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Centronuclear Myopathy
Centronuclear myopathies (CNM) are a group of congenital myopathies where cell nuclei are abnormally located in the center of muscle cells instead of their normal location at the periphery. Symptoms of CNM include severe hypotonia, hypoxia-requiring breathing assistance, and scaphocephaly. Among centronuclear myopathies, the X-linked myotubular myopathy form typically presents at birth, and is thus considered a congenital myopathy. However, some centronuclear myopathies may present later in life. Presentation As with other myopathies, the clinical manifestations of MTM/CNM are most notably muscle weakness and associated disabilities. Congenital forms often present with neonatal low muscle tone, severe weakness, delayed developmental milestones (particularly gross motor milestones such as head control, crawling, and walking) and pulmonary complications (presumably due to weakness of the muscles responsible for respiration). Involvement of the facial muscles may cause ophth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H&E Stain
Hematoxylin and eosin stain ( or haematoxylin and eosin stain or hematoxylin–eosin stain; often abbreviated as H&E stain or HE stain) is one of the principal tissue stains used in histology. It is the most widely used stain in medical diagnosis and is often the ''gold standard.'' For example, when a pathologist looks at a biopsy of a suspected cancer, the histological section is likely to be stained with H&E. H&E is the combination of two histological stains: hematoxylin and eosin. The hematoxylin stains cell nuclei a purplish blue, and eosin stains the extracellular matrix and cytoplasm pink, with other structures taking on different shades, hues, and combinations of these colors. Hence a pathologist can easily differentiate between the nuclear and cytoplasmic parts of a cell, and additionally, the overall patterns of coloration from the stain show the general layout and distribution of cells and provides a general overview of a tissue sample's structure. Thus, patte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamin
Dynamin is a GTPase protein responsible for endocytosis in the eukaryotic cell. Dynamin is part of the "dynamin superfamily", which includes classical dynamins, dynamin-like proteins, MX1, Mx proteins, OPA1, MFN1, mitofusins, and Guanylate-binding protein, GBPs. Members of the dynamin family are principally involved in the scission of newly formed vesicle (biology), vesicles from the membrane of one cellular compartment and their targeting to, and fusion with, another compartment, both at the cell surface (particularly caveolae internalization) as well as at the Golgi apparatus.Hinshaw, J"Research statement, Jenny E. Hinshaw, Ph.D." National Institute of Diabetes & Digestive & Kidney Diseases, Laboratory of Cell Biochemistry and Biology. Accessed 19 March 2013. Dynamin family members also play a role in many processes including division of organelles, cytokinesis and microbial pathogen resistance. Structure Dynamin itself is a 96 kilodalton, kDa enzyme, and was first isolated ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RYR1
Ryanodine receptor 1 (RYR-1) also known as skeletal muscle calcium release channel or skeletal muscle-type ryanodine receptor is one of a class of ryanodine receptors and a protein found primarily in skeletal muscle. In humans, it is encoded by the ''RYR1'' gene. Function RYR1 functions as a calcium release channel in the sarcoplasmic reticulum, as well as a connection between the sarcoplasmic reticulum and the transverse tubule. RYR1 is associated with the dihydropyridine receptor (L-type calcium channels) within the sarcolemma of the T-tubule, which opens in response to depolarization, and thus effectively means that the RYR1 channel opens in response to depolarization of the cell. RYR1 plays a signaling role during embryonic skeletal myogenesis. A correlation exists between RYR1-mediated Ca2+ signaling and the expression of multiple molecules involved in key myogenic signaling pathways. Of these, more than 10 differentially expressed genes belong to the Wnt family which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BIN1
Myc box-dependent-interacting protein 1, also known as Bridging Integrator-1 and Amphiphysin-2 is a protein that in humans is encoded by the ''BIN1'' gene. This gene encodes several isoforms of a nucleocytoplasmic adaptor protein, one of which was initially identified as a MYC-interacting protein with features of a tumor suppressor. Isoforms that are expressed in the central nervous system may be involved in synaptic vesicle endocytosis and may interact with dynanim, synaptojanin, endophilin, and clathrin. Isoforms that are expressed in muscle and ubiquitously expressed isoforms localize to the cytoplasm and nucleus and activate a caspase-independent apoptotic process. Studies in mouse suggest that this gene plays an important role in cardiac muscle development. Alternate splicing of the gene results in ten transcript variants encoding different isoforms. Aberrant splice variants expressed in tumor cell lines have also been described. Clinical significance In humans, mutatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked Myotubular Myopathy
X-linked myotubular myopathy (MTM) is a form of centronuclear myopathy (CNM) associated with mutations in the myotubularin 1 gene. It is found almost always in male infants. It is one of the severest congenital muscle diseases and is characterized by marked muscle weakness, hypotonia and feeding and breathing difficulties. Genetics This condition is caused by mutations in the myotubularin ( MTM1) gene which is located on the long arm of the X chromosome (Xq28). Thus, almost all cases of X-linked MTM occurs in males. Females can be "carriers" for an X-linked genetic abnormality, but usually they will not be clinically affected themselves. Two exceptions for a female with a X-linked recessive abnormality to have clinical symptoms: one is a manifesting carrier and the other is X-inactivation. A manifesting carrier usually has no noticeable problems at birth; symptoms show up later in life. In X-inactivation, the female (who would otherwise be a carrier, without any symptoms), actuall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MTM1
Myotubularin is a protein that in humans is encoded by the ''MTM1'' gene. This gene is a member of a gene family that encodes lipid phosphatases. Myotubularin is required for muscle cell differentiation and mutations in this gene have been identified as being responsible for X-linked myotubular myopathy X-linked myotubular myopathy (MTM) is a form of centronuclear myopathy (CNM) associated with mutations in the myotubularin 1 gene. It is found almost always in male infants. It is one of the severest congenital muscle diseases and is characterized .... References Further reading * * * * * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on X-Linked Myotubular Myopathy or Centronuclear Myopathy Human proteins {{gene-X-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OMIM
Online Mendelian Inheritance in Man (OMIM) is a continuously updated catalog of human genes and genetic disorders and traits, with a particular focus on the gene-phenotype relationship. , approximately 9,000 of the over 25,000 entries in OMIM represented phenotypes; the rest represented genes, many of which were related to known phenotypes. Versions and history OMIM is the online continuation of Victor A. McKusick's ''Mendelian Inheritance in Man'' (MIM), which was published in 12 editions between 1966 and 1998.McKusick, V. A. ''Mendelian Inheritance in Man. Catalogs of Autosomal Dominant, Autosomal Recessive and X-Linked Phenotypes.'' Baltimore, MD: Johns Hopkins University Press, 1st ed, 1996; 2nd ed, 1969; 3rd ed, 1971; 4th ed, 1975; 5th ed, 1978; 6th ed, 1983; 7th ed, 1986; 8th ed, 1988; 9th ed, 1990; 10th ed, 1992. Nearly all of the 1,486 entries in the first edition of MIM discussed phenotypes. MIM/OMIM is produced and curated at the Johns Hopkins School of Medicine ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the Phenotype, effect of a different variant of the same gene on Homologous chromosome, the other copy of the chromosome. The first variant is termed dominant and the second is called recessive. This state of having Heterozygosity, two different variants of the same gene on each chromosome is originally caused by a mutation in one of the genes, either new (''de novo'') or Heredity, inherited. The terms autosomal dominant or autosomal recessive are used to describe gene variants on non-sex chromosomes (autosomes) and their associated traits, while those on sex chromosomes (allosomes) are termed X-linked dominant, X-linked recessive or Y-linked; these have an inheritance and presentation pattern that depends on the sex of both the parent and the child (see Sex linkage). Since there is only one Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Deletion
In genetics, a deletion (also called gene deletion, deficiency, or deletion mutation) (sign: Δ) is a mutation (a genetic aberration) in which a part of a chromosome or a sequence of DNA is left out during DNA replication. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome. Some chromosomes have fragile spots where breaks occur, which result in the deletion of a part of the chromosome. The breaks can be induced by heat, viruses, radiation, or chemical reactions. When a chromosome breaks, if a part of it is deleted or lost, the missing piece of chromosome is referred to as a deletion or a deficiency. For synapsis to occur between a chromosome with a large intercalary deficiency and a normal complete homolog, the unpaired region of the normal homolog must loop out of the linear structure into a deletion or compensation loop. The smallest single base deletion mutations occur by a single base flipping in the template DNA, followed by temp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatase
In biochemistry, a phosphatase is an enzyme that uses water to cleave a phosphoric acid Ester, monoester into a phosphate ion and an Alcohol (chemistry), alcohol. Because a phosphatase enzyme catalysis, catalyzes the hydrolysis of its Substrate (chemistry), substrate, it is a subcategory of hydrolases. Phosphatase enzymes are essential to many biological functions, because phosphorylation (e.g. by protein kinases) and dephosphorylation (by phosphatases) serve diverse roles in cell growth, cellular regulation and cell signaling, signaling. Whereas phosphatases remove phosphate groups from molecules, kinases catalyze the transfer of phosphate groups to molecules from Adenosine triphosphate, ATP. Together, kinases and phosphatases direct a form of post-translational modification that is essential to the cell's regulatory network. Phosphatase enzymes are not to be confused with phosphorylase enzymes, which catalyze the transfer of a phosphate group from hydrogen phosphate to an acce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myotubularin
Myotubularin domain represents a region within eukaryotic myotubularin-related proteins that is sometimes found with the GRAM domain. Myotubularin is a dual-specific lipid phosphatase that dephosphorylates phosphatidylinositol 3-phosphate and phosphatidylinositol (3,5)-bi-phosphate. Mutations in gene encoding myotubularin-related proteins have been associated with disease. Human proteins containing this domain MTM1 Myotubularin is a protein that in humans is encoded by the ''MTM1'' gene. This gene is a member of a gene family that encodes lipid phosphatases. Myotubularin is required for muscle cell differentiation and mutations in this gene have been ident ...; MTMR1; MTMR2; MTMR3; MTMR4; MTMR6; MTMR7; MTMR8; MTMR9; MTMR10; MTMR11; MTMR12; MTMR14; SBF1; SBF2; References External links * - Myotubularin phosphatase domain in PROSITE {{Protein tyrosine phosphatases Protein domains Peripheral membrane p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Chromosome
The X chromosome is one of the two sex chromosomes in many organisms, including mammals, and is found in both males and females. It is a part of the XY sex-determination system and XO sex-determination system. The X chromosome was named for its unique properties by early researchers, which resulted in the naming of its counterpart Y chromosome, for the next letter in the alphabet, following its subsequent discovery. Discovery It was first noted that the X chromosome was special in 1890 by Hermann Henking in Leipzig. Henking was studying the testicles of '' Pyrrhocoris'' and noticed that one chromosome did not take part in meiosis. Chromosomes are so named because of their ability to take up staining (''chroma'' in Greek means ''color''). Although the X chromosome could be stained just as well as the others, Henking was unsure whether it was a different class of the object and consequently named it ''X element'', which later became X chromosome after it was established that it w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
