question: What are congenital disorders of glycosylation?
answer: Congenital disorders of glycosylation (CDG) are a growing group of inherited metabolic disorders where enzymatic defects in the formation or processing of glycolipids and/or glycoproteins lead to variety of different diseases.
  More than 100 rare human genetic disorders that result from deficiencies in the different glycosylation pathways are known today.	
  The patients have hundreds of misglycosylated products, which afflict a myriad of processes, including cell signaling, cell-cell interaction, and cell migration.