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Hereditary Cancer Syndrome
A hereditary cancer syndrome (familial/family cancer syndrome, inherited cancer syndrome, cancer predisposition syndrome, cancer syndrome, etc.) is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancer and may also cause early onset of these cancers. Hereditary cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors. Many of these syndromes are caused by mutations in tumor suppressor genes, genes that are involved in protecting the Cell (biology), cell from turning cancerous. Other genes that may be affected are DNA repair genes, oncogenes and genes involved in the production of blood vessels (angiogenesis). Common examples of inherited cancer syndromes are hereditary breast-ovarian cancer syndrome and hereditary non-polyposis colon cancer (Lynch syndrome). Background Hereditary cancer syndromes underlie 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carcinoid Tumor
A carcinoid (also carcinoid tumor) is a slow-growing type of neuroendocrine tumor originating in the cells of the neuroendocrine system. In some cases, metastasis may occur. Carcinoid tumors of the midgut ( jejunum, ileum, appendix, and cecum) are associated with carcinoid syndrome. Carcinoid tumors are the most common malignant tumor of the appendix, but they are most commonly associated with the small intestine, and they can also be found in the rectum and stomach. They are known to grow in the liver, but this finding is usually a manifestation of metastatic disease from a primary carcinoid occurring elsewhere in the body. They have a very slow growth rate compared to most malignant tumors. The median age at diagnosis for all patients with neuroendocrine tumors is 63 years. Signs and symptoms While most carcinoids are asymptomatic through the natural life and are discovered only upon surgery for unrelated reasons (so-called ''coincidental carcinoids''), all carcinoids are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Dominant
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendelian Inheritance
Mendelian inheritance (also known as Mendelism) is a type of biological inheritance following the principles originally proposed by Gregor Mendel in 1865 and 1866, re-discovered in 1900 by Hugo de Vries and Carl Correns, and later popularized by William Bateson. These principles were initially controversial. When Mendel's theories were integrated with the Boveri–Sutton chromosome theory of inheritance by Thomas Hunt Morgan in 1915, they became the core of classical genetics. Ronald Fisher combined these ideas with the theory of natural selection in his 1930 book '' The Genetical Theory of Natural Selection'', putting evolution onto a mathematical footing and forming the basis for population genetics within the modern evolutionary synthesis. History The principles of Mendelian inheritance were named for and first derived by Gregor Johann Mendel, a nineteenth-century Moravian monk who formulated his ideas after conducting simple hybridisation experiments with pea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allele
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chromosomal or genomic location of a gene or any other genetic element is called a locus (plural: loci) and alternative DNA sequences at a locus are called alleles." The simplest alleles are single nucleotide polymorphisms (SNP). but they can also be insertions and deletions of up to several thousand base pairs. Popular definitions of 'allele' typically refer only to different alleles within genes. For example, the ABO blood grouping is controlled by the ABO gene, which has six common alleles (variants). In population genetics, nearly every living human's phenotype for the ABO gene is some combination of just these six alleles. Most alleles observed result in little or no change in the function of the gene product it codes for. However, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary Care Physician
A primary care physician (PCP) is a physician who provides both the first contact for a person with an undiagnosed health concern as well as continuing care of varied medical conditions, not limited by cause, organ system, or diagnosis. The term is primarily used in the United States. In the past, the equivalent term was 'general practitioner' in the US; however in the United Kingdom and other countries the term general practitioner is still used. A core element in general practice is continuity that bridges episodes of various illnesses. Greater continuity with a general practitioner has been shown to reduce the need for out-of-hours services and acute hospital admittance. Furthermore, continuity by a general practitioner reduces mortality. All physicians first complete medical school ( MD, MBBS, or DO). To become primary care physicians, medical school graduates then undertake postgraduate training in primary care programs, such as family medicine (also called family pract ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sebaceous Carcinoma
Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma is an uncommon malignant cutaneous tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. SGc can be divided into 2 types: periocular and extraocular. The periocular region is rich in sebaceous glands making it a common site of origin. The cause of these lesions in the vast majority of cases is unknown. Occasional cases may be associated with Muir-Torre syndrome. SGc accounts for approximately 0.7% of all skin cancers, and the incidence of SGc is highest in Caucasian, Asian, and Indian populations. Due to the rarity of this tumor and variability in clinical and histological presentation, SGc is often misdiagnosed as an inflammatory condition or a more common neoplasm. SGc is commonly treated with wide local excision or Mohs micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oncocytoma
An oncocytoma is a tumor made up of oncocytes, epithelial cells characterized by an excessive amount of mitochondria, resulting in an abundant acidophilic, granular cytoplasm. The cells and the tumor that they compose are often benign but sometimes may be premalignant or malignant. Presentation An oncocytoma is an epithelial tumor composed of oncocytes, large eosinophilic cells having small, round, benign-appearing nuclei with large nucleoli. Oncocytoma can arise in a number of organs. Renal oncocytoma Renal oncocytoma is thought to arise from the intercalated cells of collecting ducts of the kidney. It represents 5% to 15% of surgically resected renal neoplasms. Salivary gland oncocytoma The salivary gland oncocytoma is a well-circumscribed, benign neoplastic growth also called an oxyphilic adenoma. It comprises about 1% of all salivary gland tumors. The histopathology is marked by sheets of large swollen polyhedral epithelial oncocytes, which are granular acidophilic pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraganglioma
A paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). When the same type of tumor is found in the adrenal gland, they are referred to as a pheochromocytoma. They are rare tumors, with an overall estimated incidence of 1/300,000. There is no test that determines benign from malignant tumors; long-term follow-up is therefore recommended for all individuals with paraganglioma. Signs and symptoms Most paragangliomas are asymptomatic, present as a painless mass, or create symptoms such as hypertension, tachycardia, headache, and palpitations. While all contain neurosecretory granules, only in 1–3% of cases is secretion of hormones such as catecholamines abundant enough to be clinically significant; in that case manifestations often resemble those of pheochromocytomas (intra-medullary paraganglioma). Genetics About 75% of paragangliomas are sporadic; the remaining 25% are hereditary (and have an incr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medullary Thyroid Cancer
Medullary thyroid cancer is a form of thyroid carcinoma which originates from the parafollicular cells (C cells), which produce the hormone calcitonin.Hu MI, Vassilopoulou-Sellin R, Lustig R, Lamont JP"Thyroid and Parathyroid Cancers"in Pazdur R, Wagman LD, Camphausen KA, Hoskins WJ (EdsCancer Management: A Multidisciplinary Approach 11 ed. 2008. Medullary tumors are the third most common of all thyroid cancers and together make up about 3% of all thyroid cancer cases. MTC was first characterized in 1959. Approximately 25% of medullary thyroid cancer cases are genetic in nature, caused by a mutation in the RET proto-oncogene. When MTC occurs by itself it is termed sporadic medullary thyroid cancer. Medullary thyroid cancer is seen in people with multiple endocrine neoplasia type 2A and 2B. When medullary thyroid cancer due to a hereditary genetic disorder occurs without other endocrine tumours it is termed familial medullary thyroid cancer. Signs and symptoms The major clinical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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