Below is an instruction from Human. Write a response.
    ### Instruction:
    How many people are affected by heterotaxy syndrome ?
    ### Response:
    The prevalence of heterotaxy syndrome is estimated to be 1 in 10,000 people worldwide. However, researchers suspect that the condition is underdiagnosed, and so it may actually be more common than this. Heterotaxy syndrome accounts for approximately 3 percent of all congenital heart defects.
    