Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Congenital mirror movement disorder ?
    ### Response:
    Congenital mirror movement disorder (CMM) is a rare condition that is characterized by mirror movements (involuntary movements of one side of the body that mirror intentional movements on the opposite side). Affected people generally develop these movements in infancy or early childhood, which usually persist throughout their life without any related signs or symptoms.
    