Assessing Genetic Linkage and Association with Robust
Components of Variance Approaches
Amos CI; Zhu DK; Boerwinkle E
Department of Epidemiology, University of Texas, M.D.
Anderson Cancer Center, Houston 77030, USA.
Annals of Human Genetics, 60(2):143-160 (1996)
Abstract
Simulation studies are used to explore the properties of procedures for estimating
components of variance and constructing test statistics in genetic linkage studies
of quantitative traits. We evaluated the bias and median squared error of
estimates of the linked additive genetic variance obtained by regression,
maximum likelihood and quasilikelihood estimation procedures. The
quasilikelihood and regression procedures provided unbiased estimates of the
additive component of variance. Maximum likelihood procedures that assumed
multivariate normality were biased for most sample sizes considered but had
more precision for most generating models than regression or quasilikelihood
methods did. Wald tests derived from quasilikelihood procedures had similar or
greater power than Wald tests based upon estimators from maximum likelihood
analyses. Quasilikelihood estimation may therefore be preferable whenever there
is uncertainty about the generating distribution for the error variance, but the
robustness of this approach is offset by its required computational complexity.
Variance component linkage analysis