| Feature | Details |
| Microcephaly | - Defined as occipitofrontal circumference <3rd percentile
- Both proportionate and disproportionate microcephaly can occur
|
| Other cranial dysmorphisms | - Craniofacial disproportion
- Overriding cranial sutures
- Craniosynostosis
- Cutis gyrata (redundant scalp)
|
| Ocular abnormalities | - Macular abnormalities (eg, focal pigmentary retinal mottling and chorioretinal atrophy)
- Optic nerve abnormalities (eg, optic nerve hypoplasia, increased cup-to-disk ratio, and pallor)
- Retinal vascular abnormalities (eg, tortuosity, straightening, attenuation, abnormal termination, and focal areas of dilation)
- Structural abnormalities (eg, microcornea, microphthalmia, iris colobomas, intraocular calcification, lens subluxation, cataracts)
- Congenital glaucoma
- Strabismus
- Nystagmus
|
| Hearing loss | - Sensorineural hearing loss
|
| Arthrogryposis | - Congenital contractures (arthrogryposis)
- Unilateral or bilateral club foot
|
| Neuromotor abnormalities | - Hypertonia/spasticity
- Hyperreflexia
- Irritability
- Dysphagia and feeding difficulties
|
| Seizures | |
| Small size for gestational age | - Defined as birth weight <10th percentile for gestational age
|
| Neuroimaging abnormalities | - Intracranial calcifications (most commonly at the junction between the cortical and subcortical white matter)
- Ventriculomegaly
- Cortical atrophy
- Reduced brain volume
- Delayed myelination
- Simplified gyral patterns (eg, polymicrogyria, pachygyria, lissencephaly)
- Thinning of hypoplasia of the corpus callosum
- Hypoplasia of the brainstem and cerebellum
- Enlargement of the cisterna magna
- Increased extra-axial fluid spaces
|
