ORPHA:457279
Houge-Janssens syndrome type 1
Also known as: PPP2R5D-related Houge-Janssens syndrome · PPP2R5D-related neurodevelopmental disorder · HJS1
Publications
673
Trials
0
Interventional, condition-specific
Researchers
265
Distinct authors in sample
Gene link
PPP2R5D
Definitive
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare, syndromic characterized by , global , limited or absent speech, , macrocephaly, mild features, and autism spectrum disorder. Associated ophthalmologic, heart, skeletal and central nervous system anomalies have been reported.
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.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0014602
- OMIM:616355
- UMLS:C5779996
Additional Mondo synonyms (5)
MRD35 · autosomal dominant intellectual disability 35 · intellectual disability, autosomal dominant type 35 · intellectual disability-macrocephaly-hypotonia-behavioral abnormalities syndrome · mental retardation, autosomal dominant type 35
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.
- Gene identifiedPresent
Definitive — PPP2R5D
- LiteraturePresent
673 matched papers (537 in last 10 years) Source
- Phenotype characterisedPresent
91 HPO annotations (e.g. Intrauterine growth retardation; Congenital hip dislocation; Strabismus) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- 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 (PPP2R5D).
GenCC classification: Definitive.
Phenotypes (Monarch / HPO)
91
Associated phenotypes · MONDO:0014602
- Intrauterine growth retardation
- Congenital hip dislocation
- Strabismus
- Pyloric stenosis
- Generalized hypotonia
Showing 5 of 91 — 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?
673
673 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=3967) is 59.
673 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).
537 in the last 10 years · low confidence
Phrase hits: 39 · MeSH hits: 0
Who's working on it?
265
Distinct author names in 39 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.
- 01
- 02Swingle MR5 papers · 2025
Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA.
Papers in Europe PMC - 03Zhang Y5 papers · 2025
National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, China.
Papers in Europe PMC - 04Calamia S4 papers · 2025
Department of Pediatrics, Columbia University Irving Medical Center, New York, New York, USA.
Papers in Europe PMC - 05Kanner CH4 papers · 2025
Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center, New York, New York, USA.
Papers in Europe PMC - 06Montes J4 papers · 2025
Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center, New York, New York, USA.
Papers in Europe PMC - 07Beard G3 papers · 2024
Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center, 617 West 168th Street, New York, NY, 10032, USA.
Papers in Europe PMC - 08Doerger J3 papers · 2024
Department of Pediatrics, Columbia University Irving Medical Center, New York, NY, USA.
Papers in Europe PMC - 09Harris M3 papers · 2024
Department of Rehabilitation and Regenerative Medicine, Columbia University Irving Medical Center, 617 West 168th Street, New York, NY, 10032, USA.
Papers in Europe PMC - 10Honkanen RE3 papers · 2024
Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, USA. Electronic address: rhonkanen@southalabama.edu.
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.
Broader category Houge-Janssens syndrome 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: Houge-Janssens syndrome
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.
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 Houge-Janssens syndrome type 1 — check Associations / patient organisations on that page.
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.
("Houge-Janssens syndrome type 1" OR "PPP2R5D-related Houge-Janssens syndrome" OR "PPP2R5D-related neurodevelopmental disorder" OR "MRD35" OR "autosomal dominant intellectual disability 35" OR "intellectual disability, autosomal dominant type 35" OR "intellectual disability-macrocephaly-hypotonia-behavioral abnormalities syndrome" OR "mental retardation, autosomal dominant type 35") OR ("PPP2R5D" OR "PPP2R5D syndrome" OR "PPP2R5D-related")ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Houge-Janssens syndrome type 1" OR "PPP2R5D-related Houge-Janssens syndrome" OR "PPP2R5D-related neurodevelopmental disorder" OR "MRD35" OR "autosomal dominant intellectual disability 35" OR "intellectual disability, autosomal dominant type 35" OR "intellectual disability-macrocephaly-hypotonia-behavioral abnormalities syndrome" OR "mental retardation, autosomal dominant type 35"
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"Houge-Janssens syndrome"
Query health: ok — strategies attempted: phrase; with hits: phrase
Run this search on ClinicalTrials.gov
Synonyms dropped by stoplist: HJS1
Confidence reasoning
- Preferred label is multi-word and distinctive
- 1 synonym(s) dropped by stoplist (may under-count)
- No label/synonym collisions with other diseases in this corpus
- Publication count (673) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-27T16:50:03.327Z