POLYMORPHISM OF APOLIPOPROTEIN-E .1. METHODOLOGICAL ASPECTS AND DIAGNOSIS OF HYPERLIPOPROTEINEMIA TYPE-III WITHOUT ULTRA-CENTRIFUGATION

Abstract

Two methods for phenotyping apolipiprotein E are compared. One is based on preparation of VLDL [very low density lipoprotein] by conventional ultracentrifugation, whereas the other uses heparin/Mg precipitation of VLDL. The same results were obtained by both methods. The group limits for the 3 different phenotypes Apo E-N, Apo E-ND and Apo E-D were slightly different by the 2 methods. Phenotype Apo E-D, the phenotype characterizing type III dyslipoproteinemia, is clearly definable by both methods. The precipitation-IEF [isoelectric focusing] method for Apo E phenotyping provides a simple tool for genetic and population genetic studies and for the routine diagnosis of hyperlipoproteinemia type III, based on the only specific marker known for this disease.