Rare diseases · Sign or symptom
Typical absence seizure
HP:0011147
What it means
A typical absence seizure is a type of generalized non-motor (absence) seizure characterized by its sudden onset, interruption of ongoing activities, a blank stare, possibly a brief upward deviation of the eyes. Usually the patient will be unresponsive when spoken to. Duration is a few seconds to half a minute with very rapid recovery. Although not always available, an EEG would usually show 3 Hz generalized epileptiform discharges during the event.
In 2017 the ILAE Commission for Classification and Terminology recommended classifying a seizure as having focal or generalized onset only when there is a high degree of confidence (>80%, arbitrarily chosen to parallel the usual allowable beta error) in the accuracy of this determination; see Dialeptic seizure. Typical absences have 2 essential components: (1) clinically the impairment of consciousness (absence), and (2) EEG generalized 3 Hz to 4 Hz (less than 2.5 Hz) spike and slow wave discharges.
Rare diseases that can present with this12
Sometimes5–29%
9- Bilateral frontoparietal polymicrogyria
- Bilateral generalized polymicrogyria
- Developmental and epileptic encephalopathy with spike-wave activation in sleep
- DYRK1A-related intellectual disability syndrome due to 21q22.13q22.2 microdeletion
- Facial dysmorphism-developmental delay-behavioral abnormalities syndrome due to WAC point mutation
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to 9q21.3 microdeletion
- Neurodevelopmental disorder-craniofacial dysmorphism-cardiac defect-skeletal anomalies syndrome due to a point mutation
- SATB2-associated syndrome due to a pathogenic variant
and 1 more in this range
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Typical absence · Typical absence seizures
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.