All thalassemias increase RBC lifespan.

The statement that all thalassemias increase RBC lifespan is false. Thalassemias are a group of inherited hemoglobin disorders characterized by reduced or absent synthesis of one or more globin chains. This imbalance in globin chain production leads to accumulation of unpaired chains, which precipitate within developing red blood cells and cause membrane damage. The result is ineffective erythropoiesis — many red cell precursors are destroyed within the bone marrow before they are ever released — as well as hemolysis of those cells that do enter the circulation. Consequently, thalassemia consistently decreases RBC lifespan rather than increasing it. In beta-thalassemia major, red cell survival can be dramatically shortened, contributing to severe hemolytic anemia that requires regular transfusions. In alpha-thalassemia, excess beta chains form unstable tetramers that also damage red cells. The degree of hemolysis varies with the severity of the thalassemia subtype, but in no form of thalassemia does RBC lifespan increase. Students sometimes confuse thalassemia with conditions where compensatory mechanisms improve red cell production, but compensation through extramedullary hematopoiesis does not extend the lifespan of individual cells. Recognizing that thalassemia causes hemolytic anemia is key to understanding its clinical presentation of pallor, splenomegaly, and jaundice.