The study was renewed several times, the last in 1992 to continue work on the genetic basis of interindividual variation in risk of essential hypertension in the population at large using the Rochester Family Heart Study (RFHS). The RFHS was used to address three major questions: 1) Which intermediate biochemical, physiological, and anthropomorphic traits predicted blood pressure and contributed to the pathogenesis of essential hypertension 2) Did allelic variation in one or more genes have large effects on any of these intermediate traits? 3) Did information about allelic variation improve prediction of risk of essential hypertension beyond what was provided by measure of the intermediate traits?