Development of a fluorometric microtiter plate-based enzyme assay for arylsulfatase B (MPS VI) using dried blood spots.

Mucopolysaccharidosis type VI or Maroteaux-Lamy syndrome is an autosomal recessive lysosomal storage disorder caused by deficiency of arylsulfatase B (ARS-B) enzyme activity. It results in mild to severe multi-organ system failure from accumulation of undigested glycosaminoglycans (GAGs); dermatan sulfate and chondroitin-4-sulfate. We have developed a single-step enzyme assay using a fluorescent substrate and dried blood spots to measure ARS-B activity to identify disease patients. This assay is robust, reproducible, specific and convenient to perform.