Behavioral abnormality, Brain atrophy, Cataract, Cerebellar atrophy, Cerebral atrophy, Decreased fetal movement, Delayed myelination, Delayed speech and language development, Developmental regression, Difficulty walking, Downslanted palpebral fissures, Dysarthria, Dyskinesia, Dystonia, EEG with multifocal slow activity, Encephalopathy, Failure to thrive, Feeding difficulties, Gait ataxia, Gastroesophageal reflux, Generalized hypotonia, Global developmental delay, High forehead, Hypodontia, Hypoplasia of the corpus callosum, Hyporeflexia, Hypsarrhythmia, Impulsivity, Intellectual disability, Intellectual disability, severe, Involuntary movements, Irritability, Limb ataxia, Limb hypertonia, Mask-like facies, Mental deterioration, Microcephaly, Myoclonus, Nystagmus, Optic atrophy, Poor eye contact, Poor head control, Ptosis, Reduced tendon reflexes, Retinal degeneration, Rigidity, Secondary microcephaly, Seizure, Short stature, Spastic gait, Spasticity, Status epilepticus, Tremor, Unsteady gait