MUTYH-associated Polyposis Syndrome

MUTYH-associated Polyposis Syndrome is a genetic condition that affects the colon and rectum, leading to the development of many small growths called polyps. These polyps are benign at first but can turn into colorectal cancer if not monitored or treated. The syndrome is caused by changes in a gene responsible for repairing DNA damage, which increases the risk of abnormal cell growth. People with this condition often develop dozens to hundreds of polyps, usually starting in adulthood. Early detection and regular screening are important because the condition significantly raises the chance of developing colon cancer over time.

MUTYH-associated Polyposis Syndrome (MAP) is an autosomal recessive hereditary colorectal cancer syndrome characterized by the development of multiple adenomatous polyps in the colon and rectum. It results from biallelic mutations in the MUTYH gene, which encodes a DNA glycosylase involved in base excision repair of oxidative DNA damage. The defective repair mechanism leads to accumulation of G:C to T:A transversions, promoting oncogenic mutations. Clinically, MAP presents with 10 to several hundred adenomatous polyps, typically fewer than seen in familial adenomatous polyposis (FAP), and an increased lifetime risk of colorectal cancer often by the 5th or 6th decade. Extra-colonic manifestations are less common than in FAP. The syndrome is significant due to its cancer predisposition and the need for genetic counseling and surveillance.