This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
First step of treatment of a person with FAP family history is 
Select and explain. 
A. colonoscopy, B. Total colectomy, C. Gene testing, D. Frozen section
C: Gene testing
Answer: C: Gene testing 
Explanation: Gene testing is performed first. If positive screening begins from 10 years of age.