[Renal tubular acidosis (RTA)].

Renal tubular acidosis (RTA) is applied to a group of transport defects involving the reabsorption of bicarbonate (proximal RTA or type II), the excretion of hydrogen ion (distal RTA or type I), or both (type III). Aldosteron deficiency and resistant state to aldosteron form hyperkalemic RTA which is called type IV RTA. A large number of etiologies of RTA have been identified. Almost all RTA in childhood are congenital. In contrast, almost all RTA in adulthood are secondary. Two renal complications such as low molecular weight proteinuria and renal cyst formation have recently been described in distal RTA. Molecular defects of RTA will be identified in the near future.