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Familial Adenomatous Polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance inherited genetic disorder that presents with numerous adenomatous polyps Adenomatous polyps Benign neoplasms derived from glandular epithelium. Colorectal Cancer in the colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy. Familial adenomatous polyposis is the most common of the polyposis syndromes, which is a group of inherited or acquired conditions characterized by the growth of polyps in the GI tract, associated with other extracolonic features. These syndromes are caused by mutations in specific genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure associated with tumor Tumor Inflammation suppression Suppression Defense Mechanisms or cell cycle Cell cycle The phases of the cell cycle include interphase (G1, S, and G2) and mitosis (prophase, metaphase, anaphase, and telophase). The cell's progression through these phases is punctuated by checkpoints regulated by cyclins, cyclin-dependent kinases, tumor suppressors, and their antagonists. Cell Cycle regulation. All patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with FAP will develop colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy cancer by age 35–40 years if left untreated. Management is with a surveillance Surveillance Developmental Milestones and Normal Growth program and colectomy.

Last updated: Sep 1, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Overview

Definition

Familial adenomatous polyposis (FAP) is an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disorder that is associated with the development of numerous colorectal adenomas.

Epidemiology

  • Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency varies: 1 in 6000 to 1 in 35,000
  • 2nd most common inherited colorectal cancer Colorectal cancer Colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths in the United States. Colorectal cancer is a heterogeneous disease that arises from genetic and epigenetic abnormalities, with influence from environmental factors. Colorectal Cancer (CRC) syndrome
  • Only 30% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with FAP have no family history Family History Adult Health Maintenance.
  • FAP has been described in all races.
  • The average age at onset of polyposis in FAP is 16 years.
  • The average age at onset of CRC is 39 years.
  • Both sexes are equally affected.

Etiology

Pathogenic mutations in the tumor Tumor Inflammation suppressor gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics adenomatous polyposis coli (APC) in chromosome Chromosome In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. Basic Terms of Genetics 5 on band 5q21:

  • Often nonsense or frameshift mutations 
  • Evolves into truncation of the APC protein, creating a nonfunctional protein

Pathophysiology

  • The APC gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics exerts a tumor-suppression function that induces apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage.
  • Dysfunctional APC protein → prevents colonic cell apoptosis Apoptosis A regulated cell death mechanism characterized by distinctive morphologic changes in the nucleus and cytoplasm, including the endonucleolytic cleavage of genomic DNA, at regularly spaced, internucleosomal sites, I.e., DNA fragmentation. It is genetically-programmed and serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth. Ischemic Cell Damage → allows β-catenin protein to accumulate intracellularly → stimulates cell growth → uncontrolled growth of cells → adenomatous polyps Adenomatous polyps Benign neoplasms derived from glandular epithelium. Colorectal Cancer → enough genetic events occur to allow the polyps to become malignant

Clinical Presentation

History

  • Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship are asymptomatic until cancer develops. 
  • Presymptomatic screening Screening Preoperative Care is key: 75%–80% have a family history Family History Adult Health Maintenance of polyps and/or CRC by < 40 years of age.
  • Nonspecific symptoms: 
    • Unexplained rectal bleeding ( hematochezia Hematochezia Gastrointestinal Bleeding)
    • Diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
    • Abdominal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways

Findings

  • Classic FAP colonic findings:
    • Multiple (100s to 1,000s) of adenomatous colorectal polyps
    • CRC tumors are mostly on the left side.
  • Fundoscopy Fundoscopy Cranial Nerve Palsies:
    • Flat, localized pigmented lesions of the retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy (no visual symptoms)
    • Congenital Congenital Chorioretinitis hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation of the retinal pigment epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology (CHRPE)
    • Highly specific for FAP 
    • Best seen by slit-lamp examination Slit-Lamp Examination Blepharitis 
    • Often multiple and bilateral
  • Head:
    • Osteomas in the mandible Mandible The largest and strongest bone of the face constituting the lower jaw. It supports the lower teeth. Jaw and Temporomandibular Joint: Anatomy or skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy
    • Brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification tumor Tumor Inflammation (e.g., medulloblastoma Medulloblastoma Medulloblastomas are malignant primitive neuroectodermal tumors that arise in the posterior fossa in children. Medulloblastomas are the most common malignant brain tumors in children. Patients with medulloblastoma present with symptoms of increased intracranial pressure and cerebellar signs, which both evolve and worsen over weeks to a few months. Medulloblastoma)
    • Dental abnormalities (e.g., supernumerary teeth Teeth Normally, an adult has 32 teeth: 16 maxillary and 16 mandibular. These teeth are divided into 4 quadrants with 8 teeth each. Each quadrant consists of 2 incisors (dentes incisivi), 1 canine (dens caninus), 2 premolars (dentes premolares), and 3 molars (dentes molares). Teeth are composed of enamel, dentin, and dental cement. Teeth: Anatomy)
  • Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess: thyroid nodules Thyroid nodules A thyroid nodule is a disordered growth of thyroid cells that produces a mass in the thyroid gland. Most thyroid nodules are benign and detected either by the patient or by the clinician on examination. In other cases, a thyroid nodule is found in radiologic imaging incidentally. Ruling out of malignancy is important. Thyroid Nodules/cancer (mostly papillary)
  • Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions and soft tissues:
    • Epidermoid cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change on the scalp, face, and back (young individuals)
    • Fibromas on the trunk, back, and extremities
  • Abdomen:
    • A palpable mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast on rectal exam in someone < 40 years: Suspect FAP.
    • Desmoid tumors: very large masses in the abdominal cavity
    • Gastric polyps and duodenal adenomas
    • Hepatoblastoma Hepatoblastoma A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. Rare Malignant Liver Tumors
    • Other tumors: pancreatic cancer, adrenal tumors

Risk of FAP-related tumors

  • Lifetime risk of CRC: 100%
  • Gastric polyps: up to 90%
  • Ampulla of Vater adenocarcinoma: 10%
  • Desmoid tumors: up to 20%
  • Thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy tumors: 2%
  • Hepatoblastoma Hepatoblastoma A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. Rare Malignant Liver Tumors: 1.6%

Variants

There are 4 syndromes from the germline mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the APC gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics:

  • FAP (classic)
  • Gardner syndrome:
    • Colonic polyposis typical of FAP 
    • Osteomas (bony growth most commonly on the skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy and the mandible Mandible The largest and strongest bone of the face constituting the lower jaw. It supports the lower teeth. Jaw and Temporomandibular Joint: Anatomy)
    • Dental abnormalities
    • Soft tissue Soft Tissue Soft Tissue Abscess tumors
    • CHRPE
  • Turcot syndrome:
    • Colonic polyposis typical of FAP
    • CNS tumors ( medulloblastoma Medulloblastoma Medulloblastomas are malignant primitive neuroectodermal tumors that arise in the posterior fossa in children. Medulloblastomas are the most common malignant brain tumors in children. Patients with medulloblastoma present with symptoms of increased intracranial pressure and cerebellar signs, which both evolve and worsen over weeks to a few months. Medulloblastoma). 
  • Attenuated adenomatous polyposis coli (AAPC):
    • Fewer colonic polyps than FAP
    • Polyps tend to develop at a later age (average age: 36 years).
    • Involve the proximal colonic area

Diagnosis

Diagnosis

  • Screening Screening Preoperative Care:
    • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with known family history Family History Adult Health Maintenance of FAP (with age at onset for relatives)
    • Starting at 10–15 years of age
    • Annual endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD) evaluation with colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening (while awaiting colectomy)
  • Diagnosis is made by visualizing > 100 polyps on flexible sigmoidoscopy Sigmoidoscopy Endoscopic examination, therapy or surgery of the sigmoid flexure. Colorectal Cancer Screening or colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening.

Testing

  • Laboratory tests:
    • No positive results in the majority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
    • CBC for iron Iron A metallic element with atomic symbol fe, atomic number 26, and atomic weight 55. 85. It is an essential constituent of hemoglobins; cytochromes; and iron-binding proteins. It plays a role in cellular redox reactions and in the transport of oxygen. Trace Elements deficiency anemia Anemia Anemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types due to polyp bleeding
    • Alpha-fetoprotein Alpha-fetoprotein The first alpha-globulins to appear in mammalian sera during fetal development and the dominant serum proteins in early embryonic life. Hepatocellular Carcinoma (HCC) and Liver Metastases ( AFP AFP The first alpha-globulins to appear in mammalian sera during fetal development and the dominant serum proteins in early embryonic life. Hepatocellular Carcinoma (HCC) and Liver Metastases) blood test for children until age 5 years to screen for hepatoblastoma Hepatoblastoma A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. Rare Malignant Liver Tumors
  • Genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies:
    • Genetic counseling Genetic Counseling An educational process that provides information and advice to individuals or families about a genetic condition that may affect them. The purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs. Psychosocial support is usually offered. Myotonic Dystrophies prior to the performance of these tests
    • Performed in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with clinical diagnosis
    • Not recommended at an early age
  • 3 genetic tests are available:
    • In vitro protein synthesis Synthesis Polymerase Chain Reaction (PCR) assay:
      • Test of choice
      • Commercially available
      • Detects truncated APC gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics product Product A molecule created by the enzymatic reaction. Basics of Enzymes
      • Accurately identifies gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics carriers Carriers The Cell: Cell Membrane in a family
    • Gene sequencing Gene sequencing Polymerase Chain Reaction (PCR):
      • Most accurate test
      • Logistically difficult
      • Reserved for research Research Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. Conflict of Interest purposes
    • Linkage testing:
      • Studies genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure near or in the APC locus Locus Specific regions that are mapped within a genome. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of chromosome 6. Many well known genetic loci are also known by common names that are associated with a genetic function or hereditary disease. Basic Terms of Genetics
      • Testing requires 2 affected family members.

Management

Observation

  • Flexible sigmoidoscopy Sigmoidoscopy Endoscopic examination, therapy or surgery of the sigmoid flexure. Colorectal Cancer Screening/ colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening yearly until colectomy
  • Esophagogastroduodenoscopy is recommended when colonic polyposis is established or for individuals with FAP (classic or attenuated) at age 20–25 years:  
  • Other work-up:
    • Periodic thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy ultrasound:
      • Because of the ↑ risk of thyroid cancer Thyroid cancer Thyroid cancer is a malignancy arising from the thyroid gland cells: thyroid follicular cells (papillary, follicular, and anaplastic carcinomas) and calcitonin-producing C cells (medullary carcinomas). Rare cancers are derived from the lymphocytes (lymphoma) and/or stromal and vascular elements (sarcoma). Thyroid Cancer
      • Start in the late teen years, repeated every 2–5 years
    • Periodic liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy examination and ultrasound (every 3–6 months) in individuals with a family history Family History Adult Health Maintenance of hepatoblastoma Hepatoblastoma A malignant neoplasm occurring in young children, primarily in the liver, composed of tissue resembling embryonal or fetal hepatic epithelium, or mixed epithelial and mesenchymal tissues. Rare Malignant Liver Tumors from infancy until 5 years of age
    • Abdominal CT:
      • In individuals at risk (e.g., positive family history Family History Adult Health Maintenance) for desmoid tumors, or when clinically indicated (e.g., palpable mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast)
      • Also performed based on individual risk for pancreatic cancer

Surgical management

  • Prophylactic colectomy with or without proctectomy
  • Indications in FAP: 

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

  • Primary cause of mortality Mortality All deaths reported in a given population. Measures of Health Status: CRC
  • Survival improves with colectomy 
  • Risk of developing non-CRC complications increases with advancing age.

Differential Diagnosis

  • Cowden disease: autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disorder caused by mutations in the tumor-suppressor gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics PTEN and characterized by the development of multiple benign Benign Fibroadenoma hamartomas. Cowden disease is a genodermatosis characterized by multiple benign Benign Fibroadenoma hamartomas in any location, mucocutaneous lesions, and macrocephaly Macrocephaly Cowden Syndrome. Management depends on the location of the hamartoma Hamartoma A focal malformation resembling a neoplasm, composed of an overgrowth of mature cells and tissues that normally occur in the affected area. Colorectal Cancer
  • Hereditary nonpolyposis colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy cancer ( HNPCC HNPCC Lynch syndrome, also called hereditary non-polyposis colorectal cancer (HNPCC), is the most common inherited colon cancer syndrome, and carries a significantly increased risk for endometrial cancer and other malignancies. Lynch syndrome has an autosomal dominant inheritance pattern involving pathogenic variants in one of the mismatch repair (MMR) genes or epithelial cell adhesion molecule (EpCAM). Lynch syndrome): also known as Lynch syndrome Lynch syndrome Lynch syndrome, also called hereditary non-polyposis colorectal cancer (HNPCC), is the most common inherited colon cancer syndrome, and carries a significantly increased risk for endometrial cancer and other malignancies. Lynch syndrome has an autosomal dominant inheritance pattern involving pathogenic variants in one of the mismatch repair (MMR) genes or epithelial cell adhesion molecule (EpCAM). Lynch syndrome. Hereditary nonpolyposis colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy cancer is an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disorder caused by mutations in the mismatch repair Mismatch repair A DNA repair pathway involved in correction of errors introduced during DNA replication when an incorrect base, which cannot form hydrogen bonds with the corresponding base in the parent strand, is incorporated into the daughter strand. Exonucleases recognize the base pair mismatch and cause a segment of polynucleotide chain to be excised from the daughter strand, thereby removing the mismatched base. Lynch syndrome ( MMR MMR A DNA repair pathway involved in correction of errors introduced during DNA replication when an incorrect base, which cannot form hydrogen bonds with the corresponding base in the parent strand, is incorporated into the daughter strand. Excinucleases recognize the base pair mismatch and cause a segment of polynucleotide chain to be excised from the daughter strand, thereby removing the mismatched base. Lynch syndrome) genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure that ultimately lead to the development of CRC in 1st-degree relatives. Management is with prophylactic colectomy and frequent endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD) for surveillance Surveillance Developmental Milestones and Normal Growth
  • Juvenile polyposis: autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance condition characterized by the growth of hamartomatous polyps (juvenile type) in the colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy. Juvenile polyposis is commonly associated with mutations in the SMAD4 and BMPR1A BMPR1A A subtype of bone morphogenetic protein receptors with high affinity for bone morphogenetic proteins. They can interact with and undergo phosphorylation by type II bone morphogenetic protein receptors. They signal primarily through receptor-regulated SMAD proteins. Familial Juvenile Polyposis genes Genes A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. DNA Types and Structure. Diagnosis is made by visualizing > 5 polyps on colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening, juvenile polyps in other areas of the GI tract, or any number of polyps plus a family history Family History Adult Health Maintenance. Management includes surveillance Surveillance Developmental Milestones and Normal Growth, polypectomy, and colectomy in cases of symptomatic GI neoplasia, increased polyps, and confirmed CRC. 
  • Colorectal cancer Colorectal cancer Colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths in the United States. Colorectal cancer is a heterogeneous disease that arises from genetic and epigenetic abnormalities, with influence from environmental factors. Colorectal Cancer (CRC): 2nd leading cause of cancer-related deaths in the United States. Colorectal cancer Colorectal cancer Colorectal cancer (CRC) is the 2nd leading cause of cancer-related deaths in the United States. Colorectal cancer is a heterogeneous disease that arises from genetic and epigenetic abnormalities, with influence from environmental factors. Colorectal Cancer is a heterogeneous disease, arising from genetic and epigenetic abnormalities, with influence from environmental factors. Almost all cases of CRC are adenocarcinoma. Most cases are asymptomatic, so screening Screening Preoperative Care is important. Diagnosis is by colonoscopy Colonoscopy Endoscopic examination, therapy or surgery of the luminal surface of the colon. Colorectal Cancer Screening. Management is primarily surgical.
  • Thyroid cancer Thyroid cancer Thyroid cancer is a malignancy arising from the thyroid gland cells: thyroid follicular cells (papillary, follicular, and anaplastic carcinomas) and calcitonin-producing C cells (medullary carcinomas). Rare cancers are derived from the lymphocytes (lymphoma) and/or stromal and vascular elements (sarcoma). Thyroid Cancer: malignancy Malignancy Hemothorax of the thyroid gland Thyroid gland The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy cells that can arise from the thyroid follicular cells Thyroid follicular cells Epithelial cells of the thyroid gland that produce and secrete thyroxine and triiodothyronine. Thyroid Hormones or the calcitonin-producing C cells C cells Calcium Hemostasis and Bone Metabolism. Papillary cancer is the most common type associated with FAP. Exposure to ionizing radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma and iodine Iodine A nonmetallic element of the halogen group that is represented by the atomic symbol I, atomic number 53, and atomic weight of 126. 90. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. Thyroid Hormones deficiency are also considered risk factors. Diagnosis is with thyroid Thyroid The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland: Anatomy function tests, imaging (ultrasound), and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management is mainly surgical.

References

  1. Chung, D., Rodgers, L., (2021). Clinical manifestations and diagnosis of familial adenomatous polyposis. UpToDate. Retrieved June 12, 2021, from https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-familial-adenomatous-polyposis
  2. Burt, R. (2021). Gardner syndrome. UpToDate. Retrieved June 11, 2021, from https://www.uptodate.com/contents/gardner-syndrome
  3. Wehbi, M. (2019). Familial adenomatous polyposis workup. Medscape. Retrieved June 13, 2021, from https://emedicine.medscape.com/article/175377-workup#c6

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