Ataxia, Atonic seizure, Attention deficit hyperactivity disorder, Atypical absence seizure, Autism, Autistic behavior, Behavioral abnormality, Bilateral tonic-clonic seizure, Brain atrophy, Cerebral atrophy, Decreased fetal movement, Delayed speech and language development, Depressed nasal bridge, Developmental regression, Difficulty walking, Downslanted palpebral fissures, Dyskinesia, Dysphagia, EEG abnormality, EEG with focal sharp slow waves, EEG with multifocal slow activity, Encephalopathy, Enlarged cisterna magna, Epileptic encephalopathy, Failure to thrive, Falls, Feeding difficulties, Focal-onset seizure, Frontotemporal cerebral atrophy, Gastroesophageal reflux, Generalized hypotonia, Generalized myoclonic seizure, Generalized tonic seizure, Gingival overgrowth, Global developmental delay, High forehead, Hyperactivity, Hypodontia, Hypoplasia of the corpus callosum, Hyporeflexia, Hypotonia, Hypsarrhythmia, Impulsivity, Inability to walk, Intellectual disability, Intellectual disability, progressive, Intellectual disability, severe, Involuntary movements, Limb hypertonia, Low-set ears, Macrocephaly, Mental deterioration, Microcephaly, Myoclonus, Nystagmus, Optic atrophy, Personality disorder, Poor head control, Posteriorly rotated ears, Psychomotor retardation, Ptosis, Recurrent respiratory infections, Reduced tendon reflexes, Retinal degeneration, Rigidity, Seizure, Self-injurious behavior, Short stature, Spasticity, Status epilepticus, Tented upper lip vermilion, Tremor, Unsteady gait

abnormal synaptic vesicle morphology, abnormal synaptic vesicle number, abnormal synaptic vesicle recycling, convulsive seizures, hunched posture, impaired limb coordination, increased or absent threshold for auditory brainstem response, nervous system phenotype, no abnormal phenotype detected, postnatal lethality, complete penetrance, premature death, preweaning lethality, complete penetrance, tonic seizures