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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

FAP is an autosomal dominant disorder characterized by the appearance of thousands of adenomatous polyps. FAP is associated with a deletion of chromosome 5q21 (known as the APC gene). Surgical prophylaxis in FAP consists of resection of the entire large bowel, to prevent malignant transformation. Hereditary Nonpolyposis Colorectal Cancer(HNPCC), like FAP, is an autosomal dominant disorder. In contrast to FAP, HNPCC is associated with an unusually high frequency of cancers in the proximal large bowel. If an adenoma or adenocarcinoma of the colon is identified, total abdominal colectomy with an ileorectal anastomosis is recommended.
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PMID:[Genetic counseling, surgical prophylaxis and treatment for familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer]. 1843 11

A multimodal approach of complementary techniques targeting primarily truncating, deletion and rearrangement mutations provides a robust screening protocol that identifies the vast majority of pathogenic germline APC gene mutations in FAP patients. Patients in whom no mutation is identified through this mutation protocol, may be sub-cohorts representing a different FAP pathogenesis including MYH associated polyposis and somatic cell mosaicism for APC gene mutations.
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PMID:Familial adenomatous polyposis. 1941 46

The molecular diagnostics of genetically conditioned disorders is based on the identification of the mutations in the predisposing genes. Hereditary cancer disorders of the gastrointestinal tracts are caused by mutations of the tumour suppressor genes or the DNA repair genes. Occurrence of recurrent mutation allows improvement of molecular diagnostics. The mutation spectrum in the genes causing hereditary forms of colorectal cancers in the Polish population was previously described. In the present work an estimation of the frequency of the recurrent mutations of the APC gene was performed. Eight types of mutations occurred in 19.4% of our FAP families and these constitute 43% of all Polish diagnosed families.
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PMID:Recurrent APC gene mutations in Polish FAP families. 1972 96

Colorectal cancer (CRC) is one of the main causes of death in South American countries. The hereditary forms of CRC are, familial adenomatous (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch Syndrome (LS), which is the most common form. The detection of mutations in the DNA repair genes (MMR) and in the APC genes enables the development of prevention strategies. Some of these methods for molecular diagnosis are applied in research and the detection of mutations of these genes, such as the partial thromboplastin time test (PTT), the single strand conformational polymorphism test (SSCP), the Denaturing High Performance Liquid Chromatography test (DHPLC) and the Polymerase Chain Reaction (PCR) in real time (qPCR).
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PMID:[Molecular research methods in the detection of germinal mutations in hereditary colorectal cancer]. 1989 97

A systematic histologic analysis of 62 gastric fundic gland polyps (FGP) was carried out. All FGP (100%) showed foveolar cells with hypertrophic cytoplasm. In 95% of the FGP, parietal cells ballooned into the lumen and in 93%, exfoliated anucleated structures with eosinophilic granules were found. Plugs of anucleated structures with eosinophilic granules, most likely derived from exfoliated parietal cells, were found to clog the outlets of the glands in 86% of the FGP. None of the 30 control gastric biopsies without FGP had similar cellular aberrations. FGP seems to evolve by cellular aberrations affecting parietal cells. This is not surprising considering that genetic mutations are recorded in FGP with a common APC/b-catenin pathway in both FAP and sporadic cases. The genetic mutations in FGP might alter the biological behavior of the parietal cells, leading to increased exfoliation with clogging of the outlets of the glands. Thus, the blocking of the glandular outflow by plugs of anucleated structures with eosinophilic granules is the most likely cause for the cystic accumulation of "normal" glandular secretions.
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PMID:Plugs clog the glandular outlets in fundic gland polyps. 1991 30

There are two major hereditary colorectal cancer syndromes: Adenomatous Polyposis, secondary to APC germline alterations (FAP, Familial Adenomatous Polyposis) or secondary to MUTYH germline alterations (MAP, MUTYH associated Polyposis), and Lynch syndrome, associated with germline mutations in mismatch repair genes (MLH1, MSH2, MSH6 and PMS2). The elucidation of their genetic basis has depicted an increasingly complex picture that has lead to the implementation of complex diagnostic algorithms that include both tumor profiling and germline analyses. A variety of techniques at the DNA, RNA and protein level are used to screen for molecular alterations both in tumor biopsies (microsatellite instability analysis, mismatch repair protein immunohistochemistry, BRAF-Val600Glu detection and MLH1 promoter hypermethylation analysis) and in the germline (point mutation screening, copy number assessment). Also functional tests are more often used to characterize variants of unknown significance. Methodological issues associated with the techniques analyzed, as well as the algorithms used, are discussed.
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PMID:Detection of genetic alterations in hereditary colorectal cancer screening. 1993 46

Familial adenomatous polyposis [FAP (OMIM 175100)] is an autosomal dominant colorectal cancer predisposition syndrome characterized by hundreds to thousands of colonic polyps and, if untreated by a combination of screening and/or surgical intervention, an approximately 99% lifetime risk of colorectal cancer. A subset of FAP patients develop an attenuated form of the condition characterized by lower numbers of colonic polyps (highly variable, but generally less than 100) and a lower lifetime risk of colorectal cancer, on the order of 70%. We report the diagnosis of three attenuated FAP families due to a 1.4-kb deletion within intron 14 of APC, originally reported clinically as a variant of unknown significance (VUS). Sequence analysis suggests that this arose through an Alu-mediated recombination event with a locus on chromosome 6q22.1. This mutation is inherited by family members who presented with an attenuated FAP phenotype, with variable age of onset and severity. Sequence analysis of mRNA revealed an increase in the level of aberrant splicing of exon 14, resulting in the generation of an exon 13-exon 15 splice-form that is predicted to lead to a frameshift and protein truncation at codon 673. The relatively mild phenotypic presentation and the intra-familial variation are consistent with the leaky nature of exon 14 splicing in normal APC. The inferred founder of these three families may account for as yet undetected affected branches of this kindred. This and similar types of intronic mutations may account for a significant proportion of FAP cases where APC clinical analysis fails because of the current limitations of testing options.
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PMID:Large intron 14 rearrangement in APC results in splice defect and attenuated FAP. 2003 12

A subset of APC mutation carriers shows a milder familial adenomatous polyposis phenotype (attenuated FAP) developing smaller number of polyps and colorectal cancer at an older age. It seems that a different mechanism to carcinogenesis is initiated according to the initial site of the germline mutation. The APC gene of a female patient with AFAP phenotypic features was analysed. A novel mutation located on the alternatively splice site of exon 9 was identified. This is the first reported mutation in the specific site. Transcripts characterization revealed disruption of splicing occurring within exon 9, resulting in the expression of a shorter mRNA transcript, which surprisingly does not affect the ratio between the two wild type transcripts, as well as the production of wild type short isoform by the mutant allele. The short wild type isoform, produced by the mutant allele, needs to be inactivated, on top of the wild type allele, for colorectal cancer to develop. These observations enhance the 'three hit hypothesis' and indicate that a distinct mechanism for the adenoma to carcinoma sequence should be followed, for truncated mutations taking place on the borderline of the alternatively spliced exon 9 of the APC gene, as well.
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PMID:A distinct mutation on the alternative splice site of APC exon 9 results in attenuated familial adenomatous polyposis phenotype. 2003 87

The case presented raised our scientific curiosity and it is worthy of being brought in front of the medical audience because of several reasons presented below. Presently, there are 3 hereditary syndromes that have a demonstrated etiological relationship with the colorectal cancer: Familiar Adenomatous Polyposis (FAP syndrome), HNPCC syndrome (Hereditary Nonpoliposis Colorectal Cancer) and MAP syndrome.Discovered only in 2002, the MAP syndrome (MYH associated polyposis) is the first hereditary syndrome that has autosomal recessive transmission. The APC gene can be mutated in several ways during the colonic oncogenesis: congenital in the FAP syndrome, somatic in sporadic colorectal cancers and secondary to the MYH gene inactivation in MAP syndrome. MAP phenotype is similar to the FAP phenotype because of the somatic mutations to the APC gene. Colonic polyposis is lower than FAP syndrome and appeared later, in the 40's and 50's. Colorectal cancers are frequent and discovered in the same moment as the colonic polyposis. Patients are diagnosed mostly in cancer stages. Colonoscopy shows polyps disseminated around the entire colic frame. Treatment in these cases is total rectocolectomy with ileoanal anastomosis. When working in a general emergency surgery clinic, physicians are often faced with colorectal cancers in different evolutive stages, and mostly they are faced with their complications.
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PMID:Map syndrome (MYH Associated Polyposis) colorectal cancer, etiopathological connections. 2150 84

FAP is characterized by 100-1000s of adenomatous polyps in colon and rectum, and is in 70% of the patients associated with extracolonic manifestations. Attenuated FAP (AFAP) is a less severe form of FAP, marked by the presence of < 100 polyps and a later onset of colorectal cancer (CRC). (A)FAP is caused by autosomal dominantly inherited mutations in the APC (Adenomatous polyposis coli) gene, a tumour suppressor gene that controls beta-catenin turnover in the Wnt pathway. De novo occurrence is reported in 30-40% of the patients. Mutations are detected in 85% of classical FAP families, while only 20%-30% of AFAP cases will exhibit a germline APC mutation. MUTYH is the second (A)FAP-related gene and is involved with base-excision repair of DNA damaged by oxidative stress. MUTYH mutations are inherited in an autosomal recessive way and account for 10%-20% of classical FAP cases without an APC mutation and for 30% of AFAP cases. Genotype-phenotype correlations exist for mutations in the APC gene, however, contradictions in the literature caution against the sole use of the genotype for decisions regarding clinical management. Once the family's specific APC mutation is identified in the proband, predictive testing for first degree relatives is possible from the age of 10 to 12 years on. For AFAP, relatives are tested at age 18 and older. Opinions about the appropriate ages at which to initiate genetic testing may vary. Physicians must have a discussion about prenatal testing with patients in childbearing age. They may either opt for conventional prenatal diagnosis (amniocentesis or chorionic villous sampling) or for preimplantation genetic diagnosis (PGD).
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PMID:The genetics of familial adenomatous polyposis (FAP) and MutYH-associated polyposis (MAP). 2210 48


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