Definitive diagnosis of anemia in the newborn may require which approach?

• A. Repeat testing later in infancy
• B. Testing during an acute hemolytic crisis that may have destroyed the older, more biochemically or morphologically abnormal cells
• C. Transfusion therapy to replace abnormal cells with adult-type, morphologically normal RBCs
• D. Genetic testing for RBC morphology

Answer: (D)

Definitive diagnosis in the newborn row of anemia often rests on identifying a specific inherited defect in red cells rather than relying on how the cells look at a single moment. In the newborn period, red cell morphology can be influenced by ongoing development, and an acute hemolytic episode can destroy older, abnormal cells, making smear findings unreliable for pinpointing the exact disorder. Waiting to test later or relying on transfusion to manage the problem does not reveal the underlying cause. Genetic testing for inherited red cell disorders—such as those affecting hemoglobin, membrane proteins, or erythrocyte enzymes—provides a definitive diagnosis that guides management, prognosis, and family counseling, independent of the current cell appearance or a transient illness.