GWAS-based predictions can be further improved by returning to first principles and incorporating family history conditional on genotype at known loci (10,24). For instance, AUC from a [now out-dated (18)] list of 30 Crohn's loci is 0.71 (10), much higher than the 0.56 mentioned above for family history alone, but less than the AUC of 0.74 for family history and GWAS combined. Since collecting family history is an important part of standard medical assessment, and can contribute independent genetic information beyond GWAS variants, it seems sensible to incorporate it into genetic risk prediction.
