ORPHA:457279
Houge-Janssens syndrome type 1
Also known as: PPP2R5D-related Houge-Janssens syndrome · PPP2R5D-related neurodevelopmental disorder · HJS1
Publications
39
48.5th percentile
Trials
1
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
An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.
- Gene identifiedPresent
Definitive — PPP2R5D
- LiteraturePresent
39 matched papers (38 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?
Yes — we know a specific gene responsible (PPP2R5D).
GenCC classification: Definitive.
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?
39
39 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=5449) is 41.
39 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).
38 in the last 10 years · medium confidence · 48.5th percentile (publications denominator)
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?
People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.
- 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?
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.
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.
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
- NCT01238250·RECRUITING·Online Study of People Who Have Genetic Changes and Features of Autism: Simons Searchlight
Conditions: 16P11.2 Deletion Syndrome · 16p11.2 Duplications · 1Q21.1 Deletion · 1Q21.1 Microduplication Syndrome (Disorder)·Matched via recall expansion
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.
"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"
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" OR "PPP2R5D"
Recall-expansion terms: PPP2R5D
Interventional trials matched via: recall-expansion (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 · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.
Parent-category trials query:
"Houge-Janssens syndrome"
Query health: ok — strategies attempted: phrase, recall-expansion; with hits: phrase, recall-expansion
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
Ingested 2026-07-27T16:50:03.327Z