Masking by hypokalemia-primary aldosteronism with undetectable aldosterone

Primary aldosteronism is the most common cause of secondary hypertension; however, the dynamic regulation of aldosterone by potassium is less well studied and current diagnostic recommendations are imprecise. We describe a young man who presented with resistant hypertension and severe hypokalemia. The workup initially revealed undetectable aldosterone despite acute potassium repletion. Chronic potassium supplementation eventually uncovered hyperaldosteronism. In situ genetic studies revealed a gain-of-function KCNJ5 mutation within an aldosterone-producing adenoma that was clinically responsive to changes in extracellular potassium. We highlight a unique presentation of Conn's syndrome and discuss the implications for the molecular mechanisms of potassium regulation of aldosterone.

Automated summary

This case study presents a unique presentation of Conn's syndrome in a young man with resistant hypertension and severe hypokalemia, eventually diagnosed as primary aldosteronism. Genetic studies revealed a gain-of-function KCNJ5 mutation within an aldosterone-producing adenoma that was responsive to changes in extracellular potassium levels, highlighting the implications for the molecular mechanisms of potassium regulation of aldosterone.