Monoallelic Variants in Recessive CRC Genes Not Associated With Increased CRC Risk
Douglas K. Rex, MD, MASGE, reviewing Mahmood K, et al. Gastroenterology 2023 Jul 13.
Increasingly, we are consulted on or asked to perform colonoscopies on patients who previously underwent multigene panel testing for oncogenes associated with colorectal cancer (CRC). Often the need for and the appropriate frequency of colonoscopies are uncertain in these patients. One such referral is patients with mutations in one allele of a recessively acting gene such as MUTYH.
In a study examining the importance of rare variants, investigators analyzed 58,998 CRC cases and 71,171 controls.
The bottom-line finding was that monoallelic variants in recessive-acting genes such as MUTYH, NTHL1, MSH3, and MBD4 are not associated with increased CRC risk. The population frequency of these variants is close to 1%.
![d-rex](/wp-content/uploads/d-rex.jpg)
COMMENTThese results support following the average-risk screening recommendations with patients referred with single-gene mutations in these recessive-acting genes.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Mahmood K, Thomas M, Qu C, et al. Elucidating the risk for colorectal cancer for variants in hereditary colorectal cancer genes. Gastroenterology 2023 Jul 13. (Epub ahead of print) (https://doi.org/10.1053/j.gastro.2023.06.032)