Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Hallermann-Streiff syndrome ?
    ### Response:
    Hallermann-Streiff syndrome is a rare, congenital condition characterized mainly by abnormalities of the skull and facial bones; characteristic facial features; sparse hair; eye abnormalities; dental defects; degenerative skin changes; and proportionate short stature.
    