CF Gene Mutation Testing

This is a test used to detect cystic fibrosis (CF) genetic mutations to establish CF carrier status or to establish the diagnosis of CF in an individual.

The CF gene mutation test identifies mutations in the CFTR gene on chromosome 7. Each cell in the human body (except sperm and eggs) has 46 chromosomes (23 inherited from the mother and 23 from the father). Genes on these chromosomes form the body's blueprint for producing proteins that control body functions. Cystic fibrosis is caused by a mutation in a pair of genes located on chromosomes 7. Both copies of this gene must be abnormal to cause CF. If only one copy of the gene pair is mutated, the patient will be a carrier. Carriers are not ill, they do not have any symptoms, but they can pass their abnormal CF gene copy on to their children.

When a newborn infant has meconium ileus (no stools in the first 24 to 48 hours of life) or when a person has symptoms of CF (salty sweat, persistent respiratory infections, wheezing, persistent diarrhea, foul-smelling greasy stools, malnutrition, and vitamin deficiency); if a person has a positive sweat chloride or IRT test or a close relative who has been diagnosed with CF; when a patient is undergoing genetic counseling and wants to find out if they are a CF carrier; or for prenatal diagnosis.


A blood sample drawn from an infant's heel; a spot of blood that is put onto filter paper; or a blood sample is drawn from a vein in the arm.


No genetic mutation.

Ranges for normal findings may vary among different laboratories and hospitals. You should always check with your doctor after having lab work or other tests done to discuss the meaning of your test results and whether your values are considered within normal limits.


Your caregiver will go over the test results with you and discuss the importance and meaning of your results, as well as treatment options and the need for additional tests if necessary.


It is your responsibility to obtain your test results. Ask the lab or department performing the test when and how you will get your results.