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ORPHA:3380

Trisomy 18 syndrome

high confidenceDisorder

Also known as: Chromosome 18 duplication · Edwards syndrome

Publications

8,043

93.6th percentile

Trials

1

Interventional, condition-specific

Researchers

1,110

Distinct authors in sample

Gene link

—

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare chromosomal abnormality characterized by the presence of an extra chromosome 18 material and manifesting with severe growth delay, and extremely variable multiple anomalies, including minor malformations (cranio-facial dysmorphia, short sternum, overlapping fingers) and major malformations, especially cardiac and cerebral. Neurological involvement may lead to and .

How rare: 1-5 / 10 000 — about one to five people per ten thousand (still uncommon, but less ultra-rare).

Orphanet entry

Cross-references

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

Additional Mondo synonyms (5)

E3 trisomy · chromosome 18 duplication · complete trisomy 18 syndrome · trisomy 18 · trisomy type 18

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 identifiedNot found

    No GenCC disease–gene assertion in this build

  2. LiteraturePresent

    8,043 matched papers (3,890 in last 10 years) Source

  3. Phenotype characterisedPresent

    75 HPO annotations (e.g. Cryptorchidism; Prominent occiput; Intrauterine growth retardation) 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 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?

Not yet — the cause hasn't been pinned down in GenCC.

No strong gene–disease assertion joined for this Orphanet entity.

Phenotypes (Monarch / HPO)

75

Associated phenotypes · MONDO:0018071

  • Cryptorchidism
  • Prominent occiput
  • Intrauterine growth retardation
  • Omphalocele
  • Ventricular septal defect

Showing 5 of 75 — 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?

8,043

8,043 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.

8,043 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).

3,890 in the last 10 years · high confidence · 93.6th percentile (publications denominator)

Phrase hits: 8,043 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,110

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
    Chen CP7 papers · 2025

    Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang Ming Chiao Tung University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang Ming Chiao Tung University, Taipei, Taiwan. Electronic address: cpc_mmh@yahoo.com.

    Papers in Europe PMC
  2. 02
    Carey JC6 papers · 2026

    Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA.

    Papers in Europe PMC
  3. 03
    Wang W6 papers · 2026

    Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.

    Papers in Europe PMC
  4. 04
    Chen J4 papers · 2026

    Guangxi Key Laboratory of Metabolic Diseases Research, Department of Clinical Laboratory of Guilin, No. 924 Hospital, 541002, Guilin, Guangxi, People's Republic of China.

    Papers in Europe PMC
  5. 05
    Zhou J4 papers · 2021

    Department of Clinical Medical Research Center, Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, Shenzhen, Guangdong, 518020, People's Republic of China.

    Papers in Europe PMC
  6. 06
    Ashida A3 papers · 2025

    Department of Pediatrics, Osaka Medical and Pharmaceutical University, Takatsuki, Osaka, Japan.

    Papers in Europe PMC
  7. 07
    Chen X3 papers · 2025

    Central Laboratory of Taizhou Hospital Affiliated to Wenzhou Medical University, Linhai, Zhejiang 317000, China. xuhh@enzemed.com.

    Papers in Europe PMC
  8. 08
    Chern SR3 papers · 2025

    Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.

    Papers in Europe PMC
  9. 09
    Dai Y3 papers · 2021

    Department of Clinical Medical Research Center, Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, The First Affiliated Hospital of Southern University of Science and Technology, The Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, Shenzhen, Guangdong, 518020, People's Republic of China. daiyong22@aliyun.com.

    Papers in Europe PMC
  10. 10
    Iwatani S3 papers · 2024

    Department of Neonatology, Hyogo Prefectural Kobe Children's Hospital Perinatal Center, Kobe, Japan.

    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. 19 trials are registered for trisomy, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 11 September 2026

1 interventional trial — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 80.1th percentile).

high confidence · 80.1th 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.

Broader category: trisomy

19

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.

Recruiting under the broader category

Observational and natural-history studies

23 observational studies match 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.

Recruiting or not-yet-recruiting

Open the complete matched search on ClinicalTrials.gov

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 11 · after dedupe 11 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 11 · 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 (11)

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 Trisomy 18 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.

"Trisomy 18 syndrome" OR "Chromosome 18 duplication" OR "Edwards syndrome" OR "E3 trisomy" OR "complete trisomy 18 syndrome" OR "trisomy 18" OR "trisomy type 18"

Run this search on Europe PMC

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

"Trisomy 18 syndrome" OR "Chromosome 18 duplication" OR "Edwards syndrome" OR "E3 trisomy" OR "complete trisomy 18 syndrome" OR "trisomy 18" OR "trisomy type 18"

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

Parent-category trials query:

"trisomy"

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

Ingested 2026-07-26T23:02:49.769Z