ENPP1 and hypophosphatemic rickets: This retrospective study is the largest to date of individuals with GACI with or without ARHR2 (N = 247), reporting the complications of GACI and hypophosphatemic rickets over a broad age range.(4, 7) The study found that the clinical spectrum for ENPP1 and ABCC6 deficiencies ranges from high risk of death before 6 months of age, to rickets later in childhood or osteomalacia in adulthood, with a potential for multiorgan involvement.