[Hemolytic disease of the newborn and chronic hypochromic microcytic anemia in one family: gamma-delta-beta thalassemia].

Ten newborn infants, all belonging to one family, suffered from severe hemolytic anemia. Four babies died shortly before or after birth, six recovered (one spontaneously, 5 after one or more exchange transfusions). In 5 out of 8 patients a mixed hyperbilirubinemia was observed in the immediate postnatal period, with elevated levels of indirect- as well as direct-reacting bilirubin. After the neonatal period, a slight hypochromic, microcytic anemia persisted, without icterus but with decreased osmotic fragility of the erytrocytes and with target cells in the blood smear. The same hematological picture was observed in one of the parents of each affected baby. All anemic adults belong to one large family; therefore, a dominant mode of inheritance is most likely. Although the hematological findings are suggestive for beta-thalassemia normal HbF and HbA2 levels were observed. In vitro incorporation of radioactive leucine into globin chains in reticulocytes demonstrated defective synthesis of beta chains in the affected adults; in two affected infants the same technique showed defective gamma-chain synthesis as well. Analysis of the hemoglobin genes proved that the affected family members are suffering from heterozygous gamma-delta-beta-thalassemia, as originally described by Kan et al. (1972).