solute carrier family 35 member A2
The SLC35A2 gene provides instructions for making an enzyme called UDP-galactose translocator (UGT). This enzyme is involved in a process called glycosylation. During this process, complex chains of sugar molecules (oligosaccharides) are added to proteins and fats (lipids). Glycosylation modifies proteins and lipids so they can fully perform their functions. The UGT enzyme transfers a simple sugar called galactose to growing oligosaccharides at a particular step in the formation of the sugar chain. Once the correct number of sugar molecules are linked together, the oligosaccharide is attached to a protein or lipid.
Two versions of the enzyme, known as UGT1 and UGT2, are produced from the SLC35A2 gene. These enzymes differ in only a few protein building blocks (amino acids) and can function together or separately in different areas of the cell.
At least nine mutations in the SLC35A2 gene have been found to cause SLC35A2-congenital disorder of glycosylation (SLC35A2-CDG). SLC35A2-CDG is an inherited condition that causes neurological problems (such as seizures, developmental delay, and intellectual disability) and abnormalities affecting other body systems.
SLC35A2 gene mutations change single amino acids in the UGT enzyme or disrupt the way the gene's instructions are used to make the enzyme. These mutations can affect one or both versions of the enzyme and lead to the production of an abnormal enzyme with reduced or no activity. Without a properly functioning enzyme, glycosylation cannot proceed normally, and oligosaccharides are incomplete. The signs and symptoms of SLC35A2-CDG are likely due to impaired glycosylation of proteins and fats that are needed for the normal function of various organs and tissues.
In some individuals with SLC35A2-CDG, glycosylation becomes normal later in childhood. The cause of this apparent correction is unknown. The restoration of glycosylation in these individuals, however, does not seem to improve the signs and symptoms of SLC35A2-CDG.
- solute carrier family 35 (UDP-galactose transporter), member 2
- solute carrier family 35 (UDP-galactose transporter), member A2
- UDP-galactose translocator