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Congenital Disorders Of Amino Acid Metabolism
Inborn errors of amino acid metabolism are metabolic disorders which impair the synthesis and degradation of amino acids. Types *Alkaptonuria *Aspartylglucosaminuria *Branched-chain keto acid dehydrogenase kinase deficiency *Methylmalonic acidemia *Maple syrup urine disease *Homocystinuria *Tyrosinemia *Trimethylaminuria *Hartnup disease *Biotinidase deficiency *Ornithine carbamoyltransferase deficiency *Carbamoyl-phosphate synthase I deficiency disease *Citrullinemia *Hyperargininemia *Hyperhomocysteinemia *Hypermethioninemia *Hyperlysinemias *Nonketotic hyperglycinemia *Propionic acidemia *Hyperprolinemia Amino acid transport disorders *Cystinuria *Dicarboxylic aminoaciduria *Hartnup disease Amino acid storage disorders *Glutaric acidemia type 2 Glutaric acidemia type 2 is an autosomal recessive metabolic disorder that is characterised by defects in the ability of the body to use proteins and fats for energy. Incompletely processed proteins and fats can build up, leading to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid '' residues'' form the second-largest component (water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling life ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbamoyl-phosphate Synthase I Deficiency Disease
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 mental retardation. In some affected individuals, signs and symptoms of carbamoyl phosphate synthetase I deficiency may be les ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dicarboxylic Aminoaciduria
Dicarboxylic aminoaciduria is a rare form of aminoaciduria (1:35 000 births) which is an autosomal recessive disorder of urinary glutamate and aspartate due to genetic errors related to transport of these amino acids. Mutations resulting in a lack of expression of the ''SLC1A1'' gene, a member of the solute carrier family, are found to cause development of dicarboxylic aminoaciduria in humans. SLC1A1 encodes for EAAT3 which is found in the neurons, intestine, kidney, lung, and heart. EAAT3 is part of a family of high affinity glutamate transporters which transport both glutamate and aspartate across the plasma membrane. Symptoms and signs Dicarboxylic aminoaciduria involves excretion of urinary glutamate and aspartate, resulting from the incomplete reabsorption of anionic amino acids from the glomerular filtrate in the kidney. This affects a diseased individual's amino acid pool, as they will have to spend additional resources to replenish the amino acids which would have otherw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystinuria
Cystinuria is an inherited autosomal recessive disease characterized by high concentrations of the amino acid cystine in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. "Cystine", not "cysteine," is implicated in this disease; the former is a dimer of the latter. Presentation Cystinuria is a cause of recurrent kidney stones. It is a disease involving the defective transepithelial transport of cystine and dibasic amino acids in the kidney and intestine, and is one of many causes of kidney stones. If not treated properly, the disease could cause serious damage to the kidneys and surrounding organs, and in some rare cases death. The stones may be identified by a positive nitroprusside cyanide test. The crystals are usually hexagonal, translucent, white. Upon removal, the stones may be pink or yellow in color, but later they turn to greenish due to exposure to air. Cystinuria is usually asymptomatic when no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperprolinemia
Hyperprolinemia is a condition which occurs when the amino acid proline is not broken down properly by the enzymes proline oxidase or 1-Pyrroline-5-carboxylate dehydrogenase, pyrroline-5-carboxylate dehydrogenase, causing a buildup of proline in the body. Genetics Mutations in the ''ALDH4A1'' and ''PRODH'' genes cause hyperprolinemia. Hyperprolinemia type I is caused by a mutation in the ''PRODH'' gene, which codes for the enzyme proline oxidase. This enzyme begins the process of degrading proline by starting the reaction that converts it to pyrroline-5-carboxylate. Hyperprolinemia type II is caused by a mutation in the ''ALDH4A1'' gene, for the enzyme 1-pyrroline-5-carboxylate dehydrogenase. This enzyme helps to break down the pyrroline-5-carboxylate produced in the previous reaction, converting it to the amino acid glutamate. The conversion between proline and glutamine, and the reverse reaction controlled by different enzymes, are important factors required to maintain prop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propionic Acidemia
Propionic acidemia, also known as propionic aciduria or propionyl-CoA carboxylase deficiency (PCC deficiency), is a rare autosomal recessive metabolic disorder, classified as a branched-chain organic acidemia. The disorder presents in the early neonatal period with poor feeding, vomiting, lethargy, and lack of muscle tone. Without treatment, death can occur quickly, due to secondary hyperammonemia, infection, cardiomyopathy, or brain damage. Symptoms and signs Propionic acidemia can vary in severity. Severe propionic acidemia lead to symptoms already seen in newborns. Symptoms include poor feeding, vomiting, dehydration, acidosis, low muscle tone (hypotonia), seizures, and lethargy. The effects of propionic acidemia quickly become life-threatening. Long-term complications can include chronic kidney disease, cardiomyopathy, and prolonged QTc interval. Pathophysiology In healthy individuals, enzyme propionyl-CoA carboxylase converts propionyl-CoA to methylmalonyl-CoA. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonketotic Hyperglycinemia
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset. The symptoms are exclusively neurological in nature, and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues, especially the cerebrospinal fluid. Glycine encephalopathy is sometimes referred to as "nonketotic hyperglycinemia" (NKH), as a reference to the biochemical findings seen in patients with the disorder, and to distinguish it from the disorders that cause "ketotic hyperglycinemia" (seen in propionic acidemia and several other inherited metabolic disorders). To avoid confusion, the term "glycine encephalopathy" is oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperlysinemias
Hyperlysinemia is an autosomal recessive metabolic disorder characterized by an abnormal increase of lysine in the blood, but appears to be benign. It is caused by mutations in ''AASS'', which encodes α-aminoadipic semialdehyde synthase. Hyperlysinemia is associated with ectopia lentis (a displacement or malposition of the eye's crystalline lens) in humans. Genetics Hyperlysinemia is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome, and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder. Diagnosis Treatment See also * Saccharopinuria Saccharopinuria (an excess of saccharopine in the urine), also called saccharopinemia, saccharopine dehydrogenase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypermethioninemia
Hypermethioninemia is an excess of the amino acid methionine, in the blood. This condition can occur when methionine is not broken down properly in the body. Presentation Genetics Hypermethioninemia can have different inheritance patterns. This condition is usually inherited in an autosomal recessive pattern, which means two copies of the gene in each cell are altered. Most often, the parents of an individual with an autosomal recessive disorder each carry one copy of the altered gene but do not show signs and symptoms of the disorder. Hypermethioninemia is occasionally inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. In these cases, an affected person usually has one parent with the condition. Pathophysiology Inherited hypermethioninemia that is not associated with other metabolic disorders can be caused by shortages in the enzymes that break down methionine. These enzymes are produced from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperhomocysteinemia
Hyperhomocysteinemia is a medical condition characterized by an abnormally high level of homocysteine in the blood, conventionally described as above 15 μmol/L. As a consequence of the biochemical reactions in which homocysteine is involved, deficiencies of vitamin B6, folic acid (vitamin B9), and vitamin B12 can lead to high homocysteine levels. Other possible causes of hyperhomocysteinemia include genetics, excessive methionine intake, and other diseases. Hyperhomocysteinemia is typically managed with vitamin B6, vitamin B9 and vitamin B12 supplementation. Hyperhomocysteinemia is a risk factor for cardiovascular disease; however, supplements of these vitamins may not improve cardiovascular disease outcomes. Signs and symptoms Elevated levels of homocysteine have been associated with a number of disease states. Cardiovascular risks Elevated homocysteine is a known risk factor for cardiovascular disease as well as thrombosis. It has also been shown to be associated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyperargininemia
Argininemia is an autosomal recessive urea cycle disorder where a deficiency of the enzyme arginase causes a buildup of arginine and ammonia in the blood. Ammonia, which is formed when proteins are broken down in the body, is toxic if levels become too high; the nervous system is especially sensitive to the effects of excess ammonia.update 2014 Signs and symptoms The presentation of argininemia, in those that are affected, is consistent with the following: Genetics Mutations in the ''ARG1'' gene cause argininemia, which belongs to a class of genetic diseases called urea cycle disorders.update 2015 The urea cycle is a sequence of reactions that occurs in liver cells (hepatocytes). This cycle processes excess nitrogen, generated when protein is used by the body, making urea that is excreted via the kidneys. The ''ARG1'' gene provides instructions for making an enzyme called arginase, this enzyme controls the last steps of the urea cycle, which produces urea by extracting nitrog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citrullinemia
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. 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, vomiting, seizures, and loss of con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
