HEAD & NECK
Head
• Hydrocephalus (variable)
Ears
• Hearing loss, sensorineural, severe-to-profound. Hearing loss may be congenital or rapidly progressive leading to severe hearing loss by age 3 years. (present in all)
NEUROLOGIC
Central Nervous System
• Hydrocephalus (variable)
• Ventriculomegaly (variable)
• Normal psychomotor development in most
• Intellectual disability, mild (uncommon)
• Seizures (uncommon)
• Brain MRI shows hypoplasia of the corpus callosum
• Partial agenesis of the corpus callosum (present in all)
• Dysplastic corpus callosum
• Cerebellar hypoplasia due to enlarged foramen magnum
• Focal cerebellar dysplasia
• Obstruction of the foramen of Monro (variable)
• Subcortical nodular gray matter heterotopia
• Polymicrogyria
• Arachnoid cysts
GPSM2