We give evidence that this extracolonic manifestation of FAP is determined by the same germline mutation of the APC gene responsible for colonic polyps and cancer but also shows some unusual features (F : M ratio = 80 : 1, absence of LOH for APC in the thyroid tumoral tissue, and indolent biological behaviour, despite frequent multicentricity and lymph nodal involvement), suggesting that the APC gene confers only a generic susceptibility to thyroid cancer, but perhaps other factors, namely, modifier genes, sex-related factors, or environmental factors, are also required for its phenotypic expression.
Here we applied whole-genome sequencing (WGS) to the DNA of a sporadic FAP patient in which we did not find any pathological APC mutations by direct sequencing.
Germ-line mutations in the adenomatous polyposis coli (APC) gene characteristic of familial adenomatous polyposis were evaluated, as well as DNA replication errors and germline mutations in nucleotide mismatch-repair genes characteristic of hereditary nonpolyposis colorectal cancer.
Our results provide information helpful to an understanding of the APC gene and will also contribute to presymptomatic diagnosis of members in FAP families.
We examined somatic mutations of the adenomatous polyposis coli (APC) gene in 63 colorectal tumors (16 adenomas and 47 carcinomas) developed in familial adenomatous polyposis (FAP) and non-FAP patients.
These data suggest that more than one gene on chromosome 5q21 may contribute to colorectal neoplasia, and that mutations of the APC gene can cause both FAP and GS.
We have found that FAP patients with germline APC mutations within a small region (codons 1,194-1,392 at most) mainly show allelic loss in their colorectal adenomas, in contrast to other FAP patients, whose 'second hits' tend to occur by truncating mutations in the mutation cluster region.
The adenomatous polyposis coli (APC) gene was analyzed for germline mutations in 113 familial adenomatous polyposis suspected families from all over Slovakia.
Duodenojejunal polyposis was evaluated in 41 consecutive patients with familial adenomatous polyposis (mean age 41 years, range 21-63 years), 33 (80%) with known APC mutation, by using a standardized endoscopic protocol.
De novo mutations in the adenomatous polyposis coli (APC) gene are estimated to constitute approximately 25% of familial adenomatous polyposis (FAP) cases.