Another explanation for apparent epistasis

Abstract

Epistasis occurs when the effect of a genetic variant on a trait is dependent on genotypes of other variants elsewhere in the genome. Hemani et al. recently reported the detection and replication of many instances of epistasis between pairs of variants influencing gene expression levels in humans1. Using whole-genome sequencing data from 450 individuals we strongly replicated many of the reported interactions but, in each case, a single third variant captured by our sequencing data could explain all of the apparent epistasis. Our results provide an alternative explanation for the apparent epistasis observed for gene expression in humans. There is a Reply to this Brief Communication Arising by Hemani, G. et al. Nature 514, http://dx.doi.org/10.1038/nature13692 (2014).