Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to congenital fiber-type disproportion ?
    ### Response:
    Mutations in multiple genes can cause congenital fiber-type disproportion. Mutations in the TPM3, RYR1 and ACTA1 genes cause 35 to 50 percent of cases, while mutations in other genes, some known and some unidentified, are responsible for the remaining cases.
    