Study of familial hypercholesterolemia (FH) has yielded information about the low-density lipoprotein (LDL) receptor pathway 1 and has had heuristic value in the understanding of the role of lipoproteins in human atherosclerosis.2 Treatment of FH by diet, drugs, plasmapheresis and portacaval shunt has resulted in mild to moderate reductions in total and LDL cholesterol concentrations in the plasma of these patients.2 However, patients with almost no residual LDL receptor function are less responsive to these therapies, and symptomatic atherosclerotic cardiovascular disease will progress.3 Continued atherogenesis is most likely due to the inability of therapy to normalize plasma lipoprotein levels. Because the LDL receptor abnormality present in skin fibroblasts in these patients was also found in homozygous FH hepatic membranes 4 and, more recently, in cultured FH hepatocytes, 5 we proposed that liver transplantation would be of benefit in this disease. The first use of liver transplantation to treat FH was with combined heart-liver transplantation, and as predicted, the plasma LDL cholesterol concentrations fell. 6 The present case is the second liver transplantation in FH to be reported.At age 18 months a yellowish xanthoma was first detected on the left ankle of patient V.P. Subsequent evaluation of blood cholesterol levels of the entire family was consistent with diagnosis of homozygous FH. At age 5 years, in addition to following a low-fat, low-cholesterol diet, he was started on a cholestyramine regimen of 3 packets twice daily, to which 500 mg nicotinic acid was added at age 9 years. Despite this treatment, the number and size of xanthomas progressed and the patient was referred to the National Institutes of Health for evaluation and treatment at age 11. Physical examination of the child was remarkable for diffuse, marked, yellow xanthomas on the elbows, hands, knees and buttocks, as well as Achilles tendon xanthomas. A 3/6 systolic ejection murmur at the cardiac base, bilateral 4/6 carotid artery bruits and 2/6 femoral artery bruits were noted. Over a 10-month period, the patient was sequentially treated with each of the following regimens for 2-month periods: cholestyramine, 12 g/ day; cholestyramine, 12 g/ day, + nicotinic acid, 3 g/ day; and cholestyramine, 12 g/ day, + nicotinic acid, 3 g/ day, + mevinolin, 40 mg/ day. Despite treatment, new-onset angina developed (characterized by exertional throat pain) and the patient had a right parietal cerebrovascular accident. Biweekly 3-liter plasma exchanges were instituted after the patient's neurologic recovery while arrangements for liver transplantation were undertaken. Liver transplantation was performed at the Children's Hospital of Pittsburgh on 6 November 1985. Subsequent cyclosporine (400 mg/day) and prednisone (10 mg/day) immunosuppression therapy has been successful in maintaining normal hepatic function.Patient V.P. clearly manifested the biochemical and genetic characteristics of homozygous FH (Table I). The total and LDL cholesterol levels were...