Inheritance of LDL peak particle diameter: Results from a segregation analysis in Israeli families

Genetic and environmental determinants of LDL peak particle diameter (LDL‐PPD) were investigated in a sample of 80 kindreds residing in kibbutz settlements in Israel. The sample included 182 males and 191 females ages 15–93 years. LDL‐PPD levels were first adjusted for variability in sex and age. Commingling analysis demonstrated that a mixture of two normal distributions fit the adjusted LDL‐PPD levels better than did a single normal distribution. Complex segregation analysis was first applied to these sex and age adjusted data but was not conclusive. However, when the regression model for sex and age allowed coefficients to be ousiotype (class) specific, the mixed environmental model was rejected while a major Mendelian model was not. These results suggest that the particular genotypes determined by the major gene, which are associated with different phenotypic variances, are likely to be more realistic, and that this analytic approach can contribute to improving our understanding of the genetics of LDL particle size. Genet. Epidemiol. 16:382–396, 1999. © 1999 Wiley‐Liss, Inc.