Genetic predisposition to CRC Minor genes: 95% Major genes: 5% 口 Sporadic/Isolated口 Familial口 Other polyposis syndromes■ HNPCC■FAP
Genetic predisposition to CRC
CRC Familial adenomatous polyposis (FAP): also called adenomatous polyposis coli (APc). an AD subtype of colon cancer that is characterized by a large number of adenomatous polyps. These polyps typically develop during the second decade of life and number in the hundreds or more(polyposis itself is defined as the presence of >100 polyps). FAP accounts for% of all Cro Penetrance of FAP is virtually 100%0 More than 700 different mutations of the APC gene(5q21) have been reported, most of which are nonsense or frameshift mutations APC: Adhesion molecule Interacts with B-catenin and when APC is mutated, the complex accumulates in the cell leading to transcriptional activation of other tumor promoting genes
CRC • Familial adenomatous polyposis (FAP): also called adenomatous polyposis coli (APC). an AD subtype of colon cancer that is characterized by a large number of adenomatous polyps. These polyps typically develop during the second decade of life and number in the hundreds or more (polyposis itself is defined as the presence of >100 polyps). FAP accounts for ~1% of all CRC. • Penetrance of FAP is virtually 100%. • More than 700 different mutations of the APC gene (5q21) have been reported, most of which are nonsense or frameshift mutations. • APC: Adhesion molecule. Interacts with β-catenin and when APC is mutated, the complex accumulates in the cell leading to transcriptional activation of other tumor promoting genes
In late childhood and early adulthood, up to 1000 and more polyps develop in the mucous membrane of the colon(1). Each polyp can develop into a carcinoma(2). In about 85% of affected persons, small hypertrophic areas not affecting vision are present in the retina(congenital hypertrophy of the retinal pigment epithelium, CHRPE, 3). WY A
In late childhood and early adulthood, up to 1000 and more polyps develop in the mucous membrane of the colon (1). Each polyp can develop into a carcinoma (2). In about 85% of affected persons, small hypertrophic areas not affecting vision are present in the retina (congenital hypertrophy of the retinal pigment epithelium, CHRPE, 3)