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

Genetic and environmental determinants of LDL peak particle diameter (LDL-P PD) were investigated in a sample of 80 kindreds residing in kibbutz settle ments in Israel. The sample included 182 males and 191 females ages 15-93 y ears. LDL-PPD levels were first adjusted for variability in sex and age. Co mmingling analysis demonstrated that a mixture of two normal distributions fit the adjusted LDL-PPD levels better than did a single normal distributio n. Complex segregation analysis was first applied to these sex and age adju sted data but was not conclusive. However, when the regression model for se x and age allowed coefficients to be ousiotype (class) specific, the mixed environmental model was rejected while a major Mendelian model was not. The se results suggest that the particular genotypes determined by the major ge ne, which are associated with different phenotypic variances, are likely to be more realistic, and that this analytic approach can contribute to impro ving our understanding of the genetics of LDL particle size. Genet. Epidemi ol. 16:382-396, 1999. (C) 1999 Wiley-Liss, Inc.