Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Nephropathic cystinosis ?
    ### Response:
    Cystinosis is an inherited condition in which the body accumulates the amino acid cystine (a building block of proteins) within the cells. Excess cystine forms crystals that can build up and damage cells. These crystals can negatively affect many systems in the body, especially the kidneys and eyes.
    