glucose-6-phosphate dehydrogenase (G6PD) deficiency, an inherited disorder characterized by red cells partially or completely deficient in G6PD, an enzyme critical in aerobic glycolysis. A sex-linked disorder, the defect is fully expressed in affected males despite a heterozygous pattern of inheritance. The disorder is associated with episodes of acute hemolysis under conditions of stress or in response to certain chemicals or drugs, particularly quinine. The anemia that results is a nonspherocytic hemolytic anemia. See also congenital nonspherocytic hemolytic anemia, favism.
