Increased fucosylation and reduced branching of serum glycoprotein N-glycans in all known subtypes of congenital disorder of glycosylation I.
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 alpha-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.
Callewaert
Nico
N
Department of Molecular Biomedical Research, Ghent University and Flanders Interuniversity Institute for Biotechnology, K.l.-ledeganckstraat 35, B-9000 Ghent, Belgium.
Schollen
Els
E
Vanhecke
Annelies
A
Jaeken
Jaak
J
Matthijs
Gert
G
Contreras
Roland
R
D000328:Adult; D002239:Carbohydrate Metabolism, Inborn Errors / Q000097:blood / Q000378:metabolism*; D005643:Fucose / Q000737:chemistry / Q000378:metabolism*; D006023:Glycoproteins / Q000097:blood / Q000737:chemistry / Q000378:metabolism*; D006026:Glycoside Hydrolases; D006031:Glycosylation; D006801:Humans; D007525:Isoelectric Focusing; D008103:Liver Cirrhosis / Q000097:blood / Q000378:metabolism; D009439:Neuraminidase; D009844:Oligosaccharides / Q000032:analysis; D017875:Phosphotransferases (Phosphomutases) / Q000172:deficiency*; D011134:Polysaccharides / Q000032:analysis / Q000097:blood; D017422:Sequence Analysis, DNA; D014168:Transferrin / Q000032:analysis / Q000378:metabolism
D006023:Glycoproteins; D009844:Oligosaccharides; D011134:Polysaccharides; D014168:Transferrin; C025469:asialooligosaccharides; D005643:Fucose; D006026:Glycoside Hydrolases; D009439:Neuraminidase; D017875:Phosphotransferases (Phosphomutases); C052799:phosphomannomutase