congenital disorder of glycosylation type IIbb

A congenital disorder of glycosylation type II that is characterized by global developmental delay, severely impaired intellectual development, microcephaly, epilepsy, facial dysmorphism, and variable neurologic findings and that has_material_basis_in homozygo

A congenital disorder of glycosylation type II that is characterized by global developmental delay, severely impaired intellectual development, microcephaly, epilepsy, facial dysmorphism, and variable neurologic findings and that has_material_basis_in homozygous mutation in the COG3 gene on chromosome 13q14.

Signs and symptoms

• Delayed CNS myelination
• Seizure
• Myoclonic seizure
• Thin corpus callosum
• Nystagmus
• Intellectual disability
• Cerebellar vermis atrophy
• Microcephaly
• Delayed speech and language development
• EEG abnormality