@lvnl I found a paper from a top Chinese hospital that CF is a spectrum, depending on what genetic mutation ( variance) the patients have, and also Asian has different mutation from Caucasian in CF. Asian CF has less symptoms than Caucasian CF, mostly showing as frequent BE infections and/or frequent sinus infections. That makes me feel BE may be another form of CF, but in a less severe form. My genetic test shows I am a carrier and my sweat test shows negative. But if I develop another mutation, I will show more CF symptoms. Of course many healthy adults are also a carrier. That means if both parents carry such a type of mutation, the child will be a CF. If only one parent carries it, the children will not develop CF, maybe just BE. In one word, BE and CF are in the same family. That is why NTM is so recurrent because patients have the genetic defects.

I am not a doctor. I just do some research and find this correlation. Please correct me.