Leading articles Molecular developments in renal tubulopathies

The renal tubule is responsible for the reabsorption of more than 99% of the water and sodium in the glomerular ultrafiltrate. Congenital or acquired tubular dysfunction can therefore readily cause profound electrolyte and volume disturbance. The tubule also has to regulate acid– base balance, mineral homoeostasis, and the excretion of organic anions and drugs. To fulfil these functions, a large number of specialised transporters and channels are specifically localised in the tubular cell membranes, some in the luminal border and others in the plasma membrane border (basolateral membrane). In the past decade (and especially in the past five years) advances in molecular genetic research have revealed the structure, function, and eVects of mutations in these transporters, thereby greatly increasing our understanding of the function and dysfunction of the renal tubule. Some renal stone disorders (for example, cystinuria, Dent’s disease) and rare genetic causes of hypertension (for example, Liddle’s syndrome) are now known to be caused by mutations in tubular transport systems.