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Inborn Errors Of Metabolism
Inborn errors of metabolism form a large class of genetic diseases involving congenital disorders of enzyme activities. The majority are due to defects of single genes that code for enzymes that facilitate conversion of various substances ( substrates) into others ( products). In most of the disorders, problems arise due to accumulation of substances which are toxic or interfere with normal function, or due to the effects of reduced ability to synthesize essential compounds. Inborn errors of metabolism are often referred to as congenital metabolic diseases or inherited metabolic disorders. Another term used to describe these disorders is "enzymopathies". This term was created following the study of biodynamic enzymology, a science based on the study of the enzymes and their products. Finally, ''inborn errors of metabolism'' were studied for the first time by British physician Archibald Garrod (1857–1936), in 1908. He is known for work that prefigured the "one gene–one enzyme" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Disease
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 chromosome 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 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 chromosome or mitochondrial DNA (due to their size). There are well over 6,000 known genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenylketonuria
Phenylketonuria (PKU) is an inborn error of metabolism that results in decreased metabolism of the amino acid phenylalanine. Untreated PKU can lead to intellectual disability, seizures, behavioral problems, and mental disorders. It may also result in a musty smell and lighter skin. A baby born to a mother who has poorly treated PKU may have heart problems, a small head, and low birth weight. Phenylketonuria is an inherited genetic disorder. It is caused by mutations in the '' PAH'' gene, which can result in inefficient or nonfunctional phenylalanine hydroxylase, an enzyme responsible for the metabolism of excess phenylalanine. This results in the buildup of dietary phenylalanine to potentially toxic levels. It is autosomal recessive, meaning that both copies of the gene must be mutated for the condition to develop. The two main types are classic PKU and variant PKU, depending on whether any enzyme function remains. Those with one copy of a mutated gene typically do not ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porphyrin
Porphyrins ( ) are heterocyclic, macrocyclic, organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (). In vertebrates, an essential member of the porphyrin group is heme, which is a component of hemoproteins, whose functions include carrying oxygen in the bloodstream. In plants, an essential porphyrin derivative is chlorophyll, which is involved in light harvesting and electron transfer in photosynthesis. The parent of porphyrins is porphine, a rare chemical compound of exclusively theoretical interest. Substituted porphines are called porphyrins. With a total of 26 π-electrons the porphyrin ring structure is a coordinated aromatic system. One result of the large conjugated system is that porphyrins absorb strongly in the visible region of the electromagnetic spectrum, i.e. they are deeply colored. The name "porphyrin" derives . Structure Porphyrin complexes consist of a square planar MN4 core. The p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium-chain Acyl-coenzyme A Dehydrogenase Deficiency
Medium-chain acyl-CoA dehydrogenase deficiency (MCAD deficiency or MCADD) is a disorder of fatty acid oxidation that impairs the body's ability to break down medium-chain fatty acids into acetyl-CoA. The disorder is characterized by hypoglycemia and sudden death without timely intervention, most often brought on by periods of fasting or vomiting. Prior to expanded newborn screening, MCADD was an underdiagnosed cause of sudden death in infants. Individuals who have been identified prior to the onset of symptoms have an excellent prognosis. MCADD is most prevalent in individuals of Northern European Caucasian descent, with an incidence of 1:4000 to 1:17,000 depending on the population. Treatment of MCADD is mainly preventive, by avoiding fasting and other situations where the body relies on fatty acid oxidation to supply energy. Signs and symptoms MCADD presents in early childhood with hypoketotic hypoglycemia and liver dysfunction, often preceded by extended periods of fasting o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial
A mitochondrion () is an organelle found in the cells of most eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'', meaning a thread-like granule, was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase popularized by Philip Siekevitz in a 1957 ''Scientific American'' article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). The multicellular animal '' Henneguya salminicola'' is known to have retained mitochondrion-related organelles despite a complete loss of their mitochondrial genome. A large number of unicellular organisms, such as microsporidia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fatty Acid Metabolism Disorders
Numerous genetic disorders are caused by errors in fatty acid metabolism. These disorders may be described as fatty oxidation disorders or as a '' lipid storage disorders'', and are any one of several inborn errors of metabolism that result from enzyme defects affecting the ability of the body to oxidize fatty acids in order to produce energy within muscles, liver, and other cell types. Some of the more common fatty acid metabolism disorders are: Coenzyme A dehydrogenase deficiencies * Very long-chain acyl-coenzyme A dehydrogenase deficiency (VLCAD) - Very long-chain acyl-coenzyme A dehydrogenase * Long-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency (LCHAD) - Long-chain 3-hydroxyacyl-coenzyme A * Medium-chain acyl-coenzyme A dehydrogenase deficiency (MCAD) - Medium-chain acyl-coenzyme A dehydrogenase * Short-chain acyl-coenzyme A dehydrogenase deficiency (SCAD) - Short-chain acyl-coenzyme A dehydrogenase * 3-hydroxyacyl-coenzyme A dehydrogenase deficiency (HADH) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Hydroxyglutaric Aciduria
2-hydroxyglutaric aciduria is a rare neurometabolic disorder characterized by the significantly elevated levels of hydroxyglutaric acid in one's urine. It is either autosomal recessive or autosomal dominant. Presentation The signs/symptoms of this condition are consistent with the following: * Intellectual disability, * Muscular hypotonia * Encephalitis * Seizures * Aphasia Cause Mutation in several genes can lead to different types of 2-hydroxyglutaric aciduria. For example, the D2HGDH and L2HGDH genes provide instructions for making enzymes that are found in mitochondria - in which these enzymes break down D-2-hydroxyglutarate and L-2-hydroxyglutarate, respectively, as a part of normal reaction series that generate energy for cell activities. Any mutations occur in either of these genes would interrupt the functional enzymes and allow both 2-hydroxyglutarates to accumulate in cells, which cause 2-hydroxyglutaric aciduria type I. Moreover, it is known that type II for L-2-hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combined Malonic And Methylmalonic Aciduria
Combined malonic and methylmalonic aciduria (CMAMMA), also called combined malonic and methylmalonic acidemia is an inherited metabolic disease characterized by elevated levels of malonic acid and methylmalonic acid. However, the methylmalonic acid levels exceed those of malonic acid. CMAMMA is not only an organic aciduria but also a defect of mitochondrial fatty acid synthesis (mtFAS). Some researchers have hypothesized that CMAMMA might be one of the most common forms of methylmalonic acidemia, and possibly one of the most common inborn errors of metabolism. Due to being infrequently diagnosed, it most often goes undetected. Symptoms and signs The clinical phenotypes of CMAMMA are highly heterogeneous and range from asymptomatic, mild to severe symptoms. The underlying pathophysiology is not yet understood. The following symptoms are reported in the literature: * metabolic acidosis * coma * hypoglycemia * seizures * gastrointestinal disease * developmental delay * speec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaptonuria
Alkaptonuria is a rare inherited genetic disease which is caused by a mutation in the ''HGD'' gene for the enzyme homogentisate 1,2-dioxygenase (); if a person inherits an abnormal copy from both parents (it is a dominance relationship, recessive condition), the body accumulates an intermediate substance called homogentisic acid in the blood and tissues. Homogentisic acid and its oxide, oxidized form ''alkapton'' are excreted in the urine, giving it an unusually dark color. The accumulating homogentisic acid causes damage to cartilage (ochronosis, leading to osteoarthritis) and heart valves, as well as precipitating as kidney stones and stones in other organs. Symptoms usually develop in people over 30 years old, although the dark discoloration of the urine is present from birth. Apart from treatment of the complications (such as analgesia, pain relief and Arthroplasty, joint replacement for the cartilage damage), the drug nitisinone has been found to suppress homogentisic acid prod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Aciduria
Organic acidemia is a term used to classify a group of metabolic disorders which disrupt normal amino acid metabolism, particularly branched-chain amino acids, causing a buildup of acids which are usually not present. The branched-chain amino acids include isoleucine, leucine and valine. Organic acids refer to the amino acids and certain odd-chained fatty acids which are affected by these disorders. The four main types of organic acidemia are: methylmalonic acidemia, propionic acidemia, isovaleric acidemia, and maple syrup urine disease. Signs and symptoms Cause Most of the organic acidemias result from defective autosomal genes for various enzymes important to amino acid metabolism. Neurological and physiological harm is caused by this impaired ability to synthesize a key enzyme required to break down a specific amino acid, or group of amino acids, resulting in acidemia and toxicity to specific organ systems. Most are inherited as autosomal recessive diseases. Diagnosis Org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrullinemia Type II (citrin Deficiency)
Citrullinemia is an autosomal recessive urea cycle disorder that causes ammonia and other toxic substances to accumulate in the blood.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . Two forms of citrullinemia have been described, both having different signs and symptoms, and are caused by mutations in different genes. Citrullinemia belongs to a class of genetic diseases called urea cycle disorders. The urea cycle is a sequence of chemical reactions taking place in the liver. These reactions process excess nitrogen, generated when protein is used for energy by the body, to make urea, which is excreted by the kidneys. Signs and symptoms Cause Diagnosis Type I Type I citrullinemia (, also known as classic citrullinemia) usually becomes evident in the first few days of life. Affected infants typically appear normal at birth, but as ammonia builds up in the body, they develop a lack of energy (lethargy), poor feeding, vomitin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbamoyl Phosphate Synthetase I Deficiency
Carbamoyl phosphate synthetase I deficiency (CPS I deficiency) is an autosomal recessive metabolic disorder that causes ammonia to accumulate in the blood due to a lack of the enzyme carbamoyl phosphate synthetase I. Ammonia, which is formed when proteins are broken down in the body, is toxic if the levels become too high. The nervous system is especially sensitive to the effects of excess ammonia. Signs and symptoms Carbamoyl phosphate synthetase I deficiency often becomes evident in the first few days of life. An infant with this condition may be lacking in energy (lethargic) or unwilling to eat, and have a poorly controlled breathing rate or body temperature. Some babies with this disorder may experience seizures or unusual body movements, or go into a coma. Complications of carbamoyl phosphate synthetase I deficiency may include developmental delay and intellectual disability. In some affected individuals, signs and symptoms of carbamoyl phosphate synthetase I deficiency may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
