Developmental regression, Dysphagia, EEG abnormality, Elevated urinary N-acetylaspartic acid level, Feeding difficulties in infancy, Flexion contracture, Gastroesophageal reflux, Generalized-onset seizure, Global developmental delay, Hearing impairment, Hypotonia, Increased CSF N-acetylaspartic acid concentration, Increased circulating N-Acetylaspartic acid concentration, Intellectual disability, Iris hypopigmentation, Lethargy, Macrocephaly, Mild global developmental delay, Nystagmus, Opisthotonus, Optic atrophy, Reduced consciousness/confusion, Seizure, Sleep disturbance, Spasticity, Visual impairment, Visual loss

abnormal retina ganglion layer morphology, abnormal retina nerve fiber layer morphology, abnormal sphingolipid level, abnormal startle reflex, abnormal synaptic neurotransmitter level, behavior/neurological phenotype, brain vacuoles, decreased anxiety-related response, decreased body length, decreased body size, decreased bone mineral content, decreased exploration in new environment, decreased food intake, decreased gamma-aminobutyric acid level, decreased glutamic acid level, decreased grip strength, decreased locomotor activity, decreased prepulse inhibition, decreased startle reflex, decreased vertical activity, enlarged lateral ventricles, increased aspartic acid level, increased fasting circulating glucose level, increased or absent threshold for auditory brainstem response, increased total body fat amount, limb grasping, muscle hypertonia, no abnormal phenotype detected, premature death, preweaning lethality, incomplete penetrance, spongiform encephalopathy