Like you and Alison, I am going through the same thing...except my new GI doc doesn't want to order the del/dupe testing. He refuses to believe my son has CF, even though he has classic symptoms. The two Ambry tests were neg for mut, but Steve suggested we get the del/ dupe. He looked into my son's tests and said they were not done. He is FTT, PI, resp. issues growth, hormone difcincy, seems to always have a "cold." Sweat test #s 41,44,42 in that order.
It really sounds like CF, but how do I know! If it is CF you're in the best place for info and support. Keep us updated, and just know, you're not alone out there.
((((HUGS)))))