An autosomal recessive, complex and progressive neurologic disorder characterized by severe neurodevelopmental delay and developmental regression, epileptic encephalopathy, postnatal microcephaly, hypotonia, and non-epileptic hyperkinetic movement disorder, including myoclonus dystonia, choreoathetosis, or generalized dyskinesia. Disease onset in infancy or first years of life. The disease is neurodevelopmental disorder with seizures and non-epileptic hyperkinetic movements (EFO_0010276).