Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Danon disease ?
    ### Response:
    Danon disease is a condition characterized by weakening of the heart muscle (cardiomyopathy); weakening of the muscles used for movement, called skeletal muscles, (myopathy); and intellectual disability. Males with Danon disease usually develop the condition earlier than females and are more severely affected.
    