Fig. 1

Workflow of the current Mendelian randomization (MR) study revealing causality from type 1 diabetes on PCOS. Assumption 1, genetic variants are robustly associated with exposure; Assumption 2, genetic variants are not associated with confounders; Assumption 3, genetic variants affect the outcomes only through the exposure of interest. SNPs, single nucleotide polymorphisms; LD, linkage disequilibrium; LOO, leave-one-out; MR-PRESSO, MR Pleiotropy RESidual Sum and Outlier