| Abstract: | A general linear model was described for multifactorial inheritance of the two plasma lipids, total cholesterol (CH), and triglyceride (TG). Analyses of two separate studies, the Honolulu Heart Study (HHS) and the Cincinnati Lipid Research Clinic (LRC), indicated some heterogeneity. Whereas the sibling environmental effect (b) was the only source of heterogeneity between the two studies for TG, the correlation between marital environments (u) may also be considered as a source of heterogeneity for CH. Under parsimonious hypothesis, intergenerational differences in heritabilities were not found to be significant for either trait (y1 = y2 = z1 = z2 = 1). Maternal effects were significant for CH but not for TG. Correlations between marital environments (u1 and u2) were not significant for TG, and may be considered nonsignificant for CH also under parsimonious hypotheses. In any case, the genetic (h2) and cultural (c2) heritabilities cannot be considered to be heterogeneous between the two studies. Based on pooled data, parsimonious hypothesis yields: h2 = .594 +/- .041 and c2 = .035 +/- .008 for CH, and h2 = .259 +/- .034 and c2 = .108 +/- .014 for TG. |
