Thalassemia, the most common hemoglobinopathy, is a disorder in which the globin chain structure is normal but the amount of globin produced is decreased. Alpha and beta thalassemia are prevalent in Africa, Asia, and the Mediterranean region and are by far the most common types. Thalassemia is named for the globin chain that is decreased. In alpha thalassemias, alpha chain production is decreased. In beta thalassemias, beta chain production is decreased.
Most thalassemias result in microcytic hypochromic anemia. In addition, bone marrow RBC precursors are destroyed due to abnormal hemoglobins, resulting in ineffective erythropoiesis. This destruction also occurs in the peripheral blood, resulting in hemolytic anemia. The severity of the anemia is dependent on how severely globin chain production is decreased.
