CONGENITAL CONGENITAL nonspherocytic hemolytic anemia is a heterogenous group of hemolytic disorders characterized by disturbances of glycolytic metabolism in the erythrocyte. One category has been associated with defects in the Embden-Meyerhof pathway of glucose metabolism; patients with erythrocytes defective in pyruvate kinase 1 and triose phosphate isomerase2 activity have been described. Another group has been associated with diminished glucose-6-phosphate dehydrogenase (G-6-PD) activity. This abnormality results in an inability to generate reduced triphosphopyridine nucleotide (TPNH) in the hexose monophosphate shunt.
Deficient erythrocyte G-6-PD activity is associated with a number of hemolytic diseases of variable severity. In some cases, red cells deficient in this enzyme activity do not ordinarily hemolyze unless the patient is exposed to certain oxidizing drugs, such as primaquine.3 This manifestation occurs in 10% to 15% of American Negro men as a sex-linked recessive trait. On the other hand, most affected Caucasians show almost constant hemolysis. Because