ENPP1 variants in patients with GACI and PXE expand the clinical and genetic heterogeneity of heritable disorders of ectopic calcification. oleh Douglas Ralph, Yvonne Nitschke, Michael A Levine, Matthew Caffet, Tamara Wurst, Amir Hossein Saeidian, Leila Youssefian, Hassan Vahidnezhad, Sharon F Terry, Frank Rutsch, Jouni Uitto, Qiaoli Li