Understand More about Cystic Fibrosis (CF)
Being diagnosed with a hereditary condition can be scary. That’s why early detection is so important and can make all the difference in the world when it comes to getting in front of a disease.
Know The Basics
What is CF?
CF is a relatively common genetic condition that mainly affects the lungs and digestive system. There is a very broad range of how severe CF can be. People with the severe form of CF usually have very thick, sticky mucus that clogs the lungs and can lead to serious lung infections. They may have frequent coughing, wheezing, or shortness of breath. Thick mucus can also cause problems in the pancreas, which prevents food from being properly broken down and absorbed. This can cause someone to have trouble gaining weight, or develop medical problems like pancreatitis and pancreatic insufficiency. Milder forms of CF also exist, and in these types people can have varying degrees of lung and pancreas problems, upper respiratory infections, or infertility in men.
What causes CF?
CF is genetic, which means it is inherited through a person’s genes. Genes have instructions for how our bodies work and develop. Everyone has two copies of each gene. We get one copy of each gene from each of our parents. Mutations (changes in the gene, like spelling mistakes) in the CFTR gene can cause CF. If someone has two mutations in their CFTR genes, he or she can have CF. If someone has one mutation in a CFTR gene, he or she is called a “carrier” and usually would not have symptoms of CF. Anyone can be a CF carrier, but is it most common in Caucasian people of Northern European background, where 1 in 25 people is a CF carrier. If both parents are CF carriers, there is a 25% chance they can have a child with CF together.
Should You Have Genetic Testing?
Medical experts recommend offering genetic testing when couples at a higher chance for CF are considering having a family (or pregnant). This testing may also help find family members that have or may develop CF or a CF-related disorder. However, testing has its limitations and learning genetic test results can cause worry and anxiety for some.
What are the Benefits of Genetic Testing
For you or your family members:
Here are some ways that genetic testing may help you or your family:
- Your testing could tell your doctor that he or she needs to consider changes to your medical care
- If your testing finds a gene mutation that causes your CF or shows that you are a CF carrier, your adult family members can choose to be tested for the same mutation(s), if they wish
What Happens if I (or a Family Member) Test Positive for Gene Mutations?
If your testing shows you have two gene mutations, this may confirm a diagnosis of CF in you. If these two mutations are on different copies of the gene (if each was inherited from a different parent), this result usually means you have CF or a CFTR-related disorder. Testing of other family members, especially parents if possible, can be helpful in finding out if these mutations are on the same or different copy of the gene.
If you have this test result, others in your family could be CF carriers or possibly also have CF. The picture shows how people carry and pass on mutations in the gene that causes CF.
Possible Genetic Test Results
positive
Two mutations were found in the gene that causes CF
This may confirm a diagnosis of CF in you. Your doctor will discuss any treatment options with you
More testing may be needed (usually of your parents, if possible) to find out if the mutations are both in the same copy of the gene, or if there is one mutation in each CFTR gene
Your adult family members can now be tested for the same mutation(s), if they would like
Carrier
One mutation was found in the gene that causes CF
You will likely not have symptoms of classic CF. Some carriers may have mild symptoms
You have a chance to have a child with CF if your partner is also a carrier
Your partner, and other adults in your family, may wish to be tested for the same mutation
Negative
Your testing did not find mutations in the gene that causes CF. If you have been diagnosed with CF, that remains the same.
You may still have a mutation in a gene for a different condition not included in this test. Talk with your doctor or genetic counselor about whether more genetic testing is right for you.
variant of unknown significance (vus)
A mutation was found in a gene that is unrelated to your medical concerns, but may affect your health in the future
A change was found in a gene, but we do not know if it causes CF or not
Testing other family members may help to understand the VUS
Talk with your doctor or genetic counselor about whether more genetic testing is right for you or your family.
A VUS can sometimes become understood after more research is done. Keeping in touch with your doctor or genetic counselor can help keep you updated.