Loss of GTs: dwarfism and skeletal abnormalities with chondrocyte hypertrophy and disrupted matrix organization in growth plate cartilageEhlers Danlos syndrome chondrodysplasialoss of GALNT3: increased bone mass, hyperphosphataemia and extra-skeletal calcificationelevated GALNT-driven glycosylation of lectins: OA and RAaccumulation of O-GlcNAc-modified proteins: hypertrophy, osteophyte formation, secretion of pro-inflammatory cytokines and matrix-degrading metalloproteinases. Here, GALNT3 is linked to hyperphosphatemia.