Contributor: Gordon K. Klintworth
The term thalassemia includes a variety of inherited disorders of hemoglobin synthesis in which the alpha or beta chain of the normal hemoglobin A tetramer is defective. Depending on which chain of hemoglobin is defective the thalassemia syndromes are divided into the alpha- thalassemias [thalassemia - alpha] and beta-thalassemias [thalassemia - beta]. Regardless of the type affected persons develop a hypochromic, microcytic anemia [anemia - hypochromic, microcytic], poikilocytosis the presence of basophilic stippling of the erythrocytes because of a reduced or absent synthesis of hemoglobin. The condition was first recognized in person living on the Italian or Greek coasts of the Mediteranean sea, but has now been identified in numerous populations. Thalassemia is common in regions where malaria was endemic and in these places the gene frequency is high (~15%).