Hypothesis: a role for quinolinic acid in the neuropathology of glutaric aciduria type I

Glutaric aciduria type I is an autosomal recessive metabolic disorder of children associated with severe dystonic motor disturbances and degeneration in the cerebral cortex, striatum and cerebellum. Biochemical studies demonstrate a deficiency in the enzyme glutaryl-CoA dehydrogenase. This enzyme metabolizes substrate derived from dietary tryptophan that could otherwise be converted to quinolinic acid within the brain. The law of mass action predicts that the production of quinolinic acid should be increased in glutaric aciduria type I. Quinolinic acid is a potent neurotoxin and convulsant when it is injected into the central nervous system of experimental animals. This paper argues that quinolinic acid may accumulate within the brain and cause the neuropathology of glutaric aciduria type I.