[Congenital hemolytic anemia--hemoglobin abnormality--thalassemia]

Thalassemias are a group of genetic disorders caused by unbalanced synthesis of alpha- and non-alpha chains of globins due to impaired globin genes. Clinical characteristics of the thalassemias are ineffective erythropoiesis and hemolytic anemia with microcytic-hypochromic erythrocytes. Surplus polypeptide chain synthesized by normal globin gene causes harmful effects to skeleton proteins of erythrocyte membrane, such as spectrin, ankirin and 4.1 protein, via a few different ways and normal integrity of membrane is disturbed. Basic mechanism of pathophysiology of thalassemias have been made clear but many problems remain to be overcame in clinical practice. Several methodological improvements in diagnosis have been coming out using DNA amplification technique and applied to prenatal diagnosis and mass-screening of thalassemias. In therapeutic methods, little improvement has been observed for last decade since introduction of bone marrow transplantation.