(Xyl)1 (Ser)1 Gal-Xyl-proteins Galactose is the second sugar added in the tetrasaccharide linker Authored: Jassal, B, 2011-11-01 Beta-1,4-galactosyltransferase 7 (B4GALT7) adds galactose to beta-xyloside in a beta-1,4 linkage creating the second addition to the tetrasaccharide linker, the precursor required for glycosaminoglycan synthesis (Almeida et al. 1999). Defects in B4GALT7 cause Ehlers-Danlos syndrome progeroid type (EDSP) (MIM:130070) (Okajima et al. 1999). EC Number: 2.4.1.133 Edited: Jassal, B, 2011-11-01 Pubmed10473568 Pubmed10506123 Reactome Database ID Release 431889981 Reactome, http://www.reactome.org ReactomeREACT_121136 Reviewed: D'Eustachio, P, 2012-03-28