Caring for someone with this diagnosis? Eleplan keeps diagnoses, medications, documents and every specialist in one plan.
Start free with EleplanLennox-Gastaut syndrome
ORPHA:2382Disease
What it is
A rare, severe early-onset developmental epileptic encephalopathy characterized by the triad of intellectual impairment, multiple seizure types, and typical electroencephalography (EEG) abnormalities.
Key facts
- Prevalence
- 1-5 / 10 000 (Europe)
- Age of onset
- Childhood, Infancy
- Inheritance
- Autosomal dominant, Multigenic/multifactorial, Not applicable
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Common30–79%
16- Abnormal brainstem morphology
- Aggressive behavior
- Atonic seizure
- Atypical absence seizure
- Atypical behavior
- Autistic behavior
- Bilateral tonic-clonic seizure
- EEG abnormalityDiagnostic criterion
- Falls
- Generalized tonic seizure
- Hyperactivity
- Irritability
- Mental deteriorationDiagnostic criterion
- Myoclonus
- Neurodevelopmental delay
- Personality disorder
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Genes
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Benefit programs to look at
Programs whose eligibility touches the same ICD-10 categories. Eligibility is decided by the administering agency, never by this page.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
Powered by Eleplan
A rare diagnosis is just the start. Eleplan keeps the whole care plan in one place.
Diagnoses, medications, documents, appointments, and the whole care team — organized and always in sync, so you are not retelling the same story to every new specialist. With Ellie, your AI care assistant, on top of it. Free to start.