Research Techniques Made Simple: Using Genetic Variants for Randomization

J Invest Dermatol. 2019 Jul;139(7):1416-1421.e1. doi: 10.1016/j.jid.2019.03.1138.

Abstract

Observational epidemiological studies have identified associations between a number of modifiable exposures and outcomes, including in dermatology, such as between smoking and psoriasis. However, it is challenging to determine if such relationships are causal because of the potential of confounding and reverse causation. Mendelian randomization (MR) is a statistical method that can be used to investigate the causal relationships between an exposure and outcome by using a genetic instrument that proxies the exposure. The resulting estimate (under certain assumptions) can be interpreted as the causal estimate, free of confounding and reverse causation. In this review, we provide an overview of how to undertake an MR analysis, with examples from the dermatology literature. We also discuss the challenges and future directions of this method.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Dermatology / methods*
  • Disease Progression
  • Genetic Predisposition to Disease*
  • Genetic Variation*
  • Humans
  • Mendelian Randomization Analysis*
  • Models, Statistical
  • Observational Studies as Topic
  • Psoriasis / complications
  • Psoriasis / therapy
  • Research Design
  • Smoking / adverse effects
  • Tobacco Use Disorder / complications
  • Tobacco Use Disorder / therapy
  • Treatment Outcome