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rs2229992(G;T)

From SNPedia
Familial Adenomatous Polyposis
Is agenotype
ofrs2229992
GeneAPC
Chromosome5
Position112,827,157
mentionedby
Magnitude6.5
ReputeBad
Geno Mag Summary
(G;T) 6.5 Familial Adenomatous Polyposis
(T;T) 0 common in clinvar

This is a genotype with recommended actions if clinically confirmed. In brief:

  • Classic Familial Adenomatous Polyposis (FAP) is characterized by the presence of ≥100 adenomatous polyps. About 10% of cases are referred to as attenuated FAP (AFAP) and have milder disease progression.
  • Treatment for FAP should include thorough counseling about the nature of the syndrome and the need for compliance with recommendations for management and surveillance.
  • Annual endoscopic surveillance (i.e., flexible sigmoidoscopy or colonoscopy) is recommended until the polyp burden necessitates that colectomy is performed.
  • Colonscopic clearance of adenomas in patients with classical FAP cannot guarantee that cancer will be prevented; therefore, removal of the at-risk epithelium ((procto)colectomy) is considered the standard of care.
  • Surveillance for gastric and proximal small bowel tumors with esophagogastroduodenoscopy using forward and side-viewing endoscopes should begin at age 20 to 30.
  • The increased relative risks relative to average population risks for various cancers for classic FAP are about 800-1000x higher for desmoid tumors, 100-300x for duodenal cancer, ~5x for pancreatic cancer, and 2-4 for adrenal masses.

The full ClinGen Actionability report about Familial Adenomatous Polyposis (FAP) can be found here.

Genetic counseling may be available to you through your health-care network. In the US, genetic counselors may be found via this webpage of the National Society of Genetic Counselors.