![[feed]](/style/images/feed-icon-14x14.png){kind=icon}
|
PDF (Original article)
- Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
501kB | |
![[img]](http://edoc.mdc-berlin.de/style/images/fileicons/application_msword.png) |
MS Word (Supplementary Materials)
384kB |
| Item Type: | Article |
|---|---|
| Title: | Estimating and testing direct genetic effects in directed acyclic graphs using estimating equations |
| Creators Name: | Konigorski, S. and Wang, Y. and Cigsar, C. and Yilmaz, Y.E. |
| Abstract: | In genetic association studies, it is important to distinguish direct and indirect genetic effects in order to build truly functional models. For this purpose, we consider a directed acyclic graph setting with genetic variants, primary and intermediate phenotypes, and confounding factors. In order to make valid statistical inference on direct genetic effects on the primary phenotype, it is necessary to consider all potential effects in the graph, and we propose to use the estimating equations method with robust Huber-White sandwich standard errors. We evaluate the proposed causal inference based on estimating equations (CIEE) method and compare it with traditional multiple regression methods, the structural equation modeling method, and sequential G-estimation methods through a simulation study for the analysis of (completely observed) quantitative traits and time-to-event traits subject to censoring as primary phenotypes. The results show that CIEE provides valid estimators and inference by successfully removing the effect of intermediate phenotypes from the primary phenotype and is robust against measured and unmeasured confounding of the indirect effect through observed factors. All other methods except the sequential G-estimation method for quantitative traits fail in some scenarios where their test statistics yield inflated type I errors. In the analysis of the Genetic Analysis Workshop 19 dataset, we estimate and test genetic effects on blood pressure accounting for intermediate gene expression phenotypes. The results show that CIEE can identify genetic variants that would be missed by traditional regression analyses. CIEE is computationally fast, widely applicable to different fields, and available as an R package. |
| Keywords: | Causal Inference, Direct Effect, Directed Acyclic Graph, Estimating Equations, Genetic Association Study, Time-to-Event Phenotype |
| Source: | Genetic Epidemiology |
| ISSN: | 0741-0395 |
| Publisher: | Wiley-Blackwell |
| Volume: | 42 |
| Number: | 2 |
| Page Range: | 174-186 |
| Date: | March 2018 |
| Additional Information: | Copyright © 2017 The Authors. Genetic Epidemiology Published by Wiley Periodicals, Inc. |
| Official Publication: | https://doi.org/10.1002/gepi.22107 |
| PubMed: | View item in PubMed |
Repository Staff Only: item control page
Download Statistics
Download Statistics
