Single cell expression quantitative trait loci and complex traits

The recently developed ability to quantify mRNA abundance and noise in single cells has allowed the effect of heritable variations on gene function to be re-evaluated. A recent study has shown that major sources of variation are masked when gene expression is averaged over many cells. Heritable variations that determine single-cell expression phenotypes may exert a regulatory function in specific cellular processes underlying disease. Masked effects on gene expression should therefore be modeled, not ignored.