Mucopolysaccharidoses: A biochemical study under limited resources

The mucopolysaccharidoses are a heterogeneous group of lysosomal storage disorders caused by deficiencies of enzymes involved in degradation of glycosaminoglycans. This study aimed to share our experience with biochemical investigations of these disorders under resource-limited conditions. Harmine extract was obtained from Peganum harmala seeds, and chromatography plates were homemade. Biochemical analysis involved urinary tests, including the Berry Spot test, the quantification of the glycosaminoglycans, as well as their characterization, and the analysis of deficient enzymes. The reference range values of glycosaminoglycans and activities of seven lysosomal enzymes, six of which are associated with these disorders were initially determined in samples of healthy subjects. The assay for β-galactosidase was described. These biochemical markers were then, evaluated in 29 patients, including 23 who were suspected of having different types of mucopolysaccharidoses and six who were diagnosed with the type I and undergoing enzymotherapy. The reference values of glycosaminoglycans and enzymes activities align with those reported in the literature. The reference value of β-galactosidase ranges from 83 to 311 nmol/17 h/mg. All the studied patients have shown the same positive pattern of Berry Spot Test in contrast of the healthy subjects. The level of GAGs was elevated by 1.1 to more than six fold but is decreased by more than six fold in patients with mucopolysaccharidosis type 1 undergoing enzymotherapy. The patients were categorized as follows: Hurler syndrome 34 %, Hunter syndrome 7 %, Sanfilippo syndrome 17 %, and Morquio syndrome 41 %. In patients for whom molecular defects were characterized, the mutations were correlated with the biochemical markers.