A bone marrow transplant is a procedure that transplants healthy bone marrow into a patient whose bone marrow is not working properly. A bone marrow transplant may be done for several conditions including hereditary blood diseases, hereditary metabolic diseases, hereditary immune deficiencies, and various forms of cancer. The healthy bone marrow may be taken from the patient prior to chemotherapy or radiation treatment, or it may be taken from a donor. Bone marrow transplant may be recommended for bone marrow deficiency disease caused by abnormal red blood cell production, such as thalassemia or sickle cell disease, aggressive cancer treatments like chemotherapy and radiation therapy given for leukemia or lymphoma, lack of normal blood cell production, immune system disorders such as congenital neutropenia and severe combined immunodeficiency syndrome, specific forms of cancer like leukemia?s, lymphomas and myelomas. The risks for procedure are reactions to medications and problems breathing during anesthesia. Chemotherapy given prior to bone marrow transplant (conditioning) may cause significant toxicity, such as mouth sores, diarrhea, liver damage, or lung damage. While waiting for bone marrow to grow, the patient is at high risk for infection. The major problem with bone marrow transplants is when the marrow comes from a donor, not the patient is graft-versus-host disease. The transplanted healthy bone marrow cells may attack the patient's cells as though they were foreign organisms. In this case, drugs to suppress the immune system must be taken, but this also decreases the body's ability to fight infections. Bone marrow transplant lengthens the life of a patient who would otherwise die. Relatively normal activities can be resumed as soon as the patient feels well enough The hospitalization period is from 4 - 6 weeks, during which time the patient is isolated and under strict monitoring because of the increased risk of infection. The patient will require attentive follow-up care for 2 - 3 months after discharge from the hospital. It may take 6 months to a year for the immune system to fully recover from this procedure.