True about familial adenomatous polyposis is?
Ans. is 'c' i.e., 100% risk of malignancy in classical variety Familial adenomatous polyposis (FAP) syndrome* Familiar polyposis coli is an autosomal dominant condition affecting males and females equally* It is also called as familial polyposis coli. It is caused by mutation in adenomatous polyposis coli gene* located on long arm of chromosome 5 (5q21). Risk of malignancy is 100%, i.e. all patients develop colorectal carcinoma if left untreated.* There are following subtypes of FAP :a) Classic FAP syndrome: A minimum of 100 polyps (adenomas) are necessary for diagnosis of classic FAP.b) Attenuated FAP: Fewer polyps are there (around 30) with less risk of malignancy (50%).c) Gardner syndrome: It is an autosomal dominant condition, characterized by presence of multiple adenomatous polyps with desmoid tumor, osteomas, epidermoid cysts, lipomas, dental abnormalities and periampullary carcinoma.d) Turcot's syndrome: It is characterized by multiple adenomatous polyps with CNS tumors (medulloblastoma glioblastoma).
Also known as Lynch syndrome
FAP gene is located on 5p21
100% risk of malignancy in classical variety
Males are usual carriers
G.I.T.