Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Pitt-Hopkins syndrome ?
    ### Response:
    Mutations in the TCF4 gene cause Pitt-Hopkins syndrome. This gene provides instructions for making a protein that attaches (binds) to other proteins and then binds to specific regions of DNA to help control the activity of many other genes. On the basis of its DNA binding and gene controlling activities, the TCF4 protein is known as a transcription factor.
    