ABSTRACT
Among disorders of GABA metabolism 4-hydroxybutyric aciduria has been more frequently encountered, probably because the key intermediate 4-hydroxybutyric acid is detectable by analysis of organic acids [2]. The fundamental defect is in the activity of the succinic semialdehyde dehydrogenase (EC 1.2.1.24) (Figure 16.1). In the reaction catalyzed by this enzyme, the product of GABA transamination is normally converted to succinic acid and hence to oxidation via the citric acid cycle [9] 4-hydroxybutyric acid is converted via -oxidation into 3,4-dihydroxybutyric acid and thereafter to its keto acid, to glycolaldehyde and glycolic acid [10].
