It doesn't bother me at all but I am really curious about it, especially when symptoms show up at a young age but there is no genetic diagnosis. Has your son had a full panel test (Ambry or Qwest) and still no mutations were found? Was his sweat test positive? Only asking bc I am curious, I imagine you have already shared this here but I just can't remember. My daughter had one "unknown mutation" but we eventually found it with testing through Qwest. Her sweat tests was in the 100's so we weren't questioning her diagnosis, just wanted to find the mutation bc I was pregnant and wanted to find out whether baby #2 had CF.
I can't imagine anyone would see your son as "less than" bc mutations haven't been found.
I know a boy who was diagnosed with CF via sweat test (just barely, his numbers were low) and responded well to enzymes but never showed any other symptoms. A few years later, he switched CF doctors and his new doctor wanted to do a dna test (dna testing was fairly new then and this doctor liked having all patients do it) so this boy shows no mutations and they say "he doesn't really have CF, must have been misdiagnosed". He stopped going to CF clinic, stopped enzymes, etc. That was years ago and this boy has been really healthy, still growing well, etc. No real point to me telling this, I just find it very interesting.