This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A child presented with polyuria, polydypria, fever, clinical features of rickets, slit lamp examination shows the following,what is the probable diagnosis? 
Select and explain. 
A. Alport syndrome, B. Hyper calcemia, C. Cystinosis, D. Dent disease
C: Cystinosis
Answer: C: Cystinosis 
Explanation: A child presented with polyuria, polydypria, growth failure rickets, fever and decreased pigmentaion of skin, blonde hair, photophobia.
On slit lamp examination, cysteine crystal can be seen in cornea.