We have a 5 month old infant who may very possibly have Cystic Fibrosis as you stated. But how can this be if we are routinely testing newborns for the disease
(assuming that birth was in this country and testing was done in this instance)? It may be true that this is a milder form of the condition, but one also needs to
look at the screening test which is used. The IRT test (immunoreactivetrypsinogen) is a screening test and not confirmatory, still needs a sweat test. The
recommendations are that only certain accredited labs perform this second test due to the fact that this test is complicated to perform. There is also the issue of
compliance in making sure that parents bring in their children for follow up testing.
Cystic Fibrosis Work up (Medscape) (Links to an external site.)