Cystinosis is a lysosomal storage disease with accumulation of cystine within lysosomes. Intermediate cystinosis shows a delayed onset and more prolonged course than the classic infantile nephropathic cystinosis.

The mutations in CTNS associated with intermediate cystinosis result in a mild-to-moderate decrease in cystinosin function.


The patient develops cystinosis nephropathy, but the onset is delayed to later childhood or adolescence. The patient may develop with polyuria, photophobia or short stature.


The onset of renal failure in untreated patients is usually between 15 and 25 years of age. In patients started on cystine-depleting therapy (cysteamine bitartrate) this can be delayed into middle age.

To read more or access our algorithms and calculators, please log in or register.