Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Apert syndrome ?
    ### Response:
    Apert syndrome is a genetic disorder characterized by the premature fusion of certain skull bones (craniosynostosis). This early fusion prevents the skull from growing normally and affects the shape of the head and face. In addition, a varied number of fingers and toes are fused together (syndactyly).
    