Use of allele scores as instrumental variables for Mendelian randomization.

ABSTRACT:

Background

An allele score is a single variable summarizing multiple genetic variants associated with a risk factor. It is calculated as the total number of risk factor-increasing alleles for an individual (unweighted score), or the sum of weights for each allele corresponding to estimated genetic effect sizes (weighted score). An allele score can be used in a Mendelian randomization analysis to estimate the causal effect of the risk factor on an outcome.

Methods

Data were simulated to investigate the use of allele scores in Mendelian randomization where conventional instrumental variable techniques using multiple genetic variants demonstrate 'weak instrument' bias. The robustness of estimates using the allele score to misspecification (for example non-linearity, effect modi

SUBMITTER: Burgess S 

PROVIDER: S-EPMC3780999 | biostudies-literature | 2013 Aug

REPOSITORIES: biostudies-literature