TITLE: A family-based test for correlation between gene 
expression and trait values.

We present a stratified family expression association test 
(FEXAT) for detecting associations between messenger RNA 
transcript abundances (a.k.a. gene expression levels) and a 
quantitative trait in family-based studies. The FEXAT is a 
useful complement to the standard unstratified test based 
on Pearson’s correlation coefficient. Depending on the 
structure of trait-expression correlation, the standard 
test may find a significant correlation when none exists or 
fail to detect within-family correlation. We illustrate the 
utility of the FEXAT via simulation and an application to 
gene expression data from lymphoblastoid cell lines form 
four CEPH families. The FEXAT detected biologically 
plausible correlations between beta-catenin and genes in 
the WNT activation pathway which the standard test did not.

Kraft P, Schadt EE, Horvath S, 19 Nov 2002.