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Albert De La Chapelle
Albert Fredrik de la Chapelle, MD, Ph.D (11 February 1933 – 10 December 2020) was a Finnish human geneticist, long-time head of Finland's first Department of Medical Genetics at the University of Helsinki, and subsequently professor of Human Cancer Genetics at Ohio State University. He was best known for his role in the elucidation of the genetics of hereditary colorectal cancer and Lynch syndrome. Biography Personal life and education Albert de la Chapelle was born in 1933, Helsinki, one of three sons (along with Claës-Henrik and Gustaf) of Claës Carl Fredrik René de la Chapelle (1900-1974) and Stina Serlachius (1902-1984). He spent his early childhood on his parents' apple growing estate. He attended school locally, transferring later to high school in Helsinki. Graduating from high school in 1950 he enrolled directly into medical school at the University of Helsinki, obtaining his MD in 1957 after a hiatus to complete 11 months of military service resulting in the rank ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohio State University
The Ohio State University, commonly called Ohio State or OSU, is a public land-grant research university in Columbus, Ohio. A member of the University System of Ohio, it has been ranked by major institutional rankings among the best public universities in the United States. Founded in 1870 as the state's land-grant university and the ninth university in Ohio with the Morrill Act of 1862, Ohio State was originally known as the Ohio Agricultural and Mechanical College and focused on various agricultural and mechanical disciplines, but it developed into a comprehensive university under the direction of then-Governor and later U.S. president Rutherford B. Hayes, and in 1878, the Ohio General Assembly passed a law changing the name to "the Ohio State University" and broadening the scope of the university. Admission standards tightened and became greatly more selective throughout the 2000s and 2010s. Ohio State's political science department and faculty have greatly contri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turner's Syndrome
Turner syndrome (TS), also known as 45,X, or 45,X0, is a genetic condition in which a female is partially or completely missing an X chromosome. Signs and symptoms vary among those affected. Often, a short and webbed neck, low-set ears, low hairline at the back of the neck, short stature, and swollen hands and feet are seen at birth. Typically, those affected do not develop menstrual periods, or breasts without hormone treatment and are unable to have children without reproductive technology. Heart defects, diabetes, and low thyroid hormone occur in the disorder more frequently than average. Most people with Turner syndrome have normal intelligence; however, many have problems with spatial visualization that may be needed in order to learn mathematics. Vision and hearing problems also occur more often than average. Turner syndrome is not usually inherited; rather, it occurs during formation of the reproductive cells in a parent or in early cell division during developme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peutz–Jeghers Syndrome
Peutz–Jeghers syndrome (often abbreviated PJS) is an autosomal dominant genetic disorder characterized by the development of benign hamartomatous polyps in the gastrointestinal tract and hyperpigmented macules on the lips and oral mucosa (melanosis). This syndrome can be classed as one of various hereditary intestinal polyposis syndromes and one of various hamartomatous polyposis syndromes. It has an incidence of approximately 1 in 25,000 to 300,000 births. Signs and symptoms The risks associated with this syndrome include a substantial risk of cancer, especially of the breast and gastrointestinal tracts. Colorectal is the most common malignancy, with a lifetime risk of 39 percent, followed by breast cancer in females with a lifetime risk of 32 to 54 percent. Patients with the syndrome also have an increased risk of developing carcinomas of the liver, lungs, breast, ovaries, uterus, testes, and other organs. Specifically, it is associated with an increased risk of sex-cord strom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positional Cloning
A genetic screen or mutagenesis screen is an experimental technique used to identify and select individuals who possess a phenotype of interest in a mutagenized population. Hence a genetic screen is a type of phenotypic screen. Genetic screens can provide important information on gene function as well as the molecular events that underlie a biological process or pathway. While genome projects have identified an extensive inventory of genes in many different organisms, genetic screens can provide valuable insight as to how those genes function. Basic screening Forward genetics (or a forward genetic screen) starts with a phenotype and then attempts to identify the causative mutation and thus gene(s) responsible for the phenotype. For instance, the famous screen by Christiane Nüsslein-Volhard and Eric F. Wieschaus, Eric Wieschaus mutagenized fruit flies and then set out to find the genes causing the observed mutant phenotypes. Successful forward genetic screens often require a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linkage Disequilibrium
In population genetics, linkage disequilibrium (LD) is the non-random association of alleles at different loci in a given population. Loci are said to be in linkage disequilibrium when the frequency of association of their different alleles is higher or lower than what would be expected if the loci were independent and associated randomly. Linkage disequilibrium is influenced by many factors, including selection, the rate of genetic recombination, mutation rate, genetic drift, the system of mating, population structure, and genetic linkage. As a result, the pattern of linkage disequilibrium in a genome is a powerful signal of the population genetic processes that are structuring it. In spite of its name, linkage disequilibrium may exist between alleles at different loci without any genetic linkage between them and independently of whether or not allele frequencies are in equilibrium (not changing with time). Furthermore, linkage disequilibrium is sometimes referred to as gamet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Marker
A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can be observed. A genetic marker may be a short DNA sequence, such as a sequence surrounding a single base-pair change ( single nucleotide polymorphism, SNP), or a long one, like minisatellites. Background For many years, gene mapping was limited to identifying organisms by traditional phenotypes markers. This included genes that encoded easily observable characteristics such as blood types or seed shapes. The insufficient number of these types of characteristics in several organisms limited the mapping efforts that could be done. This prompted the development of gene markers which could identify genetic characteristics that are not readily observable in organisms (such as protein variation). Types Some commonly used types of genetic markers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Founder Effect
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall Wright. As a result of the loss of genetic variation, the new population may be distinctively different, both genotypically and phenotypically, from the parent population from which it is derived. In extreme cases, the founder effect is thought to lead to the speciation and subsequent evolution of new species. In the figure shown, the original population has nearly equal numbers of blue and red individuals. The three smaller founder populations show that one or the other color may predominate (founder effect), due to random sampling of the original population. A population bottleneck may also cause a founder effect, though it is not strictly a new population. The founder effect occurs wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysplasia
Dysplasia is any of various types of abnormal growth or development of cells (microscopic scale) or organs (macroscopic scale), and the abnormal histology or anatomical structure(s) resulting from such growth. Dysplasias on a mainly microscopic scale include epithelial dysplasia and fibrous dysplasia of bone. Dysplasias on a mainly macroscopic scale include hip dysplasia (human), hip dysplasia, myelodysplastic syndrome, and multicystic dysplastic kidney. In one of the modern histopathology, histopathological senses of the term, dysplasia is sometimes differentiated from other categories of tissue change including hyperplasia, metaplasia, and neoplasia, and dysplasias are thus generally not cancerous. An exception is that the myelodysplasias include a range of benign tumor, benign, precancerous condition, precancerous, and cancerous forms. Various other dysplasias tend to be precancerous. The word's meanings thus cover a spectrum of histopathological variations. Microscopic sca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome ( haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and female will fuse to create a cell with two copies of each chromosome again, the zygote. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoautosomal Region
The pseudoautosomal regions, PAR1, PAR2, are homologous sequences of nucleotides on the X and Y chromosomes. The pseudoautosomal regions get their name because any genes within them (so far at least 29 have been found for humans) are inherited just like any autosomal genes. PAR1 comprises 2.6 Mbp of the short-arm tips of both X and Y chromosomes in humans and great apes (X and Y are 155 Mbp and 59 Mbp in total). PAR2 is at the tips of the long arms, spanning 320 kbp. Location The locations of the PARs within GRCh38 are: The locations of the PARs within GRCh37 are: Inheritance and function Normal male mammals have two copies of these genes: one in the pseudoautosomal region of their Y chromosome, the other in the corresponding portion of their X chromosome. Normal females also possess two copies of pseudoautosomal genes, as each of their two X chromosomes contains a pseudoautosomal region. Crossing over between the X and Y chromosomes is normally restricted to the pseudoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyotype
A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is discerned by determining the chromosome complement of an individual, including the number of chromosomes and any abnormalities. A karyogram or idiogram is a graphical depiction of a karyotype, wherein chromosomes are organized in pairs, ordered by size and position of centromere for chromosomes of the same size. Karyotyping generally combines light microscopy and photography, and results in a photomicrographic (or simply micrographic) karyogram. In contrast, a schematic karyogram is a designed graphic representation of a karyotype. In schematic karyograms, just one of the sister chromatids of each chromosome is generally shown for brevity, and in reality they are generally so close together that they look as one on photomicrographs as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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