Below is an instruction from Human. Write a response.
    ### Instruction:
    How many people are affected by Townes-Brocks Syndrome ?
    ### Response:
    The prevalence of this condition is unknown, although one study estimated that it may affect 1 in 250,000 people. It is difficult to determine how frequently Townes-Brocks syndrome occurs because the varied signs and symptoms of this disorder overlap with those of other genetic syndromes.
    