Glycosylation is the most common postranslational modification. Defects in this pathway lead to autosomal recessive disorders, called congenital disorders of glycosylation (CDG). Up to date about 50 CDGs have been identified and more are expected to be discovered. This category of metabolic disorders can be divided into four basic groups depending on where the glycosylation process occurs on the molecule. The depicts pathway depicts the group of N-glycosylation. Generally, N-glycosylation processes spread over three cellular compartments - cytosol, endoplasmic reticulum and Golgi apparatus. The associated mortality rate in combination with the limited treatment options for CDG, points out the relevance for further investigations of this pathway. Disorders resulting from an enzyme defect are highlighted in pink. This pathway was inspired by Chapter 30 of the book of Blau (ISBN 3642403360 (978-3642403361)).