Snapshot A 3-year-old child has gait abnormalities, absent deep tendon reflexes on both legs. Labs show a increases CSF protein with normal glucose and cell count, and a urine sediment that stains positive with toluidine blue O. Introduction Disorder of myelin metabolism caused by arylsulfatase deficiency part of a larger group of lysosomal storage diseases Six different disorders classified by exact gene mutation and age of onset All forms of the disease involve a progressive deterioration of motor and neurocognitive function Incidence is estimated to be 1 case per 40,000 population. Presentation Symptoms gait disturbances that progress to complete inability to walk speech is slurred intellectual decline Physical exam extremities become hypotonic and deep tendon reflexes are lost nystagmus is present Evaluation Labs CSF shows elevated protein metachromic granules in urine suggest metachromic leukodystrophy Neurologic testing Imaging presence of white matter abnormalities and atrophy on brain images is characteristic Differential Krabbe disease Tay-sachs disease Arylsulfatase A pseudodeficiency Treatment No effective treatment Prognosis, Prevention, and Complications Death from bronchopneumonia by 5 to 6 years