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ORPHA:870

Down syndrome

medium confidenceDisorder

Also known as: Trisomy 21

Publications

85,557

99.3th percentile

Trials

283

Interventional, condition-specific

Researchers

1,216

Distinct authors in sample

Gene link

—

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A total trisomy that is caused by the presence of a third (partial or total) copy of chromosome 21 and that is characterized by variable , muscular , and joint laxity, often associated with a characteristic facial dysmorphism and various anomalies such as cardiac, gastrointestinal, neurosensorial or endocrine defects.

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 (4)

Down syndrome, Isolated cases · Down's syndrome · leukemia, megakaryoblastic, with or without Down syndrome, somatic · trisomy 21 (Down 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.”

4/6 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

    85,557 matched papers (39,512 in last 10 years) Source

  3. Phenotype characterisedPresent

    122 HPO annotations (e.g. Epicanthus; Short neck; Specific learning disability) Source

  4. Animal modelPresent

    30 genotype models (Mus musculus) Source

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPresent

    283 matched on ClinicalTrials.gov (71 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?

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

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

Phenotypes (Monarch / HPO)

122

Associated phenotypes · MONDO:0008608

  • Epicanthus
  • Short neck
  • Specific learning disability
  • Depressed nasal bridge
  • Increased total neutrophil count

Showing 5 of 122 — open Monarch for the full list.

Animal models (Monarch / Alliance)

30

Model associations linked to this Mondo ID

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

20

Drugs / clinical candidates · MONDO_0008608

CTD chemicals (MyDisease.info)

4 associated chemicals · 118 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Risperidone · therapeutic
  • Colchicine · marker/mechanism
  • Formiminoglutamic Acid · marker/mechanism
  • Phenytoin · marker/mechanism

Pathways: Glutathione metabolism; One carbon pool by folate; Metabolism of xenobiotics by cytochrome P450; Drug metabolism - cytochrome P450; Metabolic pathways; Carbon metabolism; Antifolate resistance; Platinum drug resistance

MyDisease.info · MONDO:0008608

Literature

Is anyone studying this?

85,557

85,557 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.

85,557 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).

39,512 in the last 10 years · medium confidence · 99.3th percentile (publications denominator)

Phrase hits: 85,557 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,216

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
    Espinosa JM5 papers · 2026

    Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz, Aurora CO, United States.

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

    Department of Epidemiology and Health Statistics, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China.

    Papers in Europe PMC
  3. 03
    Galbraith MD4 papers · 2026

    Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz, Aurora, USA.

    Papers in Europe PMC
  4. 04
    Barone E3 papers · 2026

    Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy.

    Papers in Europe PMC
  5. 05
    Chen H3 papers · 2026

    Department of Obstetrics and Gynecology, the Reproductive Medicine Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.

    Papers in Europe PMC
  6. 06
    Corcoran E3 papers · 2026

    Down's Syndrome Research Foundation, Tunbridge Wells, UK.

    Papers in Europe PMC
  7. 07
    Di Domenico F3 papers · 2026

    Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy.

    Papers in Europe PMC
  8. 08
    Farrell C3 papers · 2026

    Cardiovascular Pulmonary Research Laboratories, University of Colorado Anschutz, Aurora, CO, United States.

    Papers in Europe PMC
  9. 09
    Forlenza OV3 papers · 2026

    Universidade de São Paulo, Faculdade de Medicina, Departamento e Instituto de Psiquiatria, Laboratório de Neurociência (LIM-27), São Paulo SP, Brazil.

    Papers in Europe PMC
  10. 10
    Fortea J3 papers · 2026

    Sant Pau Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Biomedical Research Institute Sant Pau, Universitat Autònoma de Barcelona, Departamento de Medicina, Barcelona, Spain.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

283

interventional trials for this specific condition

283 interventional trials matched this specific condition name; 71 currently recruiting in our sample.

Data as of 11 September 2026

283 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 99.5th percentile).

medium confidence · 99.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

149 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 67 · after dedupe 67 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 67 · 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 (67)

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 Down 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.

"Down syndrome" OR "Trisomy 21" OR "Down syndrome, Isolated cases" OR "Down's syndrome" OR "leukemia, megakaryoblastic, with or without Down syndrome, somatic" OR "trisomy 21 (Down syndrome)"

Run this search on Europe PMC

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

"Down syndrome" OR "Trisomy 21" OR "Down syndrome, Isolated cases" OR "Down's syndrome" OR "leukemia, megakaryoblastic, with or without Down syndrome, somatic" OR "trisomy 21 (Down syndrome)"

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: 283 interventional · 149 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 short or not clearly distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T15:42:20.471Z