Renal Tubular Acidosis Presenting as Nephrogenic Diabetes Insipidus.

Background: Nephrogenic diabetes insipidus (DI) can be primary or secondary to various causes. Case characteristics: One child with Fanconi syndrome with proximal renal tubular acidosis (RTA) due to nephropathic cystinosis, and other with Distal RTA with hearing loss. Observation: Both cases showed features of nephrogenic DI, which resolved after treating the primary pathology. Message: Renal Tubular acidosis may cause nephrogenic DI.