Support for genetic testing with negative sweat test

[Aboveallislove]

I know we often say you can have a negative sweat test and still have cf and have noted several here have had that happen and have recommended posters to push doctors for genetic tests when cf symptoms but negative sweat test. But it sounds like the doctors don't buy it...well in searching for something else I found this from cff.org

https://www.cff.org/PDF-Archive/Diagnostic-Sweat-Testing-CFF-Guidelines-J-Pediatrics-2007.pdf

Guideline 16 summarizes this point with a reference to a journal article. So those pushing for genetic testing based on symptoms this might help.

 

[Ratatosk]

Fortunately a neonatologist suspected CF in DS's case and ordered a basic blood panel with the most common mutations, but if we'd been at the local hospital, they would've take the results of his normal (32) sweat test and who knows if and when he'd have been diagnosed. A colleague's daughter suffered from "interstitial lung disease" for years, along with failure to thrive and frequent lung infections, but she didn't have cf because she passed "the test" -- a sweat test given to her as a small child.

 

[alikat0079]

I've noticed in my reading that a lot of people who have class 4 and 5 mutations have negative sweat tests. I had it done twice. Both times were negative. I think my results were around a 31 and 34. They diagnosed me through a full panel genetic testing. I'm so thankful they finally figured me out and my dr persisted after the negative sweat test.