Thalassemia

Thalassemia is an inherited disorder, characterized by abnormal hemoglobin. It is also known as Cooley’s
anemia or Mediterranean anemia. It is more common in Thailand and to some extent in Mediterranean
countries.Thalassemia is of two types:
i. α-thalassemia
ii. β-thalassemia.
The β-thalassemia is very common among these two.In normal hemoglobin, number of α and β polypeptide
chains is equal. In thalassemia, the production of these chains become imbalanced because of defective synthesis of globin genes. This causes the precipitation of the polypeptide chains in the immature RBCs, leading to disturbance in erythropoiesis. The precipitation also occurs in mature red cells, resulting in hemolysis.α-thalassemia occurs in fetal life or infancy. In this α-chains are less, absent or abnormal. In adults, β-chains are in excess and in children, γchains are in excess. This leads to defective erythropoiesis and hemolysis. The infants may be stillborn or may die immediately after birth.In β-thalassemia, βchains are less in number, absent or abnormal with an excess of αchains. The αchains precipi tate causing defective erythropoiesis and hemolysis.