Mendelian randomization in family data

Mendelian randomization in family data

The phrase "mendelian randomization" has become associated with the use of genetic polymorphisms to uncover causal relationships between phenotypic variables. The statistical methods useful in mendelian randomization are known as instrumental variable techniques. We present an approach to instrumental variable estimation that is useful in family data and is robust to the use of weak instruments...

Running Head: Mendelian Randomization Using Genetic Information to Infer Causality in Observational Data: Mendelian Randomization

5. Mendelian randomization

Associations between modifiable exposures and disease seen in observational epidemiology are sometimes confounded and thus misleading, despite our best efforts to improve the design and analysis of studies. Mendelian randomization, the random assortment of genes from parents to offspring that occurs during gamete formation and conception provides one method for assessing the causal nature of so...

Pleiotropy-robust Mendelian randomization.

Background The potential of Mendelian randomization studies is rapidly expanding due to: (i) the growing power of genome-wide association study (GWAS) meta-analyses to detect genetic variants associated with several exposures; and (ii) the increasing availability of these genetic variants in large-scale surveys. However, without a proper biological understanding of the pleiotropic working of ge...

Missing data methods in Mendelian randomization studies with multiple instruments.

Mendelian randomization studies typically have low power. Where there are several valid candidate genetic instruments, precision can be gained by using all the instruments available. However, sporadically missing genetic data can offset this gain. The authors describe 4 Bayesian methods for imputing the missing data based on a missing-at-random assumption: multiple imputations, single nucleotid...