Bone marrow transplantation reverses metabolic alterations in multiple sulfatase deficiency: a case series.

Background: Multiple sulfatase deficiency (MSD) is an exceptionally rare neurodegenerative disorder due to the absence or deficiency of 17 known cellular sulfatases. The activation of all these cellular sulfatases is dependent on the presence of the formylglycine-generating enzyme, which is encoded by the SUMF1 gene. Disease-causing homozygous or compound heterozygous variants in SUMF1 result in MSD. Other than symptomatic treatment, no curative therapy exists as of yet for MSD. Eight out of these 17 sulfatases are primarily localized in the lysosome.

Methods: Two siblings with attenuated MSD underwent hematopoietic cell transplantation (HCT), evaluating the possibility of lysosomal enzymatic cross-correction from the donor cells.

Results: There is evidence of correction of currently available biomarkers within 3 months post-HCT. Untargeted metabolomics also shows continued correction of multiple biochemical abnormalities in the post-HCT period. Furthermore, this article also presents the neuropsychological outcomes of these children as well as the results of untargeted metabolomics analysis in this condition.

Conclusions: These data suggest biochemical benefits post-transplant along with slowing of disease progression. Long-term follow-up is necessary to fully evaluate the therapeutic benefit of HCT in MSD.