**Question:** Following genetic counseling in a family for Familial Polyposis Coli (FPC) in a 15-year-old person, APC gene mutation is present. Next step of screening is:

A. Colonoscopy
B. Total colonoscopy
C. Total colectomy
D. Immediate surgery

**Core Concept:** Familial Polyposis Coli (FPC) is a rare autosomal dominant hereditary disorder characterized by the presence of multiple polyps in the colon and rectum. The APC gene mutation is a key diagnostic marker for FPC.

**Why the Correct Answer is Right:** The correct answer is A. Colonoscopy because it is a minimally invasive procedure that allows for the visualization and biopsy of the colorectal mucosa to evaluate for the presence of polyps. Colonoscopy is essential for early detection and management of FPC, as the disease progresses rapidly, and timely intervention can prevent colorectal cancer.

**Why Each Wrong Option is Incorrect:**

B. Total colonoscopy is not needed as it is an invasive procedure and carries a higher risk compared to colonoscopy.
C. Total colectomy is an extensive surgical procedure with significant morbidity and mortality, which should be considered only if colonoscopy fails to detect polyps or when polyps are large and malignant.
D. Immediate surgery is not a suitable option as it is an extensive procedure without proper evidence-based indication for such a procedure in a 15-year-old patient.

**Why Each Wrong Option is Incorrect:**

A. Colonoscopy is essential for initial screening in FPC as it allows for the detection and removal of polyps, preventing malignant conversion if detected early. Colonoscopy is a safer and more appropriate procedure for a 15-year-old patient.
B. Total colonoscopy is not required as it is more invasive and carries a higher risk compared to colonoscopy.
C. Total colectomy is an extensive surgical procedure with significant morbidity and mortality, which should be considered only if colonoscopy fails to detect polyps or when polyps are large and malignant.
D. Immediate surgery is not a suitable option in a 15-year-old patient without any clinical symptoms or signs of FPC.

**Clinical Pearl:** Colonoscopy is the appropriate initial screening procedure for FPC, as it allows for the detection and removal of polyps, preventing malignant conversion if detected early. Early detection and intervention are crucial in minimizing the risk of colorectal cancer in FPC patients, including young individuals.