ORPHA:10
48,XXYY syndrome
Clinical definition (Orphanet)
A rare sex chromosome number anomaly disorder characterized, genetically, by the presence of an extra X and Y chromosome in males and, clinically, by tall stature, dysfunctional testes associated with infertility and insufficient testosterone production, cognitive, affective and social functioning impairments, global , and an increased risk of malformations.
How rare: How common this is has not been clearly measured.
Is anyone studying this?
97
97 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=183) is 38.
97 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 38 (publications denominator n=183).
45 in the last 10 years · high confidence · 53.6th percentile (publications denominator)
Is a treatment being tested?
0
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).
Data as of 26 July 2026
No matched interventional trials. This is true for 59.2% of diseases in the trials denominator (151 of 255). Here are the researchers publishing on it.
high confidence · 29.6th percentile (trials denominator)
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.
Who's working on it?
441
Distinct author names in 97 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.
- 01Tartaglia N9 papers · 2026
Department of Pediatrics, University of Colorado Denver, School of Medicine, Aurora, Colorado, USA. tartaglia.nicole@tchden.org
Papers in Europe PMC - 02Howell S8 papers · 2026
Department of Pediatrics, University of Colorado School of Medicine, 13123 East 16th Avenue, Aurora, CO 80045, USA; Developmental Pediatrics, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Avenue B140, Aurora, CO 80045, USA.
Papers in Europe PMC - 03Davis S5 papers · 2026
Department of Pediatrics, University of Colorado School of Medicine, 13123 East 16th Avenue, Aurora, CO 80045, USA; Department of Endocrinology, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Avenue B265, Aurora, CO 80045, USA.
Papers in Europe PMC - 04Ross J5 papers · 2026
Department of Pediatrics, Thomas Jefferson University School of Medicine, 833 Chestnut Street, Philadelphia, PA 19107, USA; Pediatric Endocrinology, Nemours A.I. DuPont Hospital for Children, 1600 Rockland Road, Wilmington, DE 19803, USA.
Papers in Europe PMC - 05Bothwell S3 papers · 2026
eXtraOrdinarY Kids Clinic and Research Team, Children's Hospital of Colorado, Colorado, Aurora, USA.
Papers in Europe PMC - 06Swenson K3 papers · 2026
eXtraOrdinarY Kids Clinic and Research Team, Children's Hospital of Colorado, Colorado, Aurora, USA.
Papers in Europe PMC - 07Tartaglia NR3 papers · 2023
Developmental Pediatrics, Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA.
Papers in Europe PMC - 08Ayari N2 papers · 2013Papers in Europe PMC
- 09Barbería JJ2 papers · 1990
Departamento de Medicina Interna, Hospital de Navarra.
Papers in Europe PMC - 10Carl A2 papers · 2025
eXtraOrdinarY Kids Clinic and Research Team, Children's Hospital of Colorado, Colorado, Aurora, USA.
Papers in Europe PMC
Recruiting interventional trials
Trials testing a treatment from the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it above — people publishing on this disease are often the practical next contact when no trial is listed.
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 below but are not added to the query string.
"48,XXYY syndrome" OR "48, XXYY Syndrome"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"48,XXYY syndrome" OR "48, XXYY Syndrome"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Cross-references (from Mondo): UMLS:C2936741 NCIT:C89801
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