Cystic Fibrosis Screening
What is cystic fibrosis?
Cystic fibrosis (CF) is a disease that affects many areas of the body. It can affect the lungs, pancreas, and reproductive organs. In most cases, this lifelong illness gets worse with age. It can affect both males and females.
What are the symptoms?
The signs of CF are different in each person. Most CF patients have both breathing and digestive problems. Others may only have breathing problems. Intelligence is not affected by this disease.
CF causes the fluids made in the body to be thick and sticky. Normal fluids are thin and watery. Thick fluid in the lungs affects the removal of germs and dust. It also can cause infections, breathing problems, and lung damage.
Thick fluid in the tube of the pancreas can keep enzymes from getting to the intestine. The enzymes help break down our food into nutrients the body needs for proper growth.
Thick fluid in the reproductive tubes can prevent males from having children and may make it difficult for females to have children.
Most CF patients are diagnosed with the disease during childhood. However, patients with mild signs may not be diagnosed until their teens or later. Common signs of CF include salty tasting sweat, chronic coughing or wheezing, frequent pneumonia, and poor growth. People with CF tend to have shorter life spans.
What causes CF?
CF is a genetic disorder. It is caused by a pair of genes that are not working properly. Each gene plays a specific part in helping the body function. Genes are passed from parents to their children. Sometimes a change occurs in a gene that prevents it from working properly. This change in a gene is called a mutation (myoo-TAY-shun).
Genes are inherited in pairs. CF occurs when both genes in the pair have a mutation. A person with cystic fibrosis inherits one CF gene from each parent. The parents of a child with CF each carry one working copy of the gene and one non-working copy. The parents are called “CF carriers” because they still have one working gene. CF carriers have no signs of CF.
What is my chance of being a CF carrier?
About one in every 2,500 Americans is born with CF. The chance of being a CF carrier depends on a person’s ethnic background. CF occurs most often in Caucasians whose ancestors came from northern Europe. But CF carriers can be found in other ethnic groups as well.
The following table shows the risk of being a CF carrier when there is no family history of CF. For example, if no one in your family has CF and you are Caucasian, then your risk of being a carrier is 1 in 29 (about 3.4 percent). A person’s chance of being a CF carrier will increase if the person is related to someone who is a CF carrier or who has CF.
CF Carrier Frequency by Ethnic Background
||Chance of Being a CF Carrier|
|Caucasian, including Ashkenazi Jewish
||1 in 29|
||1 in 46|
||1 in 65|
| Asian American
|| 1 in 90|
What is CF carrier screening?
CF carrier screening is a test that looks for changes or mutations in the CF gene. This test can be done using a blood or saliva sample.
What do the results mean?
A positive result means that a change was found in the CF gene. This person is now considered a CF carrier. When one parent is found to be a carrier, the other parent should be tested. If both parents are carriers, each of their babies has a 25 percent chance of having CF. There are other tests that can show if the developing baby has CF. UPMC offers genetic counseling to review the results of these tests. We also can help you locate community resources and services for your family.
A negative screening result means that a change was not found in the CF gene. It is possible that a person who receives a negative result could be a carrier for CF, but the chance is very small.
Who should have CF carrier screening?
The decision to have CF screening is a personal one. The American College of
Obstetricians and Gynecologists (ACOG) recommends CF screening for the following people:
- All women of childbearing age, best before becoming pregnant
- Those who have a family member with CF
- Those who have a partner with CF
- Any couple in which one or both partners are Caucasian or Ashkenazi Jewish descent and are planning a pregnancy or are pregnant
Here are some points to consider when determining if you should have CF screening.
- Does CF seem like a serious condition to you?
- Would you consider having amniocentesis or CVS (chorionic villus sampling) to determine whether the baby has CF?
- Do you think the results would be reassuring?
How is CF treated?
Currently, there is no cure for CF. Treatments are available that improve the length and quality of life for people with CF. Aerosol sprays are used to ease breathing. Chest physical therapy helps to remove mucus from the lungs. Hospital stays may be needed for severe lung problems. Frequent, high-calorie meals can help maintain weight. Special enzymes are taken with meals to help digest food.
How much does CF screening cost?
CF screening may or may not be covered by your insurance company. Contact your insurance provider to find out how much you would have to pay.
Where can I get more information about genetic counseling?
If you have questions regarding CF, or if you are interested in CF testing, please call the UPMC Center for Medical Genetics at 412-641-4168, or toll-free 1-800-454-8155.
Revised September 2011