The study addressed seven phenotypes, all derived from fasting blood samples: total cholesterol, total triglyceride, LDL-cholesterol, HDL-cholesterol, VLDL-cholesterol, uric acid, and glucose levels. The data had already been collected at Lipid Research Clinics in Cincinnati, Iowa, Oklahoma, Minneapolis, and Stanford. Univariate and bivariate segregation analysis were conducted on the mode of inheritance of familial combined hyperlipidemia and familial primary hypoalphalipoproteinemia. Path analysis was used to resolve cultural and biological inheritance for each phenotype within each clinic and for resolution of population heterogeneity among the five Lipid Research Clinics. A general bivariate path model was used to analyze the associations among the various phenotypes. General models were used to analyze temporal trends in family resemblance for the seven phenotypes.