FGF23 and osteogenesis imperfecta: Dysregulation of sclerostin has since been implicated in osteoporosis, osteogenesis imperfecta, vascular calcification and breast cancer while other osteocytic genes play functional roles in the pathogenesis of conditions such as hypophosphataemic rickets (DMP1, PHEX, FGF23), chronic kidney disease (FGF23) and tumor-induced osteomalacia (FGF23) (3).