The spectrum of the severity and the natural history of the disorder was characterized. Modifying environmental and genetic factors important in regulation of blood pressure were determined. Also, renal physiology was studied in GRA patients to determine how these patients escaped hypokalemia in spite of mineralocorticoid excess. There were four specific aims including: 1) to determine the natural history and prevalence of GRA in various hypertensive populations, 2) to characterize the magnitude of effect imparted on blood pressure by inheritance of GRA and the sources of variation in phenotype expression of the hypertension, 3) to investigate the renal and hormonal mechanisms regulating potassium conservation and loss in GRA, and 4) to characterize the disequilibrium of GRA with Irish and Scottish descent and specific alleles of the aldosterone synthase gene.