Polymorphism of apolipoprotein E. II. Genetics of hyperlipoproteinemia type III.

Apolipoprotein E from human serum shows a genetic polymorphism determined by two autosomal codominant alleles, Apo En and Apo Ed. Homozygosity for the gene Apo Ed (phenotype Apo E-D) results in primary dysbetalipoproteinemia, but only some individuals with this phenotype develop gross hyperlipidemia (hyperlipoproteinemia type III). Vertical transmission of dysbetalipoproteinemia represents pseudodominance due to the high frequency of the gene Apo Ed.

Polymorphism of apolipoprotein E. I. Methodological aspects and diagnosis of hyperlipoproteinemia type III without ultracentrifugation.

Two methods for phenotyping apolipoprotein E are compared. One is based on preparation of VLDL by conventional ultracentrifugation, whereas the other uses heparin/Mg precipitation of VLDG. In principle, the same results were obtained by both methods.

Studies on the metabolic defect in Broad-beta disease (hyperlipoproteinaemia type III).

The apoprotein composition of the main lipoprotein fractions (VLDL, LDL-1, LDL-2 and HDL) was studied initially in 15 patients with Broad-beta disease. Analytical isoelectric focusing of urea-soluble apo-VLDL and apo LSL-1 demonstrated a variant pattern of the polymorphic Apoprotein E with a deficient Apo E-III band in all patients. The Apo E-III deficiency pattern was seen in only six out of 304 hyperlipidaemic controls.

Prenatal diagnosis of homoxygous familial hypercholesterolemia: investigation of a case at risk.

Cultivated amnion cells obtained from a pregnancy at risk for the homozygous form of familial hypercholesterolemia were analyzed, as were fibroblasts from normal, heterozygous and homozygous controls. Three different methods were employed in order to compare their diagnostic value: i. Acetate incorporation into the cellular 3beta-OH-sterol fraction; ii.

Plasma lipoprotein abnormalities in a case of primary high-density lipoprotein (HDL) deficiency.

A 53-year-old patient with primary HDL-deficiency is reported. About 2% of the normal concentration of alpha1 HDL was present in his plasma. The alpha1-high-density-lipoproteins separated into two fast-moving components in polyacrylamide gel electrophoresis.

Isolation and partial characterization of an arginine-rich apolipoprotein from human plasma very-low-density lipoproteins: apolipoprotein E.

A water-insoluble apoprotein was isolated from apo-VLDL by column chromatography on Sephadex G-200 in sodium dodecylsulfate followed by preparative polyacrylamide gel electrophoresis in a discontinous sodium dodecylsulfate system, or by preparative electrophoresis alone. The protein was similar in amino acid composition to the "arginine-rich protein" reported by Shore and Shore. It represented about 10% of the total protein mass of VLDL.

Lipoproteins in lecithin-cholesterol-acyltransferase(LCAT)-deficiency. II. Further studies on the abnormal high-density-lipoproteins.

The lipoproteins from two sibs with familial lecithin-cholesterol-acyltransferase(LCAT)-deficiency were further characterized. Comparatively lipoproteins from patients with secondary LCAT-deficiency were studied. Both groups of patients had particles of unusual size and shape in the alpha1-(HD-2)-lipoprotein subfraction.