: When a gene affects multiple traits independently, potentially biasing the causal estimate.
MR uses genetic variants as "natural experiments" to determine if an exposure (like high blood pressure) truly causes a disease (like stroke), rather than just being associated with it. ⚖️ The Three Pillars of MR Validity Diseases - Mr Validity
: There are no common causes (confounders) shared between the genetic variants and the outcome. : When a gene affects multiple traits independently,
: Used to study the causal impact of alcohol, smoking, blood pressure, and cholesterol on various chronic diseases . ⚠️ Challenges to Validity Diseases - Mr Validity