Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two hereditary disorders of sulfur amino acid metabolism, beta-mercaptolactate-cysteine disulfideuria and sulfite oxidase deficiency, were described twenty years ago. Other examples of these disorders have been limited to about 5 of each in the world literature since then. Reasons for the apparent rarity of these conditions are discussed and the analytical procedures to identify them are reviewed. The detection of the first depends on the positive result of a cyanide-nitroprusside test followed by positive identification of the specific mixed disulfide. The enzyme mercaptopyruvate sulfur transferase has been shown to be deficient. In the second disorder of sulfite oxidase deficiency, the clinical presentation with progressive dystonia and dislocated lenses in an infant should suggest further laboratory investigations for this disorder which would not be detected by conventional laboratory screening procedures. Laboratory diagnosis can be obtained by use of the Merckoquant sulfite test on a fresh urine sample. Quantitative thiosulfate and taurine measurements can also be made. Positive identification of the specific amino acid S-sulfo-L-cysteine should also be made. The enzyme sulfite oxidase is missing from such organs as liver, kidney and brain. This latter condition may also be associated with xanthinuria. For this combined disorder of sulfite oxidase and xanthine oxidase, a deficiency of a molybdenum-containing cofactor has been demonstrated.
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PMID:A review of the clinical presentation and laboratory findings in two uncommon hereditary disorders of sulfur amino acid metabolism, beta-mercaptolactate cysteine disulfideuria and sulfite oxidase deficiency. 388 41

Seizures are a common presenting manifestation in children with disorders of amino acid metabolism. However, seizures may be very common in some specific diseases, but are rare in other diseases. In patients with classical maple syrup urine disease (MSUD), seizures commonly occur in the neonatal stage. But in intermittent or intermediate MSUD, seizures may develop in a later stage, or are uncommon. Patients with nonketotic hyperglycinemia often present with early myoclonic encephalopathy in the first weeks of life. However, in patients with atypical variants, seizures may be rare. In addition, patients with sulfite oxidase deficiency, serine deficiency, or GABA-related disorders may also present with different types of seizures. In monoamine biosynthesis disorders, seizures are rare, but paroxysmal dystonia is frequently misdiagnosed as seizures. Therefore, the incidence of seizures in disorders of amino acid metabolism is variable. Timely diagnosis and early treatment may improve the prognosis of these disorders.
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PMID:Disorders of amino acid metabolism associated with epilepsy. 2180 16