Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Congenital central hypoventilation syndrome ?
    ### Response:
    Congenital central hypoventilation syndrome (CCHS) is a disorder of the autonomic nervous system that affects breathing. It causes a person to hypoventilate (especially during sleep), resulting in a shortage of oxygen and a buildup of carbon dioxide in the blood.
    