Red Blood Cell Disorders

Congenital nonimmune hemolytic anemias are disorders of the red blood cells (RBCs) that occur infrequently in children and adults. These disorders can be divided into three categories: disorders affecting RBC metabolism, the RBC membrane, and hemoglobin synthesis. In this chapter, we briefly describe these conditions and the blood smear morphology. Increasing use of ektacytometry, flow cytometry, or the less sensitive osmotic fragility test can help in analyzing RBC membrane disorders. In addition to morphology of RBCs, RBC enzyme and/or genetic testing can be confirmatory for diagnosis.