Which of the following is NOT true of thalassemias?

Thalassemias are a group of inherited blood disorders characterized by the reduced production of hemoglobin, leading to various degrees of anemia. The nature of thalassemias primarily results in microcytic, hypochromic anemia rather than macrocytic anemia. In thalassemia, the red blood cells are smaller (microcytic) and have less hemoglobin (hypochromic) than normal. This distinction is crucial because macrocytic anemia typically indicates a different underlying issue, such as vitamin B12 or folate deficiency.

The other statements reflect true characteristics of thalassemias. Elevated levels of fetal hemoglobin are observed in some forms of thalassemia, particularly in those where there is a defect in beta-globin production. Thalassemias are indeed caused by genetic mutations, specifically mutations in the genes that regulate hemoglobin production. Additionally, chronic hemolysis and ineffective erythropoiesis associated with thalassemia can lead to iron overload due to increased intestinal absorption of iron, especially as patients often receive multiple transfusions.

Understanding these specifics helps reinforce the core characteristics of thalassemias and accurately distinguishes them from other forms of anemia.