CFTR DeltaF508

Sample

Your Carrier Status Result

Disease/condition: Cystic fibrosis

Gene name: CFTR

Genotype: Heterozygote/carrier for DeltaF508

Summary of Your Result:

You are a carrier for cystic fibrosis (CF).
You do not have cystic fibrosis.
Your biological children have an increased chance of having CF.
If your partner is also a carrier, each child has a 1 in 4 (25 percent) chance of having CF.
The change on your gene is called DeltaF508.

What does it mean to be a carrier for cystic fibrosis?

As a CF carrier, you do not have the condition. You inherited one mutated copy from only one parent—and that parent was also a carrier.

As a carrier, you have an increased chance of having a biological child with CF. If your partner is also a CF carrier, each child you have together will have a 1 in 4 (25 percent) chance of having cystic fibrosis.

What is cystic fibrosis?

Cystic fibrosis is a serious inherited disease that causes the body to produce thick, sticky mucus that clogs the lungs, often leading to infection. The abnormal mucus also blocks the pancreas, which stops digestive enzymes from reaching the intestine where they help to digest food. CF can also affect the reproductive system.

Babies born with cystic fibrosis are diagnosed usually in the first two years of life because they start to have problems with breathing and growth. In the past, babies born with cystic fibrosis rarely lived into adulthood. Today, research and medical advances are helping people with CF live into their 30s and 40s.

How do genetic changes in the CFTR gene cause cystic fibrosis?

CF is caused by mutations in the cystic fibrosis transmembrane regulator (CFTR) gene. Since the gene was discovered in 1989, more than 900 mutations have been identified.

The CFTR gene provides the body with instructions for making a protein called the cystic fibrosis transmembrane conductance regulator. This protein works as a “conductor” across cell membranes in cells that produce mucus, sweat, saliva, tears and digestive enzymes. Mutations in the CFTR gene stop the body from being able to correctly produce and transport these important substances. This causes the cells in the airways of the lungs and in other organs to make sticky, thick mucus that prevents the organs from working properly.

In order to have CF, a person must inherit two mutated copies of the CFTR gene, typically one copy from each of their parents. If the person inherits only one mutated copy, he or she is a CF carrier, and does not have the disease.

How many people are cystic fibrosis carriers?

In the U.S., about 1 person in every 20 is an unaffected carrier of an abnormal CFTR gene. Most carriers are European Americans whose ancestors came from Northern Europe, although individuals from anywhere in the world can be carriers. The 12 million CF carriers usually are unaware that they are carriers.

Risk factors for cystic fibrosis carrier status

Genetics and ancestry are the only known risk factors for cystic fibrosis.

Benefits of knowing your cystic fibrosis carrier status

Knowing your cystic fibrosis carrier status may help with family planning and deciding whether or not your partner should get tested for carrier status.

Risks of knowing your cystic fibrosis carrier status

After learning your CF carrier status, you may have questions about your health, your family’s health, and the health of any future children. Talking with a genetic counselor or your healthcare professional may help answer your questions.

Next steps

You can talk to your doctor about getting a laboratory test for your partner to see if the two of you are at risk for giving birth to a child with cystic fibrosis. Carrier testing cannot detect all cystic fibrosis gene changes (mutations). In rare cases, a person can have a normal test result and still be a cystic fibrosis carrier. If both parents are carriers, they may want to consult with a genetic counselor for help in deciding whether to conceive or whether to have the baby tested for cystic fibrosis before it is born.

You may want to meet or talk with a genetic counselor, a clinical geneticist, or other healthcare professional to discuss what your CF carrier status means for you and your family.

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