The Distribution of Hemoglobin Types in Thalassemic

In homozygous 8-thalassemia the erythrocyte population is largely nonhomogeneous; no other condition presents such a variation of size, shape, and content of hemoglobin in the red cells. In addition, red cell morphology may differ from patient to patient as concerns degree and quality of alterations. This variability, evident at mere examination of red cell morphology, has been supported by the early studies on red cell sur-vival, which showed that the red cell population contains very short-living as well as rather long-living cells (1). Essentially similar findings were obtained in some studies by using chromated erythrocytes (2, 3); in other studies no initial rapid fall of the chromium survival curve was observed, but there was indirect evidence com-patible with the presence of a very short-lived population of red cells (4). Support for hetero-geneity has also been obtained by the technique for the histochemical demonstration of hemoglobin F (5), all reports agreeing on the nonuniform distribution of fetal hemoglobin over the red cell population (6-8). In 1963 further data concerning the hetero-geneity of red cells in homozygous 18-thalassemia were reported. a) It was shown that a large proportion of red cell precursors, but only occa-sional red cells, present Heinz-body-like precipi-tates of hemoglobin (9).1 Although one may consider a splenic "pitting out " mechanism for removal of the inclusions, studies on the fate of erythrocytes in hemoglobin H disease (10) and in induced Heinz-body anemias (11) failed to *Submitted for publication August 7, 1964; accepte