Serum lipids, lipoproteins and apolipoprotein E phenotypes in relatives of patients with type III hyperlipoproteinaemia

Abstract

Relatives (86) of 19 probands with type-III hyperlipoproteinemia were studied to determine the occurrence of hyperlipidemia and to investigate the relation between apo E phenotypes, the occurrence of hyperlipidemia, and the composition of the very-low-density-lipoprotein (VLDL) fraction. Relatives (39) were hyperlipidemic: 4 type IIa or IIb, 9 type III and 26 type IV. The prediposition for hyperlipidemia was independent of the apo E phenotype. Hyperlipidemic relatives with apo E phenotype E2/2 had a significantly (P < 0.01) higher VLDL-cholesterol/VLDL-triglycerides ratio (1.26 .+-. 0.35, n = 9) than those heterozygous for apo E allele .epsilon.2 (0.66 .+-. 0.12, n = 23) or without apo E allele .epsilon.2 (0.69 .+-. 0.11, n = 7). Normolipidemic homozygous apo E-2 relatives also had a significantly (P < 0.05) higher ratio (0.97 .+-. 0.19, n = 6) than those heterozygous for (0.77 .+-. 0.19, n = 31) or without the apo E allele .epsilon.2 (0.74 .+-. 0.13, n = 10). Both hyper- and normolipidemic apo E2 homozygotes have higher concentrations of VLDL remnants than the subjects heterozygous or without allele .epsilon.2.