Traits

Traits linked to ZIC1

Zic family zinc finger 1

The Human Phenotype Ontology links 57 traits to ZIC1, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of head or neck

Trait	How often it is seen
Deformity of the skull	Always
Big calvaria	Very often (80–99%)
Broad forehead	Very often (80–99%)
Broad head shape	Very often (80–99%)
Dandy-Walker malformation	Very often (80–99%)
Flattening of the skull base	Very often (80–99%)
Prominent back of the head	Very often (80–99%)
Abnormally small head	Often (30–79%)
Bicoronal synostosis	Often (30–79%)
Downward slanting of the opening between the eyelids	Often (30–79%)
Enlarged posterior fossa	Often (30–79%)
Flattened bony protrusion above eyes	Often (30–79%)
Frontal bossing	Often (30–79%)
High forehead	Often (30–79%)
Asymmetry of the posterior head	Sometimes (5–29%)
Cleft palate	Sometimes (5–29%)
Delayed closure of the soft spot on the skull	Sometimes (5–29%)
Delayed cranial suture closure	Sometimes (5–29%)
Encephalocele	Sometimes (5–29%)
Flat back of skull	Sometimes (5–29%)
Holes in parietal bones	Sometimes (5–29%)
Lambdoidal craniosynostosis	Sometimes (5–29%)
Low frontal hairline	Sometimes (5–29%)
Midface retrusion	Sometimes (5–29%)
Right unilambdoid synostosis	Sometimes (5–29%)
Tall shaped head	Sometimes (5–29%)
Facial asymmetry	Not recorded

Abnormality of the nervous system

Trait	How often it is seen
Intellectual disability	Always
Too much cerebrospinal fluid in the brain	Very often (80–99%)
Aplasia/Hypoplasia of the cerebellar vermis	Often (30–79%)
Dilated fourth ventricle	Often (30–79%)
Hypoplasia of the pons	Often (30–79%)
Rise in pressure inside skull	Often (30–79%)
Small cerebellum	Often (30–79%)
Agenesis of corpus callosum	Sometimes (5–29%)
Aplasia/Hypoplasia of the corpus callosum	Sometimes (5–29%)
Autism spectrum disorder	Sometimes (5–29%)
Lateral ventricle dilatation	Sometimes (5–29%)
Motor delay	Sometimes (5–29%)
Spina bifida occulta	Sometimes (5–29%)
Instability or lack of coordination of central trunk muscles	Rarely (1–4%)
Degeneration of cerebellum	Not recorded
Global developmental delay	Not recorded

Abnormality of the eye

Trait	How often it is seen
Bulging eye	Often (30–79%)
Cross-eyed	Often (30–79%)
Drooping upper eyelid	Often (30–79%)
Optic nerve hypoplasia	Sometimes (5–29%)
Wide-set eyes	Sometimes (5–29%)
Involuntary, rapid, rhythmic eye movements	Rarely (1–4%)

Abnormality of limbs

Trait	How often it is seen
Fused long bones of hand	Sometimes (5–29%)
Short fingers or toes	Sometimes (5–29%)

Abnormality of prenatal development or birth

Trait	How often it is seen
Enlarged fetal cisterna magna	Often (30–79%)
Mild fetal ventriculomegaly	Often (30–79%)

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Often (30–79%)
Sensorineural hearing impairment	Sometimes (5–29%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Low muscle tone	Often (30–79%)
Scoliosis	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 ZIC1 and how often each is seen. Find out more at hpo.jax.org.

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