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Inclusion of biological knowledge in a Bayesian shrinkage model for joint estimation of SNP effects.
journal contributionposted on 2019-03-04, 10:03 authored by M Pereira, JR Thompson, CX Weichenberger, DC Thomas, C Minelli
With the aim of improving detection of novel single-nucleotide polymorphisms (SNPs) in genetic association studies, we propose a method of including prior biological information in a Bayesian shrinkage model that jointly estimates SNP effects. We assume that the SNP effects follow a normal distribution centered at zero with variance controlled by a shrinkage hyperparameter. We use biological information to define the amount of shrinkage applied on the SNP effects distribution, so that the effects of SNPs with more biological support are less shrunk toward zero, thus being more likely detected. The performance of the method was tested in a simulation study (1,000 datasets, 500 subjects with ∼200 SNPs in 10 linkage disequilibrium (LD) blocks) using a continuous and a binary outcome. It was further tested in an empirical example on body mass index (continuous) and overweight (binary) in a dataset of 1,829 subjects and 2,614 SNPs from 30 blocks. Biological knowledge was retrieved using the bioinformatics tool Dintor, which queried various databases. The joint Bayesian model with inclusion of prior information outperformed the standard analysis: in the simulation study, the mean ranking of the true LD block was 2.8 for the Bayesian model versus 3.6 for the standard analysis of individual SNPs; in the empirical example, the mean ranking of the six true blocks was 8.5 versus 9.3 in the standard analysis. These results suggest that our method is more powerful than the standard analysis. We expect its performance to improve further as more biological information about SNPs becomes available.
This work was carried out as part of a PhD project funded by the National Heart and Lung Institute (NHLI) foundation. D.C.T. has grant support from the NIH grants P01 CA196569, R01 ES019876, P30 ES07048, and P30 CA014089.
CitationGenetic Epidemiology, 2017, 41 (4), pp. 320-331
Author affiliation/Organisation/COLLEGE OF LIFE SCIENCES/School of Medicine/Department of Health Sciences
- AM (Accepted Manuscript)
Published inGenetic Epidemiology
PublisherWiley for International Genetic Epidemiology Society (IGES)
NotesAdditional Supporting Information may be found online in the supporting information tab for this article.