Certified Pediatric Hematology Oncology Nurse (CPHON) Practice Exam 2025 – Comprehensive All-in-One Resource for Exam Excellence!

In patients with thalassemia, the production of hemoglobin A, which is the most common form of adult hemoglobin composed of two alpha and two beta chains, is typically abnormal. Thalassemia is a genetic blood disorder characterized by reduced or absent production of one of the globin chains that make up hemoglobin.

In cases of alpha thalassemia, there is a deficiency of alpha globin chains, while in beta thalassemia, there is a deficiency of beta globin chains. The abnormality in the production of these chains leads to an imbalance and results in the presence of hemoglobin variants or other forms of hemoglobin, but the hallmark of the disease is the diminished synthesis of hemoglobin A.

Patients with thalassemia often exhibit higher levels of fetal hemoglobin (hemoglobin F), which is composed of two alpha and two gamma chains, due to the compensatory response of the body to generate more of this form of hemoglobin where the beta chains are deficient. Therefore, while various forms of hemoglobin may be present, the primary abnormality remains with hemoglobin A, which is quintessential for diagnosing and understanding the disease’s pathophysiology.

The other types of hemoglobin listed can