Addition of the seventh mannose to the N-glycan precursor by ALG9, inside the ER lumen Authored: Dall'Olio, GM, 2009-11-10 Edited: Jassal, B, 2009-11-10 Pubmed12030331 Pubmed15148656 Pubmed15945070 Pubmed16859551 Reactome Database ID Release 43446215 Reactome, http://www.reactome.org ReactomeREACT_22123 Reviewed: Gagneux, P, 2010-04-16 The seventh mannose is added to the N-glycan precursor. This reaction occurs in the ER lumen and uses dolichyl phosphate D-mannose as the mannose donor with ALG9 mediating the reaction. Defects in ALG9 are the cause of congenital disorder of glycosylation type 1L (CDG1L) (Frank CG et al, 2004; Weinstein M et al, 2005). For many years ALG9 has been thought to be involved in bipolar affective disorder (Baysal BE et al, 2002), but this hypothesis has been proven wrong (Baysal BE et al, 2006).