Learning you have two MUTYH variants, or two copies of a MUTYH variant, can cause many different emotions. 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 have 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 who have two MUTYH variants, or two copies of a MUTYH variant have an increased risk of developing colorectal cancer and may have a slightly increased risk for certain other cancers. However, proper screening and surveillance can help lower cancer risk.
In the general population, about 4% of people are expected to develop colorectal cancer over the course of their lifetime. For individuals with two MUTYH variants or two copies of a MUTYH variant, this risk increases to 43-100% without appropriate surveillance. In addition, risk for small bowel (duodenal) cancer and certain other cancers may be slightly increased.
For your family:
MUTYH variants are passed down through families, so your result for this report is relevant to your family members. If any of your relatives also have two MUTYH variants or two copies of a MUTYH variant, they would also have an increased risk for colorectal cancer and potentially certain other cancers. In addition, any family members who have one MUTYH variant may have a slightly increased risk for colorectal cancer. However, more studies are needed to establish exact risk estimates for people with one variant. Any family members with one or more variants could also pass those variants on to their children.
If you have two different MUTYH variants, both of your parents and each of your children likely have at least one of these variants. Your siblings may also be at risk for MAP. If your partner has a variant linked to MAP, each child most likely has a 50% chance of having this condition.
If you have two copies of the same MUTYH variant, both of your parents and each of your children likely have this variant. Your siblings may also be at risk for MAP. If your partner has a variant linked to MAP, each child has a 50% chance of having this condition.
What should I do now?
We strongly recommend that people with two variants or two copies of a variant in the MUTYH gene talk to a healthcare professional about their result.
Talk to your doctor or a genetic counselor about confirming your result:
It’s important to confirm a 23andMe MUTYH result with additional testing in a clinical setting before taking any medical action. This is because the 23andMe test is performed at-home rather than in a doctor's office, and also because the results you receive from 23andMe are not intended for diagnostic use. If you're not sure who to talk to, genetic counselors are a good option. Genetic counselors are trained to help people understand genetic testing options, and they can work with other healthcare professionals to coordinate your care. Ask your healthcare provider about access to genetic counseling services, or see below to learn how to search for a genetic counselor near you.
Discuss screening and prevention options:
It's important to talk to a healthcare professional to confirm your result and discuss options for cancer screening and prevention. 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. There are guidelines that may help you and your doctor create a screening plan that's right for you. Learn more from GeneReviews.
Professional guidelines recommend that people with MAP should be screened for colorectal cancer earlier and more often using a procedure called colonoscopy. Guidelines also recommend these individuals be screened for small bowel cancer. Depending on your screening results, your doctor can advise you on the best screening and prevention plan for you.
Consider talking to your family about your results:
Since MUTYH variants are passed down from generation to generation, your family members may also carry the variant(s) 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 factors other than genetics, such as lifestyle choices
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, although research is ongoing into how these lifestyle factors may impact cancer risk in people with your genetic result. It's important to talk with a healthcare professional before making any major lifestyle changes.
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
Learning that you have genetic variants that increase your risk for colorectal cancer can be difficult, but know that you’re not alone. There are several organizations that provide support resources for people with a genetic risk of cancer. 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.