MR GxE
Resources
Code (Language: R) Website Paper (Pub Date: 2018-11-20)
Other URLS: none
Method Contact: Jack Bowden ( J.Bowden2@exeter.ac.uk)
Entry Contact: Gibran Hemani ( g.hemani@bristol.ac.uk)
Context
Analysis Type: UVMR MVMR Network MR Bi-Directional MR Non-Linear
Input Data Types: Ind/Ind Ind/SS SS/Ind SS/SSfamily
Exposure Trait Types: Quantitative Binary Time to event
Outcome Trait Types: Quantitative Binary Time to event
Assumptions and Sources of Bias
| Source of Bias | Addressed |
|---|---|
| Weak instruments | ✗ |
| Winner’s curse | ✗ |
| Sample overlap | ✗ |
| Uncorrelated horizontal pleiotropy | ✓ |
| Correlated horizontal pleiotropy | ✓ |
| Ancestry differences in samples | ✗ |
| Residual confounding in GWAS | ✗ |
| Cross-trait assortative mating | ✗ |
| Index-event/conditioning on heritable trait | ✗ |
Description
MR using Gene-by-Environment interactions (MRGxE) is a framework capable of identifying and correcting for pleiotropic bias. If an instrument–covariate interaction induces variation in the association between a genetic instrument and exposure, it is possible to identify and correct for pleiotropic effects. The interpretation of MRGxE is similar to conventional summary MR approaches, with a particular advantage of MRGxE being the ability to assess the validity of an individual instrument.