Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to protein S deficiency ?
    ### Response:
    Protein S deficiency is caused by mutations in the PROS1 gene. This gene provides instructions for making protein S, which is found in the bloodstream and is important for controlling blood clotting. Protein S helps block the activity of (inactivate) certain proteins that promote the formation of blood clots.
    