Hypophosphatemic Rickets, Autosomal Recessive, 2, also known as arhr2, is related to hypophosphatemic rickets, autosomal recessive, 1 and blood group, i system. An important gene associated with Hypophosphatemic Rickets, Autosomal Recessive, 2 is ENPP1 (Ectonucleotide Pyrophosphatase/Phosphodiesterase 1). Affiliated tissues include bone and kidney, and related phenotypes are carious teeth and hypophosphatemic rickets