New insights into idiopathic infantile arterial calcinosis. Three patient reports.

We describe the occurrence of idiopathic infantile arterial calcinosis in three newborn siblings. Unusual features in this disease include ultrasonographic prenatal diagnosis in the second two siblings and ultrastructural studies of the third patient that might shed light on the pathophysiologic characteristics of this disease. Ruthenium-red staining for proteoglycans showed a clearly abnormal structure for the granules in areas of calcification. The granules appeared disorganized, with loss of their normal honeycomb interconnections. They also varied in size and density. In addition, matrix vesicles that might serve as nucleation sites for crystalline calcium phosphate were observed in zones of calcification.