Cystathioninuria not Associated with Vitamin B₆ Dependency: A Probably New Type of Cystathioninuria

Abstract

An infantile case of cystathioninuria was described. The patient had retarded development and marked cystathioninuria. Large doses of vitamin B₆, were of no effect in diminishing cystathionine excretion, this finding being different from that in other patients with cystathioninuria so far reported. Using liver specimens biopsied from the patient, a difinitely low activity of cystathionase was demonstrated in the presence of an excess of pyridoxal phosphate.
Both in vivo and in vitro studies indicate a defect in cystathionase itself. The present patient is thought to have a new type of cystathioninuria without vitamin B6₆ dependency.