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Pierre Robin Sequence
Pierre Robin sequence (; abbreviated PRS) is a congenital defect observed in humans which is characterized by facial abnormalities. The three main features are micrognathia (abnormally small mandible), which causes glossoptosis (downwardly displaced or retracted tongue), which in turn causes breathing problems due to obstruction of the upper airway. A wide, U-shaped cleft palate is commonly also present. PRS is not merely a syndrome, but rather it is a sequence—a series of specific developmental malformations which can be attributed to a single cause. Signs and symptoms PRS is characterized by an unusually small mandible, posterior displacement or retraction of the tongue, and upper airway obstruction. Cleft palate (incomplete closure of the roof of the mouth) is present in the majority of patients. Hearing loss and speech difficulty are often associated with PRS. Causes Mechanical basis The physical craniofacial deformities of PRS may be the result of a mechanical problem in wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Genetics
Medical genetics is the branch tics in that human genetics is a field of scientific research that may or may not apply to medicine, while medical genetics refers to the application of genetics to medical care. For example, research on the causes and inheritance of genetic disorders would be considered within both human genetics and medical genetics, while the diagnosis, management, and counselling people with genetic disorders would be considered part of medical genetics. In contrast, the study of typically non-medical phenotypes such as the genetics of eye color would be considered part of human genetics, but not necessarily relevant to medical genetics (except in situations such as albinism). ''Genetic medicine'' is a newer term for medical genetics and incorporates areas such as gene therapy, personalized medicine, and the rapidly emerging new medical specialty, predictive medicine. Scope Medical genetics encompasses many different areas, including clinical practice of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chin
The chin is the forward pointed part of the anterior mandible (List_of_human_anatomical_regions#Regions, mental region) below the lower lip. A fully developed human skull has a chin of between 0.7 cm and 1.1 cm. Evolution The presence of a well-developed chin is considered to be one of the morphological characteristics of ''Homo sapiens'' that differentiates them from other human ancestors such as the closely related Neanderthal, Neanderthals. Early human ancestors have varied Mandibular symphysis, symphysial morphology, but none of them have a well-developed chin. The origin of the chin is traditionally associated with the anterior–posterior breadth shortening of the dental arch or tooth row; however, its general mechanical or functional advantage during feeding, developmental origin, and link with human speech, physiology, and social influence are highly debated. Functional perspectives Robinson (1913) suggests that the demand to resist Mastication, masticatory stresses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inward-rectifier Potassium Channel
Inward-rectifier potassium channels (Kir, IRK) are a specific lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are activated by phosphatidylinositol 4,5-bisphosphate ( PIP2). The malfunction of the channels has been implicated in several diseases. IRK channels possess a pore domain, homologous to that of voltage-gated ion channels, and flanking transmembrane segments (TMSs). They may exist in the membrane as homo- or heterooligomers and each monomer possesses between 2 and 4 TMSs. In terms of function, these proteins transport potassium (K+), with a greater tendency for K+ uptake than K+ export. The process of inward-rectification was discovered by Denis Noble in cardiac muscle cells in 1960s and by Richard Adrian and Alan Hodgkin in 1970 in skeletal muscle cells. Overview of inward rectification A channel that is "inwardly-rectifying" is one that passes current (positive cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kir2
KIR, Kir or kir may refer to: Biology *Inward-rectifier potassium channel Kir *Killer-cell immunoglobulin-like receptor, a receptor protein expressed on the surface of natural killer cells and some T-cells Bodies of water *Kir (river), in northern Albania * Kir Lake, near Dijon, France People * Kir Fard, Armenian nobleman of the 12th–13th centuries * Kir Nesis (1934–2003), Russian biologist *Kir Bulychev, Russian writer * Félix Kir (1876–1968), priest in the French Resistance *Kir, a character in ''Detective Conan'' Places *Republic of Kiribati in the central Pacific (ISO code: KIR) *Kir of Moab, biblical stronghold *Land of Kir, biblical location Transport * Katihar Junction railway station, Bihar; station code KIR * Kerry Airport, Ireland (IATA code: KIR) * Kirkby railway station, Merseyside, England; National Rail station code KIR Other * Kir (cocktail), alcoholic beverage * Kyrgyz language (ISO code: kir) * Krajowa Izba Rozliczeniowa, an automated clearing hou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNJ2
The Kir2.1 inward-rectifier potassium channel is a lipid-gated ion channel encoded by the gene. Clinical significance A defect in this gene is associated with Andersen-Tawil syndrome. A mutation in the KCNJ2 gene has also been shown to cause short QT syndrome. In research In neurogenetics, Kir2.1 is used in ''Drosophila'' research to inhibit neurons, as overexpression of this channel will hyperpolarize cells. In optogenetics, a trafficking sequence from Kir2.1 has been added to halorhodopsin to improve its membrane localization. The resulting protein eNpHR3.0 is used in optogenetic research to inhibit neurons with light. Expression of Kir2.1 gene in human HEK293 cells induce a transient outward current, creating a steady membrane potential close to the reversal potential of potassium. Interactions Kir2.1 has been shown to interact with: * DLG4, * Interleukin 16, and * TRAK2 Trafficking kinesin-binding protein 2 is a protein that in humans is encoded by the ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SOX9
Transcription factor SOX-9 is a protein that in humans is encoded by the ''SOX9'' gene. Function SOX-9 recognizes the sequence CCTTGAG along with other members of the HMG-box class DNA-binding proteins. It is expressed by proliferating but not hypertrophic chondrocytes that is essential for differentiation of precursor cells into chondrocytes and, with steroidogenic factor 1, regulates transcription of the anti-Müllerian hormone (AMH) gene. SOX-9 also plays a pivotal role in male sexual development; by working with Sf1, SOX-9 can produce AMH in Sertoli cells to inhibit the creation of a female reproductive system. It also interacts with a few other genes to promote the development of male sexual organs. The process starts when the transcription factor Testis determining factor (encoded by the sex-determining region SRY of the Y chromosome) activates SOX-9 activity by binding to an enhancer sequence upstream of the gene. Next, Sox9 activates FGF9 and forms feedforward loop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PVRL1
Poliovirus receptor-related 1 (PVRL1), also known as nectin-1 and CD111 (formerly herpesvirus entry mediator C, HVEC) is a human protein of the immunoglobulin superfamily (IgSF), also considered a member of the nectins. It is a membrane protein with three extracellular immunoglobulin domains, a single transmembrane helix and a cytoplasmic tail. The protein can mediate Ca2+-independent cellular adhesion further characterizing it as IgSF cell adhesion molecule (IgSF CAM). Function PVRL1 is an adhesion molecule found in a wide range of tissues where it localizes in various junctions such as the adherens junction of epithelial tissue or the chemical synapse of neurons. The cytoplasmic tail of PVRL1 can bind the protein afadin which is a scaffolding protein that binds actin. In the chemical synapse PVRL1 interacts with PVRL3 (nectin-3) and both proteins can be found in neuronal tissue already in early stages of brain development as well as in aging brains. The two proteins have b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GAD1
Glutamate decarboxylase 1 (brain, 67kDa) (GAD67), also known as GAD1, is a human gene. This gene encodes one of several forms of glutamic acid decarboxylase, identified as a major autoantigen in insulin-dependent diabetes. The enzyme encoded is responsible for catalyzing the production of gamma-aminobutyric acid from L-glutamic acid. A pathogenic role for this enzyme has been identified in the human pancreas since it has been identified as an autoantigen and an autoreactive T cell target in insulin-dependent diabetes. This gene may also play a role in the stiff man syndrome. Deficiency in this enzyme has been shown to lead to pyridoxine dependency with seizures. Alternative splicing of this gene results in two products, the predominant 67-kD form and a less-frequent 25-kD form. Interactions GAD1 has been shown to interact with GAD2. See also * Glutamate decarboxylase Glutamate decarboxylase or glutamic acid decarboxylase (GAD) is an enzyme that catalyzes the decarboxyla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hereditary
Heredity, also called inheritance or biological inheritance, is the passing on of traits from parents to their offspring; either through asexual reproduction or sexual reproduction, the offspring cells or organisms acquire the genetic information of their parents. Through heredity, variations between individuals can accumulate and cause species to evolve by natural selection. The study of heredity in biology is genetics. Overview In humans, eye color is an example of an inherited characteristic: an individual might inherit the "brown-eye trait" from one of the parents. Inherited traits are controlled by genes and the complete set of genes within an organism's genome is called its genotype. The complete set of observable traits of the structure and behavior of an organism is called its phenotype. These traits arise from the interaction of its genotype with the environment. As a result, many aspects of an organism's phenotype are not inherited. For example, suntanned skin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disorder
A genetic disorder is a health problem caused by one or more abnormalities in the genome. It can be caused by a mutation in a single gene (monogenic) or multiple genes (polygenic) or by a chromosomal abnormality. Although polygenic disorders are the most common, the term is mostly used when discussing disorders with a single genetic cause, either in a gene or chromosome. The mutation responsible can occur spontaneously before embryonic development (a ''de novo'' mutation), or it can be Heredity, inherited from two parents who are carriers of a faulty gene (autosomal recessive inheritance) or from a parent with the disorder (autosomal dominant inheritance). When the genetic disorder is inherited from one or both parents, it is also classified as a hereditary disease. Some disorders are caused by a mutation on the X chromosome and have X-linked inheritance. Very few disorders are inherited on the Y linkage, Y chromosome or Mitochondrial disease#Causes, mitochondrial DNA (due to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard Palate
The hard palate is a thin horizontal bony plate made up of two bones of the facial skeleton, located in the roof of the mouth. The bones are the palatine process of the maxilla and the horizontal plate of palatine bone. The hard palate spans the alveolar process, alveolar arch formed by the alveolar process that holds the upper teeth (when these are developed). Structure The hard palate is formed by the palatine process of the maxilla and horizontal plate of palatine bone. It forms a partition between the nasal passages and the mouth. On the anterior portion of the hard palate are the plicae, irregular ridges in the mucous membrane that help facilitate the movement of food backward towards the larynx. This partition is continued deeper into the mouth by a fleshy extension called the soft palate. On the ventral surface of hard palate, some projections or transverse ridges are present which are called as palatine rugae. Function The hard palate is important for feeding and sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
