In 2008, NIH began the Undiagnosed Diseases Program to identify mysterious medical conditions that fit no known diagnosis.  Most undiagnosed diseases are rare to extremely rare, but recently the Program identified a new vascular disease it named “ACDC” (Arterial Calcification involving Cluster of Differentiation 73), arising from a mutated gene. Only nine unrelated people are known to have ACDC, but for them, the accumulation of calcium and eventual arterial blockage causes pain and risks amputations.  MORE