LocusFocus

LocusFocus performs colocalization analysis by integrating SNP-level GWAS associations with eQTL data to prioritize candidate genes and tissues underlying trait associations.

Key Features:

• Colocalization Analysis (Simple Sum): Implements the Simple Sum formal testing approach to assess colocalization between GWAS loci and eQTL signals.
• Integration of GWAS and eQTL data: Combines SNP-level association statistics from GWAS with eQTL datasets to link non-coding association signals to candidate genes and tissues.
• Robustness to LD and allelic heterogeneity: Applies a method effective in genomic regions with high linkage disequilibrium and allelic heterogeneity to improve identification of causal signals.
• Prioritization of genes and tissues: Produces hypotheses that prioritize specific genes and tissues likely responsible for observed trait associations.

Scientific Applications:

• Genetic epidemiology: Interprets GWAS findings by linking association signals to putative regulatory effects on gene expression in specific tissues.
• Functional follow-up prioritization: Guides selection of candidate genes and tissues for experimental validation and mechanistic studies.
• Gene-trait hypothesis generation: Generates testable hypotheses about molecular mechanisms underlying trait associations for downstream investigation.

Methodology:

The Simple Sum approach quantitatively assesses the likelihood of colocalization between GWAS signals and eQTLs and accounts for linkage disequilibrium and allelic heterogeneity.