This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal Polyps, Colon & Anal Cancer, Subject name: Pathology
[{'content': 'Colon carcinoma is associated with all except: \nSelect and explain. \nA. Rb, B. Mismatch repair genes, C. APC, D. b-catenin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: - Rb gene mutation is associated with Retinoblastoma of eye not Colon cancer. Genetic risk factors of colon cancer: HNPCC / Lynch syndrome/ CEO syndrome caused d/t defect in DNA mismatch repair genes resulting in microsatellite instability - Cancer. FAP caused d/t defect in APC/b-catenin pathway resulting in- increased adenomatous polyps - increased risk of colon cancer Etiology Molecular defect Target gene Transmission Familial adenomatous polyposis APC/WNT pathway APC Autosomal dominant Hereditary nonpolyposis colorectal cancer DNA mismatch repair MSH2, MLH1 Autosomal dominant Sporadic colon cancer APC/WNT pathway APC None Sporadic colon cancer DNA mismatch repair MSH2, MLH1 None', 'role': 'assistant'}]