ORPHA:8
47,XYY syndrome
Also known as: Double Y syndrome · Jacobs syndrome · XYY syndrome · Y disomy
Publications
2,975
94.1th percentile
Trials
1
Interventional, condition-specific
Researchers
1,244
Distinct authors in sample
Gene link
—
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare sex chromosome aneuploidy where males receive an additional Y chromosome, that is characterized clinically by tall stature evident from childhood, macrocephaly, facial features (mild hypertelorism, low set ears, a mildly flat malar region), speech delay and an increased risk for social and emotional difficulties, attention deficit hyperactive disorder and autistic spectrum disorder.
How rare: 1-5 / 10 000 — about one to five people per ten thousand (still uncommon, but less ultra-rare).
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0019339
- MeSH:C535317
- UMLS:C3266843
- NCIT:C85237
Additional Mondo synonyms (5)
47,XYY · Double Y · XYY Syndrome · XYY karyotype · disomy Y
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
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
2,975 matched papers (1,302 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?
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?
2,975
2,975 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.
2,975 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).
1,302 in the last 10 years · medium confidence · 94.1th percentile (publications denominator)
Phrase hits: 2,975 · MeSH hits: 0
Who's working on it?
1,244
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.
- 01Raznahan A17 papers · 2026
Section on Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA. raznahana@mail.nih.gov.
Papers in Europe PMC - 02Ross J12 papers · 2026
Department of Pediatrics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.
Papers in Europe PMC - 03Rau S10 papers · 2026
Center for Autism Spectrum Disorders and Division of Neuropsychology, Children's National Hospital, Washington, DC, USA.
Papers in Europe PMC - 04Liu S9 papers · 2026
Section On Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health Intramural Research Program, Bethesda, MD, 20892, USA.
Papers in Europe PMC - 05Schaffer L9 papers · 2026
Section On Developmental Neurogenomics, Human Genetics Branch, National Institute of Mental Health Intramural Research Program, Magnuson Clinical Center, Room 4N242, MSC 1367, Bethesda, MD, 20814, USA.
Papers in Europe PMC - 06Bothwell S8 papers · 2026
Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado.
Papers in Europe PMC - 07Gravholt CH8 papers · 2023
Department of Molecular Medicine, Aarhus University Hospital, Aarhus, Denmark.
Papers in Europe PMC - 08Tartaglia N8 papers · 2026
Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA.
Papers in Europe PMC - 09Davis S7 papers · 2026
Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado.
Papers in Europe PMC - 10Davis SM7 papers · 2025
eXtraordinarY Kids Clinic and Research Program, Children's Hospital Colorado, Aurora, Colorado, USA.
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).
medium 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.
Observational and natural-history studies
2 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
- NCT03396562·RECRUITING·The eXtroardinarY Babies Study: Natural History of Health and Neurodevelopment in Infants and Young Children With Sex Chromosome Trisomy
Conditions: Klinefelter Syndrome · Trisomy X · XYY Syndrome · XXXY and XXXXY 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.
"47,XYY syndrome" OR "Double Y syndrome" OR "Jacobs syndrome" OR "XYY syndrome" OR "Y disomy" OR "47,XYY" OR "Double Y" OR "XYY karyotype" OR "disomy Y"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"47,XYY syndrome" OR "Double Y syndrome" OR "Jacobs syndrome" OR "XYY syndrome" OR "Y disomy" OR "47,XYY" OR "Double Y" OR "XYY karyotype" OR "disomy Y"
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 · 2 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 multi-word and distinctive
- No synonyms dropped by stoplist
- "Jacobs syndrome" also appears on ORPHA:2848
Ingested 2026-07-26T12:04:05.303Z