colonic polyposis

The APC I1307K polymorphism is associated with an increased risk of colon cancer but does not cause colonic polyposis.

MADH4 mutations, which cause colonic polyposis in addition to HHT, comprise about 2% of disease-causing mutations.

Two features of particular clinical interest that are apparently associated with APC mutations are (1) the density of colonic polyposis and (2) the development of extracolonic tumors.