Regimen B for Fanconi Anemia

This study proposes the use of a reduced intensity chemotherapy/radiation therapy regimen followed by stem cell transplantation, as compared to standard ablative chemotherapy regimens associated with stem cell transplantation, in a population of patients with non-malignant diseases (non-cancer). Eligible patients will have a non-malignant disease in one of the following four strata: bone marrow failure syndromes, immunodeficiencies, inborn errors of metabolism, or histiocytoses. Patients will be assigned to therapy according to diagnosis. Patients will be stratified by disease into one of four strata and treatment regimens will be based on specific disease criteria and conditions. Although these diseases are non-malignant in name, they are often malignant by nature of the disease progression, treatment and associated complications.