MR-GxE is an extension to TSLS that exploits gene-covariate interactions to test for correct for invalid instruments within a linear interaction model framework.
Requires a strong gene-environment interaction and the pleiotropic effect to be constant across covariate subgroups.
References
- Slichter D. Testing Instrument Validity and Identification with Invalid Instruments. http://wwwsole-joleorg/14436pdf 2014.
- Cho Y, Shin S-Y, Won S, Relton CL, Davey Smith G, Shin M-J. Alcohol intake and cardiovascular risk factors: A Mendelian randomisation study. Scientific Reports 2015;5:18422.
- Spiller W, Slichter D, Bowden J, Davey Smith G. Detecting and correcting for bias in Mendelian randomization analyses using Gene-by-Environment interactions. International Journal of Epidemiology 2018:dyy204-dyy204.