抄録
An infant with hypouricemia due to a defect of 5-phosphoribosyl-l-pyrophosphate synthetase (PRPP synthetase) (E. C. 2. 7. 6. 1. ) was described, who was characterized by severe mental retardation, megaloblastic changes in the bone marrow, an abnormally high level of urinary excretion of orotic acid, an4 decreased levels of uric acid in the plasma and urine.