In addition to the gain in power, genotype imputation also produced a much denser and better localized map of eQTLs, as illustrated by the TIMM22 locus from the MRCA data set (Fig. 6). In this example, HapMap imputation produced minimal additional information, but the 1000G imputation increased the maximum –log10(P) from nine to 23 and allowed finer localization of the peak effect to the 3′ UTR of TIMM22.
