ß-Thalassemia Major With Autologous CD34+ Hematopoietic Progenitor Cells Transduced With TNS9.3.55 a Lentiviral Vector Encoding the Normal Human ß-Globin Gene

The patient has inherited ß-thalassemia major through the genes. These genes have mistakes in them, so the body cannot make normal red blood cells. Stem cells are made in the bone marrow. They are the earliest form of blood cells. This study is being done to see if the investigators can make the stem cells produce normal red blood cells and hemoglobin. The investigators do this by collecting the stem cells. The genes with mistakes are removed from the cells. These cells are then treated so they have the corrected gene for making normal hemoglobin. These treated cells are given back to the patient through an injection (shot) in the vein. This is also known as gene transfer. In order for the body to accept these cells, the patient will need to receive a low dose of a drug called busulfan. It is a drug that will prepare the body to receive the new stem cells. This study will let the investigators know: * If it is safe to give the patient the treated stem cells * If the treated stem cells will go into the bone marrow without causing side effects. Gene transfer has been used for the past five years. It has been successful in treating many blood disorders. At least 20 patients have received the type of treatment that the patient will get on this study. This treatment for B-thalassemia major was developed at Memorial Sloan Kettering (MSK). It was studied for a long time in the lab before being given to patients.