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Pyruvate Kinase Deficiency
Pyruvate kinase deficiency is an inherited metabolic disorder of the enzyme pyruvate kinase which affects the survival of red blood cells. Both autosomal dominant and recessive inheritance have been observed with the disorder; classically, and more commonly, the inheritance is autosomal recessive. Pyruvate kinase deficiency is the second most common cause of enzyme-deficient hemolytic anemia, following G6PD deficiency. Signs and symptoms Symptoms can be extremely varied among those suffering from pyruvate kinase deficiency. The majority of those suffering from the disease are detected at birth while some only present symptoms during times of great physiological stress such as pregnancy, or with acute illnesses ( viral disorders). Symptoms are limited to or most severe during childhood. Among the symptoms of pyruvate kinase deficiency are: * Mild to severe hemolytic anemia * Cholecystolithiasis * Tachycardia * Hemochromatosis * Icteric sclera * Splenomegaly * Leg ulcers * Jaundi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Phosphoenolpyruvate
Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the carboxylic acid derived from the enol of pyruvate and a phosphate anion. It exists as an anion. PEP is an important intermediate in biochemistry. It has the high-energy phosphate, highest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved in glycolysis and gluconeogenesis. In plants, it is also involved in the biosynthesis of various aromatic compounds, and in carbon fixation; in bacteria, it is also used as the source of energy for the phosphotransferase system. In glycolysis PEP is formed by the action of the enzyme enolase on 2-phosphoglyceric acid. Metabolism of PEP to pyruvic acid by pyruvate kinase (PK) generates adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within Cell (biology), cells. In gluconeogenesis PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Iron Overload
Iron overload is the abnormal and increased accumulation of total iron in the body, leading to organ damage. The primary mechanism of organ damage is oxidative stress, as elevated intracellular iron levels increase free radical formation via the Fenton reaction. Iron overload is often ''primary'' (i.e hereditary haemochromatosis, aceruloplasminemia) but may also be ''secondary'' to other causes (i.e. transfusional iron overload). Iron deposition most commonly occurs in the liver, pancreas, skin, heart, and joints. People with iron overload classically present with the triad of liver cirrhosis, secondary diabetes mellitus, and bronze skin. However, due to earlier detection nowadays, symptoms are often limited to general chronic malaise, arthralgia, and hepatomegaly. Signs and symptoms Organs most commonly affected by hemochromatosis include the liver, heart, and endocrine glands. Hemochromatosis may present with the following clinical syndromes: * liver: chronic liver di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Compound Heterozygosity
In medical genetics, compound heterozygosity is the condition of having two or more heterogeneous recessive alleles at a particular locus that can cause genetic disease in a heterozygous state; that is, an organism is a compound heterozygote when it has two recessive alleles for the same gene, but with those two alleles being different from each other (for example, both alleles might be mutated but at different locations). Compound heterozygosity reflects the diversity of the mutation base for many autosomal recessive genetic disorders; mutations in most disease-causing genes have arisen many times. This means that many cases of disease arise in individuals who have two unrelated alleles, who technically are heterozygotes, but both the alleles are defective. These disorders are often best known in some classic form, such as the homozygous recessive case of a particular mutation that is widespread in some population. In its compound heterozygous forms, the disease may have lower pene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Zygosity
Zygosity (the noun, zygote, is from the Greek "yoked," from "yoke") () is the degree to which both copies of a chromosome or gene have the same genetic sequence. In other words, it is the degree of similarity of the alleles in an organism. Most eukaryotes have two matching sets of chromosomes; that is, they are diploid. Diploid organisms have the same locus (genetics), loci on each of their two sets of homologous chromosomes except that the sequences at these loci may differ between the two chromosomes in a matching pair and that a few chromosomes may be mismatched as part of a chromosomal Sex-determination system#Chromosomal determination, sex-determination system. If both alleles of a diploid organism are the same, the organism is #Homozygous, homozygous at that locus. If they are different, the organism is #Heterozygous, heterozygous at that locus. If one allele is missing, it is #Hemizygous, hemizygous, and, if both alleles are missing, it is #Nullizygous, nullizygous. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Missense Mutation
In genetics, a missense mutation is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid. It is a type of nonsynonymous substitution. Missense mutations change amino acids, which in turn alter proteins and may alter a protein's function or structure. These mutations may arise spontaneously from mutagens like UV radiation, tobacco smoke, an error in DNA replication, and other factors. Screening for missense mutations can be done by sequencing the genome of an organism and comparing the sequence to a reference genome to analyze for differences. Missense mutations can be repaired by the cell when there are errors in DNA replication by using mechanisms such as DNA proofreading and DNA mismatch repair, mismatch repair. They can also be repaired by using genetic engineering technologies or pharmaceuticals. Some notable examples of human diseases caused by missense mutations are Rett syndrome, cystic fibrosis, and Sickle cell disease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Red Blood Cell
Red blood cells (RBCs), referred to as erythrocytes (, with -''cyte'' translated as 'cell' in modern usage) in academia and medical publishing, also known as red cells, erythroid cells, and rarely haematids, are the most common type of blood cell and the vertebrate's principal means of delivering oxygen () to the body tissue (biology), tissues—via blood flow through the circulatory system. Erythrocytes take up oxygen in the lungs, or in fish the gills, and release it into tissues while squeezing through the body's capillary, capillaries. The cytoplasm of a red blood cell is rich in hemoglobin (Hb), an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells and the blood. Each human red blood cell contains approximately 270 million hemoglobin molecules. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological Cell (biology), cell function such as erythrocyte deformabil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Isozyme
In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. different ''K''M values), or are regulated differently. They permit the fine-tuning of metabolism to meet the particular needs of a given tissue or developmental stage. In many cases, isozymes are encoded by homologous genes that have diverged over time. Strictly speaking, enzymes with different amino acid sequences that catalyse the same reaction are isozymes if encoded by different genes, or allozymes if encoded by different alleles of the same gene; the two terms are often used interchangeably. Introduction Isozymes were first described by R. L. Hunter and Clement Markert (1957) who defined them as ''different variants of the same enzyme having identical functions and present in the same individual''. This definition encompasses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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PKLR
Pyruvate kinase PKLR is an enzyme that in humans is encoded by the ''PKLR'' gene. The protein encoded by this gene is a pyruvate kinase Pyruvate kinase is the enzyme involved in the last step of glycolysis. It catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to adenosine diphosphate (ADP), yielding one molecule of pyruvate and one molecule of ATP. Pyruv ... that catalyzes the production of pyruvate and ATP from phosphoenolpyruvate. Defects in this enzyme, due to gene mutations or genetic variations, are the common cause of chronic hereditary nonspherocytic hemolytic anemia (CNSHA or HNSHA). Alternatively spliced transcript variants encoding distinct isoforms have been described. Interactive pathway map References Further reading * * * * * * * * * * * * * * * * * * {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Phosphoenolpyruvate
Phosphoenolpyruvate (2-phosphoenolpyruvate, PEP) is the carboxylic acid derived from the enol of pyruvate and a phosphate anion. It exists as an anion. PEP is an important intermediate in biochemistry. It has the high-energy phosphate, highest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved in glycolysis and gluconeogenesis. In plants, it is also involved in the biosynthesis of various aromatic compounds, and in carbon fixation; in bacteria, it is also used as the source of energy for the phosphotransferase system. In glycolysis PEP is formed by the action of the enzyme enolase on 2-phosphoglyceric acid. Metabolism of PEP to pyruvic acid by pyruvate kinase (PK) generates adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within Cell (biology), cells. In gluconeogenesis PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Shortness Of Breath
Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign. Dyspnea is a normal symptom of heavy physical exertion but becomes disease, pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, cardiac ischemia, reflux/LPR, cardiac ischemia, COVID-19, interstitial lung di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Fatigue
Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated with medical conditions including autoimmune disease, organ failure, chronic pain conditions, mood disorders, heart disease, infectious diseases, and post-infectious-disease states. However, fatigue is complex and in up to a third of primary care cases no medical or psychiatric diagnosis is found. Fatigue (in the general usage sense of normal tiredness) often follows prolonged physical or mental activity. Physical fatigue results from muscle fatigue brought about by intense physical activity. Mental fatigue results from prolonged periods of Cognition, cognitive activity which impairs cognitive ability, can manifest as sleepiness, lethargy, or directed attention fatigue, and can also impair physical performance. Definition Fatigue in a medica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |