Almost all of the proteins that are part of cell membranes or are secreted from cells are oligosaccarides. Deficiencies of the enzymes required to break down and recycle oligosaccharide cause a group of disorders called oligosaccharidoses (glycoprotein storage diseases). These disorders are variable in severity and symptoms but all are neurodegenerative, progressive and can involve many organ systems.

Examples of glycoprotein storage diseases are: mannosidoses (alpha and beta), fucosidosis, galactosialidosis, aspartylglucosaminuria, Schindler disease, mucolipidosis I, II, III.

This test is a screen and presumptive diagnoses need to be confirmed by enzyme assay.