| Main clinical features
|
severe multisystem developmental disorder characterized by delayed psychomotor development and intellectual disability
characteristic dysmorphic facial features, hypotonia, seizures, poor feeding, poor overall growth, and eye or visual abnormalities; also musculoskeletal abnormalities, and some have congenital defects of the heart and urogenital system
brain imaging usually shows developmental abnormalities such as gyral changes, cortical and/or cerebellar atrophy, ventriculomegaly, Arnold-Chiari malformations, arachnoid cysts, corpus callosum abnormality |