One obvious use of genotype imputation based analysis is to accelerate fine-mapping studies. Once an association signal has been identified and confirmed, genotype imputation can be used to evaluate the evidence for association at each of several nearby SNPs and help focus the search for potential causal variants. An example of the approach occurs in the fine-mapping study of Orho-Melander et al. (76). In order to fine-map an association signal linking SNPs in the glucokinase regulatory protein (GCKR) gene and triglyceride levels in blood, Orho-Melander examined evidence for association with genotyped and imputed SNPs in the region and showed that an imputed common missense variant in the GCKR gene was more strongly associated with triglyceride levels than any other nearby SNP, a result that was subsequently confirmed by direct genotyping (76).
