CHICAGO—Among patients with multiple colorectal polyps, the prevalence of certain gene mutations varied considerably by polyp count, according to a study in the August 1 issue of JAMA.
"Patients with multiple colorectal adenomas [polyps] may carry germline [those cells of an individual that have genetic material that could be passed to offspring] mutations in the APC or MUTYH genes," according to background information in the article. The authors write that guidelines for when genetic evaluation should be performed in individuals with multiple colorectal adenomas vary, and data to support such guidelines are limited.
Shilpa Grover, MD, MPH, of Brigham and Women's Hospital, Boston, and colleagues conducted a study to evaluate the frequency of APC and MUTYH mutations by the number of colorectal adenomas among individuals who had undergone clinical genetic testing. The researchers also studied the relationship between the number of adenomas and age at diagnosis of adenoma and colorectal cancer and the prevalence of pathogenic APC or MUTYH mutations. The study included 8,676 individuals who had undergone full gene sequencing between 2004 and 2011. Individuals with a certain mutation of the MUTYH gene (Y179C and G396D) underwent full MUTYH gene sequencing. APC and MUTYH mutation prevalence was evaluated by the number of polyps.