The frequent coexistence of familial xanthomatosis and coronary heart disease has been well established. 1-7 There have been, however, relatively few reports of the pathologic findings in such patients, 1,2,5,6,8,9 and in only two reports 1,9 were the histologic findings reported in any detail. To our knowledge, necropsy studies of affected siblings have not been previously reported. The current findings relate to a sister and brother who died in their teens and belonged to a family previously studied by Curtis and co-workers 10,11 and Wilkinson and associates. 12 This family has been recently reexamined 13 ; the sister died in the interval between the two studies; the brother, during the course of the present survey. Both parents, although hypercholesteremic, are living and healthy. Four of their other children had died suddenly, presumably of xanthomatous heart disease; of the surviving twelve children, seven have hypercholesteremia without xanthomatosis and are clinically healthy. Clinical History and Necropsy Findings of Two Patients Case 1.—The first patient, the sister, was