variants may offer several potential advantages by being robust to the effects of genetic heterogeneity or in reducing the total multiple testing burden in analysis. However, this approach is dependent on the quality of annotation of the pathways being investigated (which can be uncertain) and assumes that risk variation falls within genes. As mentioned in our description of GWAS studies for 37 human diseases, a large subset of identified genetic risk variation (43%) fell outside gene boundaries. Arguably the principal advantage of this approach is to establish additional information relating to function over and above the statistical SNP GWAS data. Implicating a molecular pathway in a disease process is likely to be more biologically informative than interpreting evidence of involvement of an anonymous genetic marker.
