I have no info re Bartters syndrome, but please, any and all of you involved in such cases, if the mother is bf and you are following, gather the evidence, test the baby, and strongly consider publishing a case report. With the MD perhaps. Then when these situations come up (so rarely) more evidence can accumulate - this will help mothers, babies, LCs and all. Laurie Wheeler, RNC, MN, IBCLC Violet Louisiana USA