Sulfite Oxidase Deficiency is a rare autosomal recessive metabolic condition, characterized by neurologic defects, such as seizures, multicystic leukoencephalopathy with brain atrophy, generalized dystonia and choreoathetosis, as well as minimal development of language. Approximately 50 cases have been reported with Sulfite Oxidase Deficiency worldwide. There is no treatment for this disease, and it is fatal in infancy or early childhood. Survivors often exhibit profound mental retardation.