Background: Allogeneic hematopoietic stem cell transplantation (ASCT) is a possible cure for many inherited disorders.
Methods: We report 20 years of experience in 71 patients. The disorders include 7 immunodeficiencies, 21 hematological disorders, 13 histiocytic disorders, 9 mucopolysaccharoidoses, 7 metachromatic leukodystrophies (MLD), 3 adrenoleukodystrophies (ALD), 2 adrenomyeloneuropathy (AMN), 6 patients with Gaucher's disease, 1 Sandhoff's disease, and 2 patients with aspartylglucosaminuria. Their median age was 4 (0-39) years. The donors were 29 HLA-identical related, 27 matched unrelated (MUD) and 15 HLA mismatches.
Results: In recipients of HLA-identical sibling grafts, none developed acute GVHD grades II-IV as against 22% in all others. The overall cumulative incidence of chronic GVHD was 17%. The 5-year survival rates were 93%, 84%, and 46% in recipients of grafts from HLA-identical siblings, MUD and HLA-mismatches, respectively. The overall 10-year survival rate was 69%. All of the surviving patients with immunodeficiencies and hemoglobinopathies are well. Four patients with Hurler's disease are also well, apart from skeletal problems. Five patients with Gaucher's disease are between 14 and 22 years after the transplant. Two infants with MLD deteriorated, a girl with the juvenile form has stable disease and one woman with the adult form has improved. Among four survivors with ALD/AMN, three are well and one has dementia. Two patients with aspartylglucosaminuria have stable disease.
Conclusion: In patients with inborn errors of metabolism, ASCT gives a high survival rate using HLA-matched donors. Beneficial effects are seen in those who are transplanted early.