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ORPHA:643549

Hao-Fountain syndrome

low confidenceDisorder

Also known as: HAFOUS

Publications

6,261

Trials

0

Interventional, condition-specific

Researchers

565

Distinct authors in sample

Gene link

USP7

Definitive

Readiness

3/6

Stages with a signal

Clinical definition (Orphanet)

A rare genetic syndrome characterized by global , , severe speech delay, behavioral abnormalities (including impulsivity, compulsivity, stubbornness, manipulative behaviors, temper tantrums, and aggressive behaviors), autism spectrum disorder and mild and variable facies (including deep-set eyes and a prominent nasal septum, extending below the alae nasi) due to point mutation of USP7 gene or 16p13.2 microdeletion where USP7 is completely or partially deleted. Behavioral abnormalities are more pronounced in microdeletion. Patients may also have , feeding problems, delayed walking with unsteady gait, hypogonadism in males, and ocular anomalies (such as myopia, esotropia, strabismus, and nystagmus).

How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (1)

USP7-Related Diseases

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.”

3/6 stages with a signal

No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.

  1. Gene identifiedPresent

    Definitive — USP7

  2. LiteraturePresent

    6,261 matched papers (5,011 in last 10 years) Source

  3. Phenotype characterisedPresent

    77 HPO annotations (e.g. Global developmental delay; Abnormal facial shape; Hypogonadism) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

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

  6. 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?

Yes — we know a specific gene responsible (USP7).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

77

Associated phenotypes · MONDO:0014805

  • Global developmental delay
  • Abnormal facial shape
  • Hypogonadism
  • Aggressive behavior
  • Intellectual disability

Showing 5 of 77 — open Monarch for the full list.

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

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

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

6,261

6,261 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.

6,261 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).

5,011 in the last 10 years · low confidence

Phrase hits: 66 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

565

Distinct author names in 66 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.

  1. 01
    Schaaf CP9 papers · 2026

    Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA. schaaf@bcm.edu.

    Papers in Europe PMC
  2. 02
    Bezsonova I8 papers · 2026

    Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06032, United States. Electronic address: bezsonova@uchc.edu.

    Papers in Europe PMC
  3. 03
    Caro P7 papers · 2026

    Institute of Human Genetics, Heidelberg University, Heidelberg, Germany.

    Papers in Europe PMC
  4. 04
    Korchak EJ7 papers · 2026

    Department of Molecular Biology and Biophysics, UConn Health, 263 Farmington Avenue, Farmington, CT 06032, United States.

    Papers in Europe PMC
  5. 05
    Henneman P6 papers · 2026

    Department of Human Genetics, Amsterdam UMC, Amsterdam, Netherlands.

    Papers in Europe PMC
  6. 06
    van der Laan L6 papers · 2026

    Department of Human Genetics, Amsterdam UMC, Amsterdam, Netherlands.

    Papers in Europe PMC
  7. 07
    van Haelst MM6 papers · 2026

    Department of Human Genetics and Amsterdam Reproduction & Development research institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.

    Papers in Europe PMC
  8. 08
    Mannens MMAM5 papers · 2026

    Department of Human Genetics and Amsterdam Reproduction & Development research institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.

    Papers in Europe PMC
  9. 09
    Alders M4 papers · 2026

    Department of Human Genetics and Amsterdam Reproduction & Development research institute, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.

    Papers in Europe PMC
  10. 10
    Bezstarosti K4 papers · 2026

    Department of Biochemistry, Erasmus University Medical Center, Rotterdam, Netherlands.

    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 on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).

Data as of 11 September 2026 · last trial check 11 September 2026

No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.

low confidence · 38.6th 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.

See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.

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 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-30

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).

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 Hao-Fountain 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.

("Hao-Fountain syndrome" OR "HAFOUS" OR "USP7-Related Diseases") OR ("USP7" OR "USP7 syndrome" OR "USP7-related")

Run this search on Europe PMC

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

"Hao-Fountain syndrome" OR "HAFOUS" OR "USP7-Related Diseases"

Study-type breakdown: 0 interventional · 0 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
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (6261) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T19:39:05.831Z