THURSDAY, January 31^st, 2008

Speaker:        Marc Coram (Assistant Professor of Biostatistics, Health Research and Policy, Stanford University)

Title:            Allele Frequency Estimation by Borrowing Strength across Populations

Abstract:        In genetic studies, allele frequency at a genetic marker is routinely inferred, often using genotypes from a small set of individuals.

Improving the accuracy of these estimates will benefit studies of human genetic variation or the genetic etiology of heritable traits.

Here, we propose an empirical Bayes approach for estimating allele frequencies at single nucleotide polymorphisms. This procedure adaptively incorporates genotypes from related samples, so that more similar samples have a greater influence on the estimates.

Applications of our method to data from recent genomic projects suggest that this empirical Bayes approach can substantially reduce the variability in the frequency estimates, while introducing little bias. Our method is particularly useful when small groups of individuals are genotyped at a large number of markers, a situation we are likely to encounter in a genome-wide association study.