title: A De Novo Germline APC Mutation (3927del5) in a Patient with Familial Adenomatous Polyposis: Case Report and Literature Review.
abstract: BACKGROUND
  Characterized by the development of hundreds to thousands of colonic adenomas, classic familial adenomatous polyposis (FAP) is one of the most common hereditary syndromes associated with an increased risk of colorectal cancer. Several studies have attempted to correlate specific APC mutations with clinical phenotype.6 However, there is considerable variability in the expression of specific phenotypes within families and among individuals with identical mutations.7
  
  
  METHODS
  A 30 year-old Hispanic female presented to the emergency department with a 2-week history of persistent, worsening, left lower quadrant abdominal pain. She had no family history of malignancy. Sigmoidoscopy revealed innumerable polyps in the rectum and sigmoid colon and a large mass in the sigmoid colon. Biopsy of the mass revealed a moderately differentiated adenocarcinoma invading the subserosa. Endoscopy revealed innumerable polyps. Genetic testing of the patient via southern blot revealed a germline APC mutation 3927del5, resulting in a premature truncation of the APC protein at amino acid position 1312.
  
  
  CONCLUSIONS
  Genetic information has only recently started being incorporated into clinical care. More research and randomized clinical trials need to be conducted to definitively characterize random mutations. Once these mutations are further understood, FAP patients may be able to be risk stratified and this may ultimately improve the screening, diagnosis, and treatment of this rare condition.
authors.affiliation: Department of Internal Medicine, Mount Sinai Medical Center Florida.
authors.forename: Simon B
authors.initials: SB
authors.lastname: Zeichner
authors.forename: Naveen
authors.initials: N
authors.lastname: Raj
authors.forename: Mike
authors.initials: M
authors.lastname: Cusnir
authors.forename: Michael
authors.initials: M
authors.lastname: Francavilla
authors.forename: Alicia
authors.initials: A
authors.lastname: Hirzel
keywords: FAP; colon cancer; familial adenomatous polyposis; sporadic mutation