The high-UMOD group (homozygous for the major allele, AA genotype) with increased uromodulin excretion, greater salt sensitivity, hypertension, normal estimated glomerular filtration rate, and greater BP response to the loop-diuretic torasemide and the low-UMOD group (1 or 2 copies of the G allele) with decreased uromodulin excretion, greater salt resistance, increased estimated glomerular filtration rate, increased proximal tubular reabsorption of Na+ (possibly related to increased GFR), a poor BP response to loop-diuretics, and possibly diminished function of NKCC2. The gene discussed is SLC12A1; the disease is Hypertension.