Below is an instruction from Human. Write a response.
    ### Instruction:
    What are the genetic changes related to pulmonary arterial hypertension ?
    ### Response:
    Mutations in the BMPR2 gene are the most common genetic cause of pulmonary arterial hypertension. This gene plays a role in regulating the number of cells in certain tissues. Researchers suggest that a mutation in this gene promotes cell division or prevents cell death, resulting in an overgrowth of cells in small arteries throughout the lungs.
    