thalassæmi

Thalassæmi, or thalassemia, is a group of inherited blood disorders caused by mutations that reduce or abolish the production of one of the hemoglobin (Hb) globin chains. The two main forms are alpha-thalassemia, due to mutations in the HBA1/HBA2 genes that lower α-globin synthesis, and beta-thalassemia, due to mutations in the HBB gene that limit β-globin production. The resulting imbalance in globin chain production leads to ineffective erythropoiesis and chronic hemolytic anemia. Thalassemias occur worldwide but are especially common in the Mediterranean, Middle East, Indian subcontinent, Southeast Asia, and parts of Africa.

Clinical features vary by type and severity. Individuals with mild thalassemia may be asymptomatic or have mild anemia, while more severe forms cause fatigue, pallor, and sometimes jaundice. Chronic anemia can stimulate bone marrow expansion, leading to skeletal deformities and facial changes. Splenomegaly is common, and iron overload from ongoing transfusions or increased intestinal absorption can cause organ damage. Regular medical care improves life expectancy, particularly for those with effective transfusion and chelation regimens.

Diagnosis typically starts with a complete blood count showing microcytic, hypochromic anemia. Iron studies help distinguish from iron deficiency. Hemoglobin analysis (electrophoresis or high-performance liquid chromatography) reveals characteristic patterns, such as elevated HbA2 and HbF in beta-thalassemia, and distinct profiles in alpha-thalassemia. Genetic testing confirms the specific mutations.

Management is supportive and tailored to severity. Beta-thalassemia major often requires lifelong red cell transfusions and iron chelation therapy to prevent iron overload; folic acid supplementation and careful infection control are common. In some cases, splenectomy, bone marrow or hematopoietic stem cell transplantation, and emerging gene therapies offer potential curative options. Prenatal and carrier screening, along with genetic counseling, are important for disease prevention.