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| = Motivation and Rationale = | | = Motivation and Rationale = |
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− | EPACTS is a software pipeline developed to perform various statistical tests for analysis of whole-genome / whole-exome sequencing data. The main motivation for using EPACTS is to use a consistent analysis framework for association analysis in the DIAGRAM consortium. In addition, for analysis of low frequency variants (minor allele frequency [MAF] < 5%), standard logistic regression Wald or likelihood ratio tests found in existing association software are conservative or anti-conservative respectively. We implemented two statistical tests recommended for analysis of low frequency variants: (1) logistic regresion-based score test and (2) Firth bias-corrected logistic regression [http://www.stat.duke.edu/~scs/Courses/Stat376/Papers/GibbsFieldEst/BiasReductionMLE.pdf (Firth, 1993)]. For analysis of common variants, any asyptotic logistic regression test has well-controlled type I error rates and asymptotically equivalent power. For simplicity and consistency, we propose the use of both score and Firth tests for testing all allele frequencies. | + | [[EPACTS|EPACTS]] is a software pipeline developed to perform various statistical tests for analysis of whole-genome / whole-exome sequencing data. The main motivation for using EPACTS is to use a consistent analysis framework for association analysis in the DIAGRAM consortium. In addition, for analysis of low frequency variants (minor allele frequency [MAF] < 5%), standard logistic regression Wald or likelihood ratio tests found in existing association software are conservative or anti-conservative respectively. We implemented two statistical tests recommended for analysis of low frequency variants: (1) logistic regresion-based score test and (2) Firth bias-corrected logistic regression [http://www.stat.duke.edu/~scs/Courses/Stat376/Papers/GibbsFieldEst/BiasReductionMLE.pdf (Firth, 1993)]. For analysis of common variants, any asyptotic logistic regression test has well-controlled type I error rates and asymptotically equivalent power. For simplicity and consistency, we propose the use of both score and Firth tests for testing all allele frequencies. |
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| = Outline of analysis protocol = | | = Outline of analysis protocol = |
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− | This is the analysis protocol for analysis of imputed DIAGRAM datasets using the EPACTS pipeline. We assume that your dataset has been imputed using [[Minimac|minimac]] or I[[IMPUTE2|mpute2]]. Starting with minimac or impute2 output: | + | This is an overview of the analysis protocol for analyzing imputed DIAGRAM datasets using the EPACTS pipeline. We assume that your dataset has been imputed using [[Minimac|minimac]] or I[[IMPUTE2|mpute2]]. Starting with minimac or impute2 output: |
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| + | #<ref>Download and install EPACTS</ref> |
| + | #Convert the minimac or impute2 output into VCF format |
| + | #Prepre PED file for phenotypes and covariates |
| + | #Run EPACTS association pipeline |
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| + | == 1. Download and install EPACTS == |
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| + | EPACTS is available for download [http://www.sph.umich.edu/csg/kang/epacts/download/index.html here]. |