Thalassemia refers to a group of genetic disorders of the erythrocytes that result in defective hemoglobins due to a disruption in the synthesis of globin chains. Differences are alpha and beta thalassemias, of which the latter are more frequent.
Depending on thalassemia, there is a gene mutation for the formation of alpha or beta globin chains. In the heterozygous presence (minor form) of a thalassemia, only minor hemolysis occurs and accordingly, there are hardly any complications. In homozygosity (major form), erythrocytes are increasingly degraded by the altered structure in the spleen, with the consequence of splenomegaly and a severe hemolytic anemia. The disease signs occur at the age of 6-24 months. The severe anemia requires systematic transfusions to maintain the Hb level in the range of 90-100 g / L and to allow normal physical activity.
The transfusion of red blood cell concentrates can lead to an iron overload. This results in an unfavorable prognosis (by the involvement of the heart) and a significant morbidity (by symptoms from the endocrine and the liver). Both alpha and beta thalassemia are autosomal recessive inherited. For the major forms, the combination of transfusions and chelators has been reported as a treatment strategy. Hematopoietic stem cell transplantation is the only curative procedure: very favorable results have been achieved in children with HLA-identical family members.