MUTYH Monoallelic gene

Associated Syndrome Name: MUTYH-associated Colorectal Cancer Risk

MUTYH Monoallelic Summary Cancer Risk Table

Cancer Genetic Cancer Risk
ColorectalElevated Risk

MUTYH Monoallelic gene Overview

MUTYH-associated Colorectal Cancer Risk 1, 2, 3, 4, 5
  • Individuals with a single MUTYH mutation (monoallelic MUTYH) may have a small increased risk for colorectal cancer. This increase in risk seems to be seen most consistently in patients who have a close relative (parent, brother, sister or child) who has had colorectal cancer, with increases in risk that are roughly equal to those associated with family history alone.
  • Individuals with mutations in both of their copies of the MUTYH gene (biallelic mutations) have a condition known as MUTYH-associated polyposis (MAP), which is associated with a high risk for cancer. This patient does not have a diagnosis of MAP, but may have relatives who are at risk for this condition. Please see the Information for Family Members section below for details.
  • Although there may be an increased risk for colorectal cancer for patients with a single MUTYH mutation, it may be possible to reduce this risk with appropriate medical management. The National Comprehensive Cancer Network (NCCN) has provided screening recommendations to address this risk. These guidelines will evolve as we learn more, and therefore it may be useful for patients with a single MUTYH mutation to be managed by a multidisciplinary team with expertise in medical genetics and the care of patients with hereditary cancer syndromes.

MUTYH Monoallelic gene Cancer Risk Table

Cancer Type Age Range Cancer Risk Risk for General Population
ColorectalTo age 801, 2, 3, 5, 63.4% to 10%2.8%

MUTYH Monoallelic Cancer Risk Management Table

The overview of medical management options provided is a summary of professional society guidelines. The most recent version of each guideline should be consulted for more detailed and up-to-date information before developing a treatment plan for a particular patient.

This overview is provided for informational purposes only and does not constitute a recommendation. While the medical society guidelines summarized herein provide important and useful information, medical management decisions for any particular patient should be made in consultation between that patient and his or her healthcare provider and may differ from society guidelines based on a complete understanding of the patient’s personal medical history, surgeries and other treatments.

Cancer Type Procedure Age to Begin Frequency
(Unless otherwise indicated by findings)
ColorectalColonoscopy for patients with a first-degree relative who has had colorectal cancer140 years, or 10 years younger than the age of diagnosis for any first-degree relative with colorectal cancerEvery 5 years
Currently there are no medical management guidelines for colorectal cancer risk in patients with a single MUTYH mutation unless colorectal cancer has been diagnosed in a first-degree relative1NANA

Information for Family Members

The following information for Family Members will appear as part of the MMT for a patient found to have a mutation in the MUTYH Monoallelic gene.

This patient's relatives are at risk for carrying the same mutation(s) and associated cancer risks as this patient. Cancer risks for females and males who have this/these mutation(s) are provided below.

Family members should talk to a healthcare provider about genetic testing. Close relatives such as parents, children, brothers and sisters have the highest chance of having the same mutation(s) as this patient. Other more distant relatives such as cousins, aunts, uncles, and grandparents also have a chance of carrying the same mutation(s). Testing of at-risk relatives can identify those family members with the same mutation(s) who may benefit from surveillance and early intervention.

This patient carries a single MUTYH mutation (monoallelic). This patient's relatives are at risk for carrying a single MUTYH mutation, or mutations in both copies of MUTYH (biallelic). A single MUTYH mutation can lead to an increased risk for colorectal cancer. Relatives who have inherited mutations in both copies of MUTYH are at risk for MUTYH-associated Polyposis syndrome (MAP), with a 43%-100% risk of colorectal cancer risk to age 80 and a 5% risk for small bowel cancer. Genetic testing may be appropriate for close family members to determine whether they are at an increased risk for colorectal and other cancers.


  1. Gupta S, et al. NCCN Clinical Practice Guidelines in Oncology® Genetic/Familial High-Risk Assessment: Colorectal. V 1.2021. May 11. Available at
  2. Jones N, et al. Increased colorectal cancer incidence in obligate carriers of heterozygous mutations in MUTYH. Gastroenterology. 2009 137:489-94 PubMed PMID: 19394335.
  3. Win AK, et al. Risk of colorectal cancer for carriers of mutations in MUTYH, with and without a family history of cancer. Gastroenterology. 2014 146:1208-11. PMID: 24444654.
  4. Nielsen M, et al. MUTYH-Associated Polyposis. 2019 Oct 10. In: Pagon RA, et al., editors. GeneReviews® [Internet]. PMID: 23035301.
  5. Jenkins MA, et al. Risk of colorectal cancer in monoallelic and biallelic carriers of MYH mutations: a population-based case-family study. Cancer Epidemiol Biomarkers Prev. 2006 15:312-4. PMID: 16492921.
  6. SEER*Explorer: An interactive website for SEER cancer statistics [Internet]. Surveillance Research Program, National Cancer Institute. [Cited 2020 Sep 14]. Available from
Last Updated on 29-Sep-2022