Apolipoprotein E genotype epsilon 4/epsilon 2 in the STANISLAS Cohort Study--dominance of the epsilon 2 allele?

Apolipoprotein (apo) E has been discussed as a marker for cardiovascular risk, but information about lipid traits in healthy individuals having one of the rare apoE genotypes (epsilon 4/epsilon 2, epsilon 2/epsilon 2 or epsilon 4/epsilon 4) is scarce. Our work was designed to answer the following questions: 1. Are the allelic effects of epsilon 2 and epsilon 4 on lipid traits additive or dominant? 2. If there is additivity, do the allelic effects of epsilon 2 and epsilon 4 have the same magnitude? 3. Are the allelic effects neutralised in epsilon 4/ epsilon 2 individuals who are under the influence of both rare alleles? Allelic effects on apoB and apoE serum levels were codominant. Allelic models are thus not adequate to study the influence of apoE polymorphism on these traits. Allelic effects were additive for total cholesterol, LDL-C, HDL-C and apoAI, with epsilon 2 having a greater impact than epsilon 4. Serum levels differed significantly between epsilon 4/epsilon 2 and epsilon 3/epsilon 3 individuals only for apoE (p < 0.001) and for apoB (p < 0.05).