Not necessarily, some people are now being diagnosed in their 20’s 30’s and beyond.
CF is very complicated as a person has to have 2 faulty mutations of the CFTR gene. These are inherited from each parent.
The guthrie test only picks up a selection of the most common mutations (abit more complicated but its the simplest way to describe), there are now about 2000 mutations in the database.
CF affects all organs throughout the body not just the lungs. The pancreas in particular often doesn’t work properly or at all in people with cf and this is why they cant put on weight properly. My daughter doesnt have this problem and if her mutations hadnt been picked up on guthrie we probably wouldnt know now she had cf as chest wise she has been really good.
It is very unlikely your son has CF so try not and over worry (hard I know) look at the tests as ruling out all possibilities and his doctors doing their best to get to the bottom of what is going on with him. Respiratory problems are very common in TOF children and ruling out CF will be a formality if he has ticked a few symptoms.
What I will say is if the sweat test comes back borderline, i’d ask for full genetic testing as it may be your son has rare mutations that haven’t triggered.
I know this may sound mad but does his skin taste salty?
I hope I havent scared you in anyway as that was not my intention at all, i’m trying to reassure you that it is probably unlikely but they need to rule it out at least.
Any questions at all, please fire them my way if I can help you at all.
xxx