Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose Dopa-responsive dystonia ?
    ### Response:
    How is dopa-responsive dystonia diagnosed? Dopa-responsive dystonia (DRD) is diagnosed based on the signs and symptoms present, results of laboratory tests (sometimes including genetic testing), and response to therapy with levodopa. If DRD is suspected, a therapeutic trial with low doses of levodopa remains the most practical approach to the diagnosis.
    