The clinical features of this disease, per organ system, include:
Central nervous system:
• Intellectual disability – severe to profound
• Epilepsy
• Hydrocephalus
• Spasticity
• Axial hypotonia
• Abnormal brain imaging: ribbon-like subcortical heterotopia, polymicrogyria-like cortex, partial or complete agenesis of the corpus callosum, interhemispheric cyst, enlarged ventricles, small basal ganglia, fused thalami, flattened pons, cerebellar hypoplasia.
• Several brain abnormalities can be detected on prenatal ultrasound/ MRI, including enlarged ventricles, colpocephaly, band heterotopia, cerebellar hypoplasia.
Head and neck:
• Macrocephaly
• Small palpebral fissures
• Low-set ears
• Small mouth
Ophthalmological:
• Strabismus
• Cerebral visual impairment
• Nystagmus
• Optical atrophy
• Retinal dystrophy
• Hypermetropia
Miscellaneous:
• Atrial septal defect (1 individual)
• Feeding difficulties, failure to thrive
• Pectus carinatum (1 individual)
EML1