Increased fucosylation and reduced branching of serum glycoprotein N-glycans in all known subtypes of congenital disorder of glycosylation I

• Published in: Glycobiology (Oxford) Vol. 13; no. 5; pp. 367 - 375
• Main Authors: Callewaert, Nico, Schollen, Els, Vanhecke, Annelies, Jaeken, Jaak, Matthijs, Gert, Contreras, Roland
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01.05.2003; Oxford Publishing Limited (England)
• Subjects: 6-pyrenetrisulfonic acid; 8-amino-1; Adult; APTS; asparagine-linked glycosylation; Carbohydrate Metabolism, Inborn Errors - blood; Carbohydrate Metabolism, Inborn Errors - metabolism; CDG; congenital disorder of glycosylation; congenital disorders of glycosylation; DNA sequencer; EDTA; ethylenediaminetetra-acetate; Fucose - chemistry; Fucose - metabolism; glycopathology; Glycoproteins; Glycoproteins - blood; Glycoproteins - chemistry; Glycoproteins - metabolism; Glycoside Hydrolases; Glycosylation; Humans; IEF; Isoelectric Focusing; Liver Cirrhosis - blood; Liver Cirrhosis - metabolism; N-glycan structure; N-glycosylation; Neuraminidase; Oligosaccharides - analysis; phosphomannomutase; Phosphotransferases (Phosphomutases) - deficiency; PMM; Polysaccharides - analysis; Polysaccharides - blood; Sequence Analysis, DNA; Transferrin - analysis; Transferrin - metabolism
• ISSN: 0959-6658; 1460-2423; 1460-2423
• DOI: 10.1093/glycob/cwg040

The N-glycans present on the total mixture of serum glycoproteins (serum N-glycome) were analyzed in 24 subjects with congenital disorder of glycosylation type I (CDG-I) and 7 healthy, age-matched individuals. No new N-glycan structures were observed in the sera of CDG-I patients as compared with normal sera. However, we observed in all subtypes a significantly increased degree of core α-1,6-fucosylation of the biantennary glycans as compared to normal, as well as a significant decrease in the amount of triantennary glycans. These serum N-glycome changes appear to be a milder manifestation of some of the changes observed in adult liver cirrhosis patients, which is compatible with the reported steatosis and fibrosis in CDG-I patients. In the CDG-Ia subgroup, the extent of the serum N-glycome changes correlates with the aberration of the serum transferrin isoelectric focusing pattern, which measures the severity of the lack of entire N-glycan chains (primary consequence of CDG-I) in the liver and is the standard diagnostic test for this category of inherited diseases.