early-onset epileptic encephalopathy and intellectual disability due to GRIN2A mutation
Findings
No curated finding names early-onset epileptic encephalopathy and intellectual disability due to GRIN2A mutation yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare intellectual disability and epilepsy syndrome due to mutation in GRIN2A gene. It is characterized by global developmental delay and mild to profound intellectual disability, multiple types of usually intractable focal and generalized seizures with variable abnormal EEG findings, and bilateral progressive parenchymal volume loss and thin corpus callosum on brain MRI.
Definition from the Mondo Disease Ontology (MONDO:0017325), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal dominant inheritance · Typified by incomplete penetrance
HPO, annotations 2026-09-02
Features
44 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- SeizureHPOHP:0001250
- 7 of 8 reported patients
- HypotoniaHPOHP:0001252
- 4 of 6 reported patients
- Atypical behaviorHPOHP:0000708
- Frequent (30% to 79% of cases)
- Bilateral tonic-clonic seizureHPOHP:0002069
- 4 of 33 reported patients
- Frequent (30% to 79% of cases)
- EEG with multifocal slow activityHPOHP:0010844
- Frequent (30% to 79% of cases)
- Floppy infant
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- GRIN2AHGNC:4585
- Strong · PanelApp Australia · Autosomal dominant · 2025
- Supportive · Orphanet · Autosomal dominant · 2021
Where it sits
Other names
1 name
Resolves to: early-onset epileptic encephalopathy and intellectual disability due to GRIN2A mutation
- Also called
- epilepsy, focal, with speech disorder and with or without impaired intellectual development