This case report describes the clinical features of a previously undocumented NR3C2 mutation, Pro701Leu, in a 60-year-old man initially suspected of having Gordon syndrome (pseudohypoaldosteronism type 2 or familial hyperkalemia and hypertension syndrome) based on his hypertension and hyperkalemia and a family history of similar features. This evidence concerns the gene NR3C2 and Hyperkalemia.