The British Genetics of Hypertension (BRIGHT) study is probably the best example for a linkage study into essential hypertension [11]. The consortium genotyped 2,010 affected sibling pairs drawn from 1599 severely hypertensive families, and completed a 10 cM genome-wide scan. Linkage analysis identified a principle locus on chromosome 6q, with a lod score of 3.21 that attained genome-wide significance (P = 0.042). Three further loci with lod scores higher than 1.57 (2q, 5q, and 9q) also showed genome-wide significance (P = 0.017) when assessed under a locus-counting analysis. Genes or functional genetic variants underlying the linkage peaks have still not been identified. The authors originally interpreted these results as evidence for an oligogenic element of human essential hypertension. However, insufficient marker density and insufficient sample size to detect genetic variants with small effects on blood pressure were thought to be limitations of the BRIGHT study. These limitations have recently been addressed by regenotyping hypertensive probands from the BRIGHT study as part of SNP based genome-wide association studies (GWAS) into common disease [78].