Patients with FH1 have low renin, increased PAC, hypokalemia (in particular after the use of nonpotassium-sparing diuretics) ( 7 , 16 ), and the presence of hybrid steroids 18-hydroxycortisol (18OHF) and 18-oxocortisol (18-oxoF); imaging studies are compatible with BAH ( 7 ). This evidence concerns the gene REN and Hypokalemia.