<div class="FTQUOTE"><begin quote>I also found it worrisome from birth that DD had an elevated IRT but was simply a carrier per the state's test.</end quote></div>
The IRT is only a screening test, not a diagnostic one. While far from all babies with an elevated IRT have cf, when a child born of two known carriers has a high result I agree that this IS a cause for concern, despite the fact that she passed her sweat tests.
Some states have a two-tiered newborn screening process for CF: they will test for the df508 gene if a baby has an elevated IRT result. If this is what happened in her case, they might be calling her a carrier because of finding the df508 gene yet having a normal sweat test. (IRT results alone <i>cannot</i> determine carrier status, so if they specifically told you she was a carrier, find out what test she has had already to lead them to believe this.)
In any case, it would be impossible to know if she was only a carrier unless she was tested for both mutations. I hope this can get resolved soon... knowing is always better.
The IRT is only a screening test, not a diagnostic one. While far from all babies with an elevated IRT have cf, when a child born of two known carriers has a high result I agree that this IS a cause for concern, despite the fact that she passed her sweat tests.
Some states have a two-tiered newborn screening process for CF: they will test for the df508 gene if a baby has an elevated IRT result. If this is what happened in her case, they might be calling her a carrier because of finding the df508 gene yet having a normal sweat test. (IRT results alone <i>cannot</i> determine carrier status, so if they specifically told you she was a carrier, find out what test she has had already to lead them to believe this.)
In any case, it would be impossible to know if she was only a carrier unless she was tested for both mutations. I hope this can get resolved soon... knowing is always better.