This is a clinical trial of bone marrow transplantation for patients with the diagnosis of a genetic disease of blood cells that do not have an HLA-matched sibling donor. Genetic diseases of blood cell include: Red blood cell defects e.g. hemoglobinopathies (sickle cell disease and thalassemia), Blackfan-Diamond anemia and congenital or chronic hemolytic anemias; White blood cells defects/immune deficiencies e.g. chronic granulomatous disease, Wiskott-Aldrich syndrome,Osteopetrosis, Kostmann's syndrome (congenital neutropenia), Hereditary Lymphohistiocytosis (HLH); Platelets defects e.g.Congenital amegakaryocytic thrombocytopenia; Metabolic/storage disorders e.g. leukodystrophies,mucopolysaccharidoses as Hurler disease;Stem cell defects e.g.reticular agenesis, among many other rare similar conditions. The study treatment plan uses a new transplant treatment regimen that aims to try to decrease the acute toxicities and complications associated with the standard treatment plans and to improve outcome The blood stem cells will be derived from either unrelated donor or unrelated umbilical cord blood.