|Accounting for winner's curse and pleiotropy in two-sample Mendelian randomization
|9:00 am - 10:00 am
|Zoom Meeting (please refer to seminar PDF)
|Dr. Chong Wu
Mendelian randomization (MR) studies use genetic variants associated with modiﬁable exposures as instrumental variables to assess their possible causal relationship with outcomes in observational studies. In recent years, the number of published two-sample MR studies has increased rapidly, partially due to the increasing availability of large-scale genome-wide association studies (GWAS) summary data. These two-sample MR studies often employ the same sample to select relevant genetic variants and construct ﬁnal causal estimates, leading to biased causal eﬀect estimates due to the winner’s curse phenomenon. On the other hand, the validity of MR analyses critically depends on instrumental variable assumptions, which often be violated in applications due to widespread pleiotropic eﬀects. Also, there are maybe unknown sample overlaps between the two GWAS summary datasets due to the current trends of collecting biobank datasets.