The thalassemias are a group of congenital anemias that have in common deficient (reduced or absent) synthesis of one or more of the globin subunits of the normal human hemoglobins .This results in excess production of the other chain which damages the red cell membrane and begins with cascade that ends with significant morbidity and mortality. They are inherited autosomal recessive disorders. The thalassemias are the commonest monogenic diseases in man. The main aim of presenting this paper is to quote various studies done in the clinical research of thalassemias.