Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Klippel Feil Syndrome ?
    ### Response:
    Klippel-Feil Syndrome is a rare disorder characterized by the congenital fusion of two or more cervical (neck) vertebrae. It is caused by a failure in the normal segmentation or division of the cervical vertebrae during the early weeks of fetal development.
    