Diagnosis

Analysis of urinary glycosaminoglycans (heparan sulfate and dermatan sulfate) was the earliest method available for diagnosis of MPS I and remains useful as a preliminary investigative test. However, definitive diagnosis can now be established by enzyme assays using fluorogenic substrates specific for alpha-L-iduronidase.^{[1, 2, 3, 4]} Cultured fibroblasts, leukocytes, or plasma are generally used, the choice of which depends on the preference of the testing laboratory.

Accurate testing is critical to ascertain the diagnosis, as I-cell disease and MPS II exhibit clinical features similar to those of MPS I.

For more information about laboratories in Belgium where testing for deficient alpha-L-iduronidase activity or urinary GAG’s can be performed, see LSD specialized laboratories in Belgium

References

1. Hall, C.W., Liebaers, I., Di Natale, P., and Neufeld, E.F. (1978) Enzymatic diagnosis of the genetic mucopolysaccharide storage disorders. Methods Enzymol 50: 439.

2. Kresse, H., von Figura, K., Klein, U., Glossl, J., Paschke, E., and Pohlmann R. (1982) Enzymatic diagnosis of the genetic mucopolysaccharide storage disorders. Methods Enzymol 83: 559.

3. Neufeld, E.F., and Muenzer, J. (1995) The mucopolysaccharidoses. In: The Metabolic and Molecular Bases of Inherited Disease. Scriver, C.R., Beaudet, A.L., Sly, W.S. and Valle, D. (eds.). 7th edition. McGraw-Hill, Medical Publishing Division, pp. 2465.

4. Neufeld, E.F., and Muenzer, J. (2001) The mucopolysaccharidoses. In: The Metabolic and Molecular Bases of Inherited Disease. Scriver, C.R., Beaudet, A.L., Sly, W.S., Valle, D., Childs, B., Kinzler, K.W., and Vogelstein, B. (eds.). 8th edition, Vol. III. McGraw-Hill, Medical Publishing Division, pp. 3421.