| Main clinical features
|
severe global developmental delay, usually with hypotonia and absence of spontaneous movements other than head control, impaired intellectual development with absent speech, distal contractures, progressive microcephaly, dysmorphic features
neonatal respiratory distress, congenital arthrogryposis and progressive microcephaly
distal skeletal abnormalities, such as rocker-bottom feet and clenched hands with camptodactyly; brain imaging tends to show a simplified gyral pattern of the cerebral cortex, delayed myelination, thin corpus callosum, and hypoplasia of the brainstem and cerebellum |