Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) nonsyndromic aplasia cutis congenita ?
    ### Response:
    Nonsyndromic aplasia cutis congenita is a condition in which babies are born with localized areas of missing skin (lesions). These areas resemble ulcers or open wounds, although they are sometimes already healed at birth. Lesions most commonly occur on the top of the head (skull vertex), although they can be found on the torso or limbs.
    