Gene Therapies for Transfusion-Dependent b-Thalassemia.

b-Thalassemia is one of the most prevalent monogenic diseases usually caused by quantitative defects in the production of b-globin, a component of adult hemoglobin (a2b2), leading to severe anemia. Technological advances in genome sequencing, stem cell selection, viral vector development, transduction and gene-editing strategies now allow for efficient ex-vivo genetic manipulation of human hematopoietic stem cells that can lead to a meaningful clinical benefit in thalassemia patients. In this perspective, the status of the gene-therapy approaches available for transfusion-dependent thalassemia and early results of clinical trials are discussed. It is highly anticipated that gene therapies will soon become a treatment option for patients lacking compatible donors for hematopoietic stem cell transplant and will offer a suitable alternative for definitive treatment of b-thalassemia, even in young children.