Asparagine Linked Glycosylation Protein 6 (ALG6)

ALG6 encodes a member of the ALG6/ALG8 glucosyltransferase family. The encoded protein catalyzes the addition of the first glucose residue to the growing lipid-linked oligosaccharide precursor of N-linked glycosylation. Mutations in this gene are associated with congenital disorders of glycosylation type Ic.

Defects in ALG6 are the cause of congenital disorder of glycosylation type 1C (CDG1C) ; also known as carbohydrate-deficient glycoprotein syndrome type V. CDGs are metabolic deficiencies in glycoprotein biosynthesis that usually cause severe mental and psychomotor retardation. They are characterized by under-glycosylated serum glycoproteins. CDG1C patients have muscular hypotonia, show a delayed statomotor development and are mentally retarded.