Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Klippel-Feil syndrome ?
    ### Response:
    Klippel-Feil syndrome is a bone disorder characterized by the abnormal joining (fusion) of two or more spinal bones in the neck (cervical vertebrae). The vertebral fusion is present from birth. Three major features result from this vertebral fusion: a short neck, the resulting appearance of a low hairline at the back of the head, and a limited range of motion in the neck.
    