Autism, Brain atrophy, Cataract, Cerebellar atrophy, Cerebral atrophy, Decreased fetal movement, Delayed myelination, Delayed speech and language development, Developmental regression, 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, obsolete Difficulty walking, Optic atrophy, Poor head control, Ptosis, Reduced eye contact, Reduced tendon reflexes, Retinal degeneration, Rigidity, Secondary microcephaly, Seizure, Short stature, Spastic gait, Spasticity, Status epilepticus, Tremor, Unsteady gait