One MYH Mutation Detected

This information is designed for individuals who have been tested for a hereditary cancer syndrome. It will help you understand the results of your test and is best reviewed with your healthcare provider. Please choose the link below that matches your test result by looking at the patient copy of your test result or contacting the healthcare provider who ordered your test.

Overview of MYH-Associated Polyposis

Mutations in BOTH copies of the MYH gene cause an adenomatous polyposis syndrome called MYH-associated polyposis (MAP). MAP is associated with the development of multiple adenomas (pre-cancerous polyps) in the colon and rectum, most often more than 10 adenomas over a lifetime. This syndrome also leads to an increased risk of colon/rectal (colorectal) cancer and possibly other types of cancer.

The Genetic Test(s) You Received

  • Gene-Specific COLARIS AP® MYH Analysis: Full sequence analysis of the MYH gene.

Your Test Result

  • One MYH Mutation Detected

Overview of Your Test Result

  • A mutation or alteration was detected in only ONE of your MYH genes. You are an MYH mutation carrier.
  • Mutations in BOTH copies of the MYH genes are necessary for a diagnosis of MYH-associated polyposis (MAP).
  • The chance that you have MAP is significantly reduced but not completely ruled out.
  • You may want to consider analysis of the APC gene, if it hasn’t been done already.

Your Cancer Risks

  • The risk of cancer and adenomas in MYH mutation carriers is unclear but it appears that any increase in risk is small and is associated with later age of onset (usually after age 50).
  • Your cancer risks should be estimated based on your personal and family history of cancer.
  • Your healthcare provider can assist you in understanding these risks.
  • The possibility remains that your cancer risks could be increased due to:
    • Other non-hereditary factors (for example: environment).
    • Another hereditary cancer syndrome.
    • A mutation in the MYH gene that current technology cannot detect

Managing Your Risks

  • Your test result has given you some helpful information but it is still best to manage your cancer risks based on your personal and family history.
  • You and your healthcare provider can develop the most appropriate plan for your medical management.
  • Your healthcare provider can help you determine whether any further genetic testing should be offered to you or to a family member.

It’s a Family Affair

  • This result reduces the chance that you have MAP.
  • In most cases, your relatives would not benefit from genetic testing.
  • In some cases, however, genetic testing should be offered to another relative who has been diagnosed with cancer or multiple adenomas in order to provide more information about hereditary risk in the family. Talk to your healthcare provider about this option.
  • Your biological children will have a 50% chance to be MYH mutation carriers. In the rare case that your reproductive partner carries an MYH mutation, your children may inherit two MYH mutations and have MAP. Your partner can be tested to determine if he/she also carries an MYH mutation.

Next Steps

Please work with your healthcare provider to determine the most appropriate next steps for you.

  • Obtain a copy of your test result.
  • Schedule consultations with appropriate healthcare providers.
  • Create a plan for medical management.
  • Ask your provider whether additional genetic testing makes sense for you or your family.
  • Share your genetic test result with your relatives.
  • Re-contact your healthcare provider on a regular basis for new information.

Additional Resources

Myriad has resources available to help you with your genetic test result.

  • Contact Myriad’s Medical Services Department at 1-800-469-7423 for:
    • Answers to questions about your test result.
    • Information about genetic testing for your relatives.
  • Online tools:

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