Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) pachyonychia congenita ?
    ### Response:
    Pachyonychia congenita is a condition that primarily affects the nails and skin. The signs and symptoms of this condition usually become apparent within the first few months of life.  Almost everyone with pachyonychia congenita has hypertrophic nail dystrophy, which causes the fingernails and toenails to become thick and abnormally shaped.
    