Abstract: Common human diseases like diabetes and hypertension have been demonstrated to possess an associated genetic component composed of numerous underlying genetic defects. Traditional positional cloning of genes which possess the mutations responsible for complex disease has been hindered by both the low statistical power each locus may afford, and by the technically-laborious nature of the positional cloning methodologies. Disclosed herein is a methodology for the rapid identification of the genes responsible for quantitative trait loci (QTL) comprised of comprehensive gene expression analysis in organs relevant to disease in combination with the positional mapping of known QTL, so as to quantitatively identify candidate genes. This aforementioned methodology was applied to a total of five tissues/organs derived from the spontaneously hypertensive rat (SHR), the stroke-prone variant of the SHR (SHR-SP) and control Wistar Kyoto rats (WKY).