Chorea, Constipation, Delayed myelination, Delayed speech and language development, Dystonia, Exotropia, Failure to thrive, Feeding difficulties in infancy, Gait disturbance, Generalized hypotonia, Global developmental delay, Hyperactivity, Hypermetropia, Hypoplasia of the corpus callosum, Hypotonia, Ileus, Intellectual disability, Joint hypermobility, Long face, Malar flattening, Mandibular prognathia, Mask-like facies, Microcephaly, Midface retrusion, Motor delay, Motor stereotypy, Myopathic facies, Narrow face, Neonatal hypotonia, obsolete Impaired social interactions, obsolete Joint hyperflexibility, Open mouth, Pes cavus, Poor hand-eye coordination, Ptosis, Reduced brain creatine level by MRS, Redundant skin, Seizure, Self-mutilation, Short stature, Spasticity, Tall stature, Underfolded superior helices, Vomiting

abnormal spatial working memory, abnormal synapse morphology, behavior/neurological phenotype, decreased aerobic running capacity, decreased body length, decreased body mass index, decreased circulating creatine level, decreased circulating glucose level, decreased creatine level, decreased fasting circulating glucose level, decreased grip strength, decreased hippocampus volume, decreased locomotor activity, decreased percent body fat/body weight, decreased urine creatine level, impaired contextual conditioning behavior, impaired spatial learning, impaired swimming, improved glucose tolerance, increased grooming behavior, increased lean body mass, increased serotonin level, increased urine creatine level, lipofuscinosis, microgliosis, skeletal muscle fiber atrophy