Sample Reproducibility of Genetic Association Using Different Multimarker TDTs in Genome-Wide Association Studies: Characterization and a New Approach Abad Grau, María Del Mar Medina Medina, Nuria Montes Soldado, Rosa Ana Matesanz, Fuencisla Bafna, Vineet DNA recombination Data processing Disease susceptibility Genetic loci Haplotypes Reproducibility Simulation and modeling Variant genotypes Multimarker Transmission/Disequilibrium Tests (TDTs) are very robust association tests to population admixture and structure which may be used to identify susceptibility loci in genome-wide association studies. Multimarker TDTs using several markers may increase power by capturing high-degree associations. However, there is also a risk of spurious associations and power reduction due to the increase in degrees of freedom. In this study we show that associations found by tests built on simple null hypotheses are highly reproducible in a second independent data set regardless the number of markers. As a test exhibiting this feature to its maximum, we introduce the multimarker -Groups TDT (mTDT2G), a test which under the hypothesis of no linkage, asymptotically follows a ... distribution with ... degree of freedom regardless the number of markers. The statistic requires the division of parental haplotypes into two groups: disease susceptibility and disease protective haplotype groups. We assessed the test behavior by performing an extensive simulation study as well as a real-data study using several data sets of two complex diseases. We show that mTDT2G test is highly efficient and it achieves the highest power among all the tests used, even when the null hypothesis is tested in a second independent data set. Therefore, mTDT2G turns out to be a very promising multimarker TDT to perform genome-wide searches for disease susceptibility loci that may be used as a preprocessing step in the construction of more accurate genetic models to predict individual susceptibility to complex diseases. 2014-03-27T13:46:43Z 2014-03-27T13:46:43Z 2012 info:eu-repo/semantics/article Abad-Grau, M.M.; et al. Sample Reproducibility of Genetic Association Using Different Multimarker TDTs in Genome-Wide Association Studies: Characterization and a New Approach. Plos One, 7(2): e29613 (2012). [http://hdl.handle.net/10481/31140] 1932-6203 doi:10.1371/journal.pone.0029613 http://hdl.handle.net/10481/31140 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Public Library of Science (PLOS)