A rare genetic neurological disorder characterized by early onset of microcephaly, severe global developmental delay and cognitive impairment, dyskinesia and hyperkinetic movements, visual impairment, autistic behavior, stereotypies, sleep disturbance, epilepsy, and cerebral malformations (such as corpus callosum hypogenesis, forebrain anomaly, and delayed myelination). Speech is minimal or absent, and ambulation is not attained. Patients with a larger 14q12 microdeletion show a more severe phenotype than those with intragenic alterations, with the addition of facial dysmorphism and agenesis of the corpus callosum. [from
ORDO]