Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) harlequin ichthyosis ?
    ### Response:
    Harlequin ichthyosis is a severe genetic disorder that mainly affects the skin. Infants with this condition are born with very hard, thick skin covering most of their bodies. The skin forms large, diamond-shaped plates that are separated by deep cracks (fissures).
    