ENPP1 and pseudoxanthoma elasticum (inherited or acquired): Genetic study of 3 patients with PXE phenotypes disclosed biallelic mutations in ENPP 1 gene which is responsible for GACI and on the other hand mutation screening of 28 patients with GACI showed ABCC 6 gene in 14 of them.62 Those overlaps shows that GACI and PXE are not two independent entities and actually they are two borders of calcification scope.63