title: 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency in a 23-year-old man.
abstract: 2-Methyl-3-hydroxybutyryl-CoA dehydrogenase (EC 1.1.1.178) deficiency is a recently described defect of isoleucine catabolism. The disorder is characterized by normal early development followed by a progressive loss of mental and motor skills. Deterioration may be rapid or may follow a slower decline with a possible stabilization of the disorder on a low-protein diet and appropriate medication. We report a 23-year-old man with 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency with a very mild clinical course. He had apparently normal early development and remained relatively well until the age of 6 years, when he contracted measles. Following this illness, his motor skills and school progress deteriorated. At 15 years he had significant dysarthria, and generalized rigidity with some dystonic and unusual posturing. He was then treated with a low-protein high-carbohydrate diet with a good response in terms of balance and gait. At 18 years he was given benzhexol (Artane), increased slowly from 2 mg to 6 mg daily, resulting in improvement in tremor and dystonia. At 23 years he can dress himself and works in sheltered employment but remains severely dysarthric.
authors.affiliation: Department of Neonatal Screening and Chemical Pathology Sheffield Children's Hospital, Sheffield, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Olpin
authors.forename: R J
authors.initials: RJ
authors.lastname: Pollitt
authors.forename: J
authors.initials: J
authors.lastname: McMenamin
authors.forename: N J
authors.initials: NJ
authors.lastname: Manning
authors.forename: G
authors.initials: G
authors.lastname: Besley
authors.forename: J P N
authors.initials: JP
authors.lastname: Ruiter
authors.forename: R J A
authors.initials: RJ
authors.lastname: Wanders
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases; D000102:Acetyl-CoA C-Acyltransferase / Q000097:blood; D000328:Adult; D000429:Alcohol Oxidoreductases / Q000097:blood / Q000172:deficiency* / Q000235:genetics*; D000592:Amino Acid Metabolism, Inborn Errors / Q000201:enzymology / Q000235:genetics*; D015415:Biomarkers; D004569:Electroencephalography; D004579:Electron Transport / Q000235:genetics; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007532:Isoleucine / Q000378:metabolism; D008297:Male; D010641:Phenotype; D011597:Psychomotor Performance; D014057:Tomography, X-Ray Computed
chemical_list: D015415:Biomarkers; D007532:Isoleucine; D000429:Alcohol Oxidoreductases; D015094:3-Hydroxyacyl CoA Dehydrogenases; C419903:2-methyl-3-hydroxybutyryl-coenzyme A dehydrogenase; D000102:Acetyl-CoA C-Acyltransferase