infantile spasms
Findings
No curated finding names infantile spasms yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A rare epilepsy syndrome characterized by onset of epileptic spasms in infants between 2 and 12 months of age, and rarely up to 24 months. Infants may have no antecedent history, or a history reflecting the underlying cause. The classical triad of epileptic spasms, hypsarrhythmia and developmental stagnation or regression is historically referred to as West syndrome.
Definition from the Mondo Disease Ontology (MONDO:0018097), read 2026-09-29. CC BY 4.0.
Features
6 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.
- Developmental regressionHPOHP:0002376
- Very frequent (80% to 99% of cases)
- HypsarrhythmiaHPOHP:0002521
- Very frequent (80% to 99% of cases)
- Infantile spasmsHPOHP:0012469
- Very frequent (80% to 99% of cases)
- MyoclonusHPOHP:0001336
- Very frequent (80% to 99% of cases)
- Abnormal skin morphologyHPOHP:0011121
- Frequent (30% to 79% of cases)
- Abnormality of the nervous systemHPOHP:0000707
- Frequent (30% to 79% of cases)
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.
- BRWD3HGNC:17342
- Limited · Ambry Genetics · Autosomal dominant · 2018
Where it sits
- A kind of
- Narrower terms (8)
- developmental and epileptic encephalopathy, 1
- developmental and epileptic encephalopathy, 12
- developmental and epileptic encephalopathy, 15
- developmental and epileptic encephalopathy, 2
- developmental and epileptic encephalopathy, 27
- developmental and epileptic encephalopathy, 30
- developmental and epileptic encephalopathy, 40
- developmental and epileptic encephalopathy, 5
Other names
6 names
Resolves to: infantile spasms
- Also called
- IESSinfantile epileptic spasms syndromeinfantile spasms syndromeintellectual disability-hypsarrhythmia syndromeWest syndromeWest's syndrome