Genotype by sex interaction in measures of lipids, lipoproteins, and apolipoproteins.

Genotype by sex (GxS) interaction in a quantitative trait indicates that the sexual dimorphism exhibited in that trait is heritable. GxS interaction has implications for the modeling of traits in segregation analyses and for the assessment of disease risk in males and females. Thirteen quantitative measures of lipids, lipoproteins, and apolipoproteins from 203 to 301 individuals in 25 to 27 kindreds were examined for evidence of GxS interaction. These measures included serum concentrations of total cholesterol, triglycerides, LDL-C, HDL-C, apo B, and apo AI, and peak LDL particle diameter, small LDL mass, large LDL mass, IDL mass, VLDL mass, HDL3 mass, and HDL2 mass. GxS interaction was indicated for transformed values of LDL-C and small LDL mass by an additive genetic correlation between males and females significantly less than 1.0, and GxS interaction was indicated for transformed values of HDL3 mass and HDL2 mass by males and females having significantly different additive genetic variances.