MedGen

Congenital disorders of glycosylation, previously called carbohydrate-deficient glycoprotein syndromes (CDGSs), are caused by defects in mannose addition during N-linked oligosaccharide assembly. CDGs can be divided into 2 types, depending on whether they impair lipid-linked oligosaccharide (LLO) assembly and transfer (CDG I), or affect trimming of the protein-bound oligosaccharide or the addition of sugars to it (CDG II) (Orlean, 2000). CDG Ic is characterized by psychomotor retardation with delayed walking and speech, hypotonia, seizures, and sometimes protein-losing enteropathy. It is the second largest subtype of CDG (summary by Sun et al., 2005). For a discussion of the classification of CDGs, see CDG1A (212065). Freeze and Aebi (1999) reviewed CDG Ib (602579) and CDG Ic. [from OMIM]

CDGs, previously called carbohydrate-deficient glycoprotein syndromes, grew from hereditary multisystem disorders first recognized by Jaeken et al. (1980). The characteristic biochemical abnormality of CDGs is the hypoglycosylation of glycoproteins, which is routinely determined by isoelectric focusing of serum transferrin. Type I CDG comprises those disorders in which there is a defect in the assembly of lipid-linked oligosaccharides or their transfer onto nascent glycoproteins, whereas type II CDG comprises defects of trimming, elongation, and processing of protein-bound glycans. For a general discussion of CDGs, see CDG1A (212065). CDG1H is a severe form of CDG. The majority of patients have brain involvement, liver pathology, gastrointestinal symptoms, dysmorphism (including brachydactyly), eye involvement (especially cataract), and skin symptoms. Most patients die within the first year of life (summary by Marques-da-Silva et al., 2017). [from OMIM]

Being confined or restricted to a particular location. [from HPO]