4-Hydroxybutyric aciduria in a patient without ataxia or convulsions

Abstract
A child presenting with mild psychomotor retardation, hypotonia, microcephaly and hyperkinesis is described. Urinary organic acid analysis by combined gas chromatography-mass spectrometry revealed 4-hydroxybutyric aciduria. Succinic semialdehyde dehydrogenase activity in extracts of white cells derived from the patient was less than 10% of control values.