Related Experiment Video
Updated: Jun 25, 2026

Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques
Published on: July 5, 2018
IGF system in children with congenital disorders of glycosylation
Bradley S Miller1, M Javad Khosravi, Marc C Patterson
1Division of Pediatric Endocrinology, Mayo Clinic, Rochester, MN 55905, USA.
Objective:
The function of IGF system components is affected by their glycosylation status in vitro. However, little is known about the role of glycosylation status of these components in vivo. In this study we determined the impact of glycosylation on the endocrine IGF system in children with the rare syndrome of congenital disorders of glycosylation (CDG).
Design:
Analyses of serum samples from children with CDG and healthy controls.
Patients:
Children with CDG (N = 12) were recruited as part of a separate clinical study of mannose therapy at the Mayo Clinic. Serum from control children (N = 11) were obtained as routine samples before discard.
Measurements:
Levels and glycosylation state of components of the IGF system and ability to form physiologically relevant ternary complexes composed of IGF, IGFBP-3, and an acid-labile subunit (ALS).
Results:
Serum levels of IGF-1, IGF-2, ALS, and IGFBP-3 were reduced (P < 0.05) in children with CDG when compared to controls. Immunoblot analysis showed incomplete glycosylation of ALS and IGFBP-3 and impaired ternary complex formation in CDG. Partial normalization of ALS and IGFBP-3 glycosylation was associated with improvement in linear growth in a child with CDG-Ib during initiation of oral mannose therapy.
Conclusions:
Inadequate glycosylation of IGFBP-3 and ALS has a negative effect on the function of these proteins in vivo. This study provides the first evidence in humans for the importance of glycosylation on components of the IGF system.
Related Concept Videos
Proteoglycans
Inborn Errors of Metabolism
Glucose Transporters
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Oligosaccharide Assembly
Multiple sugar molecules that may or may...
Protein Glycosylation
Glycosylation occurs in...
Lysosomal Hydrolases