The metabolism of glutamate in man, animals, and bacteria has been widely investigated in recent years. From these studies an impressive array of disorders of glutamate metabolism has emerged (Table 1). Most of the disorders appear to be associated with or even responsible for dysfunction of the central nervous system (CNS) in man. This is not surprising since glutamate and its metabolites play an important role in the intermediary metabolism of the brain, as well as in chemical neurotransmission at syн napses (1-9). Although all of the disorders discussed here have been recorded in literature, it has not been widely appreciated that this whole family of disorders is frequently associated with neurological dysfunction.