Congenital disorders of N-glycosylation including diseases associated with O- as well as N-glycosylation defects.
The congenital disorders of N-glycosylation (CDG), a steadily increasing group of multi-systemic disorders, have severe clinical implications in infancy and early childhood. The various inborn errors responsible adversely affect N-glycosylation of lysosomal proteins because of either failing assembly of lipid-linked (LL) oligosaccharides (OS) in the endoplasmic reticulum, CDG Type I, or faulty processing of the asparagines (N)-linked OS in the ER and in the Golgi, CDG Type II. The overlap of phenotypes precludes specific clinical delineation. Isoelectric focusing (IEF) of plasma transferrin remains a valuable, albeit imperfect, screening tool. IEF of plasma ApoC-III protein, introduced O-glycosylation defects that delineated some new CDGs due to mutations of both N- and O-glycosylation. Only CDG-Ib is amenable to treatment with free mannose supplementation. Hence, early specific diagnosis of any one entity is crucial for genetic counseling and elective preventive measures.
Leroy
Jules G
JG
Department of Pediatrics, Ghent University School of Medicine and University, B-9000 Ghent, Belgium. leroy@ugent.be
D002239:Carbohydrate Metabolism, Inborn Errors / Q000175:diagnosis / Q000235:genetics* / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D006031:Glycosylation; D006056:Golgi Apparatus / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009844:Oligosaccharides / Q000378:metabolism*
D009844:Oligosaccharides