospital, Lanzhou, China.
Papers in Europe PMC - 06Schepens-Franke AN3 papers · 2021
Department of Anatomy and Museum for Anatomy and Pathology, Radboud University Medical Centre, Geert Grooteplein Noord 21, 6525 EZ, Nijmegen, The Netherlands.
Papers in Europe PMC - 07
- 08Adam MP2 papers · 2026
Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, Washington, USA.
Papers in Europe PMC - 09Garrido-Allepuz C2 papers · 2012
Instituto de Biomedicina y Biotecnología de Cantabria-IBBTEC, CSIC-SODERCAN-Universidad de Cantabria, Santander, Spain.
Papers in Europe PMC - 10González-Lamuño D2 papers · 2012Papers 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 27 July 2026
No matched interventional trials. This is true for 73% of diseases in the trials denominator (5114 of 7003). Here are the researchers publishing on it.
low confidence · 36.5th 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.
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 2026-07-26This 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.
"Sirenomelia" OR "symmelia"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Sirenomelia" OR "symmelia" OR "caudal regression-sirenomelia spectrum"
Recall-expansion terms: caudal regression-sirenomelia spectrum
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase
Run this search on ClinicalTrials.gov
Confidence reasoning
- Preferred label is short or not clearly distinctive
- No synonyms dropped by stoplist
- No label/synonym collisions with other diseases in this corpus
- Publication count (717) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-26T22:23:09.237Z