B4GALT7 encodes beta-1,4-galactosyltransferase 7, a Golgi transmembrane enzyme essential for proteoglycan biosynthesis 1. The protein catalyzes the critical step of linking glycosaminoglycans to core proteins via tetrasaccharide linker region formation in the extracellular matrix 23. B4GALT7 also participates in heparan sulfate biosynthesis by facilitating UDP-xylose-dependent modifications of heparan sulfate proteoglycans 4. Biallelic B4GALT7 mutations cause spondylodysplastic Ehlers-Danlos syndrome (spEDS-B4GALT7) and Larsen of La Réunion Island syndrome, autosomal recessive linkeropathies characterized by skeletal dysplasia, short stature, and joint hypermobility 531. Cardinal features include growth restriction, micromelia, forearm bone abnormalities, large joint dislocations, clubfeet, and characteristic facial dysmorphism 5. Ocular manifestations including corneal clouding, cataracts, and colobomas have been documented 6. Zebrafish models with partial B4galt7 loss demonstrate impaired cartilage development, reduced sulfated glycosaminoglycan levels, and skeletal deformities 1. Beyond inherited disease, B4GALT7 is highly expressed in hepatocellular carcinoma where it promotes tumor cell proliferation, migration, and invasion through Cdc2/CyclinB1 and miR-338-3p/MMP2 pathways, suggesting therapeutic targeting potential 2.