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Mitochondrial Complex II Deficiency
Mitochondrial complex II deficiency, also called CII deficiency, is an extremely rare mitochondrial disease caused by deficiency of mitochondrial complex II, also known as Succinate dehydrogenase (SDH). SDH plays a key role in cellular respiration within the tricarboxylic acid (TCA) cycle and the electron transport chain. As of 2020, about sixty-one cases have been documented in literature.Fullerton M, McFarland R, Taylor RW, Alston CL. The genetic basis of isolated mitochondrial complex II deficiency. Mol Genet Metab. 2020 Sep-Oct;131(1-2):53-65. doi: 10.1016/j.ymgme.2020.09.009. Epub 2020 Oct 3. PMID 33162331; PMCID: PMC7758838. Signs and symptoms Mitochondrial complex II deficiency affects the body's mitochondria and can have a variety of presentations. In some cases, the brain, heart, liver, kidneys, and muscles are affected, while in other cases, only the heart and muscles are affected. The condition can present differently among different individuals, even those in the same f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Succinate Dehydrogenase
Succinate dehydrogenase (SDH) or succinate-coenzyme Q reductase (SQR) or respiratory complex II is an enzyme complex, found in many bacterial cells and in the inner mitochondrial membrane of eukaryotes. It is the only enzyme that participates in both the citric acid cycle and the electron transport chain. Histochemical analysis showing high succinate dehydrogenase in muscle demonstrates high mitochondrial content and high oxidative potential. In step 6 of the citric acid cycle, SQR catalyzes the oxidation of succinate to fumarate with the reduction of ubiquinone to ubiquinol. This occurs in the inner mitochondrial membrane by coupling the two reactions together. Structure Subunits Mitochondrial and many bacterial SQRs are composed of four structurally different subunits: two hydrophilic and two hydrophobic. The first two subunits, a flavoprotein (SdhA) and an iron-sulfur protein (SdhB), form a hydrophilic head where enzymatic activity of the complex takes place. Sdh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondria
A mitochondrion (; ) is an organelle found in the Cell (biology), cells of most Eukaryotes, such as animals, plants and Fungus, fungi. Mitochondria have a double lipid bilayer, 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'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into mitosome, other structures. One eukaryote, ''Monocercomonoides'', is known to have completely lost its mitocho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Babinski Sign
The plantar reflex is a reflex elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms. In healthy adults, the plantar reflex causes a downward response of the hallux (flexion). An upward response (extension) of the hallux is known as the Babinski response or Babinski sign, named after the neurologist Joseph Babinski. The presence of the Babinski sign can identify disease of the spinal cord and brain in adults, and also exists as a primitive reflex in infants. While first described in the medical literature by Babinski in 1896, the reflex has been identified in art at least as early as Botticelli's '' Virgin and Child with an Angel'', painted in the mid- 15th century. Methods The lateral side of the sole of the foot is rubbed with a blunt instrument or device so as not to cause pain, discomfort, or injury to the skin; the instrument is run from the heel along a curve to the toes (metatarsal pads). Many reflex hammers taper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amyotrophy
Amyotrophy is progressive wasting of muscle tissues. Muscle pain is also a symptom. It can occur in middle-aged males with type 2 diabetes. It also occurs with motor neuron disease. Differential diagnosis The following are considered differential diagnosis for Amyotrophy: * compressive and infective causes of polyradiculopathy * structural disc diseases * chronic demyelinating neuropathies See also * Diabetic amyotrophy * Monomelic amyotrophy * Amyotrophic lateral sclerosis Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND) or Lou Gehrig's disease, is a neurodegenerative disease that results in the progressive loss of motor neurons that control voluntary muscles. ALS is the most comm ... References External links Muscular disorders {{musculoskeletal-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Developmental Regression
Developmental regression is when a child who has reached a certain developmental stage begins to lose previously acquired milestones. It differs from developmental delay in that a child experiencing developmental delay is either not reaching developmental milestones or not progressing to new developmental milestones, while a child experiencing developmental regression will lose milestones and skills after acquiring them. Developmental regression is associated with diagnoses of autism spectrum disorder, childhood disintegrative disorder, Rett syndrome, Landau-Kleffner syndrome, and neuro-degenerative diseases. The loss of motor, language, and social skills can be treated with occupational therapy, physical therapy, and speech therapy. Associated Diagnoses Developmental regression is typically a symptom of neurological disorder. Autism Spectrum Disorder Autism spectrum disorder is a developmental disorder in which a child's communication and social skills are affected. Childr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear DNA
Nuclear DNA (nDNA), or nuclear deoxyribonucleic acid, is the DNA contained within each cell nucleus of a eukaryotic organism. It encodes for the majority of the genome in eukaryotes, with mitochondrial DNA and plastid DNA coding for the rest. It adheres to Mendelian inheritance, with information coming from two parents, one male and one female—rather than matrilineally (through the mother) as in mitochondrial DNA. Structure Nuclear DNA is a nucleic acid, a polymeric biomolecule or biopolymer, found in the nucleus of eukaryotic cells. Its structure is a double helix, with two strands wound around each other, a structure first described by Francis Crick and James D. Watson (1953) using data collected by Rosalind Franklin. Each strand is a long polymer chain of repeating nucleotides. Each nucleotide is composed of a five-carbon sugar, a phosphate group, and an organic base. Nucleotides are distinguished by their bases: purines, large bases that include adenine and guanine; and pyr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal
An autosome is any chromosome that is not a sex chromosome. The members of an autosome pair in a diploid cell have the same morphology, unlike those in allosome, allosomal (sex chromosome) pairs, which may have different structures. The DNA in autosomes is collectively known as atDNA or auDNA. For example, humans have a diploid human genome, genome that usually contains 22 pairs of autosomes and one allosome pair (46 chromosomes total). The autosome pairs are labeled with numbers (1–22 in humans) roughly in order of their sizes in base pairs, while allosomes are labelled with their letters. By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. Unusual combinations of XYY syndrome, XYY, Klinefelter syndrome, XXY, Triple X syndrome, XXX, XXXX syndrome, XXXX, XXXXX syndrome, XXXXX or XXYY syndrome, XXYY, among Aneuploidy, other Salome combinations, are known to occur and usually cause developmental abnormalities. Autosomes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SDHA
Succinate dehydrogenase complex, subunit A, flavoprotein variant is a protein that in humans is encoded by the ''SDHA'' gene. This gene encodes a major catalytic subunit of succinate-ubiquinone oxidoreductase, a complex of the mitochondrial respiratory chain. The complex is composed of four nuclear-encoded subunits and is localized in the mitochondrial inner membrane. SDHA contains the FAD binding site where succinate is deprotonated and converted to fumarate. Mutations in this gene have been associated with a form of mitochondrial respiratory chain deficiency known as Leigh Syndrome. A pseudogene has been identified on chromosome 3q29. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. Structure The ''SDHA'' gene is located on the p arm of chromosome 5 at locus 15 and is composed of 16 exons. The SDHA protein encoded by this gene is 664 amino acids long and weighs 72.7 kDA. SDHA protein has four subdomains, including capping ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SDHAF1
Succinate dehydrogenase complex assembly factor 1 (SDHAF1), also known as LYR motif-containing protein 8 (LYRM8), is a protein that in humans is encoded by the ''SDHAF1,'' or ''LYRM8,'' gene. SDHAF1 is a Chaperone (protein), chaperone protein involved in the assembly of the succinate dehydrogenase (SDH) complex (Succinate dehydrogenase, complex II). Mutations in this gene are associated with SDH-defective infantile leukoencephalopathy and mitochondrial complex II deficiency. Structure ''SDHAF1'' is located on the Locus (genetics), q arm of chromosome 19 in position 13.12 and has 1 exon. The ''SDHAF1'' gene produces a 12.8 kDa protein composed of 115 amino acids. ''SDHAF1'' is ubiquitously expressed and belongs to the complex I LYR family and SDHAF1 subfamily. As such, SDHAF1 is one of at least eight proteins that has a LYR tripeptide motif, thought to be important for Fe-S metabolism. ''SDHAF1'' also contains an N-terminus, N-terminal mitochondrial targeting sequence that does n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complex II
Succinate dehydrogenase (SDH) or succinate-coenzyme Q reductase (SQR) or respiratory complex II is an enzyme complex, found in many bacterial Cell (biology), cells and in the inner mitochondrial membrane of eukaryotes. It is the only enzyme that participates in both the citric acid cycle and the electron transport chain. Histochemical analysis showing high succinate dehydrogenase in muscle demonstrates high mitochondrial content and high oxidative potential. In step 6 of the citric acid cycle, SQR catalyzes the oxidation of succinate to fumarate with the redox, reduction of ubiquinone to ubiquinol. This occurs in the inner mitochondrial biological membrane, membrane by coupling the two reactions together. Structure Subunits Mitochondrion, Mitochondrial and many bacterial SQRs are composed of four structurally different Protein subunit, subunits: two hydrophilic and two hydrophobic. The first two subunits, a flavoprotein (SdhA) and an iron-sulfur protein (SdhB), form a hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leigh Syndrome
Leigh syndrome (also called Leigh disease and subacute necrotizing encephalomyelopathy) is an inherited neurometabolic disorder that affects the central nervous system. It is named after Archibald Denis Leigh, a British neuropsychiatrist who first described the condition in 1951. Normal levels of thiamine, thiamine monophosphate, and thiamine diphosphate are commonly found but there is a reduced or absent level of thiamine triphosphate. This is thought to be caused by a blockage in the enzyme thiamine-diphosphate kinase, and therefore treatment in some patients would be to take thiamine triphosphate daily. Signs and symptoms The symptoms of Leigh syndrome are classically described as beginning in infancy and leading to death within a span of several years; however, as more cases are recognized, it is apparent that symptoms can emerge at any age—including adolescence or adulthood—and patients can survive for many years following diagnosis. Symptoms are often first seen after a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
