ORPHA:477673
Postnatal microcephaly-infantile hypotonia-spastic diplegia-dysarthria-intellectual disability syndrome
Query health: suspect — Only one of 2 strategies returned hits (phrase).
Publications
18
34.8th percentile
Trials
0
Interventional, condition-specific
Researchers
167
Distinct authors in sample
Gene link
GPT2
Definitive
Readiness
2/6
Stages with a signal
Clinical definition (Orphanet)
A rare genetic neurological disorder characterized by postnatal microcephaly, during infancy followed in most cases by spasticity mainly affecting the lower limbs, and spastic diplegia or paraplegia, , delayed or absent speech, and dysarthria. and mildly features have been described in some patients.
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:0014567
- OMIM:616281
- UMLS:C4225388
Additional Mondo synonyms (7)
GPT2 Deficiency · GPT2 deficiency · glutamate pyruvate transaminase 2 deficiency · mental retardation, autosomal recessive 49 · mental retardation, autosomal recessive type 49 · neurodevelopmental disorder with microcephaly and spastic paraplegia · postnatal microcephaly-infantile hypotonia-spastic diplegia-dysarthria-intellectual disability syndrome
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.”
2/6 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 — GPT2
- LiteraturePresent
18 matched papers (17 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?
Yes — we know a specific gene responsible (GPT2).
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?
18
18 papers have ever been indexed 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.
18 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).
17 in the last 10 years · high confidence · 34.8th percentile (publications denominator)
Phrase hits: 18 · MeSH hits: 0
Who's working on it?
167
Distinct author names in 18 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.
- 01Morrow EM7 papers · 2026
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Institute for Brain Science, Brown University, Providence, RI 02912; Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital and Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, East Providence, RI 02915; dhousman@mit.edu Ganesh.Mochida@childrens.harvard.edu Eric_Morrow@brown.edu.
Papers in Europe PMC - 02DeBerardinis RJ5 papers · 2026
Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA. Ralph.Deberardinis@UTSouthwestern.edu.
Papers in Europe PMC - 03Baytas O4 papers · 2024
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Institute for Brain Science, Brown University, Providence, RI 02912;
Papers in Europe PMC - 04Davidson SM3 papers · 2024
Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139;
Papers in Europe PMC - 05Mathews TP3 papers · 2026
Children's Research Institute and Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Papers in Europe PMC - 06Ouyang Q3 papers · 2026
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Institute for Brain Science, Brown University, Providence, RI 02912; Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital and Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, East Providence, RI 02915;
Papers in Europe PMC - 07Schmidt M3 papers · 2026
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912; Institute for Brain Science, Brown University, Providence, RI 02912; Developmental Disorders Genetics Research Program, Emma Pendleton Bradley Hospital and Department of Psychiatry and Human Behavior, Alpert Medical School of Brown University, East Providence, RI 02915;
Papers in Europe PMC - 08Abdullah KG2 papers · 2026
Department of Neurosurgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Papers in Europe PMC - 09Agathocleous M2 papers · 2026
Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Papers in Europe PMC - 10Banaszynski LA2 papers · 2026
Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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 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.
high 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.
See who's working on it — 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 on the overview but are not added to the query string.
"Postnatal microcephaly-infantile hypotonia-spastic diplegia-dysarthria-intellectual disability syndrome" OR "GPT2 Deficiency" OR "glutamate pyruvate transaminase 2 deficiency" OR "mental retardation, autosomal recessive 49" OR "mental retardation, autosomal recessive type 49" OR "neurodevelopmental disorder with microcephaly and spastic paraplegia"
ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Postnatal microcephaly-infantile hypotonia-spastic diplegia-dysarthria-intellectual disability syndrome" OR "GPT2 Deficiency" OR "glutamate pyruvate transaminase 2 deficiency" OR "mental retardation, autosomal recessive 49" OR "mental retardation, autosomal recessive type 49" OR "neurodevelopmental disorder with microcephaly and spastic paraplegia" OR "GPT2"
Recall-expansion terms: GPT2
Study-type breakdown: 0 interventional · 0 observational · 0 expanded access. Only interventional studies enter the trial headline.
Query health: suspect — strategies attempted: phrase, recall-expansion; 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
Ingested 2026-07-27T17:07:42.625Z