I know this post is a few months old... but I wanted to comment just... well, because. ha!
My son was born Double Delta without either my husband or I knowing about our carrier status. We both have children from previous marriages without an issue (we now know that my daughter from previously is a carrier, though). Anyhoo... obviously we both carry the one deletion of delta f508. I specifically asked the pulmonologist about the carrier experiencing mild or limited symptoms of the disease and she said "it's not entirely impossible, but very unlikely." My hubby has a HORRIBLE cough every day that brings up odd colored mucous sometimes tinged with blood (ewww, I know)... and sometimes the cough even gets so violent that it makes him gag and vomit. Again, sorry for the TMI... He also gets chest pains occasionally that are associated with his breathing. In addition to that, his entire family has sinus problems and a few have had surgery to remove nasal polyps.
On my side, I have had pancreatitis twice in my life, pyelonephritis (both requiring hospitalization and IV antibiotics), and am predisposed to get bronchitis or a severe lung infection every winter- never fails. I also have inconsistent bowel issues and intestinal pains after eating that have never been explained or diagnosed as anything besides "irritable bowel." Which I think is a cover-up for the doctor(s) not being able to really figure out what's wrong... but that's another post.
So, I am a definite believer in the carrier symptoms. While they may not be defined or diagnosed as the actual disease because the person lacks the second mutation, I think it's possible to experience symptoms. As carriers, we still have a mutation in our genes, why isn't it possible that it causes issues related to the single mutation? And doesn't it make sense that the issues would be related to the disease that we have "half" of? Ok... that was a long shot statement... but you get the point.
MJ