Generalization of the extended transmission disequilibrium test to two unlinked disease loci

Abstract

The extended transmission disequilibrium test (ETDT) of Sham and Curtis [1995] is a powerful test of the null hypothesis of no linkage between a multi-allelic marker locus and a disease susceptibility locus of unknown location in the presence of association between alleles at the two loci. We propose a generalization of the ETDT to test simultaneously for linkage of markers to two unlinked disease loci. Analysis of the simulated data for Problem 2 would suggest improvements in power to detect linkage to pairs of disease loci over single locus tests. This is as a result of the two locus model taking account of epistasis between the disease loci.