ABSTRACT
In this chapter, we consider extensions to the basic Mendelian randomization paradigm. These include approaches with multiple exposure variables and those which aim to estimate a parameter other than that estimated in a standard Mendelian randomization investigation. We consider in turn multivariable Mendelian randomization, network Mendelian randomization, non-linear Mendelian randomization, factorial Mendelian randomization, bidirectional Mendelian randomization, and meta-analysis in Mendelian randomization.
