Modulation of Fetal Hemoglobin Synthesis by Iron Deficiency

NORMAL erythrocytes may contain three types of hemoglobin.1 In adults, the largest proportion of hemoglobin is hemoglobin A (96 per cent α2β2); hemoglobin A2 occurs in much smaller amounts (3 per cent α2δ2). Some cells (F cells) also contain hemoglobin F (α2γ2), although, in normal adults, hemoglobin F usually constitutes less than 1 per cent of the total hemoglobin. The proportion of each hemoglobin is determined principally by the transcriptional activity of the non-α-globin genes. During intrauterine life, the γ-globin genes are the most active, which produces . . .