ORPHA:11
Pentasomy X syndrome
Also known as: 49,XXXXX syndrome · Penta-X · Poly-X
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
2,375
Trials
0
Interventional, condition-specific
Researchers
1,092
Distinct authors in sample
Gene link
—
Readiness
1/6
Stages with a signal
Clinical definition (Orphanet)
A rare sex-chromosome number anomaly characterized by the presence of five X chromosomes in females instead of the usual two. Patients present with global , , musculoskeletal abnormalities (mostly small hands and feet, camptodactyly, clinodactyly, radioulnar synostosis), and craniofacial anomalies (such as microcephaly, plagiocephaly, upslanting palpebral fissures, hypertelorism, flat nasal bridge, ear malformations, microganthia). Cardiovascular malformations can sometimes be present as well as immunoglobulin anomalies and an increased susceptibility to infections. External genitalia are generally normal but gonadal dysfunction has 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:0015228
- MeSH:C535319
- UMLS:C2937419
- NCIT:C89802
Additional Mondo synonyms (7)
49, XXXXX syndrome · Penta X Syndrome · Pentasomy type X · XXXXX syndrome · penta X syndrome · penta-X · poly-X
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.”
1/6 stages with a signal
Research-stage checklist from open sources (GenCC, literature, Monarch when enriched, ClinicalTrials.gov). Not a prognosis or care recommendation.
- Gene identifiedNot found
No GenCC disease–gene assertion in this build
- LiteraturePresent
2,375 matched papers (478 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 trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
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?
2,375
2,375 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.
2,375 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).
478 in the last 10 years · low confidence
Phrase hits: 2,375 · MeSH hits: 0
Who's working on it?
1,092
Distinct author names in 200 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.
- 01Wang Y5 papers · 2026
Department of Cardiology, Luzhou People's Hospital, Luzhou, China.
Papers in Europe PMC - 02Li W4 papers · 2025
Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China (Hong Kong).
Papers in Europe PMC - 03
- 04Chen C3 papers · 2023
Key Laboratory of Interventional Pulmonology of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
Papers in Europe PMC - 05Chen J3 papers · 2025
The First School of Medicine, School of Information and Engineering, Wenzhou Medical University, Wenzhou, China.
Papers in Europe PMC - 06Li R3 papers · 2025
Department of Child Health Care, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430016, China. dr_lrz@163.com.
Papers in Europe PMC - 07Liu L3 papers · 2024
Department of Cardiovascular, The First Affiliated Hospital of Heilongjiang University of Traditional Chinese Medicine, Harbin, China.
Papers in Europe PMC - 08Liu X3 papers · 2025
The First Hospital of Shanxi Medical University, Taiyuan, Shanxi, China.
Papers in Europe PMC - 09Luo J3 papers · 2025
Department of Cardiology, The Second Hospital of Shanxi Medical University, Wuyi Road, Taiyuan, Shanxi, 030000, China.
Papers in Europe PMC - 10Sun L3 papers · 2025
Department of Child Health Care, Wuhan Children's Hospital (Wuhan Maternal and Child Healthcare Hospital), Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430016, China.
Papers 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. 1 observational study did — shown below because natural-history and cohort work can be an important step toward a trial.
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.
low 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.
Broader category pentasomy also has no matched interventional trial. See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
Broader category: pentasomy
0
Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.
Parent-category matching found a broader label but no interventional trials under it. How we count trials.
Observational and natural-history studies
1 observational study matches 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.
"Pentasomy X syndrome" OR "49,XXXXX syndrome" OR "49, XXXXX syndrome" OR "Penta X Syndrome" OR "Pentasomy type X" OR "XXXXX syndrome"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Pentasomy X syndrome" OR "49,XXXXX syndrome" OR "49, XXXXX syndrome" OR "Penta X Syndrome" OR "Pentasomy type X" OR "XXXXX syndrome" OR "Penta-X"
Recall-expansion terms: Penta-X
Study-type breakdown: 0 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"pentasomy"
Query health: suspect — strategies attempted: phrase, recall-expansion; with hits: phrase
Run this search on ClinicalTrials.gov
Synonyms dropped by stoplist: Penta-X; Poly-X
Confidence reasoning
- Preferred label is multi-word and distinctive
- 2 synonym(s) dropped by stoplist (may under-count)
- No label/synonym collisions with other diseases in this corpus
- Publication count (2375) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity
Ingested 2026-07-26T12:04:46.978Z