Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Mutation Analysis, Whole Blood

What This Test Checks

The CFTR gene provides instructions for a protein that controls the movement of salt and water in and out of cells. This test analyzes your DNA, typically from a whole blood sample, to detect certain mutations in that gene. Different testing panels may look for a limited set of common mutations or may examine the gene more broadly, so the exact variants covered depend on the specific test ordered.

Why It May Be Ordered

Healthcare providers may order CFTR testing when cystic fibrosis is suspected because of symptoms such as persistent lung problems, poor growth, or digestive issues. It may also be used to confirm a diagnosis, to identify carriers who have no symptoms, or in family planning discussions. Newborn screening programs sometimes lead to follow-up CFTR testing as well.

How the Sample Is Collected

The test is usually performed on a blood sample drawn from a vein in your arm. In some situations, other sample types may be used at the provider's discretion. Collection is brief, and you can typically resume normal activities afterward.

What Results Can Mean

Results are reported in terms of which specific CFTR variants, if any, were detected. Finding two disease-causing mutations generally supports a diagnosis of cystic fibrosis, while finding one may indicate carrier status depending on the context. A negative result does not always rule out the condition, because some tests only cover the most common mutations. Your care team will interpret results alongside symptoms, family history, and other testing.