Nephropathic cystinosis results from lysosomal cystine storage and, if untreated with cysteamine, results in end-stage renal disease by 10 years of age. The renal Fanconi syndrome occurs in the first year of life and is accompanied by a characteristic "swan neck" deformity of the proximal renal tubule. The linkage between cystine storage, Fanconi syndrome, and renal failure has not been underst...