In this work, humans and mice with heterozygous mutations in the acidic domain of WNK1 display an inherited phenotype with hyperkalemia, hyperchloremia, and metabolic acidosis, but without arterial hypertension, that is nevertheless accompanied by low renin expression levels, suggesting a mild volume expansion that is, however, not enough to produce hypertension. The gene discussed is WNK1; the disease is Hyperkalemia.