In the Open Targets Genetics Portal, what is the “credible set overlap”?

The credible is the set of genetic variants, selected by fine-mapping analyses, that have 95% probability of containing the causal variant for a given genetic signal (if the assumptions of the model are correct).

For studies with summary statistics in European populations, we apply fine-mapping and determine credible sets for independent signals.

These credible sets are used in two ways:

  • For colocalisation, only pairs of signals that have at least one overlapping variant in their credible sets are tested for coloc.
  • For L2G scoring, a number of predictive features are computed as an average across credible set variants, weighted by each variant’s posterior probability.