- Hypertension, diabetes, and obesity are common diseases that are genetically expressed as complex traits. The clinical expression of these diseases, which run in families but have no clear pattern of inheritance, has been attributed to the interaction between multiple genes and the environment. Identifying the underlying genes, a crucial step in understanding the molecular pathogenesis of complex diseases, has had limited success so far, stressing the need for novel strategies to move this process forward. Innovative integrative genetic-genomic approaches have been proposed recently for the identification of new high-priority candidate genes. These strategies, which combine expression profiling with genetic linkage in different ways, may represent a breakthrough in the search for the genes involved in complex diseases.