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Estimation of False Discovery Rates in Multiple Testing: Application to Gene Microarray Data
Author(s) -
Tsai ChenAn,
Hsueh Hueymiin,
Chen James J.
Publication year - 2003
Publication title -
biometrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.298
H-Index - 130
eISSN - 1541-0420
pISSN - 0006-341X
DOI - 10.1111/j.0006-341x.2003.00123.x
Subject(s) - false discovery rate , mathematics , multiple comparisons problem , statistics , hypergeometric distribution , statistical hypothesis testing , algorithm , biology , gene , genetics
Summary . Testing for significance with gene expression data from DNA microarray experiments involves simultaneous comparisons of hundreds or thousands of genes. If R denotes the number of rejections (declared significant genes) and V denotes the number of false rejections, then V / R , if R > 0 , is the proportion of false rejected hypotheses. This paper proposes a model for the distribution of the number of rejections and the conditional distribution of V given R , V | R . Under the independence assumption, the distribution of R is a convolution of two binomials and the distribution of V | R has a noncentral hypergeometric distribution. Under an equicorrelated model, the distributions are more complex and are also derived. Five false discovery rate probability error measures are considered: FDR = E( V / R ), p FDR = E( V / R | R > 0) (positive FDR), c FDR = E( V / R | R = r ) (conditional FDR), m FDR = E( V )/E( R ) (marginal FDR), and e FDR = E( V )/ r (empirical FDR). The p FDR, c FDR, and m FDR are shown to be equivalent under the Bayesian framework, in which the number of true null hypotheses is modeled as a random variable. We present a parametric and a bootstrap procedure to estimate the FDRs. Monte Carlo simulations were conducted to evaluate the performance of these two methods. The bootstrap procedure appears to perform reasonably well, even when the alternative hypotheses are correlated (ρ = .25) . An example from a toxicogenomic microarray experiment is presented for illustration.