Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Bartter syndrome ?
    ### Response:
    Bartter syndrome is a group of similar kidney disorders that cause an imbalance of potassium, sodium, chloride, and other molecules in the body. In some cases, the condition manifests before birth with increased amniotic fluid surrounding the affected fetus (polyhydramnios).
    