Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to hereditary hyperekplexia ?
    ### Response:
    At least five genes are associated with hereditary hyperekplexia. Most of these genes provide instructions for producing proteins that are found in nerve cells (neurons). They play a role in how neurons respond to a molecule called glycine. This molecule acts as a neurotransmitter, which is a chemical messenger that transmits signals in the nervous system.
    