Abstract
1. Three cases of hereditary hemolytic disease secondary to G-6-PD deficiency are described. Two of the cases were first cousins of Scotch-Irish-English descent and the mode of inheritance was believed to be sex-linked. The third case was of Turkish origin; no family studies were availale.
2. The mothers, who were heterozygous for G-6-PD deficiency, showed only minimal expression of the defect, which was manifested by a slightly decreased red cell survival in both mothers and an abnormal methemoglobin reduction test in one of them.
3. All three cases showed a more pronounced fall in erythrocyte ATP after incubation with phenylhydrazine than that observed in primaquine-sensitive Negroes whose red cells were less deficient in G-6-PD.
4. It is suggested that the inability of the G-6-PD-deficient erythrocyte to maintain adequate levels of ATP may be an important factor in the pathogenesis of the hemolytic process.
