This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics, Subject name: Pathology
Familial polyposis coli is associated with following genetic defect? 
Select and explain. 
A. MLH1, B. MSH2, C. APC, D. RET
C: APC
Answer: C: APC 
Explanation: Ans is ;c' i.e., APC * Familial adenomatous polyposis (FAP) syndrome (familial polyposis coli) is caused by mutation in adenomatous polyposis coli gene(APC) located on long arm of chromosome 5 (5q21). Risk of malignancy is 100%, i.e. all patients develop colorectal carcinoma if left untreated.