Because the risk for colorectal cancer among people with one MUTYH variant is uncertain, learning that you have one MUTYH variant may be a little confusing. You likely have questions about what this result means for you and what you can do. You may also wonder what your result means for your family. There are important conversations you should consider having with healthcare professionals. In this article, we’ll help you begin to think about these conversations and explore what next steps you can take.
What does this result mean?
MUTYH-associated polyposis (MAP) is a genetic condition that increases the risk of developing colorectal cancer and certain other cancers. MAP is an autosomal recessive condition, which means a person needs to have two MUTYH variants or two copies of a MUTYH variant in order to have the condition. People with only one MUTYH variant do not have MAP. However, you could still have another variant not included in our test.
In the general population, about 4% of people are expected to develop colorectal cancer over the course of their lifetime. Currently, scientists are uncertain as to how having one MUTYH variant may affect your risk of developing colorectal cancer. Some studies suggest that people with this result may have a slightly increased risk, particularly if they have a family history of colorectal cancer. However, the evidence is still limited, and more studies are needed to establish exact risk estimates.
For your family:
MUTYH variants are passed down through families, so your result for this report is relevant to your family members. There is a chance your family members may also have the variant we detected. People with one variant may have a slightly increased risk for colorectal cancer, especially if they have a family history of colorectal cancer. However, more studies are needed to establish exact risk estimates. In addition, if any of your relatives have two MUTYH variants or two copies of a MUTYH variant, they would have an increased risk for colorectal cancer and potentially certain other cancers due to MAP.
Since you have one MUTYH variant, at least one of your parents is also expected to have this variant. In addition, each of your siblings has at least a 50% chance of having this variant, and each of your children has a 50% chance of inheriting this variant from you. If your partner has a variant linked to MAP, each child has a 25% chance of having this condition.
What should I do now?
We recommend people with one variant consider discussing their results with a healthcare professional, especially if they have a personal or family history of colorectal cancer. Additionally, you may wish to learn more about screening and prevention as well as speak with your family members about your results.
Consider talking to your doctor or a genetic counselor, especially if you have a personal or family history of colorectal cancer: If you have a personal or family history of colorectal cancer, it’s important to discuss your result with a healthcare professional, such as a doctor or a genetic counselor, as they may recommend additional screening or genetic testing options for you. Genetic counselors are trained to help people understand genetic testing options, and they can work with other healthcare professionals to develop a plan that is best for you.
If you're not sure who to talk to, ask your healthcare provider about access to genetic counseling services, or see below to learn how to search for a genetic counselor near you.
Learn more about screening and prevention options: Current U.S. guidelines recommend that people with one MUTYH variant without a personal or family history of colorectal cancer should follow screening guidelines for the general population, which is to start screening at age 50. Screening can be done through a visual examination that looks at the colon and rectum, such as a colonoscopy exam, or through a stool-based test that looks for signs of cancer. Depending on the test, screening should be repeated every 1 to 10 years. Learn more from the U.S. Preventive Services Task Force.
For people with one MUTYH variant who have had a first-degree relative with colorectal cancer, guidelines recommend screening earlier and more often than the general population. Screening can help detect cancers at an earlier stage, when they may be more treatable. Screening can also detect precancerous polyps, which may allow them to be removed before they become cancerous. Consider talking to a healthcare professional to confirm your result and discuss options for cancer screening and prevention.
Consider talking to your family about your results: Since MUTYH variants are passed down from generation to generation, your family members may also have the variant you do. Informing family members about their potential genetic health risks so that they can take action can be an important benefit of finding out your own MUTYH result. We encourage you to review our help article, Shared Risk: Talking To Family Members About Genetic Test Results, which includes a few important questions to think about and some ideas that may help you find the right approach for sharing genetic risk information.
Risk for colorectal cancer is also influenced by other factors
In the general population, eating a healthy diet, maintaining a healthy weight, engaging in physical activity, limiting alcohol consumption, and avoiding smoking can reduce the risk for colorectal cancer. It's important to talk with a healthcare professional before making any major lifestyle changes.
People with a first-degree relative who has been diagnosed with colorectal cancer are about twice as likely to develop colorectal cancer themselves, compared to the general population. The risk is even higher if that relative was diagnosed before the age of 45 or if there are two or more first-degree relatives who have developed colorectal cancer. For people with one MUTYH variant with a personal or family history of colorectal cancer, guidelines may recommend screening for colorectal cancer earlier and more often than the general population.
Other genetic factors:
Keep in mind that you could still have another variant in the MUTYH gene that is not included in our test. The two variants included in this report account for 80-90% of cancer-related MUTYH variants found in people of Northern European descent. However, this report does not include other variants found in people of other ethnicities. In addition, this report does not include variants in other genes linked to other hereditary colorectal cancer syndromes, such as Lynch syndrome and familial adenomatous polyposis (FAP).
Need more support?
There are a lot of resources available to individuals with MUTYH variants. If you do not have a healthcare provider currently, these resources may provide you with some useful information.
Genetic counselors are healthcare professionals who specialize in hereditary conditions and are specifically trained to help people understand their genetics in the context of personal and family history. They can provide both medical knowledge and emotional support. Speaking with a genetic counselor about your result can ensure that you have a clear understanding of what your result means for you personally. A genetic counselor can also help you think about different screening and preventive options, and work with other healthcare professionals to develop a plan that is best for you.
Your healthcare provider may be able to provide you with a recommendation for a genetic counselor. You can also visit the National Society of Genetic Counselors (NSGC) or American Board of Genetic Counseling websites to find a genetic counselor convenient for you.
To search for a genetic counselor using the NGSC website:
Choose whether you'd like to talk with a genetic counselor in person or by phone.
Enter information about where you live to match with a genetic counselor who is nearby, or who is able to consult with people from your state via phone.
(Optional) Choose whether you'd like a genetic counselor who specializes in a certain topic area. Because you'll be talking about cancer risk, we encourage you to select "cancer" from the list of options.
Be sure to click the check-box that says "board-certified."
After clicking "search," you'll be provided with a list of genetic counselors and a way to contact each of them.
Education and support from advocacy organizations
If you wish to learn more about colorectal cancer, there are several organizations that provide resources. Services offered by these organizations may include educational materials, online discussion forums, peer-to-peer support programs, helplines, and access to genetic counselors. This list of resources is for informational purposes to help you navigate your healthcare decision making and may be updated over time.
American Cancer Society: The American Cancer Society is a nonprofit organization that provides information on all types of cancers. In regards to colorectal cancer, they provide information on causes, risk factors, prevention, early detection, diagnosis, treatment, and post-treatment options.
Colorectal Cancer Alliance: The Colorectal Cancer Alliance raises awareness, provides support, and inspires the efforts that fund research to end colorectal cancer. They provide resources for patient and family support, including their free helpline that is staffed by certified patient and family support navigators; a 24-hour online group chat where you can connect with patients, survivors, and caregivers; resources on knowing your family history and screening for prevention and early detection; and their certified patient and family support navigators.
Fight Colorectal Cancer: Fight Colorectal Cancer empowers the community to push for better policies and to support research, education, and awareness for colorectal cancer. They provide resources on understanding genetics, including webinars and their Genetics Mini Magazine which provides an overview of hereditary cancer and genetic testing. Fight Colorectal Cancer also offers resources on screening options, including their Screening Mini Magazine which provides an overview of the importance of screening and the different types of tests available.