In alpha thalassemia major, anemia is actually fatal. Red blood cell (RBC) count is increased while hemoglobin is severely decreased. Both the MCV and MCHC are decreased. Red cell distribution width (RDW) is increased. RBC morphology shows slight hypochromic microcytosis with codocytes, schistocytes, and nucleated RBCs. Reticulocytes are increased.
Hemoglobin electrophoresis demonstrates abnormal pattern on cord blood:
- Hb A - absent
- Hb Bart's - 80-90%
- Hb Portland - 0-20%
Aside: Hb Portland is an embryonic hemoglobin having 2 gamma and 2 zeta chains.
Note: Bone marrow demonstrates marked erythroid hyperplasia.