- 期刊
APC Gene Mutations in Familial Adenomatous Polyposis: A Four Family Analysis
並列摘要
Purpose. APC-associated polyposis conditions include: familial adenomatous polyposis (FAP), attenuated FAP, Gardner syndrome, and Turcot syndrome. FAP is a syndrome with a predisposition for colon cancer, in which hundreds-to-thousands of pre-cancerous colonic polyps develop, with a mean age of onset of 16 years (range, 7-36 years). A colectomy is advised in those affected with classic FAP; however, in those choosing not to undergo a colectomy, colon cancer is inevitable by 39 years of age. We report herein four families with FAP, including a phenotype and genotype analysis. Methods. This study included five members in four families registered at the ChungHua Christian Hospital. DNA was extracted either from plasma or fresh healthy colonic tissue, and direct DNA sequencing was performed of the mutation cluster region (MCR). Results. With respect to the phenotype, not all family members expressed polyposis coli. Regarding the genotype, however, three mutations were noted, two of which were novel. All three mutations were heterozygous, one involving codon 1114 (c.3341 insT), one involving codon 1505 (c.4515 delC insAG), and the last involving codon 1556 (c.4669 insA). There were no abnormalities at MCR in one family. There was one polymorphism involving codon 1493 (ACG → ACA) affecting three families. Conclusion. By using the APC gene MCR testing, we identified three mutation points; nevertheless, taking a detailed family history and conducting a thorough physical examination remain important.