|A.||an increased amount of fetal hemoglobin (HbF) or hemoglobin A2 (HbA2)|
increased osmotic fragility of the red cells
absent bone marrow iron
increased macroglobulins in the serum
An increased amount of HbF or HbA2 would be expected. As beta-chains are decreased in beta-thalassemia, the excess alpha-chains combine with gamma- and delta-chains to make HbF and HbA2, respectively.