What Is Cystic Fibrosis?

Cystic fibrosis (CF) is a common genetic disease that causes mucus in the body to become thick and sticky. The mucus builds up and causes problems in many of the body's organs, especially the lungs and the pancreas. People who have CF can have serious breathing problems and lung disease.

What Causes It?

CF is caused by a changed (mutated) gene that a child inherits from both parents. The changed gene causes problems with the way salt and water move in and out of the cells that make mucus. This causes the mucus to be thick and sticky. This glue-like mucus builds up and causes problems in many of the body's organs, especially the lungs and the pancreas.

Many people don't know they have the changed gene.

What Is Carrier Screening?

Cystic fibrosis (CF) carrier screening is a genetic test that shows if you are a carrier of the changed gene that causes CF. The test can help you find out if you and your partner have an increased chance of having a child born with CF.

What If You Are a Carrier?

If tests show that you are a carrier of a genetic disease, your partner also should be tested. In most cases, both parents must be carriers for a child to get the disease.

• If you were tested before getting pregnant, genetic counseling can help you understand your risks and options when you are thinking about having a child.
• If you are already pregnant, you may want to talk with your doctor about genetic counseling and testing for your baby. Your baby may be tested using a sample of your blood or an amniocentesis or chorionic villus sampling.

Is Screening Accurate?

This test does a good job of detecting if a person is a carrier of the most common changes in the gene that can cause cystic fibrosis (CF). But not all gene changes that cause CF are included in the screening. There is a small risk that you may still be a CF carrier even when the test results show that you are not a carrier.

Should You Be Screened?

The decision to have cystic fibrosis (CF) carrier screening is a personal one. You may wish to be tested if you are concerned that you or your partner might be carriers of CF. This may be more likely if either of you has a family member with the disease.

Some people decide to be tested before having children to help find out their risks of passing the CF gene on to their children. Among white people, the chances of being a carrier are higher than in other racial and ethnic groups.

You may decide to have carrier screening for CF if you are already pregnant. The test results may influence your decision about your pregnancy or help you make decisions about the care of your newborn child.

There may be reasons some people may choose not to have CF carrier testing.

• You are already pregnant and the information obtained from testing will not affect your decision to continue your pregnancy. Remember, though, that CF test results can provide valuable information for having a healthy pregnancy.
• Carrier testing may be expensive. You may decide not to have testing if your insurance does not pay for it.
• Testing does not identify all people who have a mutation in the CF gene. There is a small chance that you are a carrier even if the results are normal (negative).