Hematopoietic stem cell transplantation for mucopolysaccharidoses and leukodystrophies.

The only effective treatment for selected metabolic diseases is a successful allogeneic hematopoietic stem cell transplantation (HCT). Best results with HCT are obtained when performed early in the course of the disease. Hence, timely identification and referral are critical. Also, early identification of affected patients during the newborn period via screening may be invaluable, particularly for the infantile onset rapidly progressive forms of diseases. Rapid availability of a donor graft is often crucial for these patients. Preliminary experience suggests that results after umbilical cord blood (UCB) transplant may be comparable to those after marrow transplants. UCB grafts have certain benefits of rapid availability and even reduced risk of GvHD. Hence, UCB transplant represents an alternative to marrow HCT. Related haploidentical HCT, possibly with very high doses of CD34+ cells, may also represent an option. However, expertise has been developed in very few transplant centers and no large reports are available of its use for patients with inherited metabolic diseases.