Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to propionic acidemia ?
    ### Response:
    Mutations in the PCCA and PCCB genes cause propionic acidemia.  The PCCA and PCCB genes provide instructions for making two parts (subunits) of an enzyme called propionyl-CoA carboxylase. This enzyme plays a role in the normal breakdown of proteins. Specifically, it helps process several amino acids, which are the building blocks of proteins.
    