From Ion Channels to Blood Pressure: Genetic Disorders of Renal Tubular Transport.

Blood pressure regulation is fundamentally dependent on renal sodium and electrolyte handling. Genetic disorders of renal tubular transport provide representative evidences that illuminate the molecular mechanisms linking ion channels to systemic hemodynamics. Monogenic conditions such as Bartter syndrome, Gitelman syndrome, Liddle syndrome, and Gordon syndrome demonstrate how specific alterations in tubular sodium, potassium, chloride, and magnesium transport translate into distinct blood pressure phenotypes. Salt-wasting disorders are characterized by hypokalemic metabolic alkalosis and low or normal blood pressure despite activation of the renin-angiotensin-aldosterone system, underscoring the dominant role of tubular sodium loss. In contrast, gain-of-function mutations enhancing distal sodium reabsorption produce volume expansion, suppressed renin levels, and hypertension, often accompanied by characteristic electrolyte abnormalities. These conditions highlight the tight coupling between sodium and potassium handling and reveal how small perturbations in distal nephron transport can exert disproportionate effects on blood pressure. Insights from these rare genetic syndromes extend beyond monogenic disease. Variants in genes regulating Na+-Cl- cotransporter, epithelial sodium channel, and with-no-lysine signaling pathways contribute to salt sensitivity and low-renin hypertension in the general population. Understanding tubular channelopathies thus provides a mechanistic framework for precision diagnosis and targeted therapy in hypertension. The current review examines how renal ion channel dysfunction translates from molecular defects to systemic blood pressure regulation.