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Familial adenomatous polyposis (FAP) is an inherited condition in which numerous polyps form mainly in the epithelium of the large intestine. While these polyps are benign, they may become malignant, predisposing patients to colorectal cancer. The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ...
// C00-D48 - Neoplasms (C00-C14) Malignant neoplasms, lip, oral cavity and pharynx (C00) Malignant neoplasm of lip (C01) Malignant neoplasm of base of tongue (C02) Malignant neoplasm of other and unspecified parts of tongue (C03) Malignant neoplasm of gum (C04) Malignant neoplasm of floor of mouth (C05) Malignant neoplasm of...
// C00-D48 - Neoplasms (C00-C14) Malignant neoplasms, lip, oral cavity and pharynx (C00) Malignant neoplasm of lip (C01) Malignant neoplasm of base of tongue (C02) Malignant neoplasm of other and unspecified parts of tongue (C03) Malignant neoplasm of gum (C04) Malignant neoplasm of floor of mouth (C05) Malignant neoplasm of...
The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ...
The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ...
The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ...
The Diseases Database is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ...
MedlinePlus (medlineplus. ...
eMedicine is an online clinical medical knowledge base that was founded in 1996. ...
Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ...
In zoology, a polyp is one of two forms of individuals found in many species of cnidarians. ...
In zootomy, epithelium is a tissue composed of a layer of cells. ...
Grays Fig. ...
Benign can refer to any medical condition which, untreated or with symptomatic therapy, will not become life-threatening. ...
In medicine, malignant is a clinical term that is used to describe a clinical course that progresses rapidly to death. ...
Colorectal cancer, also called colon cancer or bowel cancer, includes cancerous growths in the colon, rectum and appendix. ...
Signs and symptoms
From the age of 16 onward, patients develop hundreds to thousands of polyps. These may bleed, leading to admixture of blood in the stool. If the blood is not visible, it is still possible for the patient to develop anemia due to gradually developing iron deficiency. If malignancy develops, this may present with weight loss, altered bowel habit, or even with metastasis in the liver or elsewhere. This article discusses the medical condition. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ...
The liver is one of the largest internal organs of the human body. ...
The genetic determinant in familial polyposis may also predispose carriers to other malignancies, e.g. of the duodenum and stomach. Other signs that may point at FAP are pigmented lesions of the retina ("congenital hypertrophy of the retinal pigment"), jaw cysts, sebaceous cysts, and osteomata (benign bone tumors). The combination of polyposis, osteomas, fibromas and sebaceous cysts is termed Gardner syndrome (with or without abnormal scarring). In anatomy of the digestive system, the duodenum is a hollow jointed tube connecting the stomach to the jejunum. ...
The stomach (Gaster) In anatomy, the stomach (in ancient Greek στόμαχος) is an organ in the gastrointestinal tract used to digest food. ...
Human eye cross-sectional view. ...
A sebaceous cyst (a form of trichilemmal cyst; also called: keratin cyst; sometimes wrongfully called: epidermal cyst or epidermoid cyst (see ICD-10 L72. ...
An osteoma is a new piece of bone growing on another piece, typically the skull. ...
Fibroma. ...
Diagnosis and treatment In patients with a strong family of colorectal cancer and symptoms suggestive of polyposis, colonoscopy is indicated, with biopsy of a number of polyps (especially of those that appear dysplastic). In severe cases, a full or partial colectomy is required. Colonoscopy is the minimally invasive endoscopic examination of the large colon and the distal part of the small bowel with a fiber optic camera on a flexible tube passed through the anus. ...
A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ...
Dysplasia is a situation where cells have changed from their original mature differentiated type into another mature differentiated cell type as an adaptive response to exposure to chronic irritation, or to a pathogen or carcinogen. ...
Colectomy is the surgical procedure by means of which part of the colon is removed. ...
Blood tests (liver enzymes) and ultrasound of the abdomen are often performed to rule out metastasis to the liver. Blood tests are laboratory tests done on blood to gain an appreciation of disease states and the function of organs. ...
Liver function tests (LFTs or LFs), are groups of clinical biochemistry laboratory blood assays designed to give a doctor or other health professional information about the state of a patients liver. ...
Medical ultrasonography (sonography) is an ultrasound-based diagnostic imaging technique used to visualize internal organs, their size, structure and any pathological lesions. ...
Metastasis (Greek: change of the state) is the spread of cancer from its primary site to other places in the body. ...
Genetic testing provides the ultimate diagnosis in 95%; genetic counseling is usually needed in families where FAP has been diagnosed. Testing may also aid in the diagnosis of borderline cases in families that are otherwise known to have the FAP mutation. Genetic testing allows the genetic diagnosis of vulnerabilities to inherited diseases, and can also be used to determine a persons ancestry. ...
Genetic counseling generally refers to prenatal counseling done when a genetic condition is suspected in a pregnancy. ...
Pathophysiology FAP is due to mutations in the APC gene, which is located on the fifth chromosome (5q21-q22), or in the MUTYH gene located on chromosome 1 (p34.3-p32.1). APC (adenomatosis polyposis coli) is a human gene that is classified as a tumor suppressor gene. ...
Figure 1: Chromosome. ...
MUTYH (mutY Homolog (E. coli)) is a human gene that carries the instructions for cells to make an enzyme that is involved in the repair of DNA. This enzyme, MYH glycosylase, corrects particular mistakes that are made when DNA is copied (replicated) in preparation for cell division. ...
APC is a tumour suppressor gene, acting as a "gatekeeper" to prevent development of tumours. Mutation of APC also occurs commonly in incident cases of colorectal carcinoma, emphasizing its importance in this form of cancer. APC (adenomatosis polyposis coli) is a human gene that is classified as a tumor suppressor gene. ...
A tumor suppressor gene is a gene that reduces the probability that a cell in a multicellular organism will turn into a tumor cell. ...
Although the polyps are inherently benign, the first step of the two-hit hypothesis has already taken place: the inherited APC mutation. Often, the remaining "normal" allele is mutated or deleted, accelerating generation of polyps. Further mutations (e.g. in p53 or KRAS) to APC-mutated cells are much more likely to lead to cancer than they would in non-mutated epithelial cells. The Knudson hypothesis is the hypothesis that cancer is the result of accumulated mutations to a cells DNA. It was first formulated by Alfred G. Knudson in 1971, and led indirectly to the identification of cancer-related genes. ...
An allele is any one of a number of viable DNA codings of the same gene (sometimes the term refers to a non-gene sequence) occupying a given locus (position) on a chromosome. ...
TP53 bound to a short DNA fragment. ...
In zootomy, epithelium is a tissue composed of a layer of cells. ...
The normal function of the APC gene product is still being investigated; it is present both the cell nucleus and the membrane. The canonical tumor-suppressor function of Apc is suppression of the oncogenic protein beta-catenin. However, other tumor-suppressor functions of Apc may be related to cell adherence and cytoskeleton organization. In cell biology, the nucleus (from Latin nucleus or nuculeus, kernel) is found in all eukaryotic cells and contains the nuclear genes which form most of the cells genetic material. ...
The cytoskeleton is a cellular scaffolding or skeleton contained, as all other organelles, within the cytoplasm. ...
MUTYH encodes DNA repair enzyme MYH glycosylase. During normal cellular activities, guanine sometimes becomes altered by oxygen, which causes it to pair with adenine instead of cytosine. MYH glycosylase fixes these mistakes by base excision repair, such that mutations do not accumulate in the DNA and lead to tumor formation. When MYH glycosylase does not function correctly, DNA errors may accrue to initiate tumorigenesis with a clinical presentation similar to that in patients with Apc mutations. MUTYH (mutY Homolog (E. coli)) is a human gene that carries the instructions for cells to make an enzyme that is involved in the repair of DNA. This enzyme, MYH glycosylase, corrects particular mistakes that are made when DNA is copied (replicated) in preparation for cell division. ...
DNA damage resulting in multiple broken chromosomes DNA repair is a process constantly operating in cells; it is essential to survival because it protects the genome from damage and harmful mutations. ...
Guanine is one of the five main nucleobases found in nucleic acids (, DNA and RNA). ...
General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ...
Adenine is one of the two purine nucleobases used in forming nucleotides of the nucleic acids DNA and RNA. In DNA, adenine (A) binds to thymine (T) via two hydrogen bonds to assist in stabilizing the nucleic acid structures. ...
Cytosine is one of the 5 main nucleobases used in storing and transporting genetic information within a cell in the nucleic acids DNA and RNA. It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an amine group at position 4 and a keto group at...
This article needs to be cleaned up to conform to a higher standard of quality. ...
In biology, mutations are changes to the genetic material (usually DNA or RNA). ...
The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid —usually in the form of a double helix— that contains the genetic instructions specifying the biological development of all cellular forms of life, and most viruses. ...
Genetics Familial adenomatous polyposis can have different inheritance patterns and different genetic causes. When this condition results from mutations in the APC gene, it is inherited in an autosomal dominant pattern, which means one copy of the altered gene is sufficient to cause the disorder. In most cases, an affected person has one parent with the condition. An autosomal dominant gene is an abnormal gene on one of the autosomal (non-sex determining) chromosomes. ...
Mutations in the MUTYH gene are inherited in an autosomal recessive pattern, which means two copies of the gene must be altered for a person to be affected by the disorder. Most often, the parents of a child with an autosomal recessive disorder are not affected but are carriers of one copy of the altered gene. In genetics, the term recessive gene refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele). ...
Prenatal testing is possible if a disease-causing mutation is identified in an affected family member; however, prenatal testing for typically adult-onset disorders is uncommon and requires careful genetic counseling. Prenatal diagnosis is the diagnosis of disease or condition in a fetus or embryo before it is born. ...
Genetic counseling generally refers to prenatal counseling done when a genetic condition is suspected in a pregnancy. ...
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Animal Models The "ApcMin" mouse model was isolated in 1990 and harbors an Apc allele with a stop codon at position 850. Heterozygosity for this mutation results in a fully penetrant phenotype, with mice on a sensitive background developing over 100 tumors in the intestinal tract. Many other models have since appeared, including a model of attenuated FAP (the 1638N model) and several conditional mutants that allow for tissue-specific or temporal ablation of gene function.
In 2005, the "ApcPirc" rat model was isolated with a stop codon at position 1137. In constrast to the mouse models where >90% of tumors form in the small intestine, the Pirc rat forms tumors preferentially (>60%) in the large intestine, similar to the human clinical presentation. Genetic screens, pharmacological testing, and other areas of research have allowed for discoveries in the mouse and rat to be applied to the study of human FAP.
Epidemiology The incidence of the mutation is between 1 in 10,000 and 1 in 15,000 births. By age 35 years, 95% of individuals with FAP have polyps. Without colectomy, colon cancer is virtually inevitable. The mean age of colon cancer in untreated individuals is 39 years (range 34-43 years).
Treatment Treatment for FAP will require frequent surveillance colonoscopy investigations; in a number of cases, removal of the colon is necessary to prevent the development of malignancy, or to cure it. If a large part of the bowel is removed, construction of an ileostomy may be necessary. Colonoscopy is the minimally invasive endoscopic examination of the large colon and the distal part of the small bowel with a fiber optic camera on a flexible tube passed through the anus. ...
An ileostomy is a stoma that has been constructed by bringing the end of the small intestine (the ileum) out onto the surface of the skin. ...
Various medications are being investigated for slowing malignant degeneration of polyps, most prominently the non-steroidal anti-inflammatory drugs (NSAIDs). Non-steroidal anti-inflammatory drugs, usually abbreviated to NSAIDs, are drugs with analgesic, antipyretic and anti-inflammatory effects - they reduce pain, fever and inflammation. ...
References - Gardner EJ. A genetic and clinical study of intestinal polyposis, a predisposing factor for carcinoma of the colon and rectum. Am J Hum Genet 1951;3:167-76. PMID 14902760
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