Hypertension, an exceedingly common trait in most developed countries, imparts an increased risk of cardiovascular, cerebrovascular and renal diseases. Nevertheless, the primary determinants of elevated blood pressure in most patients are unknown. Recognizing that a sizable portion of variation in blood pressure is genetically determined, one line of research has focused on identifying genetic variants that contribute to the pathogenesis of hypertension. However, standard genetic linkage analysis using "hypertension" as a phenotype may lack power due to the multifactorial nature of the disorder. A way to overcome this challenge is to subdivide hypertensive subjects into more homogenous subgroups.