Homocystinuria: Excretion of a New Sulfur-Containing Amino Acid in Urine

Science  06 May 1966:
Vol. 152, Issue 3723, pp. 776-778
DOI: 10.1126/science.152.3723.776


An unusual homocysteine-containing compound, 5-amino-4-imidazolecarboxamide-5'-S-homocysteinylriboside, was isolated from the urine of a child with homocystinuria and detected in the urines of six homocystinurics. Its metabolic origin is not clear, and the data suggest the existence in man of now unknown alternate pathways for the metabolism of methionine and of purines.