QCAT: testing causality of variants using only summary association statistics

Genome-wide and, very soon, sequencing association studies, might yield multiple regions harbouring interesting association signals. Given that each region encompasses numerous variants in high linkage disequilibrium, it is not clear which are i) truly causal or ii) just reasonably close to the causal ones. Researchers proposed many methods to predict, albeit not test, the causal SNPs in a region, a process commonly denoted as fine-mapping. Unfortunately, all existing fine-mapping methods output posterior causality probabilities assuming that causal SNPs are among those already measured in the study, or have been catalogued elsewhere. However, due to technological and computational obstacles