as covariate effects, the effects of previously identified common variants, or other collapsed sets of rare variants - then the power to detect the association involving rare variants could increase substantially (Figure 1C). Not all analysis methods proposed for rare variant studies, however, can accommodate additional factors in their formulations and hence leverage conditioning effects. In addition, not all models can accommodate quantitative trait analysis unless the phenotype is broken into quantiles and stratified analysis is pursued (Table 2).
