A1126
Title: MR-MAGIC: Robust causal inference using many weak genetic interactions
Authors: BaoLuo Sun - National University of Singapore (Singapore) [presenting]
Zhonghua Liu - Columbia University (United States)
Di Zhang - National University of Singapore (Singapore)
Minhao Yao - University of Hong Kong (Hong Kong)
Abstract: Mendelian randomization (MR) studies commonly use genetic variants as instrumental variables to estimate the causal effects of exposures on outcomes. However, the presence of invalid instruments - even when numerous - can lead to biased causal estimates. A novel identification strategy is proposed that remains valid even when all candidate instruments are invalid by leveraging genetic interactions that collectively explain substantial exposure variation. Recognizing that individual interaction effects may be weak, MR-MAGIC (Mendelian randomization with many weak genetic interactions for causality) is developed, a robust method that simultaneously addresses instrument invalidity and improves estimation efficiency under a many-weak-interactions asymptotic framework.
