common variants with allelic odds ratios of the order of 1.5–1.7 [The Wellcome Trust Case Control Consortium, 2007]. The study identified many novel genetic associations, the majority of which have now been replicated in independent samples from the same and/or different populations [Frayling et al., 2007; Parkes et al., 2007; Samani et al., 2007; Todd et al., 2007; Zeggini et al., 2007]. However, these studies have also highlighted the fact that many loci of more modest effect (allelic odds ratios below 1.5) remain undetected.
