ORPHA:1756
Caudal duplication
Also known as: Dipygus · Split notochord syndrome
Publications
346
70.2th percentile
Trials
1
Interventional, condition-specific
Researchers
951
Distinct authors in sample
Gene link
AXIN1
Limited
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
Caudal duplication (CD) is a rare developmental anomaly in which structures derived from the embryonic cloaca and notochord are duplicated to varying extents.
How rare: How common this is has not been clearly measured.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0011928
- MeSH:C564315
- OMIM:607864
- UMLS:C1842884
Additional Mondo synonyms (2)
dipygus · split notochord 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
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedPresent
Limited — AXIN1
- LiteraturePresent
346 matched papers (125 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 trialPresent
1 matched on ClinicalTrials.gov
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 AXIN1.
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?
346
346 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=5449) is 41.
346 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).
125 in the last 10 years · high confidence · 70.2th percentile (publications denominator)
Phrase hits: 346 · MeSH hits: 0
Who's working on it?
951
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.
- 01Wang KC4 papers · 2022
Neuro-oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Korea.
Papers in Europe PMC - 02Kim KH3 papers · 2022
Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea.
Papers in Europe PMC - 03Lee JY3 papers · 2022
Division of Pediatric Neurosurgery, Seoul National University Children's Hospital, Seoul, Korea.
Papers in Europe PMC - 04Yang J3 papers · 2022
Neuro-oncology Clinic, Center for Rare Cancers, National Cancer Center, Goyang, Korea.
Papers in Europe PMC - 05AbouZeid AA2 papers · 2019
Ain-Shams University, Lotefy El-Sayed, Abbassia, Cairo, Egypt.
Papers in Europe PMC - 06Afridi A2 papers · 2022
Anesthesia and Intensive Care, Cork University Hospital, Cork, IRL.
Papers in Europe PMC - 07Bademci G2 papers · 2025
John P. Hussmann Institute for Human Genomics (M.F.V., G.B.), University of Miami Miller School of Medicine, Miami, Florida, USA; Department of Human Genetics (G.B.), University of Miami Miller School of Medicine, Miami, Florida, USA.
Papers in Europe PMC - 08Chaturvedi A2 papers · 2018
Department of Pediatric Radiology, Golisano Children's Hospital, University of Rochester Medical Center, 601, Elmwood Avenue, Rochester, NY, 14642, USA.
Papers in Europe PMC - 09Chen Y2 papers · 2022
Department of General Surgery, National Center for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, China.
Papers in Europe PMC - 10Erdener A2 papers · 1996
Department of Pediatric Surgery, Ege University, Faculty of Medicine, Izmir, Turkey.
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; none in our sample are currently recruiting.
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).
high 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.
No currently recruiting studies in the matched set. Open the same 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 2026-07-26This 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.
"Caudal duplication" OR "Dipygus" OR "Split notochord syndrome"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Caudal duplication" OR "Dipygus" OR "Split notochord syndrome" OR "AXIN1"
Recall-expansion terms: AXIN1
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 · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
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
Ingested 2026-07-26T18:04:34.357Z