Abstract | BACKGROUND/AIMS: METHODS: This study evaluated the phenotype of 74 patients with familial adenomatous polyposis from 11 unrelated families with an identical 5-base pair deletion at codon 1309 of the APC gene. RESULTS:
Polyp density in the sigmoid colon of 16 patients from 9 families varied from 3.8 to 13.1/cm2, and mean polyp diameter ranged from 1.4 +/- 0.1 to 2.7 +/- 0.1 mm. The distribution of colonic adenomas also varied, with diffuse polyposis in 6 patients but relative polyp sparing in the more proximal colon in 6 others. Age at diagnosis of colorectal cancer ranged from 19 to 62 years, but the mean age did not differ among the 4 families with multiple cases. Colorectal cancers occurred predominantly in the rectosigmoid (80%) but also in the more proximal colon. The percentage of patients affected by various extracolonic lesions differed widely among and within the 11 families (range, 0%-100%). CONCLUSIONS: APC gene mutation at codon 1309 results in intrafamily and interfamily phenotypic variation in familial adenomatous polyposis. Environmental and/or other genetic factors must play roles in the expression of germline APC gene mutations.
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Authors | F M Giardiello, A J Krush, G M Petersen, S V Booker, M Kerr, L L Tong, S R Hamilton |
Journal | Gastroenterology
(Gastroenterology)
Vol. 106
Issue 6
Pg. 1542-7
(Jun 1994)
ISSN: 0016-5085 [Print] United States |
PMID | 8194700
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
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Topics |
- Adenomatous Polyposis Coli
(genetics, pathology)
- Adult
- Codon
- Colon
(pathology)
- Colorectal Neoplasms
(pathology)
- Female
- Gene Deletion
- Humans
- Male
- Middle Aged
- Mutation
- Phenotype
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