Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Moebius Syndrome ?
    ### Response:
    Moebius syndrome is a rare birth defect caused by the absence or underdevelopment of the 6th and 7th cranial nerves, which control eye movements and facial expression. Many of the other cranial nerves may also be affected, including the 3rd, 5th, 8th, 9th, 11th and 12th.
    