Adenylosuccinase deficiency: a patient with impaired erythrocyte activity and anomalous response to intravenous fructose.

Clinical and biochemical data are presented on an Italian patient with adenylosuccinase deficiency of both erythrocytes and mixed peripheral blood lymphocytes. The erythrocyte enzyme showed normal substrate affinity, but decreased thermal stability. The patient displayed an anomalous response to an intravenous fructose tolerance test with a rise in plasma [Mg2+] and [K+] and a drop in plasma levels of inorganic phosphate, glucose, urate and succinylnucleosides upon fructose injection.