Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Cowden syndrome ?
    ### Response:
    How is Cowden syndrome diagnosed? A diagnosis of Cowden syndrome is based on the presence of characteristic signs and symptoms. Genetic testing for a change (mutation) in the PTEN gene can then be ordered to confirm the diagnosis. If a mutation in PTEN is not identified, genetic testing for the other genes known to cause Cowden syndrome can be considered.
    