Abstract

A girl with spastic diplegia excreted large amounts of lysine and saccharopine in the urine, and had more than 10 times the normal plasma lysine concentration and a saccharopine peak in the plasma amino acid chromatogram. Unlike the earlier reported case of saccharopinuria, this patient had normal plasma and urine levels of citrulline. This case affords further evidence that the main degradative pathway of lysine metabolism in man is via saccharopine and α-aminoadipic acid.

The fact that in this patient there is no other known cause of the spastic diplegia and that the diplegia seems to be progressing suggest a connexion with the metabolic disturbance.