Chapter 2:

In this chapter, we illustrate in more depth the conceptual framework and motivation for Mendelian randomization, explaining how Mendelian randomization offers opportunities to address some of the problems of conventional epidemiology. We describe the specific characteristics of genetic data which give rise to the Mendelian randomization approach, and provide a classification of Mendelian randomization investigations.

Mendelian randomization has the potential to be a useful tool in a range of scientific contexts to investigate claims of causal relationships. When properly used, it gives insights into the underlying causal relationships between variables which are difficult to obtain reliably from other approaches.