title: Urinary excretion of 2-methylacetoacetate, 2-methyl-3-hydroxybutyrate and tiglylglycine after isoleucine loading in the diagnosis of 2-methylacetoacetyl-CoA thiolase deficiency.
abstract: The concentrations of 2-methylacetoacetate, 2-methyl-3-hydroxybutyrate and tiglylglycine were determined by gas chromatography-mass spectrometry in urine collected before and for 8 h after loading with 100 mg of isoleucine per kg of body weight. The sum of 2-methylacetoacetate and 2-butanone, a decarboxylation product, was determined as the 2-butanone dinitrophenylhydrazone derivative. Substantial increases in each compound were encountered in a patient with a documented defect of 2-methylacetoacetyl-CoA thiolase. Increased quantities of 2-methyl-3-hydroxybutyrate and tiglylglycine were also found in four children with clinical symptoms similar to those associated with 2-methylacetoacetyl-CoA thiolase deficiency but in whom the activity of the enzyme was found to be normal. The concentration of 2-methylacetoacetate plus 2-butanone in the urine increased after an isoleucine load only in the patient with 2-methylacetoacetyl-CoA thiolase deficiency.
authors.affiliation: Department of Pediatrics, University of California San Diego, La Jolla 92093.
authors.forename: S
authors.initials: S
authors.lastname: Aramaki
authors.forename: D
authors.initials: D
authors.lastname: Lehotay
authors.forename: L
authors.initials: L
authors.lastname: Sweetman
authors.forename: W L
authors.initials: WL
authors.lastname: Nyhan
authors.forename: S C
authors.initials: SC
authors.lastname: Winter
authors.forename: B
authors.initials: B
authors.lastname: Middleton
mesh_terms: D000090:Acetoacetates / Q000652:urine*; D000102:Acetyl-CoA C-Acyltransferase / Q000172:deficiency*; D002074:Butanones / Q000652:urine; D005998:Glycine / Q000031:analogs & derivatives* / Q000652:urine; D006801:Humans; D006885:Hydroxybutyrates / Q000652:urine*; D007223:Infant; D007532:Isoleucine; D008297:Male
chemical_list: D000090:Acetoacetates; D002074:Butanones; D006885:Hydroxybutyrates; D007532:Isoleucine; C003603:tiglylglycine; C016579:2-methyl-3-hydroxybutyric acid; C005222:methylethyl ketone; C005217:methyl acetoacetate; D000102:Acetyl-CoA C-Acyltransferase; D005998:Glycine