Traits

Traits linked to SNAPIN

SNAP associated protein

The Human Phenotype Ontology links 39 traits to SNAPIN, 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
Abnormal periventricular white matter morphology	Always
Brainstem dysplasia	Always
Cerebellar vermis atrophy	Always
Cortical dysplasia	Always
Delayed CNS myelination	Always
Encephalopathy	Always
Fewer or absent grooves in brain	Always
Generalized brain degeneration	Always
Interhemispheric cyst	Always
Lateral ventricle dilatation	Always
More grooves in brain	Always
Periventricular heterotopia	Always
Periventricular nodular heterotopia	Always
Schizencephaly	Always
Simplified gyral pattern	Always
Subcortical heterotopia	Always
Thin corpus callosum	Always
Agenesis of corpus callosum	Very often (80–99%)
Small cerebellum	Very often (80–99%)
Ventriculomegaly	Very often (80–99%)

Abnormality of limbs

Trait	How often it is seen
Club feet	Always
Small hand	Always
Hand clenching	Often (30–79%)
Overlapping fingers	Often (30–79%)
Talipes	Often (30–79%)

Abnormality of head or neck

Trait	How often it is seen
Cleft palate	Always
Little lower jaw	Very often (80–99%)
Small head present at birth	Often (30–79%)

Abnormality of the eye

Trait	How often it is seen
Abnormally small eyeball	Always
Clouding of the lens of the eye	Always
Optic atrophy	Always

Abnormality of prenatal development or birth

Trait	How often it is seen
Enlarged fetal cisterna magna	Always
Less than 10 fetal movements in 12 hours	Always

Laboratory abnormality

Trait	How often it is seen
Fetal skin edema	Always
Hydrops fetalis	Always

Abnormality of the cardiovascular system

Trait	How often it is seen
Hole in heart wall separating two lower heart chambers	Always

Abnormality of the endocrine system

Trait	How often it is seen
Reduced circulating growth hormone concentration	Always

Abnormality of the musculoskeletal system

Trait	How often it is seen
Flexed joint that cannot be straightened	Often (30–79%)

Growth abnormality

Trait	How often it is seen
Prenatal growth deficiency	Always

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

One test. A lifetime of answers.

From $449Free shipping · Results in 6–8 weeks

Get my Genome Test