Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to Treacher Collins syndrome ?
    ### Response:
    Mutations in the TCOF1, POLR1C, or POLR1D gene can cause Treacher Collins syndrome. TCOF1 gene mutations are the most common cause of the disorder, accounting for 81 to 93 percent of all cases. POLR1C and POLR1D gene mutations cause an additional 2 percent of cases.
    