A common genetic mechanism determines plasma apolipoprotein B levels and dense LDL subfraction distribution in familial combined hyperlipidemia

It appears that a major gene with pleiotropic effects on LDL particle size and apolipoprotein B (apoB) levels may be the gene behind familial combined hyperlipidemia (FCH) in 40 studied families. The families were well-defined FCH families. FCH involves a common genetic mechanism that determines plasma apolipoprotein B levels and the dense LDL subfraction distribution. FCH is a common lipid disorder characterized by elevations of plasma cholesterol and/or triglyceride in first-degree relatives. A predominance of small, dense LDL particles and elevated apoB levels is found often in members of FCH families. A bivariate genetic analysis has been carried out to evaluate the hypothesis that there is a common genetic mechanism for elevation of apoB levels and predominance of small, dense LDL particles in FCH.