Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Marfan Syndrome ?
    ### Response:
    Your doctor will diagnose Marfan syndrome based on your medical and family histories, a physical exam, and test results. He or she also will consult a set of guidelines called Ghent criteria, which are used to diagnose Marfan syndrome.
                
Marfan syndrome can be hard to diagnose.
    