Dolichyl-P-Man:Man(5)GlcNAc(2)-PP-dolichyl mannosyltransferase is an enzyme that in humans is encoded by the ALG3gene.
This gene encodes a member of the ALG3 family. The encoded protein catalyses the addition of the first dol-P-Man derived mannose in an alpha 1,3 linkage to Man5GlcNAc2-PP-Dol. Defects in this gene have been associated with congenital disorder of glycosylation type Id (CDG-Id) characterized by abnormal N-glycosylation.
Denecke J, Kranz C, Kemming D et al. (2004). "An activated 5' cryptic splice site in the human ALG3 gene generates a premature termination codon insensitive to nonsense-mediated mRNA decay in a new case of congenital disorder of glycosylation type Id (CDG-Id).". Hum. Mutat.23 (5): 477–86. doi:10.1002/humu.20026. PMID15108280.