Follow-up of nine patients with Hurler syndrome after bone marrow transplantation.

We report our experience in nine patients with Hurler syndrome (six with a severe and three with an intermediate phenotype) who successfully engrafted after bone marrow transplantation. The donor was a human leukocyte antigen-identical sibling in six cases, the human leukocyte antigen-identical father in one case, and an unrelated donor in two cases. One patient with Hurler syndrome and an intermediate phenotype received two successive grafts from the same donor. There was a beneficial effect of bone marrow transplantation on visceral features (hepatosplenomegaly, obstruction of the upper airway, and coarse facies); however, dysostosis multiplex worsened. All patients but one required surgery for carpal tunnel syndrome. Visual acuity was low because of corneal clouding, and two patients had glaucoma several years after the graft. Five patients had normal hearing before the graft that remained normal, and four had hearing impairment that improved. All patients had learning difficulties, but none had severe mental retardation (IQ ranging from 75 to 103). The follow-up of patients with severe Hurler syndrome engrafted for more than 10 years emphasizes the limits and benefits of bone marrow transplantation.