Mutations in GALNT3 cause the related diseases, familial tumoral calcinosis, which is characterized by hyperphosphatemia and ectopic calcifications around major joints, and hyperostosis-hyperphosphatemia syndrome, which is characterized by hyperphosphatemia and recurrent long bone lesions with hyperostosis [5,6,7,8]. The gene discussed is GALNT3; the disease is hyperphosphatemia.