A 42-year-old man with familial adenomatous polyposis presents with abdominal pain, fatigue, and iron-deficiency anemia. Vital signs: BP 128/82, HR 92, RR 16, temp 37.2°C, SpO2 98%. Laboratory studies show hemoglobin 9.2 g/dL and ferritin 18 ng/mL. Colonoscopy reveals hundreds of adenomatous polyps throughout the colon with a malignant mass in the rectum. No extraintestinal manifestations noted. Which genetic mutation explains this syndrome and predisposes to inevitable colorectal cancer progression?

1. A)BRAF V600E mutation activating the MAPK pathway
2. B)Mismatch repair gene mutations (MLH1, MSH2) causing microsatellite instability
3. C)Reactivation of telomerase through TERT promoter mutation
4. D)Germline BRCA1/BRCA2 mutations with defective homologous recombination
5. E)Germline inactivation of the APC tumor suppressor gene leading to constitutive Wnt signaling and polyp formationGABARITO