Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Tracheal agenesis ?
    ### Response:
    Tracheal agenesis is a rare birth defect in which the trachea (windpipe) is completely absent (agenesis) or significantly underdeveloped (atresia). Signs and symptoms include polyhydramnios during pregnancy and respiratory distress, bluish skin color (cyanosis) and no audible cry shortly after birth.
    