So sorry mom for the delay in getting back to you and for the abrupt first note. I was typing on an Ipad and only had a minutes. Anyway, I am so sorry for what you are going through. CF sucks. But your duaghter is such a blessing and the former will never take away the later! Anyway, residual function means that some of the CFTR still functions. A "normal" person has 100% function. YOu and me have about 90% function because we are carriers. Our son has ddf508 so he has 2 copies of a more serious mutation and likely only 1-3% function. Depending on the mutation the CFTR function works or doesn't work right in different ways. With a residual function mutation the problem happens later and there is some function. Well Kalydeco is a drug that just got approved by the FDA for g551 mutation which is a gating mutation. The label will be expanded shortly to other gating mutations. But it is believed (almost certainly) to work for those with residual function. If your doctors said her mutations are "mild forms of cf" she I'd think have a residual function (or possibly gating) mutation and would thus benefit from Kalydeco. It would be off-label meaning that it isn't approved yet for her mutation, but meds are given off label all the time. the problem is this one cost $300,000 per year (yes, not a typo), so you need to have all your ducks in a row before trying to get it covered by insurance. So you'll want to talk to your doctor and find out if her mutation is a gating or residual function. Have him call Vertex (the manufacturer) and ask for any research showing the drug works on her mutations. The doctor can give her a prescription for the meds, but then you might need to fight the insurance company which will mean the doctor will have to justify why he is prescribing. Which is where that research comes in. I know this is a lot but this med works wonders for folks. Those with g551 get cftr function to 50% and recently Vertex announced 2 drugs together get them to 80% function which is close to what you and I have. In other words, we are very close to getting a real good treatment. If it were I, after I got my witts together, I'd follow-up with the doctors on this and push to get it for your daughter. Also, one final point: This is a shock. This is a "loss" of normal. Grieve. And take your own time. When ds was diagnosed at 2 weeks another cf mom told me it was 2 years before she ever thought life would be good again. I never felt like that but hearing it made me feel my horrible agony was "normal." And so is yours. Hugs. (oh, and go to sixtyfiverosesblog.wordpress.com. She posts here too but not as often and has posted on the blog lots of info that is amazing to explain everything!!) You might try emailing her with mutations and she might be able to tell you re residual function.