|
Mannosidosis
Mannosidosis is a deficiency in mannosidase, an enzyme. There are two types: alpha-mannosidosis and beta-mannosidosis. Both disorders are related to the lysosome and have similar presentation; the former is caused by defective lysosomal α-mannosidase and the latter by defective lysosomal β-mannosidase. In both cases, the defect causes accumulation of oligosaccharides rich in mannose in the neural tissue and organ tissue. Both alpha- and beta-mannosidosis are known to result from autosomal recessive genetic mutations. Alpha-mannosidosis Alpha-mannosidosis is an inherited lysosomal storage disease that causes hearing loss, intellectual disability, facial and skeletal abnormalities, and immunological deficiencies. The main characteristics include skeletal abnormalities, hearing impairment, gradual impairment of mental functions and speech, and frequent periods of psychosis. Immune deficiency is manifested by recurrent infections, especially in the first decade of life. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-mannosidosis
Alpha-mannosidosis is a lysosomal storage disorder, first described by Swedish physician Okerman in 1967.''Malm D, Nilssen O (2008). "Alpha-mannosidosis". Orphanet J Rare Dis. 3 (1): 21. PubMed Central, PMC 2515294 . PubMed Identifier, PMID 18651971'' In humans it is known to be caused by an autosomal recessive genetic mutation in the gene MAN2B1, located on chromosome 19, affecting the production of the enzyme alpha-D-mannosidase, resulting in its deficiency.''Alpha-Mannosidosis Mutation Database. Tromsø University. Available at'' Consequently, if both parents are carriers, there will be a 25% chance with each pregnancy that the defective gene from both parents will be inherited, and the child will develop the disease. There is a two in three chance that unaffected siblings will be carriers (Figure 1). In livestock alpha-mannosidosis is caused by chronic poisoning with swainsonine from locoweed. Symptoms and signs Alpha-mannosidosis is a lifelong multi-systemic progressive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-mannosidosis
Beta-mannosidosis, also called lysosomal beta-mannosidase deficiency, is a disorder of oligosaccharide metabolism caused by decreased activity of the enzyme beta-mannosidase. This enzyme is coded for by the gene '' MANBA'', located at 4q22-25. Beta-mannosidosis is inherited in an autosomal recessive manner. Affected individuals appear normal at birth, and can have a variable clinical presentation. Infantile onset forms show severe neurodegeneration, while some children have intellectual disability. Hearing loss and angiokeratomas are common features of the disease. Symptoms and signs The initial affected individual described in 1986 had a complex phenotype, and was later found to have both beta-mannosidosis and Sanfilippo syndrome. People have been described with a wide spectrum of clinical presentations, from infants and children with intellectual disability to adults who present with isolated skin findings ( angiokeratomas). Most cases are identified in the first year o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Α-Mannosidase
α-Mannosidase (, ''α-D-mannosidase'', ''p-nitrophenyl-α-mannosidase'', ''α-D-mannopyranosidase'', ''1,2-α-mannosidase'', ''1,2-α-D-mannosidase'', ''exo-α-mannosidase'') is an enzyme involved in the cleavage of the α form of mannose. Its List of enzymes, systematic name is ''α-D-mannoside mannohydrolase''. Isoenzymes Humans express the following three α-mannosidase isoenzymes: Applications It can be utilized in experiments that determine the effects of the presence or absence of mannose on specific molecules, such as recombinant proteins that are used in vaccine development. Pathology A deficiency can lead to alpha-mannosidosis, α-mannosidosis. References External links GeneReviews/NCBI/NIH/UW entry on Alpha-Mannosidosis * EC 3.2.1 {{3.2-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysosomal Storage Disease
Lysosomal storage diseases (LSDs; ) are a group of over 70 rare inherited metabolic disorders that result from defects in lysosomal function. Lysosomes are sacs of enzymes within cells that digest large molecules and pass the fragments on to other parts of the cell for recycling. This process requires several critical enzymes. If one of these enzymes is defective due to a mutation, the large molecules accumulate within the cell, eventually killing it. Lysosomal storage disorders are caused by lysosomal dysfunction usually as a consequence of deficiency of a single enzyme required for the metabolism of lipids, glycoproteins (sugar-containing proteins), or mucopolysaccharides. Individually, lysosomal storage diseases occur with incidences of less than 1:100,000; however, as a group, the incidence is about 1:5,000 – 1:10,000. Most of these disorders are autosomal recessively inherited such as Niemann–Pick disease, type C, but a few are X-linked recessively inherited, such as Fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Î’-Mannosidase
β-Mannosidase (}, ''mannanase'', ''mannase'', ''β-D-mannosidase'', ''β-mannoside mannohydrolase'', ''exo-β-D-mannanase'', ''lysosomal β A mannosidase'') is an enzyme with systematic name ''β-D-mannoside mannohydrolase'', which is in humans encoded by the ''MANBA'' gene. This enzyme catalyses the following chemical reaction : Hydrolysis of terminal, non-reducing β-D-mannose residues in β-D-mannosides This gene encodes a member of the glycosyl hydrolase 2 family. The encoded protein localizes to the lysosome where it is the final exoglycosidase in the pathway for ''N''-linked glycoprotein oligosaccharide catabolism. Mutations in this gene are associated with β-mannosidosis, a lysosomal storage disease Lysosomal storage diseases (LSDs; ) are a group of over 70 rare inherited metabolic disorders that result from defects in lysosomal function. Lysosomes are sacs of enzymes within cells that digest large molecules and pass the fragments on to other ... that has a wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swainsonine
Swainsonine is an indolizidine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug. As a toxin in locoweed (likely its primary toxin) it also is a significant cause of economic losses in livestock industries, particularly in North America. It was first isolated from '' Swainsona canescens''. Pharmacology Swainsonine inhibits glycoside hydrolases, specifically those involved in ''N''-linked glycosylation. Disruption of Golgi alpha-mannosidase II with swainsonine induces hybrid-type glycans. These glycans have a Man5GlcNAc2 core with processing on the 3-arm that resembles so-called complex-type glycans. The pharmacological properties of this product have not been fully investigated. Sources Some plants, such as '' Oxytropis ochrocephala'', do not produce the toxic compound themselves, but are host to endophytic fungi which produces swainsonine, such as ''Alternaria oxytropis''. Biosynthesis The bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mannosidase
Mannosidase is an enzyme which hydrolyses mannose. There are two types: * alpha-Mannosidase * beta-Mannosidase A deficiency is associated with mannosidosis. A family of mannosidases are also responsible for processing newly formed glycoproteins in the endoplasmic reticulum The endoplasmic reticulum (ER) is a part of a transportation system of the eukaryote, eukaryotic cell, and has many other important functions such as protein folding. The word endoplasmic means "within the cytoplasm", and reticulum is Latin for ... into mature glycoproteins containing highly heterogeneous complex-type glycans. References EC 3.2.1 {{3.2-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signs And Symptoms
Signs and symptoms are diagnostic indications of an illness, injury, or condition. Signs are objective and externally observable; symptoms are a person's reported subjective experiences. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showing on a medical scan. A symptom is something out of the ordinary that is experienced by an individual such as feeling feverish, a headache or other pains in the body, which occur as the body's immune system fights off an infection. Signs and symptoms Signs A medical sign is an objective observable indication of a disease, injury, or medical condition that may be detected during a physical examination. These signs may be visible, such as a rash or bruise, or otherwise detectable such as by using a stethoscope or taking blood pressure. Medical signs, along with symptoms, help in forming a diagnosis. Some examples of signs are nail clubbing of either the fingernail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psychosis
In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or incoherent thoughts or speech. Psychosis is a description of a person's state or symptoms, rather than a particular mental illness, and it is not related to psychopathy (a personality construct characterized by impaired empathy and remorse, along with bold, disinhibited, and egocentric traits). Common causes of chronic (i.e. ongoing or repeating) psychosis include schizophrenia or schizoaffective disorder, bipolar disorder, and brain damage (usually as a result of alcoholism). Acute (temporary) psychosis can also be caused by severe distress, sleep deprivation, sensory deprivation, some medications, and drug use (including alcohol, cannabis, hallucinogens, and stimulants). Acute psychosis is termed primary if it results from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intellectual Disability
Intellectual disability (ID), also known as general learning disability (in the United Kingdom), and formerly mental retardation (in the United States), Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010).Archive is a generalized neurodevelopmental disorder characterized by significant impairment in intellectual and adaptive functioning that is first apparent during childhood. Children with intellectual disabilities typically have an intelligence quotient (IQ) below 70 and deficits in at least two adaptive behaviors that affect everyday living. According to the DSM-5, intellectual functions include reasoning, problem solving, planning, abstract thinking, judgment, academic learning, and learning from experience. Deficits in these functions must be confirmed by clinical evaluation and individualized standard IQ testing. On the other hand, adaptive behaviors include the social, developmental, and practical skills people learn to perform tasks in their everyday lives. Deficits in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
