ORPHA:1724
Mosaic trisomy 20 syndrome
Also known as: Mosaic trisomy chromosome 20 · Trisomy 20 mosaicism
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
75
26.3th percentile
Trials
0
Interventional, condition-specific
Researchers
345
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
Mosaic trisomy 20 is a rare chromosomal anomaly syndrome with a highly variable ranging from normal (in the majority of cases) to a mild, subtle principally characterized by spinal abnormalities (i.e. stenosis, vertebral fusion, and kyphosis), , lifelong constipation, sloped shoulders, skin pigmentation abnormalities (i.e. linear and whorled nevoid hypermelanosis) and significant learning disabilities despite normal intelligence. More severe phenotypes, with patients presenting psychomotor and speech delay, mild facial dysmorphism, cardiac (i.e. ventricular septal defect, dysplastic tricuspid mitral valve) and renal anomalies (e.g. horseshoe kidneys), have also been reported.
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:0015764
- UMLS:C5979884
Additional Mondo synonyms (1)
Mosaic trisomy type 20
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.”
2/6 stages with a signal
No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
75 matched papers (9 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 trialPartial
None under the specific name; 20 for broader category trisomy
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?
75
75 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.
75 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).
9 in the last 10 years · high confidence · 26.3th percentile (publications denominator)
Phrase hits: 75 · MeSH hits: 0
Who's working on it?
345
Distinct author names in 75 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.
- 01Hsu LY3 papers · 1991
Prenatal Diagnosis Laboratory of New York City Medical and Health Research Association of N.Y.C. Inc 10016.
Papers in Europe PMC - 02Chen CP2 papers · 2023
Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan. cpc_mmh@yahoo.com
Papers in Europe PMC - 03Holzgreve W2 papers · 1989Papers in Europe PMC
- 04Kaffe S2 papers · 1991Papers in Europe PMC
- 05Miny P2 papers · 1989Papers in Europe PMC
- 06Perlis TE2 papers · 1991Papers in Europe PMC
- 07Schwinger E2 papers · 1985Papers in Europe PMC
- 08Spinner NB2 papers · 2020
Division of Genomic Diagnostics, Department of Pathology and Laboratory Medicines at The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Papers in Europe PMC - 09Tolmie JL2 papers · 2015
West of Scotland Clinical Genetics Service, Southern General Hospital, Glasgow DD1 9SY, UK.
Papers in Europe PMC - 10Abuelo DN1 paper · 1986Papers 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). 20 trials are registered for trisomy, the broader category — shown separately because they may or may not enrol this specific subtype.
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.
high 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.
20 interventional trials matched trisomy, the broader category — listed below. Those studies are not counted in the condition-specific total.
Broader category: trisomy
20
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
- NCT05231798·RECRUITING·Cholinergic Integrity in Down Syndrome in Association With Aging, Alzheimer's Disease Pathology, and Cognition
Conditions: Down Syndrome · Down Syndrome, Partial Trisomy 21 · Alzheimer Disease·Matched via name phrase
- NCT06911944·NOT YET RECRUITING·Amyloid Lowering for Alzheimer's in Down's With Donanemab Investigation
Conditions: Down Syndrome (DS) · Down Syndrome (Trisomy 21) · Alzheimer Disease · Amyloid Beta Protein·Matched via name phrase
- NCT07658053·NOT YET RECRUITING·Effects of a Pacifier on Obstructive Sleep Apnea and Its Repercussions in Infants With Down Syndrome
Conditions: Obstructive Sleep Apnea · Down Syndrome (Trisomy 21)·Matched via name phrase
- NCT07234695·RECRUITING·LEvetiracetam to Prevent Seizures in Symptomatic Alzheimer's Disease in Adults With Down Syndrome
Conditions: Down Syndrome · Down Syndrome (DS) · Down Syndrome (Trisomy 21) · Alzheimer Dementia·Matched via name phrase
- NCT06938542·ENROLLING BY INVITATION·Palliative Care Needs of Children With Rare Diseases and Their Families
Conditions: Trisomy 13 Syndrome · Arthrogryposis Congenita Multiplex With Intestinal Atresia · Asparagine Synthetase Deficiency · CHARGE Syndrome·Matched via name phrase
- NCT05527652·RECRUITING·Self-Supporting Nasopharyngeal Airway (ssNPA) Treating Upper Airway Obstruction in Hypotonia
Conditions: Obstructive Sleep Apnea · Hypertonia, Muscle · Nasal Airway Obstruction · Tolerance·Matched via name phrase
- NCT05970965·RECRUITING·Periodontitis and Inflammation in Children With Down Syndrome/Trisomy 21: Study on Biological Samples
Conditions: Periodontitis · Trisomy 21·Matched via name phrase
- NCT06783725·RECRUITING·Sleep Intervention and Quality of Life in Down Syndrome
Conditions: Down Syndrome · Down Syndrome (Trisomy 21)·Matched via name phrase
- NCT07334912·RECRUITING·AEF0217 in Participants With Down Syndrome
Conditions: Down Syndrome (Trisomy 21)·Matched via name phrase
- NCT06740162·RECRUITING·Physical Activity and Community EmPOWERment Project
Conditions: Intellectual Disability · Neurodevelopmental Disorders · Autism Spectrum Disorder · Down Syndrome·Matched via name phrase
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.
"Mosaic trisomy 20 syndrome" OR "Mosaic trisomy chromosome 20" OR "Trisomy 20 mosaicism" OR "Mosaic trisomy type 20"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Mosaic trisomy 20 syndrome" OR "Mosaic trisomy chromosome 20" OR "Trisomy 20 mosaicism" OR "Mosaic trisomy type 20" OR "chromosome 20 trisomy"
Recall-expansion terms: chromosome 20 trisomy
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"trisomy"
Query health: suspect — strategies attempted: phrase, recall-expansion; 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 2026-07-26T18:02:37.885Z