Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Pachyonychia congenita ?
    ### Response:
    What causes pachyonychia congenita? Pachyonychia congenita (PC) is caused by changes (mutations) in one of five genes: KRT6A, KRT6B, KRT6C, KRT16, and KRT17. These genes provide instructions for making a protein called keratin, which is found in the skin, hair, and nails.
    