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Zorluk: OrtaGastroenterology and Hepatology

Match the following hereditary gastrointestinal polyposis and cancer syndromes with their defining genetic, clinical, or phenotypic characteristics.

  • Familial Adenomatous Polyposis (FAP)Associated with an APC gene mutation, presenting with hundreds of colonic adenomas without prominent extra-intestinal soft-tissue or bone tumors.
  • Lynch Syndrome (HNPCC)Associated with defective DNA mismatch repair genes (e.g., MLH1, MSH2) leading to right-sided colon cancers and endometrial carcinoma.
  • Peutz-Jeghers SyndromeAssociated with an STK11 gene mutation, presenting with hamartomatous gastrointestinal polyps and perioral hyperpigmented macules.
  • Gardner SyndromeAssociated with an APC gene mutation, distinctly featuring widespread colonic adenomas alongside osteomas, epidermoid cysts, and desmoid tumors.

Cevap

Familial Adenomatous Polyposis matches with the APC mutation without extra-intestinal tumors; Lynch Syndrome matches with mismatch repair gene mutations and endometrial cancer; Peutz-Jeghers Syndrome matches with STK11 mutations and perioral pigmentation; Gardner Syndrome matches with an APC mutation accompanied by osteomas and desmoid tumors.
Each hereditary gastrointestinal syndrome has a distinct genetic and phenotypic profile. Classic FAP and Gardner syndrome both arise from APC gene mutations, but Gardner syndrome is distinguished by its unique extra-intestinal manifestations like osteomas and desmoid tumors. Lynch syndrome is fundamentally different, driven by DNA mismatch repair mutations, and presents with fewer polyps but a high risk of right-sided colon and endometrial cancers. Peutz-Jeghers syndrome is uniquely defined by STK11 mutations causing hamartomatous (rather than primarily adenomatous) polyps and mucocutaneous hyperpigmentation.

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1
Identify the characteristics of Familial Adenomatous Polyposis (FAP)
Matches with an APC gene mutation causing hundreds of adenomas but lacking the distinct extra-intestinal bone/soft-tissue tumors.
Classic FAP primarily affects the colon with massive polyp burden, leading to a near 100% risk of colon cancer if prophylactic colectomy is not performed.
2
Identify the characteristics of Lynch Syndrome
Matches with defective DNA mismatch repair genes and an association with endometrial carcinoma.
Lynch Syndrome, or HNPCC, is uniquely characterized by DNA mismatch repair defects (e.g., MLH1, MSH2) and poses a high risk for non-GI cancers, most notably endometrial and ovarian.
3
Identify the characteristics of Peutz-Jeghers Syndrome
Matches with an STK11 gene mutation, hamartomatous polyps, and perioral hyperpigmented macules.
The combination of hamartomas (which can cause intussusception and bleeding) and mucocutaneous melanin deposits is pathognomonic for Peutz-Jeghers.
4
Identify the characteristics of Gardner Syndrome
Matches with an APC gene mutation that distinctly features osteomas, epidermoid cysts, and desmoid tumors.
Gardner syndrome is a specific variant of FAP where the APC mutation manifests with significant and characteristic extra-intestinal lesions, specifically osteomas and desmoid tumors.

Anahtar Kavram

Genetics and clinical manifestations of hereditary gastrointestinal polyposis and colorectal cancer syndromes.
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