Affiliations: Monique and Jacques Roboh Department of Genetic
Research, Hadassah-Hebrew University Medical Center, Jerusalem, Israel | Department of Genetic and Metabolic Diseases,
Hadassah- Hebrew University Medical Center, Jerusalem, Israel
Note: [] Corresponding author: Ann Saada (Reisch), Department of Genetic
and Metabolic Diseases, Hadassah Medical Center, POB 12000, Jerusalem 91120,
Israel. Tel.: +972 2 6776844; Fax: +972 2 6 779018; E-mail:
[email protected]
Abstract: Mucopolysaccharidoses (MPS) are a heterogeneous group of inherited
lysosomal storage disorders (LSDs), due to impaired breakdown of
glycosaminoglycans (GAGs), resulting from dysfunctional lysosomal acid
hydrolases. Determination of urinary GAG content is a first-line screening
assay for MPS. We modified and evaluated a quantitative colorimetric method
based on 1,9 Dimethyl-Methylene Blue (DMB) and were able to identify seven new
pediatric cases of MPS within a year and subsequently confirmed them by
enzymatic analysis. In addition, three cases with borderline urinary GAG
content were subsequently diagnosed with other LSDs. We monitored a child with
MPS III (Sanfilippo) type C treated with genistein at a dose of 5 mg/kg/day for
over a year and we found no change in urine GAG content. In conclusion: the
modified DMB colorimetric method is an, accurate and convenient method for
measuring urinary GAGs content and facilitates the diagnosis and monitoring of MPS.
