Traits

Traits linked to PLCB1

phospholipase C beta 1

The Human Phenotype Ontology links 35 traits to PLCB1, 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
Epileptic encephalopathy	Always
Epileptic spasm	Always
Grand mal seizures	Always
Hypsarrhythmia	Always
Loss of developmental milestones	Always
Seizure affecting one half of brain	Always
Tonic seizure	Always
Cognitive impairment	Very often (80–99%)
Inability to walk	Very often (80–99%)
Infantile spasms	Very often (80–99%)
Jerking	Very often (80–99%)
Multifocal epileptiform discharges	Very often (80–99%)
Neurodevelopmental delay	Very often (80–99%)
Abnormality of the nervous system	Often (30–79%)
Bilateral tonic-clonic seizure with focal onset	Often (30–79%)
Degeneration of cerebrum	Often (30–79%)
Focal emotional seizure with laughing	Often (30–79%)
Focal hemiclonic seizure	Often (30–79%)
Focal impaired awareness seizure	Often (30–79%)
Myoclonic seizure	Often (30–79%)
Abnormal corpus callosum morphology	Sometimes (5–29%)
Delayed myelination	Sometimes (5–29%)
Increased reflexes	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Involuntary muscle stiffness, contraction, or spasm	Always
Low muscle tone in trunk	Always
Functional motor deficit	Very often (80–99%)
Low muscle tone	Often (30–79%)
Scoliosis	Sometimes (5–29%)
Spasticity and rigidity of muscles	Sometimes (5–29%)

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Often (30–79%)

Abnormality of the cardiovascular system

Trait	How often it is seen
Aortopulmonary collateral arteries	Sometimes (5–29%)

Abnormality of the endocrine system

Trait	How often it is seen
Early onset of puberty	Rarely (1–4%)

Abnormality of the eye

Trait	How often it is seen
Visual impairment	Sometimes (5–29%)

Abnormality of the integument

Trait	How often it is seen
Abnormal skin structure	Often (30–79%)

Growth abnormality

Trait	How often it is seen
Faltering weight	Sometimes (5–29%)

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 PLCB1 and how often each is seen. Find out more at hpo.jax.org.

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