The Use of Measured Genotype Information in the
Analysis of Quantitative Phenotypes in Man.
I. Models and Analytical Methods
Boerwinkle E; Chakraborty R; Sing CF
Department of Human Genetics, University of Michigan, Ann Arbor
48109-0015.
Annals of Human Genetics, 50(2):181-194 (May 1986)
Abstract
Improved laboratory methods allow one to investigate the contribution of
measured allelic variability at a locus physiologically involved in determining
the expression of a quantitative trait. We present statistical methods that
incorporate measured genotype information into the analysis of a
quantitative phenotype that allows one simultaneously to detect and estimate
the effects of a measured single locus and residual polygenic effects.
Likelihoods are presented for the joint distribution of the quantitative
phenotype and a measured genotype that are appropriate when the data are
collected as a sample of unrelated individuals or as a sample of nuclear
families. Application of this method to the analysis of serum cholesterol
levels and the concentration of the group specific component (Gc) are
presented. The analysis of the contribution of the common Gc
polymorphism to the determination of quantitative variability in Gc using
samples of related and unrelated individuals presents, for the first time, the
simultaneous estimation of the frequencies and the effects of the genotypes
at a measured locus, and the contribution of residual unmeasured polygenes
to phenotypic variability.
Variance component linkage analysis