Visual attention in children with Morquio syndrome

inhibited in Idua−/− recipients, and there is a similar engraftment defect in Idua−/− recipients under non-myeloablative conditioning regimens. Idua−/− bone marrow HS is present in significant excess, particularly in extracellular matrix, cell surface and golgi, with significant increases in 2-O-, 6-Oand N-sulphation. Finally we show that excess HS, and particularly HS rich in 2-O-sulphate modifications, which is the most prevalent modification in MPS IH, functionally inhibits haematopoietic cell migration. Conclusion: These data provide novel insight into the mechanism behind historical graft failure after HSCT in MPS I and identify a functional role for highly sulphated HS in inhibiting CXCL12 mediated haematopoietic cell migration in the Idua−/− mouse model of MPS I.