Idiopathic arterial calcification of infancy with unusual clinical presentations in sisters.

Two cases of idiopathic arterial calcification of infancy that occurred in sisters are reported. One patient died at age 14 months after a protracted course characterized by the nephrotic syndrome, blood chemistry abnormalities, hypertension, seizures, and a microangiopathic hemolytic anemia. Her sister died at age 3 weeks after a precipitous illness that initially was misinterpreted at autopsy as Reye's syndrome.