Using multiple genetic variants as instrumental variables for modifiable risk factors.

ABSTRACT: Mendelian randomisation analyses use genetic variants as instrumental variables (IVs) to estimate causal effects of modifiable risk factors on disease outcomes. Genetic variants typically explain a small proportion of the variability in risk factors; hence Mendelian randomisation analyses can require large sample sizes. However, an increasing number of genetic variants have been found to be robustly associated with disease-related outcomes in genome-wide association studies. Use of multiple instruments can improve the precision of IV estimates, and also permit examination of underlying IV assumptions. We discuss the use of multiple genetic variants in Mendelian randomisation analyses with continuous outcome variables where all relationships are assumed to be linear. We describe possible vi

SUBMITTER: Palmer TM 

PROVIDER: S-EPMC3917707 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature