Pediatric Pearls. More on the Newborn Screen: Seven Facts about Cystic Fibrosis

September 26, 2023

I think most newborn screens include a test for cystic fibrosis. You should check, though, to be sure on what your state or province or area screens for. I know the newborn screen in my state, Massachusetts, USA does include it.

#1 What is cystic fibrosis?

Cystic fibrosis (CF) is a hereditary disease that occurs due to structural changes in certain proteins in the body. These proteins manage how cells, tissues, and glands regulate sweat and mucus production. Mucus is normally slippery and protects the linings of the airways, digestive tract, and other organs and tissues. People who have cystic fibrosis make thick, sticky mucus that can build up and lead to blockages, damage, or infections in the affected organs.

#2 How is cystic fibrosis inherited?

CF is an autosomal recessive disorder. This mean the infant inherits a copy of the gene that contains an error, in this case a mutated cystic fibrosis transmembrane conductance regulator (CFTR) gene, from both the mother and the father. The gene that contains the mutation is pretty common. One in 25 people walking around are completely normal with no symptoms but have a copy of the gene with the mutation. (1)  

When two carriers of the defective gene have a child, there’s a 25 percent chance their child will have cystic fibrosis. There are an estimated 2,000 different mutations in the gene that can cause the disease.