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Tay–Sachs Disease
Tay–Sachs disease is a genetic disorder that results in the destruction of nerve cells in the brain and spinal cord. The most common form is infantile Tay–Sachs disease, which becomes apparent around three to six months of age, with the baby losing the ability to turn over, sit, or crawl. This is then followed by seizures, hearing loss, and inability to move, with death usually occurring by the age of three to five. Less commonly, the disease may occur in later childhood or adulthood (juvenile or late-onset). These forms tend to be less severe, but the juvenile form typically results in death by age 15. Tay–Sachs disease is caused by a genetic mutation in the ''HEXA'' gene on chromosome 15, which codes form a subunit of the hexosaminidase enzyme known as hexosaminidase A. It is inherited from a person's parents in an autosomal recessive manner. The mutation disrupts the activity of the enzyme, which results in the build-up of the molecule GM2 ganglioside within cells, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cherry-red Spot
A cherry-red spot is a finding in the macula of the eye in a variety of lipid storage disorders and in central retinal artery occlusion. It describes the appearance of a small circular choroid shape as seen through the fovea centralis. Its appearance is due to a relative transparency of the macula; storage disorders cause the accumulation of storage material within the cell layers of the retina, however, the macula, which is relatively devoid of cellular layers, does not build up this material, and thus allows the eye to see through the macula to the red choroid below. The sign was first described by Warren Tay, founding member of the British Ophthalmological Society, in 1881, with reference to a patient with Tay–Sachs disease. The cherry red spot is seen in central retinal artery occlusion, appearing several hours after the blockage of the retinal artery occurs.Rakel, Robert E., Textbook of Family Medicine, 7th ed, Chapter 53 The cherry red spot is seen because the macula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizure
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness ( tonic-clonic seizure), to shaking movements involving only part of the body with variable levels of consciousness ( focal seizure), to a subtle momentary loss of awareness ( absence seizure). Most of the time these episodes last less than two minutes and it takes some time to return to normal. Loss of bladder control may occur. Seizures may be provoked and unprovoked. Provoked seizures are due to a temporary event such as low blood sugar, alcohol withdrawal, abusing alcohol together with prescription medication, low blood sodium, fever, brain infection, or concussion. Unprovoked seizures occur without a known or fixable cause such that ongoing seizures are likely. Unprovoked seizures may be exacerbated by stress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashkenazi Jews
Ashkenazi Jews ( ; he, יְהוּדֵי אַשְׁכְּנַז, translit=Yehudei Ashkenaz, ; yi, אַשכּנזישע ייִדן, Ashkenazishe Yidn), also known as Ashkenazic Jews or ''Ashkenazim'',, Ashkenazi Hebrew pronunciation: , singular: , Modern Hebrew: are a Jewish diaspora population who coalesced in the Holy Roman Empire around the end of the first millennium CE. Their traditional diaspora language is Yiddish (a West Germanic language with Jewish linguistic elements, including the Hebrew alphabet), which developed during the Middle Ages after they had moved from Germany and France into Northern Europe and Eastern Europe. For centuries, Ashkenazim in Europe used Hebrew only as a sacred language until the revival of Hebrew as a common language in 20th-century Israel. Throughout their numerous centuries living in Europe, Ashkenazim have made many important contributions to its philosophy, scholarship, literature, art, music, and science. The rabbinical t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supportive Care
Symptomatic treatment, supportive care, supportive therapy, or palliative treatment is any medical therapy of a disease that only affects its symptoms, not the underlying cause. It is usually aimed at reducing the signs and symptoms for the comfort and well-being of the patient, but it also may be useful in reducing organic consequences and sequelae of these signs and symptoms of the disease. In many diseases, even in those whose etiologies are known (e.g., most viral diseases, such as influenza and Rift Valley fever), symptomatic treatment is the only treatment available so far. For more detail, see supportive therapy. For conditions like cancer, arthritis, neuropathy, tendinopathy, and injury, it can be useful to distinguish treatments that are supportive/palliative and cannot alter the natural history of the disease ( disease modifying treatments). Examples Examples of symptomatic treatments: * Analgesics, to reduce pain * Anti-inflammatory agents, for inflammation cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingolipidosis
Sphingolipidoses are a class of lipid storage disorders or degenerative storage disorders caused by deficiency of an enzyme that is required for the catabolism of lipids that contain ceramide,Lynn, D. Joanne, Newton, Herbert B. and Rae-Grant, Alexander D. eds. 5-Minute Neurology Consult, The. 2nd Edition. Two Commerce Square, 2001 Market Street, Philadelphia, PA 19103 USA: Lippincott Williams & Wilkins, 2012. Books@Ovid. Web. 03 December, 2020 also relating to sphingolipid metabolism. The main members of this group are Niemann–Pick disease, Fabry disease, Krabbe disease, Gaucher disease, Tay–Sachs disease and metachromatic leukodystrophy. They are generally inherited in an autosomal recessive fashion, but notably Fabry disease is X-linked recessive. Taken together, sphingolipidoses have an incidence of approximately 1 in 10,000, but substantially more in certain populations such as Ashkenazi Jews. Enzyme replacement therapy is available to treat mainly Fabry disease and Ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GM2 Gangliosidoses
The GM2 gangliosidoses are a group of three related genetic disorders that result from a deficiency of the enzyme beta-hexosaminidase. This enzyme catalyzes the biodegradation of fatty acid derivatives known as gangliosides. The diseases are better known by their individual names: Tay–Sachs disease, AB variant, and Sandhoff disease. Beta-hexosaminidase is a vital hydrolytic enzyme, found in the lysosomes, that breaks down lipids. When beta-hexosaminidase is no longer functioning properly, the lipids accumulate in the nervous tissue of the brain and cause problems. Gangliosides are made and biodegraded rapidly in early life as the brain develops. Except in some rare, late-onset forms, the GM2 gangliosidoses are fatal. All three disorders are rare in the general population. Tay–Sachs disease has become famous as a public health model because an enzyme assay test for TSD was discovered and developed in the late 1960s and early 1970s, providing one of the first "mass screening" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GM2 Ganglioside
In organic chemistry, GM2 is a type of ganglioside. G refers to ganglioside, the M is for monosialic (as in it has one sialic acid), and 2 refers to the fact that it was the second monosialic ganglioside discovered. It is associated with GM2 gangliosidoses such as Tay–Sachs disease. See also * Ganglioside GM2 activator protein GM2 ganglioside activator also known as GM2A is a protein which in humans is encoded by the ''GM2A'' gene. Function The protein encoded by this gene is a small glycolipid transport protein which acts as a substrate specific co-factor for the ... Additional images Image:Sphingolipidoses.svg, Sphingolipidoses Image:Structure of GM1, GM2, GM3.png, Structures of GM1, GM2, GM3 gangliosides References External links * {{Sphingolipids Glycolipids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexosaminidase
Hexosaminidase (, ''beta-acetylaminodeoxyhexosidase'', ''N-acetyl-beta-D-hexosaminidase'', ''N-acetyl-beta-hexosaminidase'', ''N-acetyl hexosaminidase'', ''beta-hexosaminidase'', ''beta-acetylhexosaminidinase'', ''beta-D-N-acetylhexosaminidase'', ''beta-N-acetyl-D-hexosaminidase'', ''beta-N-acetylglucosaminidase'', ''hexosaminidase A'', ''N-acetylhexosaminidase'', ''beta-D-hexosaminidase'') is an enzyme involved in the hydrolysis of terminal N-acetyl-D- hexosamine residues in N-acetyl-β-D-hexosaminides. Elevated levels of hexosaminidase in blood and/or urine have been proposed as a biomarker of relapse in the treatment of alcoholism. Hereditary inability to form functional hexosaminidase enzymes are the cause of lipid storage disorders Tay-Sachs disease and Sandhoff disease. Isozymes and genes Lysosomal A, B, and S isozymes Functional lysosomal β-hexosaminidase enzymes are dimeric in structure. Three isozymes are produced through the combination of α and β subunits t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Subunit
In structural biology, a protein subunit is a polypeptide chain or single protein molecule that assembles (or "''coassembles''") with others to form a protein complex. Large assemblies of proteins such as viruses often use a small number of types of protein subunits as building blocks. A subunit is often named with a Greek or Roman letter, and the numbers of this type of subunit in a protein is indicated by a subscript. For example, ATP synthase has a type of subunit called α. Three of these are present in the ATP synthase molecule, leading to the designation α3. Larger groups of subunits can also be specified, like α3β3-hexamer and c-ring. Naturally-occurring proteins that have a relatively small number of subunits are referred to as oligomeric.Quote: ''Oligomer molecule: A molecule of intermediate relative molecular mass, the structure of which essentially comprises a small plurality of units derived, actually or conceptually, from molecules of lower relative molecular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 15
Chromosome 15 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 15 spans about 102 million base pairs (the building material of DNA) and represents between 3% and 3.5% of the total DNA in cells. Chromosome 15 is an acrocentric chromosome, with a very small short arm (the "p" arm, for "petite"), which contains few protein coding genes among its 19 million base pairs. It has a larger long arm (the "q" arm) that is gene rich, spanning about 83 million base pairs. The human leukocyte antigen gene for β2-microglobulin is found on chromosome 15, as well as the FBN1 gene, coding for both fibrillin-1 (a protein critical to the proper functioning of connective tissue), and aprosin (a small protein produced from part of the transcribed FBN1 gene mRNA), which is involved in fat metabolism. Genes Number of genes The following are some of the gene count estimates of human chromosome 15. Because researchers use different appro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HEXA
Numeral or number prefixes are prefixes derived from numerals or occasionally other numbers. In English and many other languages, they are used to coin numerous series of words. For example: * unicycle, bicycle, tricycle (1-cycle, 2-cycle, 3-cycle) * dyad, triad (2 parts, 3 parts) * biped, quadruped (2 legs, 4 legs) * September, October, November, December (month 7, month 8, month 9, month 10) * decimal, hexadecimal (base-10, base-16) * septuagenarian, octogenarian (70-79 years old, 80-89 years old) * centipede, millipede (around 100 legs, around 1000 legs) In many European languages there are two principal systems, taken from Latin and Greek, each with several subsystems; in addition, Sanskrit occupies a marginal position. There is also an international set of metric prefixes, which are used in the metric system and which for the most part are either distorted from the forms below or not based on actual number words. Table of number prefixes in English In the following p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
