Hereditary Hemolytic Anemia Associated with Glucosephosphate Isomerase (GPI) Deficiency— a New Enzyme Defect of Human Erythrocytes

A new congenital hemolytic anemia not characterized by spherocytosis has been defined as due to a deficiency in another glycolytic enzyme, glucosephosphate isomerase, the catalyst specific for the second step of the Embden-Meyerhof glycolytic pathway. The leukocytes and the plasma are involved as well as the erythrocytes, but there is no clinical evidence of dysfunction other than the hemolytic anemia. Family studies are consistent with an autosomal-recessive mode of inheritance with the asymptomatic heterozygotes demonstrating an intermediate enzyme deficiency, and the symptomatic homozygote, the propositus, demonstrating a marked enzyme deficiency.