title: Rapid diagnosis of glycine encephalopathy by 13C-glycine breath test.
abstract: OBJECTIVE
  It is currently problematic to confirm the clinical diagnosis of glycine encephalopathy, requiring either invasive liver biopsy for enzymatic analysis of the glycine cleavage system or exhaustive mutation analysis. Because the glycine cleavage system breaks down glycine generating carbon dioxide, we suppose that the glycine cleavage system activity could be evaluated in vivo by measuring exhaled (13)CO(2) after administration of [1-(13)C]glycine.
  
  
  METHODS
  The [1-(13)C]glycine breath test was performed in 10 control subjects and 5 glycine encephalopathy patients with GLDC mutation, including 1 patient with mild glycine encephalopathy.
  
  
  RESULTS
  All the patients showed lower (13)CO(2) excretion than any control subject.
  
  
  CONCLUSIONS
  Not only typical GE but also atypical GE can be reliably diagnosed by the (13)C-glycine breath test. Because it is rapid, non-invasive, and requires little expertise, the breath test could be useful as a standard test for diagnosing GE.
authors.affiliation: Department of Medical Genetics, Tohoku University School of Medicine, Sendai, Japan. skure@mail.tains.tohoku.ac.jp
authors.forename: Shigeo
authors.initials: S
authors.lastname: Kure
authors.forename: Stanley H
authors.initials: SH
authors.lastname: Korman
authors.forename: Junko
authors.initials: J
authors.lastname: Kanno
authors.forename: Ayumi
authors.initials: A
authors.lastname: Narisawa
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Kubota
authors.forename: Toshimitsu
authors.initials: T
authors.lastname: Takayanagi
authors.forename: Masaki
authors.initials: M
authors.lastname: Takayanagi
authors.forename: Takashi
authors.initials: T
authors.lastname: Saito
authors.forename: Akira
authors.initials: A
authors.lastname: Matsui
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Kamada
authors.forename: Yoko
authors.initials: Y
authors.lastname: Aoki
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Ohura
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsubara
mesh_terms: D000293:Adolescent; D001925:Brain Damage, Chronic / Q000175:diagnosis* / Q000235:genetics; D001944:Breath Tests; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D002648:Child; D002675:Child, Preschool; D005260:Female; D005998:Glycine / Q000032:analysis* / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D006943:Hyperglycemia / Q000175:diagnosis* / Q000235:genetics; D007223:Infant; D008297:Male; D010084:Oxidation-Reduction; D015203:Reproducibility of Results
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D005998:Glycine