Neuropediatrics 1984; 15(3): 165-169
DOI: 10.1055/s-2008-1052362
© Georg Thieme Verlag KG Stuttgart · New York

Gamma-Aminobutyric Acid-Transaminase Deficiency: A Newly Recognized Inborn Error of Neurotransmitter Metabolism

J.  Jaeken1 , P.  Casaer1 , P.  de Cock1 , L.  Corbeel1 , R.  Eeckels1 , E.  Eggermont1 , P. J. Schechter2 , J. -M. Brucher3
  • 1Department of Pediatrics, Catholic University of Leuven, Belgium
  • 2Merrell Dow Research Institute, Strasbourg, France
  • 3Unité de Neuropathologie, Université Catholique de Louvain, Bruxelles, Belgique
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Publication History

Publication Date:
19 March 2008 (online)

Abstract

Cerebrospinal fluid aminoacid analysis in a girl with severe psychomotor retardation, hypotonia, hyperreflexia and growth acceleration showed highly increased levels of free γ-aminobutyric acid (4.8 µmol/l; range in twenty controls 0.04-0.12, median 0.08), homocarnosine, a dipeptide of γ-aminobutyric acid and histidine (23.4 µmol/l; control range 4.0-8.7, median 7.6) and of β-alanine, an alternative substrate for γ-aminobutyric acid-transaminase (0.48 µmol/l; control range 0.02-0.06, median 0.05). Liver γ-aminobutyric acid-transaminase activity was deficient (0.07 µmol/mg protein h; range in ten controls 0.31-0.69, median 0.38). Fasting plasma growth hormone levels were increased (7.9-38.4 ng/ml; nl < 5). Brain evoked responses were suggestive of leukodystrophy. A brother of this patient, showing a similar clinical picture, had died at one year. Postmortem examination of his brain showed leukodystrophy of the type seen in amino acidopathies such as phenylketonuria. This appears to be the first report of γ-aminobutyric acid-transaminase deficiency.

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