7. Linkage studies
In contrast to candidate gene studies we have seen significant developments in the area of genome-wide linkage and association studies since publication of our previous review [14]. Historically, linkage studies were the first technically feasible genome-wide studies of human hypertension. Linkage studies examine transmission of disease loci from parents to offspring, but modifications of this concept allowed studies complex traits in the form of affected sib-pair studies [76]. The latter is a powerful method of performing linkage studies with small family sizes, but there are practical issues in recruitment of families with a mobile adult population worldwide, although we have recently demonstrated that family-based recruitment is still possible [77].