In biochemistry, the process of glycosylation describes a series of enzymatic or chemical reactions in which carbohydrates are bound to proteins, lipids or other aglycons. The reaction product is called glycoside. If a carbohydrate is transferred to proteins, the reaction product is called glycoprotein or peptidoglycan. Glycosyl transferases are involved in the different reactions.
Mutations of the glycosylation lead to a disturbance of a glycosylation process in various hereditary diseases. Depending on the mutation, the substrate to be glycosylated or the glycosylating enzyme may be defective.
For example, a form of Marfan syndrome (Q87.4) is caused by a mutation in the fibrillin-1 gene (FBN1), which codes for cysteine-rich glycoprotein - fibrillin-1. The mutation leads to a defective glycosylation of fibrillin.
In the MUTYH-associated polyposis, for example, there is a mutation in the MUTYH gene (MYH gene) on chromosome 1p34.1. The MUTYH gene encodes a glycosylase that specifically repairs DNA damage.