Familial study on the "double pre-beta lipoproteinemia" and on a polymorphic pattern of apolipoprotein E (EIV "variant" pattern) from human very low density lipoproteins (VLDL).

The familial aggregation of the "double pre-beta lipoproteinemia" (double-PBL) and of a "variant" pattern of the apolipoprotein E (EIV) from human very low density lipoproteins (VLDL) was investigated. Although double-PBL does not discriminate between blood relatives (BR) and controls (C), the former can be clearly distinguished from the latter as they have significantly higher VLDL-TG/TG and Apo-E/C-peptide ratios, implying that the proportion of "remnant" particles is significantly higher in the BR than in the C. Family subjects carrying apolipoprotein E enriched particles as the BR with the double-PBL phenomenon, exhibit significantly higher serum and LDL cholesterol levels as compared to C subjects with "single pre-beta lipoproteinemia" (single-PBL). The familial distribution of the apo-EIV "variant" pattern suggests an autosomal dominant transmission. The significantly higher prevalence of the double-PBL phenomenon in the group of EIV positive (+) as compared to the EIV negative (-) subjects suggests, but does not prove, that these two factors are possibly causally related. The clinical importance of such a finding, which seems to be substantiated in the light of recent experimental observations, is discussed.