Thalassemia: Molecular Bases, Recent Advances in Diagnosis and Treatment Challenges

Thalassemia is a genetic disease whose main characteristic is the reduced presence or complete absence of one of the globin subunits, mainly α and β. α-thalassemia is a genetic inheritance of autosomal recessive trait, characterized by a hypochromic, microcytic anemia. The molecular basis is characterized by deletions and point mutations, which affect the expression of α genes. Whereas β-thalassemia is caused by mutations that result in a quantitative decrease of structurally normal β globin chains, and most mutations, unlike in α-thalassemia, are non-deletive. Non-deletion mutations reduce β-globin gene expression through almost all stages of gene expression, like transcription, RNA processing, and translation of β-globin mRNA. Thus, the objective of this chapter was to present recent information about the molecular basis of α- and β-thalassemia. Furthermore, the diagnostic methods used in the identification of thalassemias such as the morphological analysis of red blood cells, hematimetric indices, evaluation of serum iron and ferritin, and the investigation of the patient's hemoglobin through alkaline pH hemoglobin electrophoresis and molecular tests were listed. Finally, a few clinical studies on gene therapy, allogeneic stem cell transplantation, and intrauterine transfusions related to the treatment of α and β thalassemias were mentioned.