Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) myosin storage myopathy ?
    ### Response:
    Myosin storage myopathy is a condition that causes muscle weakness (myopathy) that does not worsen or worsens very slowly over time. This condition is characterized by the formation of protein clumps, which contain a protein called myosin, within certain muscle fibers.
    