different phenotypes associated with the same gene may be the endpoints of disease progression sharing a common mechanism that is regulated by the gene. For example, we observed that several well known aging genes, including Klotho, were associated with vasoocclusive complications of sickle cell anemia [139,140]. Based on this observation, we searched for common genes that simultaneously affect the overall severity of sickle cell anemia and aging in GWAS of sickle cell anemia phenotypes and exceptional longevity. Preliminary findings show that both traits are associated with the same several SNPs and these association would not be detected by studying the two traits alone [141]. It may be valuable to study different phenotypes not in a vacuum but transversely to increase the chance of identifying biologically important genes [142]. Tools developed to describe phenome-genome networks may be valuable to link phenotypes through common physiological mechanisms [143,144].
