MR-Base

MR-Base performs Mendelian randomization analyses by providing access to a curated GWAS summary-statistic repository and analytical methods to investigate causal relationships between genetic variants and phenotypes.

Key Features:

• Database Integration: Integrates a curated GWAS summary-statistic database containing 11 billion single nucleotide polymorphism-trait associations from 1677 GWAS without filtering by statistical significance.
• Analytical Capabilities: Supports 2-sample Mendelian randomization to estimate causal effects between phenotypes using genetic instruments and automates two-sample MR analyses.
• Sensitivity Analyses: Implements sensitivity analyses to assess horizontal pleiotropy and other potential violations of Mendelian randomization assumptions.

Scientific Applications:

• Phenome-wide causal scans: Enables phenome-wide scans to explore millions of potential causal associations across diverse phenotypes using GWAS summary statistics.
• Causal discovery and hypothesis testing: Supports novel causal analyses and hypothesis-driven investigations of exposure–outcome relationships.
• Replication and validation: Facilitates replication of causal findings across independent GWAS datasets.
• Risk factor and drug-target appraisal: Aids identification of risk factors and appraisal of potential drug targets using causal evidence from MR.

Methodology:

Implements 2-sample Mendelian randomization using genetic variants as instrumental variables and GWAS summary statistics, with sensitivity analyses for horizontal pleiotropy and without requiring individual-level data.