Dolichyl pyrophosphate Man9GlcNAc2 alpha-1,3-glucosyltransferase is an enzyme that in humans is encoded by the ALG6 gene.

This gene 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.