Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Marfan syndrome ?
    ### Response:
    Marfan syndrome is a disorder that affects the connective tissue in many parts of the body. Connective tissue provides strength and flexibility to structures such as bones, ligaments, muscles, blood vessels, and heart valves. The signs and symptoms of Marfan syndrome vary widely in severity, timing of onset, and rate of progression.
    