CF is due to genetic defects in thecystic fibrosis transmembrane conductance regulator (CFTR) gene.
People with CF carry two defective copies of the CFTR gene, one from each parent.
People who carry only one defective CFTR gene do not have CF but are CF carriers.
Verywell / Jessica Olah
Although CF is rare, being a CF carrier is relatively common.
Genetic tests look at your DNA (genetic material).
The standard genetic test for CF looks for the 23 most common CF-causing mutations in the CFTR gene.
The exact mutations screened for in the test will depend on your ethnic background and family history.
Who Should Get Tested?
Getting tested for CF is a personal choice.
Your other relatives may also wish to be screened to see if they carry a CF-causing mutation.
It is still possible, although unlikely, that you carry a rare mutation not screened for.
Research has identified over 1,700 different mutations that can cause CFbut most of these mutations are extremely rare.
Be sure your doctor is aware of your family history and any concerns you might have.
Only two carriers can have a baby with CF.
These tests are performed via chorionic villus sampling or amniocentesis in the first half of pregnancy.
The DNA is then analyzed for common genetic disorders, including CF.
If you decline prenatal screening, your baby will be screened at birth.
All newborns in the United States are now screened for CF shortly after birth.
This is done with a blood sample collected via a heel stick.
Recent research, however, has found that CF carriers do face certain elevated health risks compared to noncarriers.
Most CF carriers will not experience any of these health problems.
A Word From Verywell
Being a cystic fibrosis carrier is very common.
Talk with your healthcare provider if you have concerns about how being a CF carrier is impacting your health.
It causes chronic lung infections and a progressive decline in lung function that shortens the lifespan.
Advances in treatment have greatly improved survival of people with CF.
Only a few decades ago, most died in childhood.
Today, babies born with CF can expect to live into their 40s and 50s.
Women who are carriers have normal fertility.
But because they do produce sperm, they can often have children with assisted reproductive techniques.
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Cystic Fibrosis: Prenatal Screening and Diagnosis.
familydoctor.org.Cystic Fibrosis Prenatal Screening and Diagnosis.
Cystic Fibrosis Foundation.Newborn Screening for CF.
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