RT Book, Section A1 Jaeken, Jaak A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 6727060 T1 Chapter 163. Congenital Disorders of Glycosylation T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=6727060 RD 2024/03/29 AB Glycosylation is an important posttranslational protein modification occurring in the cytoplasm, the endoplasmic reticulum, and the Golgi apparatus. A rapidly growing family of genetic diseases is due to defects in protein glycosylation (congenital disorders of glycosylation [CDG]). Most CDG are severe, multisystem diseases with important neurological involvement. Some 30 CDG have been identified. CDG due to an N-glycosylation defect (there are 18 disorders) comprise two groups: CDG-I (with absence of one or more glycans; CDG-Ia through CDG-IL) and CDG-II (with incomplete glycans; CDG-IIa through CDG-IIf). Six disorders have been identified in O-glycosylation, including some long-known diseases such as hereditary multiple exostoses; another six disorders have a combined N- and O-glycosylation defect. Important tools in the diagnosis are transferrin isoelectric focusing, analysis of lipid-linked oligosaccharides and of protein-linked glycans, and mutation analysis.