Arrhythmia, Ataxia, Axial hypotonia, Babinski sign, Bilateral tonic-clonic seizure, Cardiomyopathy, Central sleep apnea, Clonus, Decreased nerve conduction velocity, Decreased phosphoribosylpyrophosphate synthetase level, Deeply set eye, Delayed myelination, Diabetes insipidus, Distal amyotrophy, Distal muscle weakness, Distal sensory impairment, Dolichocephaly, Drooling, Dysarthria, Dysphagia, Elevated amniotic fluid alpha-fetoprotein, Excessive daytime somnolence, Exotropia, Gait disturbance, Gastrostomy tube feeding in infancy, Generalized hypotonia, Global developmental delay, Gout, Growth delay, Hearing impairment, Hyperactive deep tendon reflexes, Hyperreflexia, Hypertelorism, Hypertension, Hyperuricemia, Hyperuricosuria, Hypoplasia of the corpus callosum, Hypotonia, Immunodeficiency, Impaired pain sensation, Increased phosphoribosylpyrophosphate synthetase level, Intellectual disability, Intellectual disability, profound, Intrauterine growth retardation, Kyphosis, Language impairment, Limb hypertonia, Low-set ears, Macular coloboma, Motor delay, Muscle mounding, Muscle weakness, Neonatal hypotonia, Neurological speech impairment, Nystagmus, Onion bulb formation, Optic atrophy, Optic disc pallor, Pancreatic fibrosis, Paraparesis, Peripheral neuropathy, Pes cavus, Polyneuropathy, Profound global developmental delay, Progressive muscle weakness, Progressive visual loss, Prolonged neonatal jaundice, Recurrent infections, Recurrent upper respiratory tract infections, Renal insufficiency, Respiratory insufficiency, Retinal dystrophy, Rod-cone dystrophy, Scoliosis, Segmental peripheral demyelination/remyelination, Seizure, Sensorineural hearing impairment, Sensory neuropathy, Severe failure to thrive, Short stature, Skeletal muscle hypertrophy, Slow pupillary light response, Spastic tetraparesis, Spinal cord posterior columns myelin loss, Strabismus, Tetraplegia, Tremor, Underdeveloped nasal alae, Undetectable visual evoked potentials, Uric acid nephrolithiasis, Visual impairment, Visual loss