ENPP1 and hypophosphatemia: ENPP1 mutations are associated with a generally severe phenotype of generalized arterial calcification of infancy; however, some patients may present with hypophosphatemia alone and its skeletal consequences in the absence of apparent arterial calcification.46, 47FAM20C mutations have been reported in Raine syndrome, though some have hypophosphatemia.48 Patients with FAM20C may have severe dental disease, intracerebral calcifications, and osteosclerosis of long bones.