1. Background

• Familial Polyposis Disorder is classified into three disorders each associated with potentially-malignant adenomatous polyps:
  1. Familial Polyposis Coli (FPC)
  2. Gardner's Syndrome
  3. Turcot's Syndrome
• the colonic manifestation (adenomatous polyposis) is common to all three disorders but the extracolonic manifestations differ
• malignancy potential
  • about 10 years usually elapses between the appearance of polyps and the development of colonic carcinomas
  • adenocarcinomas
    • develop in 100% of patients by age 50
    • may develop by as early as 9 years
    • are frequently multifocal and low grade

2. Genetic Defect

• genetic defect -> multiple mutations within the APC gene (includes single base pair mutations, small insertions, and small deletions) -> truncation of the APC gene product in a majority (82%) of cases (Powell et al., NEJM 329(27): 1982 (1993) or a reduced levels of normal APC transcripts
• the disorder may be caused by a pleitropic gene responsible for the colonic involvement in all patients with variable penetrance being responsible for one or several of the extracolonic manifestations.
• the mutant gene may result in the failure to repress DNA synthesis as DNA synthesis is seen throughout the glandular crypts in isolated adenomatous polyps whereas normally DNA synthesis is confined to the lower half of the crypts

1. Gastrointestinal Manifestations

2. Extracolonic Manifestations

1. Colonoscopy/Endoscopy

• colon carpetted by 100's of small, sessile polyps
• endoscopy for extracolonic lesions
• biopsy - adenomas without inflammatory or cystic changes

2. Imaging Studies

• barium enema with air contrast

1. Surveillance

• colonscopy every 2 years after age 8-9 years
• genetic counselling

2. Surgery

• total proctocolectomy with terminal ileostomy or Kock procedure
• subtotal colectomy with stripping of the rectal mucosa and anoileal anastomosis (rectal preservation not recommended in children)