It appears that your state does a genetic test for the most common mutations responsible for causing CF if the IRT levels are elevated. This is a much more thorough newborn screen than most states perform (most states only test for elevated IRT levels and as Heather posted, the vast majority of these babies don't have CF.) A question to ask of the pediatrician would be the specific results of the genetic testing performed- how many mutations were discovered. Two mutations from one of these panels would confirm a dx of CF, one means the baby is at least a carrier (more thorough genetic testing is available to test for additional mutations if warranted), or if no mutations were found and they are doing the sweat test based on IRT alone.
Wishing the very best and that your child does NOT have CF and is at most just a carrier. A 'screen' is just that- a screen- and flags more babies than those that actually have the disease. However, in those states that actually include genetic testing, the NBS will narrow down more babies w/CF than those that simply go by IRT results alone.
