Traits

Traits linked to EFHC1

EF-hand domain containing 1

The Human Phenotype Ontology links 21 traits to EFHC1, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Brief seizures with staring spells	Always
EEG with spike-wave complexes (>3.5 Hz)	Always
Morning generalized tonic-clonic seizures	Always
EEG with polyspike wave complexes	Very often (80–99%)
Generalized-onset seizure	Very often (80–99%)
Grand mal seizures	Very often (80–99%)
Morning myoclonic jerks	Very often (80–99%)
Jerking	Often (30–79%)
Myoclonic seizure	Often (30–79%)
Abnormal emotional state	Sometimes (5–29%)
Anxiety	Sometimes (5–29%)
Febrile seizure (within the age range of 3 months to 6 years)	Sometimes (5–29%)
Photosensitive tonic-clonic seizure	Sometimes (5–29%)
Repeated seizures without recovery between them	Sometimes (5–29%)
Specific learning disability	Sometimes (5–29%)
Aggressive behavior	Rarely (1–4%)
EEG with generalized polyspikes	Not recorded
Generalized myoclonic seizure	Not recorded
Intellectual disability	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Abnormality of the mouth	Often (30–79%)

Abnormality of the eye

Trait	How often it is seen
Abnormality of eye movement	Often (30–79%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to EFHC1 and how often each is seen. Find out more at hpo.jax.org.

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