Globin synthesis during erythroid cell maturation in alpha thalassemia

Globin chain synthesis was examined in erythroid cells of increasing maturity, fractionated from bone marrow of two patients with hemoglobin H disease and in one alpha thalassemia 1 heterozygote. In contrast to beta thalassemia where a gradient of alpha/beta chain ratios increasing with erythroid cell maturation is observed, in alpha thalassemia the alpha/beta chain ratio remains constant throughout maturation. This finding suggests that in alpha thalassemia there is no modification of the imbalance in globin chain synthesis either by increased alpha chain production or decreased beta chain synthesis in erythroid precursors. Furthermore, the constant alpha/beta ratio reflects a limited degree of beta chain destruction, indicating that the ability of the excess beta chains to associate into tetramers protects them from proteolytic digestion.