Traits

Traits linked to GJC2

gap junction protein gamma 2

The Human Phenotype Ontology links 68 traits to GJC2, 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
Ataxia	Always
Babinski sign	Always
Choreoathetosis	Always
CNS hypomyelination	Always
Difficulty articulating speech	Always
Increased reflexes	Always
Motor delay	Always
Underdevelopment of part of brain called corpus callosum	Always
Abnormal auditory evoked potentials	Very often (80–99%)
Abnormal motor evoked potentials	Very often (80–99%)
Abnormality of somatosensory evoked potentials	Very often (80–99%)
Abnormal gait	Often (30–79%)
Cognitive impairment	Often (30–79%)
Decreased sensation in extremities	Often (30–79%)
Epilepsy	Often (30–79%)
Focal impaired awareness seizure	Often (30–79%)
Somatic sensory dysfunction	Often (30–79%)
Delayed motor skills	Sometimes (5–29%)
Focal aware seizure	Sometimes (5–29%)
Cerebral hypomyelination	Not recorded
Decreased motor nerve conduction velocity	Not recorded
Degeneration of cerebrum	Not recorded
Demyelinating motor neuropathy	Not recorded
Dystonia	Not recorded
Global developmental delay	Not recorded
Head titubation	Not recorded
Intention tremor	Not recorded
Lack of coordination of movement	Not recorded
Leukodystrophy	Not recorded
Poor speech	Not recorded
Sensory axonal neuropathy	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Lower limb spasticity	Always
Poor head control	Always
Spastic paraparesis	Always
Spastic paraplegia	Always
Spastic walk	Always
Uncontrollable movement in upper arms	Always
Scoliosis	Often (30–79%)
Bacterial infection of skin	Sometimes (5–29%)
Low muscle tone in trunk	Not recorded
Progressive spasticity	Not recorded
Rigidity	Not recorded

Abnormality of the eye

Trait	How often it is seen
Involuntary, rapid, rhythmic eye movements	Always
Abnormality of visual evoked potentials	Very often (80–99%)
Cross-eyed	Very often (80–99%)
Slow eye movements	Often (30–79%)
Drooping upper eyelid	Rarely (1–4%)
Close sighted	Not recorded
Optic atrophy	Not recorded
Rotary nystagmus	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Abnormal lymphatic vessel morphology	Often (30–79%)
Underdeveloped lymphatic vessels	Often (30–79%)
Poorly functioning veins	Sometimes (5–29%)
Varicose veins	Sometimes (5–29%)

Laboratory abnormality

Trait	How often it is seen
Predominantly lower limb lymphedema	Often (30–79%)
Edema of the dorsum of hands	Sometimes (5–29%)
Genital edema	Rarely (1–4%)
Swelling caused by excess lymph fluid under skin	Not recorded

Abnormality of limbs

Trait	How often it is seen
High-arched foot	Always
Ankle swelling	Often (30–79%)
Fluid accumulation in lower limbs	Often (30–79%)

Abnormality of head or neck

Trait	How often it is seen
Bell's palsy	Always
Facial puffiness	Sometimes (5–29%)

Abnormality of the genitourinary system

Trait	How often it is seen
Loss of bladder control	Often (30–79%)
Urinary bladder sphincter dysfunction	Often (30–79%)

Abnormality of the digestive system

Trait	How often it is seen
Constipation	Often (30–79%)

Abnormality of the ear

Trait	How often it is seen
Sensorineural hearing impairment	Often (30–79%)

Abnormality of the immune system

Trait	How often it is seen
Recurrent skin infections	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 GJC2 and how often each is seen. Find out more at hpo.jax.org.

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