Lynch syndrome (HNPCC) is caused by defects in mismatch repair genes. Among the Amsterdam II criteria, the minimum pedigree requirement includes:
- A Three first-degree relatives with Lynch-related cancers across two generations, one diagnosed before 50 ✓
- B Two affected relatives, both diagnosed before 60, in one generation
- C Three relatives with colorectal cancer across three generations, none requiring FAP exclusion
- D Two first-degree relatives with colorectal cancer diagnosed after 60 plus one with endometrial cancer
Correct answer: A. Three first-degree relatives with Lynch-related cancers across two generations, one diagnosed before 50
Explanation
Amsterdam II criteria require: (1) at least three relatives with Lynch-associated cancers (colorectal, endometrial, small bowel, ureter/renal pelvis), (2) spanning at least two generations, (3) one being a first-degree relative of the other two, (4) at least one diagnosed before age 50, and (5) FAP excluded. These are the clinical diagnostic criteria before genetic testing is pursued.
Reference: Bailey & Love's Short Practice of Surgery, 27th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.