title: [(11)C]flumazenil positron emission tomography analyses of brain gamma-aminobutyric acid type A receptors in Angelman syndrome.
abstract: OBJECTIVE
  To evaluate the role of the gamma-aminobutyric acid type A (GABA(A)) receptor in Angelman syndrome (AS).
  
  
  METHODS
  We performed [(11)C]flumazenil positron emission tomography (PET) and examined GABA(A) receptor expression in 7 patients with AS of various genotypes (5 with the deletion, 1 with an imprinting defect [ID], and 1 with a UBE3A mutation) and 4 normal control healthy volunteers.
  
  
  RESULTS
  Relative to the control subjects, the [(11)C]flumazenil binding potentials (BPs) were significantly higher in the cerebral cortex and cerebellum in the 5 patients with the deletion and in the 1 patient with a UBE3A mutation, and were less frequently or barely increased in adult patients with the deletion and in the patient with IDs.
  
  
  CONCLUSIONS
  Total GABA(A) receptor expression was increased in patients with AS with various genotypes. We suggest that a developmental dysregulation of the GABA(A) receptor subunits occurs in patients with AS.
authors.affiliation: Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Asahina
authors.forename: Tohru
authors.initials: T
authors.lastname: Shiga
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Egawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Shinobu
authors.initials: S
authors.lastname: Kohsaka
authors.forename: Shinji
authors.initials: S
authors.lastname: Saitoh
mesh_terms: D000328:Adult; D017204:Angelman Syndrome / Q000000981:diagnostic imaging / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D005442:Flumazenil; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D049268:Positron-Emission Tomography; D011963:Receptors, GABA-A / Q000378:metabolism*; D012016:Reference Values
chemical_list: D011963:Receptors, GABA-A; D005442:Flumazenil