Cystic Fibrosis

Mayo Clinic Q&A: Cystic fibrosis often identified before symptoms start

DEAR MAYO CLINIC: Recently, my niece was diagnosed with cystic fibrosis at 16. No one else in our family has been diagnosed with it, and, until recently, she didn't have any symptoms. Now I'm worried about my kids, ages 4 and 6. Their newborn screenings for cystic fibrosis were negative, but should I have them tested anyway?

ANSWER: Because of the way cystic fibrosis is passed from parents to children, one member of an extended family may be affected, while many others are not. If your children are healthy, without any signs of the disease, it's unlikely they will develop cystic fibrosis, especially because their newborn screenings were negative. However, the test for cystic...