FAMILIAL HYPERCHOLESTEROLEMIA-LIKE SYNDROME WITH APOLIPOPROTEIN E-7 ASSOCIATED WITH MARKED ACHILLES-TENDON XANTHOMAS AND CORONARY-ARTERY DISEASE - A REPORT OF 2 CASES

We observed two patients with hypercholesterolaemia and tendon xanthom as associated with apolipoprotein (apoE-7) E-7, a rare variant of the apoE isoforms. Both suffered from coronary artery disease and had unde rgone a coronary bypass operation. Their cholesterol levels were 268 a nd 310 mg dl(-1), respectively. Both patients had marked xanthomas in the Achilles tendons. Both also suffered from diabetes. Although their clinical and laboratory findings were compatible with typical familia l hyper cholesterolaemia (FH), the analysis of low-density lipoprotein (LDL) receptors in cultured fibroblasts showed no abnormality of bind ing, internalization or degradation of I-125-LDL. Diabetic control wit h a low-calorie, low-fat diet led to the rapid reduction of serum chol esterol. Other family members of the patients with apoE-7, who were no rmoglycaemic, showed normal cholesterol levels and no xanthomas. These findings suggest that coexistent diabetes mellitus may induce overt h yperlipidaemia and accumulation of lipids in tissues in subjects with apoE7.