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Old 06-07-2010, 08:11 AM   #2
Senior Veteran
Join Date: Nov 2003
Location: Midwest
Posts: 2,006
Ratatosk HB UserRatatosk HB User
Re: Question for anyone with sweat test in the 30's.

Being that DS had a normal 32 for his sweat test, yet blood tests showed positive for CF, I'm not a fan. Sweat tests are GREAT for indicating CF if they're high, but there tend to be a lot of false negatives. Meaning if the sweat test is high, it usually means CF, but that's not necessarily the case if the result is low. There are over 1500 genetic mutations for CF and I know of several individuals whose children had very low results, but due to family history and/or symptoms, they pushed for ambry amplified testing.

Sometimes it has to do with not being able to get a good sample, that the child is too young and doesn't sweat or conditions are such that they don't sweat.

Another thing that can skew results is experience of the technician doing the test. The Cystic Fibrosis Foundation suggests the tests be done at an accreditted cf care center and not a local clinic.