Using the 7 hypokalemia-only patients as a control group for the 12 hyperkalemia-only patients, we found no statistically significant differences between the groups in the use of potassium chloride therapy (3 patients only in the entire population), medications that interrupt the renin-angiotensin system (43% vs. 17%, respectively), small-molecule transport status (71% vs 67% low/low-average transporters, respectively), or residual renal urea clearance, i.e. KT/V from urine: 0.44 ± 0.50 vs 0.50 ± 0.63 per week, respectively. The gene discussed is REN; the disease is Hyperkalemia.