QTLs (quantitative trait loci) are genetic regions associated with quantitative traits. The most widely studied molecular trait is gene expression, corresponding to expression QTLs (eQTLs). We perform eQTL studies and integrate eQTL data with other genetic, molecular and phenotypic data, e.g. from genome-wide association studies (GWAS).

Analyses are facilitated by our public, web-based tool Qtlizer, which is based on the, to-date, most comprehensive database of published eQTLs. Using Qtlizer we also perform comparative assessments for QTL data.

Figure: A SNP is an eQTL if it is associated with an allelic difference in mRNA levels of a gene. (Right) For an eQTL gene under investigation, a corresponding eQTL SNP occurs on the top of a peak in a regional association plot, i.e. has a low association p-value compared to other SNPs nearby.