Traits

Traits linked to NAGA

alpha-N-acetylgalactosaminidase

The Human Phenotype Ontology links 64 traits to NAGA, 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
Intellectual disability, mild	Always
Abnormal pyramidal sign	Very often (80–99%)
Abnormal shape of brainstem	Very often (80–99%)
Autism	Very often (80–99%)
Epilepsy	Very often (80–99%)
Global developmental delay	Very often (80–99%)
Intellectual disability	Very often (80–99%)
Intellectual disability, severe	Very often (80–99%)
Loss of developmental milestones	Very often (80–99%)
Abnormality of extrapyramidal motor function	Often (30–79%)
Damage to nerves that sense feeling	Often (30–79%)
Jerking	Often (30–79%)
Paralysis or weakness of one side of body	Often (30–79%)
Peripheral neuropathy	Often (30–79%)
Absent/small cerebellum	Sometimes (5–29%)
Pins and needles feeling	Sometimes (5–29%)
Abnormal posterior periventricular white matter morphology	Not recorded
Axonal degeneration	Not recorded
Cognitive impairment	Not recorded
Decreased sensation in extremities	Not recorded
Degeneration of cerebrum	Not recorded
Distal sensory impairment of all modalities	Not recorded
Increased reflexes	Not recorded
Peripheral axonal neuropathy	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Tortuosity of conjunctival vessels	Always
Spider veins of the lip	Very often (80–99%)
Spider veins of the oral mucosa	Very often (80–99%)
Coarse facial features	Often (30–79%)
Depressed nasal bridge	Often (30–79%)
Full lips	Often (30–79%)
Full lower lip	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Diffuse skeletal muscle wasting	Very often (80–99%)
Involuntary muscle stiffness, contraction, or spasm	Very often (80–99%)
Low muscle tone	Very often (80–99%)
Muscle weakness	Very often (80–99%)
Generalized decreased muscle tone	Not recorded
Osteopenia	Not recorded
Weakness of outermost muscles	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Angiokeratoma corporis diffusum	Always
Lacunar stroke	Always
Telangiectasia of the skin	Very often (80–99%)
Enlarged and thickened heart muscle	Often (30–79%)
Enlarged heart	Often (30–79%)
Spider veins	Often (30–79%)

Abnormality of the eye

Trait	How often it is seen
Cerebral visual impairment	Very often (80–99%)
Clouding of the lens of the eye	Very often (80–99%)
Cross-eyed	Very often (80–99%)
Involuntary, rapid, rhythmic eye movements	Often (30–79%)
Opacification of the corneal stroma	Often (30–79%)
Optic atrophy	Often (30–79%)

Abnormality of the ear

Trait	How often it is seen
Dizziness	Very often (80–99%)
Hearing impairment	Very often (80–99%)
Ringing in ears	Often (30–79%)
Sensorineural hearing impairment	Not recorded

Abnormality of the integument

Trait	How often it is seen
Firm lump under the skin	Very often (80–99%)
Hyperkeratosis	Very often (80–99%)
Papule	Very often (80–99%)
Dry skin	Not recorded

Laboratory abnormality

Trait	How often it is seen
Swelling caused by excess lymph fluid under skin	Often (30–79%)
Abnormal urinary amino-acid findings	Not recorded
Increased urinary O-linked sialopeptides	Not recorded
Reduced tissue alpha-N-acetylgalactosaminidase activity	Not recorded

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Petechiae	Always

Abnormality of the digestive system

Trait	How often it is seen
Enlarged liver	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 NAGA and how often each is seen. Find out more at hpo.jax.org.

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