Traits

Traits linked to GAN

gigaxonin

The Human Phenotype Ontology links 47 traits to GAN, 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
Absent reflexes	Always
Lateral ventricle dilatation	Always
Motor delay	Always
Abnormal gait	Very often (80–99%)
CNS hypomyelination	Very often (80–99%)
Diffuse axonal swelling	Very often (80–99%)
Abnormality of the cerebellum	Often (30–79%)
Decreased sensation in extremities	Often (30–79%)
Intellectual disability	Often (30–79%)
Unsteady walk	Often (30–79%)
Babinski sign	Sometimes (5–29%)
Falls	Sometimes (5–29%)
Abnormal pyramidal sign	Not recorded
Abnormal pyramidal tract morphology	Not recorded
Decreased number of peripheral myelinated nerve fibers	Not recorded
Difficulty articulating speech	Not recorded
High stepping	Not recorded
Increased reflexes	Not recorded
Motor axonal neuropathy	Not recorded
Sensory axonal neuropathy	Not recorded

Abnormality of limbs

Trait	How often it is seen
Abnormality of the Achilles tendon	Very often (80–99%)
Abnormal shape of hand	Often (30–79%)
Club feet	Often (30–79%)
High-arched foot	Often (30–79%)
Knock knees	Sometimes (5–29%)
Limb muscle weakness	Sometimes (5–29%)
Areflexia of lower limbs	Not recorded
Dropped arches	Not recorded
Hyporeflexia of lower limbs	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Double-Jointed	Very often (80–99%)
Generalized decreased muscle tone	Very often (80–99%)
Proximal neurogenic muscle weakness	Very often (80–99%)
Involuntary muscle stiffness, contraction, or spasm	Often (30–79%)
Scoliosis	Often (30–79%)
Weakness of outermost muscles	Often (30–79%)
Distal muscle wasting	Not recorded
Spastic paraplegia	Not recorded

Abnormality of the eye

Trait	How often it is seen
Cross-eyed	Always
Extreme sensitivity of the eyes to light	Always
Involuntary, rapid, rhythmic eye movements	Not recorded

Abnormality of the integument

Trait	How often it is seen
Pili canaliculi	Very often (80–99%)
Afro-textured hair	Often (30–79%)
Curly hair	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Big calvaria	Always
Bell's palsy	Often (30–79%)

Abnormality of the digestive system

Trait	How often it is seen
Vomiting	Always

Abnormality of the endocrine system

Trait	How often it is seen
Abnormal pituitary gland morphology	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 GAN and how often each is seen. Find out more at hpo.jax.org.

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