Tel Aviv-Heidelberg three-generation offspring study: genetic determinants of apolipoprotein A1 and apolipoprotein B

The contribution of major gene and multifactorial effects on variation of plasma apolipoproteins A1 and B has been tested in a large sample of population-based Israeli pedigrees. Our most parsimonious and best fitting model for both apolipoproteins is consistent with Mendelian transmissibility, with significant contribution of major genes (with 2 alleles recessive and dominant within each locus) and polygenes, but neglects effects of common sib environment as well as related intergeneration differences in polygenic effects. Total genetic effects explain 71 and 58% of phenotypic variance of APO-A1 and APO-B levels. The major genes account for about 44 and 32% of the variance in APO-A1 and APO-B, respectively, and the frequency of the recessive alleles determining the high level of apolipoproteins under the study in the Israeli population is in the vicinity of 40% at each locus.