Familial hypercholesterolemia: mechanism of inheritance.

We have studied a large family of 95 members with a defect in the metabolism of cholesterol, which is transmitted through three generations. The following characteristics of the family support the classification of the disorder as familial hypercholesterolemia : hypercholesterolemia, increased levels of phospholipids an beta-lipoproteins, normal values of triglycerides, pre-beta-lipoproteins and blood sugar, xanthomas, xanthelasmas, corneal arcus and early appearance of ischemic heart disease. Segregation analyses of the hypercholesterolemia and the findings of a bimodal distribution of total plasma cholesterol in the family suggest a monogenic autosomal dominant mechanism of transmission of this lipid disorder.