Outcome in six children with mucopolysaccharidosis type IH, Hurler syndrome, after haematopoietic stem cell transplantation (HSCT).
OBJECTIVE
To follow-up six children with severe mucopolysaccharidosis type IH, Hurler syndrome, who were treated before 24 months of age with haematopoietic stem cell transplantation.


METHODS
In Sweden, during the last 10-year period, six consecutive children born with severe mucopolysaccharidoses type IH have been successfully transplanted using matched unrelated donors between the ages of 11 and 24 months (mean age 18 months). Three children received intravenous enzyme replacement therapy once a week, from diagnosis until engraftment of their bone marrow.


RESULTS
Two children developed chimerism and a progressive increase in recipient cells and later received a successful re-transplantation. One to two years after transplantation the children demonstrated some developmental delays in cognitive function. Latterly this was followed by normalization. Orthopaedic operations on the spine and hips and carpal tunnel syndrome were still required following transplantation. Cardiac valve involvement remained progressive in the children.


CONCLUSIONS
The outcome of six children in this study confirms that early haematopoietic stem cell transplantation in mucopolysaccharidosis type I, Hurler syndrome, preserves an affected child's mental ability. Consequently, it is essential that clinical recognition and early diagnosis take place, providing an additional challenge to paediatricians treating this condition.
Malm
Gunilla
G
Department of Clinical Science, Intervention and Technology, Division of Paediatrics, Karolinska Institutet, Huddinge, Sweden. gunilla.malm@karolinska.se
Gustafsson
Britt
B
Berglund
Gunilla
G
Lindström
Maria
M
Naess
Karin
K
Borgström
Birgit
B
von Döbeln
Ulrika
U
Ringdén
Olle
O
D002648:Child; D002675:Child, Preschool; D046528:Chimerism; D003072:Cognition Disorders / Q000453:epidemiology / Q000517:prevention & control; D042241:Early Diagnosis; D005260:Female; D005838:Genotype; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006801:Humans; D006956:Hyperopia; D007223:Infant; D008297:Male; D008059:Mucopolysaccharidosis I / Q000175:diagnosis* / Q000235:genetics / Q000628:therapy*; D017354:Point Mutation / Q000235:genetics; D013548:Sweden; D013997:Time Factors