Leukodystrophy and bone marrow transplantation: Role of mixed hematopoietic chimerism

Bone Marrow Transplantation (BMT) is currently the most physiologic treatment for some types of leukodystrophies. In enzyme deficiency states, replacement of defective genes with cells carrying "normal'' copies of these genes offers a natural form of gene therapy. This review will cover the various disease states which may be treated using bone marrow transplantation as well as the obstacles and advantages offered by this treatment modality. The potential for mixed hematopoietic chimerism, with reference to the advantages and disadvantages of treating various leukodystrophies, is reviewed. Finally, certain approaches which would reduce the morbidity and mortality associated with conventional BMT are discussed. If these obstacles can be overcome, BMT may offer the hope of cure to a number, but certainly not all, leukodystrophies.