Pediatrics & Therapeutics
Open Access

Abstract

The Emerging Field of Diagnostics in Glycosylation Disorders

Wendy Heywood, Peter Clayton, Kevin Mills and Stephanie Grunewald

Protein glycosylation is an important post-translational modification. It enhances the functional diversity of proteins, half-life and influences their biological activity. Defective glycosylation often leads to multisystem disease and adds itself to the expanding group of ‘Congenital disorders or glycosylation’ which are predominantly disorders of N-linked glycosylation. Another rapidly growing group of disorders are defects in O-linked glycosylation, including a subset of dystroglycanopathies. Current diagnostic strategies for glycosylation disorders are compounded by the multivariate clinical phenotype of many of the diseases. Biochemical tests such as the isoelectric focusing of transferrin and apolipoprotein CIII are used to assess a patient’s glycoform profile before in depth enzyme and genetic analysis is initiated. Whilst the glycoform profiling has been instrumental in screening for many glycosylation disorders, there is a need for a more sensitive and informative test. This short review gives an overview of the recent methods used in glycobiology research that could be used to devise such a test, which alongside currently used diagnostic tests should further facilitate the delineation of CDG subtypes. It provides a view to a potential strategy using marker glycopeptides to develop a mass spectrometry based assay that could be implemented into clinical diagnostic laboratories.