A small number of eQTLs are detectable in all three datasets tested. A proportion of these common eQTLs demonstrated strong effect sizes, such as SNPs associated with Type 1 diabetes on chromosome 12 (Barrett et al., 2009, Burton et al., 2007, Cooper et al., 2008, Hakonarson et al., 2008, Todd et al., 2007) or associated with smoking behavior on chromosome 19 (Furberg et al., 2010). We have therefore demonstrated that coincident eQTLs exist between blood and brain tissues and therefore discrete eQTLs are found in more than one human primary tissue as previously suggested (Bullaughey et al., 2009, Ding et al., 2010, Greenawalt et al., 2011).
