Home HealthTopics Health Centers Reference Library Research
Join us on Facebook Join us on Facebook Share on Facebook

Cystic Fibrosis




If a newborn screen comes back as a positive, category B and so far one gene detected, it is still possible to have the disease? The 1st sweat test came back with not enough sweat to measure so a repeat will be next week. Thank-you.


I am unable to give any percentages or likelihood numbers because of state-to-state differences in panels which are used for newborn screen.  However, in general, since we are never 100% sure of what new gene may be present (and fails to be picked up on the panel) and not be detected, the proof of diagnosis of "CF vs not CF" is usually not available until the sweat test or other definitive test is completed successfully. 

I am not, nor was our genetics counselor, familiar with category B. 

For more information:

Go to the Cystic Fibrosis health topic, where you can:

Response by:

Karen S McCoy, MD Karen S McCoy, MD
Professor of Pediatrics
Professor at the School of Allied Medical Professionals
College of Medicine
The Ohio State University