Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to nemaline myopathy ?
    ### Response:
    Mutations in one of many genes can cause nemaline myopathy. These genes provide instructions for producing proteins that play important roles in skeletal muscles. Within skeletal muscle cells, these proteins are found in structures called sarcomeres. Sarcomeres are necessary for muscles to tense (contract).
    