β-Thalassemia intermedia homozygous for normal hemoglobin A₂ β-thalassemia. Study in four families

Four homozygotes for β-thalassemia with normal hemoglobins A₂ and F were studied. The absence or scarcity of transfusion requirement and comparatively low hemoglobin F content were the most important findings. Both parents of 3 patients showed the findings of β-thalassemia with normal hemoglobins A₂ and F. Biosynthetic studies in 2 patients and both their parents showed moderate or mild β-chain deficiency. The possible reason for this comparatively mild course of a β-thalassemia syndrome lies in a mild deficit in β-chain production.