LDL RECEPTOR STUDIES IN CHILDREN WITH HETEROZYGOUS FAMILIAL HYPERCHOLESTEROLEMIA (FH): MEASUREMENT OF STEROL SYNTHESIS IN BLOOD LYMPHOCYTES

Abstract

Sterol synthesis was measured in lymphocytes from 48 members of 10 families with familial hypercholesterolemia (FH) under 3 sets of conditions. The synthesis of LDL [low density lipoprotein] receptors and sterols was maximally stimulated by incubation of lymphocytes in lipoprotein-deficient serum. Sterol synthesis was suppressed by the addition of LDL and was maximally suppressed by the addition of 7-ketocholesterol. In 5 of the 10 families, LDL suppression of sterol synthesis in FH heterozygotes was only about half of the LDL suppression in normals. In 4 families, there was a considerable overlapping of LDL suppression in FH heterozygotes and normals. In 1 family, LDL suppression was strictly normal in FH heterozygotes who appeared to have a different type of FH not involving an impaired LDL receptor function.