Corneal Dystrophy, Juvenile Epithelial of Meesmann
Corneal Dystrophies, Hereditary
Keratin-12
Fuchs' Endothelial Dystrophy
Muscular Dystrophies
Collagen Type VIII
Myotonic Dystrophy
Cornea
Muscular Dystrophy, Duchenne
Corneal Opacity
Pedigree
Descemet Membrane
Extracellular Matrix Proteins
Bowman Membrane
Muscular Dystrophy, Animal
Keratoplasty, Penetrating
Keratoconus
Keratan Sulfate
Corneal Stroma
Corneal Transplantation
Mutation
Current Procedural Terminology
Retinal Dystrophies
Dimethylallyltranstransferase
Transforming Growth Factor beta
Muscular Dystrophy, Facioscapulohumeral
Keratin-3
Dystrophin
Mutation, Missense
Exons
Sulfotransferases
Heterozygote
A novel mutation of the Keratin 12 gene responsible for a severe phenotype of Meesmann's corneal dystrophy. (1/5)
PURPOSE: To determine if a mutation within the coding region of the keratin 12 gene (KRT12) is responsible for a severe form of Meesmann's corneal dystrophy. METHODS: A family with clinically identified Meesmann's corneal dystrophy was recruited and studied. Electron microscopy was performed on scrapings of corneal epithelial cells from the proband. Mutations in the KRT12 gene were sought using direct genomic sequencing of leukocyte DNA from two affected and two unaffected family members. Subsequently, the observed mutation was screened in all available family members using polymerase chain reaction and direct sequencing. RESULTS: A heterozygous missense mutation (Arg430Pro) was found in exon 6 of KRT12 in all 14 affected individuals studied. Unaffected family members and 100 normal controls were negative for this mutation. CONCLUSIONS: We have identified a novel mutation in the KRT12 gene that is associated with a symptomatic phenotype of Meesmann's corneal dystrophy. This mutation results in a substitution of proline for arginine in the helix termination motif that may disrupt the normal helix, leading to a dramatic structural change of the keratin 12 protein. (+info)Genetics of Meesmann corneal dystrophy: a novel mutation in the keratin 3 gene in an asymptomatic family suggests genotype-phenotype correlation. (2/5)
PURPOSE: Juvenile epithelial corneal dystrophy of Meesmann (MCD, OMIM 122100) is a dominantly inherited disorder characterized by fragility of the anterior corneal epithelium and intraepithelial microcyst formation. Although the disease is generally mild and affected individuals are often asymptomatic, some suffer from recurrent erosions leading to lacrimation, photophobia, and deterioration in visual acuity. MCD is caused by mutations in keratin 3 (KRT3) or keratin 12 (KRT12) genes, which encode cornea-specific cytoskeletal proteins. Seventeen mutations in KRT12 and two in KRT3 have been described so far. The purpose of this study was to investigate the genetic background of MCD in a Polish family. METHODS: We report on a three-generation family with MCD. Epithelial lesions characteristic for MCD were visualized with slit-lamp examination and confirmed by in vivo confocal microscopy. Using genomic DNA as a template, all coding regions of KRT3 and KRT12 were amplified and sequenced. Presence of the mutation was verified with restriction endonuclease digestion. RESULTS: In the proband, direct sequencing of the polymerase chain reaction (PCR) product from amplified coding regions of KRT3 and KRT12 revealed a novel 1493A>T heterozygous missense mutation in exon 7 of KRT3, which predicts the substitution of glutamic acid for valine at codon 498 (E498V). Using PCR-Restriction Fragment Length Polymorphism (RFLP) analysis, the mutation was demonstrated to segregate with the disease (four affected members, three non-affected) and to be absent in 100 controls from the Polish population, indicating that it is not a common polymorphism. CONCLUSIONS: Location of the E498V mutation emphasizes the functional relevance of the highly conserved boundary motifs at the COOH-terminus of the alpha-helical rod domain in keratin 3 (K3). (+info)Development of allele-specific therapeutic siRNA in Meesmann epithelial corneal dystrophy. (3/5)
(+info)Severe Meesmann's epithelial corneal dystrophy phenotype due to a missense mutation in the helix-initiation motif of keratin 12. (4/5)
(+info)Allele-specific siRNA silencing for the common keratin 12 founder mutation in Meesmann epithelial corneal dystrophy. (5/5)
(+info)Juvenile epithelial corneal dystrophy of Meesmann is a rare hereditary eye condition that affects the cornea, which is the clear front part of the eye. This condition is typically present at birth or appears during infancy and can affect both eyes. It is caused by mutations in the K3 and K12 genes, which provide instructions for making proteins called keratins that are found in the corneal epithelial cells.
In this condition, there is a abnormal accumulation of these misfolded keratin proteins in the corneal epithelium, leading to the formation of tiny opaque bumps or microcysts on the surface of the cornea. These microcysts can cause visual symptoms such as photophobia (light sensitivity), tearing, and decreased vision. The severity of the condition can vary widely among affected individuals, ranging from mild to severe.
The progression of juvenile epithelial corneal dystrophy of Meesmann is generally slow, but in some cases, it may lead to more serious complications such as corneal erosions, scarring, and loss of vision. Currently, there is no cure for this condition, and treatment is mainly focused on managing the symptoms and preventing complications. This may include the use of artificial tears, ointments, or bandage contact lenses to protect the cornea and alleviate symptoms. In severe cases, a corneal transplant may be necessary.
Corneal dystrophies, hereditary are a group of genetic disorders that affect the cornea, which is the clear, outermost layer at the front of the eye. These conditions are characterized by the buildup of abnormal material in the cornea, leading to decreased vision, pain, or cloudiness in the eye.
There are many different types of corneal dystrophies, each affecting a specific layer of the cornea and having its own pattern of inheritance. Some common types include:
1. Fuchs' endothelial dystrophy: This affects the inner lining of the cornea (endothelium) and causes swelling and cloudiness in the cornea. It is typically inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the condition if one parent has it.
2. Granular dystrophy: This affects the stroma, which is the middle layer of the cornea. It causes the formation of opaque, grayish-white deposits in the cornea that can affect vision. It is typically inherited in an autosomal dominant or recessive manner.
3. Lattice dystrophy: This also affects the stroma and is characterized by the formation of a lattice-like pattern of fine, whitish lines in the cornea. It is typically inherited in an autosomal dominant manner.
4. Macular dystrophy: This affects the central part of the cornea (macula) and can cause cloudiness, leading to decreased vision. It is typically inherited in an autosomal recessive manner.
Treatment for corneal dystrophies may include eyedrops, medications, or surgery, depending on the severity of the condition and its impact on vision. In some cases, a corneal transplant may be necessary to restore vision.
Keratin-1
Fuchs' Endothelial Dystrophy is a medical condition that affects the eye's cornea. It is a slowly progressing disorder that causes the endothelium, a thin layer of cells lining the inner surface of the cornea, to deteriorate and eventually fail to function properly. This results in swelling of the cornea, leading to cloudy vision, distorted vision, and sensitivity to light.
The condition is typically inherited and tends to affect both eyes. It is more common in women than in men and usually becomes apparent after the age of 50. There is no cure for Fuchs' Endothelial Dystrophy, but treatments such as corneal transplantation can help improve vision and alleviate symptoms.
Muscular dystrophies are a group of genetic disorders that primarily affect skeletal muscles, causing progressive weakness and degeneration. They are characterized by the lack or deficiency of a protein called dystrophin, which is essential for maintaining the integrity of muscle fibers. The most common form is Duchenne muscular dystrophy (DMD), but there are many other types with varying symptoms and severity. Over time, muscle wasting and weakness can lead to disability and shortened lifespan, depending on the type and progression of the disease. Treatment typically focuses on managing symptoms, maintaining mobility, and supporting quality of life.
Collagen type VIII is a less common type of collagen that is found in the eyes, specifically in the basement membrane of the cornea and the blood vessels of the eye. It is a network-forming collagen and is believed to play a role in maintaining the structural integrity and stability of these tissues. Mutations in the genes encoding for collagen type VIII have been associated with certain eye disorders, such as Fuchs' endothelial corneal dystrophy.
Here is a medical definition from the US National Library of Medicine:
"Collagen, type VIII, alpha-1 (COL8A1) is a gene that provides instructions for making one component of a type VIII collagen protein called collagen VIII alpha-1 chain. Collagen proteins are important building blocks for many tissues in the body, including tendons, ligaments, and the cornea, which is the clear outer covering of the eye.
Collagen VIII is found in the basement membrane, a thin layer of protein that surrounds many types of cells and helps to anchor them to surrounding tissue. In the eye, collagen VIII is produced by cells called endothelial cells, which line the inside surface of the cornea. Collagen VIII forms networks with other proteins that help maintain the structural integrity and stability of the cornea.
Mutations in the COL8A1 gene can cause Fuchs' endothelial corneal dystrophy, a progressive eye disorder characterized by the gradual clouding of the cornea." ()
Myotonic dystrophy is a genetic disorder characterized by progressive muscle weakness, myotonia (delayed relaxation of muscles after contraction), and other symptoms. It is caused by an expansion of repetitive DNA sequences in the DMPK gene on chromosome 19 (type 1) or the ZNF9 gene on chromosome 3 (type 2). These expansions result in abnormal protein production and accumulation, which disrupt muscle function and can also affect other organs such as the heart, eyes, and endocrine system. Myotonic dystrophy is a progressive disease, meaning that symptoms tend to worsen over time. It is typically divided into two types: myotonic dystrophy type 1 (DM1), which is more common and severe, and myotonic dystrophy type 2 (DM2), which tends to be milder with a later onset of symptoms.
The cornea is the clear, dome-shaped surface at the front of the eye. It plays a crucial role in focusing vision. The cornea protects the eye from harmful particles and microorganisms, and it also serves as a barrier against UV light. Its transparency allows light to pass through and get focused onto the retina. The cornea does not contain blood vessels, so it relies on tears and the fluid inside the eye (aqueous humor) for nutrition and oxygen. Any damage or disease that affects its clarity and shape can significantly impact vision and potentially lead to blindness if left untreated.
Duchenne Muscular Dystrophy (DMD) is a genetic disorder characterized by progressive muscle weakness and degeneration. It is caused by the absence of dystrophin, a protein that helps keep muscle cells intact. Without dystrophin, the muscle cells break down and are replaced with scar tissue, leading to loss of muscle function over time.
DMD primarily affects boys, as it is inherited in an X-linked recessive pattern, meaning that females who carry one affected X chromosome typically do not show symptoms but can pass the gene on to their offspring. Symptoms usually begin in early childhood and include difficulty with motor skills such as walking, running, and climbing stairs. Over time, the muscle weakness progresses and can lead to loss of ambulation, respiratory and cardiac complications, and ultimately, premature death.
Currently, there is no cure for DMD, but various treatments such as corticosteroids, physical therapy, and assisted ventilation can help manage symptoms and improve quality of life. Gene therapy approaches are also being investigated as potential treatments for this disorder.
Corneal opacity refers to a condition in which the cornea, the clear front part of the eye, becomes cloudy or opaque. This can occur due to various reasons such as injury, infection, degenerative changes, or inherited disorders. As a result, light is not properly refracted and vision becomes blurred or distorted. In some cases, corneal opacity can lead to complete loss of vision in the affected eye. Treatment options depend on the underlying cause and may include medication, corneal transplantation, or other surgical procedures.
I must clarify that the term "pedigree" is not typically used in medical definitions. Instead, it is often employed in genetics and breeding, where it refers to the recorded ancestry of an individual or a family, tracing the inheritance of specific traits or diseases. In human genetics, a pedigree can help illustrate the pattern of genetic inheritance in families over multiple generations. However, it is not a medical term with a specific clinical definition.
The Descemet membrane is the thin, transparent basement membrane that is produced by the corneal endothelial cells. It is located between the corneal stroma and the corneal endothelium, which is the innermost layer of the cornea. The Descemet membrane provides structural support for the corneal endothelium and helps to maintain the proper hydration and clarity of the cornea. It is named after the French physician Jean Descemet, who first described it in 1752.
Extracellular matrix (ECM) proteins are a group of structural and functional molecules that provide support, organization, and regulation to the cells in tissues and organs. The ECM is composed of a complex network of proteins, glycoproteins, and carbohydrates that are secreted by the cells and deposited outside of them.
ECM proteins can be classified into several categories based on their structure and function, including:
1. Collagens: These are the most abundant ECM proteins and provide strength and stability to tissues. They form fibrils that can withstand high tensile forces.
2. Proteoglycans: These are complex molecules made up of a core protein and one or more glycosaminoglycan (GAG) chains. The GAG chains attract water, making proteoglycans important for maintaining tissue hydration and resilience.
3. Elastin: This is an elastic protein that allows tissues to stretch and recoil, such as in the lungs and blood vessels.
4. Fibronectins: These are large glycoproteins that bind to cells and ECM components, providing adhesion, migration, and signaling functions.
5. Laminins: These are large proteins found in basement membranes, which provide structural support for epithelial and endothelial cells.
6. Tenascins: These are large glycoproteins that modulate cell adhesion and migration, and regulate ECM assembly and remodeling.
Together, these ECM proteins create a microenvironment that influences cell behavior, differentiation, and function. Dysregulation of ECM proteins has been implicated in various diseases, including fibrosis, cancer, and degenerative disorders.
The Bowman membrane, also known as the Bowman's capsule, is a part of the nephron in the kidney. It is the outermost layer of the renal corpuscle and surrounds the glomerulus. The primary function of the Bowman membrane is to filter blood and produce urine.
The Bowman membrane is composed of two layers: an inner visceral layer, which is closely applied to the glomerular capillaries, and an outer parietal layer, which forms the inner lining of the Bowman's capsule. The space between these two layers is called the urinary space or Bowman's space.
The filtration process in the Bowman membrane allows for the passage of small molecules such as water, glucose, and amino acids from the blood into the urinary space, while larger molecules like proteins and blood cells are retained in the bloodstream. The fluid that passes through the Bowman membrane then flows into the tubular part of the nephron, where it is further modified before being excreted as urine.
I'm sorry for any confusion, but "Muscular Dystrophy, Animal" is not a standard medical term. Muscular Dystrophy is a group of genetic disorders that cause progressive weakness and loss of muscle mass. They are primarily human diseases and there are no known animal models of muscular dystrophy that directly correspond to any type of muscular dystrophy in humans.
However, scientists often use animals (like mice, dogs, and cats) as models for human diseases, including various types of muscular dystrophies. These animal models are used to study the disease process and to test potential treatments. For example, the mdx mouse is a well-known model of Duchenne Muscular Dystrophy (DMD), which is caused by a mutation in the dystrophin gene. This mouse lacks the muscle protein dystrophin, similar to humans with DMD, and shows many of the same symptoms, making it a valuable tool for research.
The endothelium of the cornea is the thin, innermost layer of cells that lines the inner surface of the cornea, which is the clear, dome-shaped structure at the front of the eye. This single layer of specialized cells is essential for maintaining the transparency and proper hydration of the cornea, allowing light to pass through it and focus on the retina.
The endothelial cells are hexagonal in shape and have tight junctions between them, creating a semi-permeable barrier that controls the movement of water and solutes between the corneal stroma (the middle layer of the cornea) and the anterior chamber (the space between the cornea and the iris). The endothelial cells actively pump excess fluid out of the cornea, maintaining a delicate balance of hydration that is critical for corneal clarity.
Damage to or dysfunction of the corneal endothelium can result in corneal edema (swelling), cloudiness, and loss of vision. Factors contributing to endothelial damage include aging, eye trauma, intraocular surgery, and certain diseases such as Fuchs' dystrophy and glaucoma.
Penetrating keratoplasty (PK) is a type of corneal transplant surgery where the entire thickness of the host's damaged or diseased cornea is removed and replaced with a similar full-thickness portion of a healthy donor's cornea. The procedure aims to restore visual function, alleviate pain, and improve the structural integrity of the eye. It is typically performed for conditions such as severe keratoconus, corneal scarring, or corneal ulcers that cannot be treated with other, less invasive methods. Following the surgery, patients may require extended recovery time and rigorous postoperative care to minimize the risk of complications and ensure optimal visual outcomes.
Keratoconus is a degenerative non-inflammatory disorder of the eye, primarily affecting the cornea. It is characterized by a progressive thinning and steepening of the central or paracentral cornea, causing it to assume a conical shape. This results in irregular astigmatism, myopia, and scattering of light leading to blurred vision, visual distortions, and sensitivity to glare. The exact cause of keratoconus is unknown, but it may be associated with genetics, eye rubbing, and certain medical conditions. It typically starts in the teenage years and progresses into the third or fourth decade of life. Treatment options include glasses, contact lenses, cross-linking, and corneal transplantation in advanced cases.
Keratan sulfate is a type of glycosaminoglycan (GAG), which is a complex carbohydrate found in connective tissues, including the cornea and cartilage. It is composed of repeating disaccharide units of galactose and N-acetylglucosamine, with sulfate groups attached to some of the sugar molecules.
Keratan sulfate is unique among GAGs because it contains a high proportion of non-sulfated sugars and is often found covalently linked to proteins in structures called proteoglycans. In the cornea, keratan sulfate plays important roles in maintaining transparency and regulating hydration. In cartilage, it contributes to the elasticity and resilience of the tissue.
Abnormalities in keratan sulfate metabolism have been associated with several genetic disorders, including corneal dystrophies and skeletal dysplasias.
Familial amyloidosis is a genetic disorder characterized by the buildup of abnormal protein deposits called amyloid fibrils in various tissues and organs throughout the body. These abnormal protein deposits can cause damage to the affected organs, leading to a variety of symptoms.
There are several types of familial amyloidosis, but the most common type is transthyretin-related hereditary amyloidosis (TTR-HA). This form of the disorder is caused by mutations in the TTR gene, which provides instructions for making a protein called transthyretin. Transthyretin is a transport protein that helps move thyroid hormones and vitamin A around the body. In TTR-HA, mutations in the TTR gene cause the transthyretin protein to misfold and form amyloid fibrils.
Symptoms of familial amyloidosis can vary widely depending on which organs are affected. Commonly affected organs include the heart, kidneys, nerves, and gastrointestinal tract. Symptoms may include:
* Heart problems such as arrhythmias (irregular heartbeat), heart failure, or cardiac conduction abnormalities
* Kidney problems such as proteinuria (protein in the urine) or kidney failure
* Nerve damage leading to numbness, tingling, or pain in the hands and feet, or autonomic nervous system dysfunction affecting digestion, bladder function, or blood pressure regulation
* Gastrointestinal problems such as diarrhea, constipation, nausea, vomiting, or abdominal pain
Familial amyloidosis is typically inherited in an autosomal dominant manner, meaning that a child has a 50% chance of inheriting the mutated gene from a parent with the disorder. However, some cases may be due to new (de novo) mutations and occur in people without a family history of the disorder.
Diagnosis of familial amyloidosis typically involves a combination of clinical evaluation, genetic testing, and tissue biopsy to confirm the presence of amyloid fibrils. Treatment may involve medications to manage symptoms, as well as liver transplantation or other experimental therapies aimed at reducing the production of abnormal proteins that form amyloid fibrils.
The corneal stroma, also known as the substantia propria, is the thickest layer of the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays a crucial role in focusing vision.
The corneal stroma makes up about 90% of the cornea's thickness and is composed of parallel bundles of collagen fibers that are arranged in regular, repeating patterns. These fibers give the cornea its strength and transparency. The corneal stroma also contains a small number of cells called keratocytes, which produce and maintain the collagen fibers.
Disorders that affect the corneal stroma can cause vision loss or other eye problems. For example, conditions such as keratoconus, in which the cornea becomes thin and bulges outward, can distort vision and make it difficult to see clearly. Other conditions, such as corneal scarring or infection, can also affect the corneal stroma and lead to vision loss or other eye problems.
DNA Mutational Analysis is a laboratory test used to identify genetic variations or changes (mutations) in the DNA sequence of a gene. This type of analysis can be used to diagnose genetic disorders, predict the risk of developing certain diseases, determine the most effective treatment for cancer, or assess the likelihood of passing on an inherited condition to offspring.
The test involves extracting DNA from a patient's sample (such as blood, saliva, or tissue), amplifying specific regions of interest using polymerase chain reaction (PCR), and then sequencing those regions to determine the precise order of nucleotide bases in the DNA molecule. The resulting sequence is then compared to reference sequences to identify any variations or mutations that may be present.
DNA Mutational Analysis can detect a wide range of genetic changes, including single-nucleotide polymorphisms (SNPs), insertions, deletions, duplications, and rearrangements. The test is often used in conjunction with other diagnostic tests and clinical evaluations to provide a comprehensive assessment of a patient's genetic profile.
It is important to note that not all mutations are pathogenic or associated with disease, and the interpretation of DNA Mutational Analysis results requires careful consideration of the patient's medical history, family history, and other relevant factors.
Corneal transplantation, also known as keratoplasty, is a surgical procedure in which all or part of a damaged or diseased cornea is replaced with healthy corneal tissue from a deceased donor. The cornea is the clear, dome-shaped surface at the front of the eye that plays an important role in focusing vision. When it becomes cloudy or misshapen due to injury, infection, or inherited conditions, vision can become significantly impaired.
During the procedure, the surgeon carefully removes a circular section of the damaged cornea and replaces it with a similarly sized piece of donor tissue. The new cornea is then stitched into place using very fine sutures that are typically removed several months after surgery.
Corneal transplantation has a high success rate, with more than 90% of procedures resulting in improved vision. However, as with any surgical procedure, there are risks involved, including infection, rejection of the donor tissue, and bleeding. Regular follow-up care is essential to monitor for any signs of complications and ensure proper healing.
A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.
Current Procedural Terminology (CPT) is a system of medical codes, developed and maintained by the American Medical Association (AMA), that are used to describe medical, surgical, and diagnostic services provided by healthcare professionals. The codes are used for administrative purposes, such as billing and insurance claims processing, and consist of a five-digit alphanumeric code that identifies the specific service or procedure performed.
The CPT code set is organized into three categories: Category I codes describe common medical, surgical, and diagnostic services; Category II codes are used for performance measurement and tracking of quality improvement initiatives; and Category III codes are used for emerging technologies, experimental procedures, and services that do not have a defined CPT code.
Healthcare professionals and facilities rely on the accuracy and specificity of CPT codes to ensure appropriate reimbursement for their services. The AMA regularly updates the CPT code set to reflect changes in medical practice and technology, and provides guidance and resources to help healthcare professionals navigate the complexities of coding and billing.
Retinal dystrophies are a group of genetic eye disorders that primarily affect the retina, a light-sensitive layer at the back of the eye. These conditions are characterized by progressive degeneration and death of photoreceptor cells (rods and cones) in the retina, leading to vision loss.
The term "dystrophy" refers to a condition that results from the abnormal or defective development and function of tissues or organs. In the case of retinal dystrophies, the photoreceptor cells do not develop or function properly, resulting in visual impairment.
Retinal dystrophies can present at any age, from infancy to adulthood, and can have varying degrees of severity. Some common symptoms include night blindness, decreased visual acuity, loss of peripheral vision, light sensitivity, and color vision abnormalities.
Examples of retinal dystrophies include retinitis pigmentosa, Stargardt disease, Usher syndrome, and Leber congenital amaurosis, among others. These conditions are typically inherited and can be caused by mutations in various genes that play a role in the development and function of the retina.
There is currently no cure for retinal dystrophies, but research is ongoing to develop treatments that may slow or halt the progression of these conditions, such as gene therapy and stem cell transplantation.
Corneal pachymetry is a medical measurement of the thickness of the cornea, which is the clear, dome-shaped surface at the front of the eye. This measurement is typically taken using a specialized instrument called a pachymeter. The procedure is quick, painless, and non-invasive.
Corneal pachymetry is an essential test in optometry and ophthalmology for various reasons. For instance, it helps assess the overall health of the cornea, identify potential abnormalities or diseases, and determine the correct intraocular lens power during cataract surgery. Additionally, corneal thickness is a crucial factor in determining a person's risk for developing glaucoma and monitoring the progression of the disease.
In some cases, such as with contact lens fitting, corneal pachymetry can help ensure proper fit and minimize potential complications. Overall, corneal pachymetry is an essential diagnostic tool in eye care that provides valuable information for maintaining eye health and ensuring appropriate treatment.
Dimethylallyltranstransferase (DMAT) is an enzyme that plays a crucial role in the biosynthesis of various natural compounds, including terpenoids and alkaloids. These compounds have diverse functions in nature, ranging from serving as pigments and fragrances to acting as defense mechanisms against predators or pathogens.
The primary function of DMAT is to catalyze the head-to-tail condensation of dimethylallyl pyrophosphate (DMAPP) with various diphosphate-bound prenyl substrates, forming prenylated products. This reaction represents the first committed step in the biosynthesis of many terpenoids and alkaloids.
The enzyme's catalytic mechanism involves the formation of a covalent bond between the pyrophosphate group of DMAPP and a conserved cysteine residue within the DMAT active site, followed by the transfer of the dimethylallyl moiety to the diphosphate-bound prenyl substrate.
DMAT is found in various organisms, including bacteria, fungi, plants, and animals. In humans, DMAT is involved in the biosynthesis of steroids, which are essential components of cell membranes and precursors to important hormones such as cortisol, aldosterone, and sex hormones.
In summary, dimethylallyltranstransferase (DMAT) is an enzyme that catalyzes the condensation of dimethylallyl pyrophosphate (DMAPP) with various prenyl substrates, playing a critical role in the biosynthesis of diverse natural compounds, including terpenoids and alkaloids.
Transforming Growth Factor-beta (TGF-β) is a type of cytokine, which is a cell signaling protein involved in the regulation of various cellular processes, including cell growth, differentiation, and apoptosis (programmed cell death). TGF-β plays a critical role in embryonic development, tissue homeostasis, and wound healing. It also has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.
TGF-β exists in multiple isoforms (TGF-β1, TGF-β2, and TGF-β3) that are produced by many different cell types, including immune cells, epithelial cells, and fibroblasts. The protein is synthesized as a precursor molecule, which is cleaved to release the active TGF-β peptide. Once activated, TGF-β binds to its receptors on the cell surface, leading to the activation of intracellular signaling pathways that regulate gene expression and cell behavior.
In summary, Transforming Growth Factor-beta (TGF-β) is a multifunctional cytokine involved in various cellular processes, including cell growth, differentiation, apoptosis, embryonic development, tissue homeostasis, and wound healing. It has been implicated in several pathological conditions such as fibrosis, cancer, and autoimmune diseases.
Facioscapulohumeral Muscular Dystrophy (FSHD) is a genetic muscle disorder characterized by the progressive weakness and wasting (atrophy) of muscles in the face, shoulders, arms, and legs. It is caused by the abnormal expression of a gene called DUX4, which is normally only active during early embryonic development. In FSHD, this gene becomes reactivated in muscle cells, leading to their degeneration and death.
The symptoms of FSHD typically begin in late childhood or adolescence, although they can also appear in adulthood. The first noticeable sign is often difficulty raising the arms above the head or a weakened grip. Over time, the muscles of the face may become affected, leading to problems with smiling, swallowing, and speaking. The muscle weakness in FSHD tends to progress slowly, but it can vary widely from person to person. Some people with FSHD may require wheelchair assistance, while others may continue to walk with only minor limitations.
FSHD is inherited in an autosomal dominant manner, which means that a child has a 50% chance of inheriting the disease-causing gene from an affected parent. However, about 30% of cases are the result of new mutations and occur in people with no family history of the disorder. Currently, there is no cure for FSHD, but various treatments can help manage its symptoms and improve quality of life. These may include physical therapy, orthotics, assistive devices, and medications to treat pain or other complications.
Corneal diseases are a group of disorders that affect the cornea, which is the clear, dome-shaped surface at the front of the eye. The cornea plays an important role in focusing vision, and any damage or disease can cause significant visual impairment or loss. Some common types of corneal diseases include:
1. Keratoconus: A progressive disorder in which the cornea thins and bulges outward into a cone shape, causing distorted vision.
2. Fuchs' dystrophy: A genetic disorder that affects the inner layer of the cornea called the endothelium, leading to swelling, cloudiness, and decreased vision.
3. Dry eye syndrome: A condition in which the eyes do not produce enough tears or the tears evaporate too quickly, causing discomfort, redness, and blurred vision.
4. Corneal ulcers: Open sores on the cornea that can be caused by infection, trauma, or other factors.
5. Herpes simplex keratitis: A viral infection of the cornea that can cause recurrent episodes of inflammation, scarring, and vision loss.
6. Corneal dystrophies: Inherited disorders that affect the structure and clarity of the cornea, leading to visual impairment or blindness.
7. Bullous keratopathy: A condition in which the endothelium fails to pump fluid out of the cornea, causing it to swell and form blisters.
8. Corneal trauma: Injury to the cornea caused by foreign objects, chemicals, or other factors that can lead to scarring, infection, and vision loss.
Treatment for corneal diseases varies depending on the specific condition and severity of the disease. Options may include eyedrops, medications, laser surgery, corneal transplantation, or other treatments.
I'm sorry for any confusion, but "Keratin-3" is not a widely recognized or established medical term in the field of dermatology or pathology. There is a protein called Keratin 3 or KRT3 (also known as Cytokeratin 12), which is primarily expressed in simple epithelia, such as those found in the cornea and conjunctiva of the eye. However, it's not typically associated with skin disorders or diseases.
If you have any more specific context or details related to this term, I would be happy to help further!
Dystrophin is a protein that provides structural stability to muscle fibers. It is an essential component of the dystrophin-glycoprotein complex, which helps maintain the integrity of the sarcolemma (the membrane surrounding muscle cells) during muscle contraction and relaxation. Dystrophin plays a crucial role in connecting the cytoskeleton of the muscle fiber to the extracellular matrix, allowing for force transmission and protecting the muscle cell from damage.
Mutations in the DMD gene, which encodes dystrophin, can lead to various forms of muscular dystrophy, including Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD). In DMD, a severe form of the disease, genetic alterations typically result in little or no production of functional dystrophin, causing progressive muscle weakness, wasting, and degeneration. In BMD, a milder form of the disorder, partially functional dystrophin is produced, leading to less severe symptoms and later onset of the disease.
A missense mutation is a type of point mutation in which a single nucleotide change results in the substitution of a different amino acid in the protein that is encoded by the affected gene. This occurs when the altered codon (a sequence of three nucleotides that corresponds to a specific amino acid) specifies a different amino acid than the original one. The function and/or stability of the resulting protein may be affected, depending on the type and location of the missense mutation. Missense mutations can have various effects, ranging from benign to severe, depending on the importance of the changed amino acid for the protein's structure or function.
Exons are the coding regions of DNA that remain in the mature, processed mRNA after the removal of non-coding intronic sequences during RNA splicing. These exons contain the information necessary to encode proteins, as they specify the sequence of amino acids within a polypeptide chain. The arrangement and order of exons can vary between different genes and even between different versions of the same gene (alternative splicing), allowing for the generation of multiple protein isoforms from a single gene. This complexity in exon structure and usage significantly contributes to the diversity and functionality of the proteome.
Sulfotransferases (STs) are a group of enzymes that play a crucial role in the process of sulfoconjugation, which is the transfer of a sulfo group (-SO3H) from a donor molecule to an acceptor molecule. These enzymes are widely distributed in nature and are found in various organisms, including humans.
In humans, STs are involved in the metabolism and detoxification of numerous xenobiotics, such as drugs, food additives, and environmental pollutants, as well as endogenous compounds, such as hormones, neurotransmitters, and lipids. The sulfoconjugation reaction catalyzed by STs can increase the water solubility of these compounds, facilitating their excretion from the body.
STs can be classified into several families based on their sequence similarity and cofactor specificity. The largest family of STs is the cytosolic sulfotransferases, which use 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a cofactor to transfer the sulfo group to various acceptor molecules, including phenols, alcohols, amines, and steroids.
Abnormalities in ST activity have been implicated in several diseases, such as cancer, cardiovascular disease, and neurological disorders. Therefore, understanding the function and regulation of STs is essential for developing new therapeutic strategies to treat these conditions.
A heterozygote is an individual who has inherited two different alleles (versions) of a particular gene, one from each parent. This means that the individual's genotype for that gene contains both a dominant and a recessive allele. The dominant allele will be expressed phenotypically (outwardly visible), while the recessive allele may or may not have any effect on the individual's observable traits, depending on the specific gene and its function. Heterozygotes are often represented as 'Aa', where 'A' is the dominant allele and 'a' is the recessive allele.
Human chromosome pair 5 consists of two rod-shaped structures present in the nucleus of human cells, which contain genetic material in the form of DNA and proteins. Each member of chromosome pair 5 is a single chromosome, and humans typically have 23 pairs of chromosomes for a total of 46 chromosomes in every cell of their body (except gametes or sex cells, which contain 23 chromosomes).
Chromosome pair 5 is one of the autosomal pairs, meaning it is not a sex chromosome. Each member of chromosome pair 5 is approximately 197 million base pairs in length and contains around 800-900 genes that provide instructions for making proteins and regulating various cellular processes.
Chromosome pair 5 is associated with several genetic disorders, including cri du chat syndrome (resulting from a deletion on the short arm of chromosome 5), Prader-Willi syndrome and Angelman syndrome (both resulting from abnormalities in gene expression on the long arm of chromosome 5).
Corneal dystrophy
List of skin conditions
List of OMIM disorder codes
Corneal dystrophy - Wikipedia
Gardner's syndrome - Wikipedia
Corneal dystrophy (CD) - An overview | Capsule Health
MedlinePlus: Genetic Conditions: J
DeCS 2020 - June 23, 2020 version
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DeCS 2007 - New terms
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Asphyxiating thoracic dysplasia - WikiProjectMed
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autosomal dominant | Hereditary Ocular Diseases
Meesmann's | Vagelos College of Physicians and Surgeons
Corneal Erosion Syndrome | Ento Key
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herenciageneticayenfermedad: Health Conditions - Genetics Home Reference: M | Published: March 7, 2017
Molecular Vision: A novel mutation (p.Glu1389AspfsX16) of the phosphoinositide kinase, FYVE finger containing gene found in a...
Aniridia
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Basement membrane dystrophy2
- Mutations in TGFBI which encodes transforming growth factor beta induced cause several forms of corneal dystrophies including granular corneal dystrophy, lattice corneal dystrophy, epithelial basement membrane dystrophy, Reis-Bucklers corneal dystrophy, and Thiel-Behnke dystrophy. (wikipedia.org)
- A familial tendency has been reported among patients with map dot fingerprint epithelial basement membrane dystrophy (EBMD). (entokey.com)
Thiel-Behnke2
- In Thiel-Behnke dystrophy, sub-epithelial corneal opacities form a honeycomb-shaped pattern in the superficial cornea. (wikipedia.org)
- Reis Bucklers and Thiel-Behnke dystrophy. (entokey.com)
Gelatinous drop-like corneal dystrophy1
- Multiple prominent gelatinous mulberry-shaped nodules form beneath the corneal epithelium during the first decade of life in gelatinous drop-like corneal dystrophy which cause photophobia, tearing, corneal foreign body sensation and severe progressive loss of vision. (wikipedia.org)
Hereditary epithelial dystrophy1
- Autosomal dominantly inherited and also called juvenile hereditary epithelial dystrophy. (columbia.edu)
Lattice1
- Lattice dystrophy starts as fine branching linear opacities in Bowman's layer in the central area and spreads to the periphery. (wikipedia.org)
Granular corneal dystrophy1
- In granular corneal dystrophy multiple small white discrete irregular spots that resemble bread crumbs or snowflakes become apparent beneath Bowman zone in the superficial central corneal stroma. (wikipedia.org)
Fuchs1
- citation needed] Posterior corneal dystrophies - Fuchs corneal dystrophy presents during the fifth or sixth decade of life. (wikipedia.org)
Autosomal3
- citation needed] Corneal dystrophies may have a simple autosomal dominant, autosomal recessive or rarely X-linked recessive Mendelian mode of inheritance: A corneal dystrophy can be caused by an accumulation of extraneous material in the cornea, including lipids and cholesterol crystals. (wikipedia.org)
- This corneal dystrophy is a rare autosomal dominant disease characterized by numerous tiny, dot-like white flecks scattered in all layers of the corneal stroma. (molvis.org)
- Description Pachyonychia congenita (PC) is an autosomal dominant genodermatosis with the main clinical features of hypertrophic nail dystrophy, painful and highly debilitating plantar keratoderma, oral leukokeratosis, and a variety of epidermal cysts. (findzebra.com)
Stromal1
- citation needed] Corneal stromal dystrophies - Macular corneal dystrophy is manifested by a progressive dense cloudiness of the entire corneal stroma that usually first appears during adolescence and eventually causing severe visual impairment. (wikipedia.org)
Recurrent2
- Recurrent corneal erosions may occur. (wikipedia.org)
- Recurrent corneal erosion syndrome (RCES) is characterized by episodes of spontaneous breakdown of the corneal epithelium associated with symptoms ranging from ocular discomfort to severe pain. (entokey.com)
Epithelium5
- citation needed] Superficial corneal dystrophies - Meesmann dystrophy is characterized by distinct tiny bubble-like, punctate opacities that form in the central corneal epithelium and to a lesser extent in the peripheral cornea of both eyes during infancy that persists throughout life. (wikipedia.org)
- Lisch epithelial corneal dystrophy is characterized by feather shaped opacities and microcysts in the corneal epithelium that are arranged in a band-shaped and sometimes whorled pattern. (wikipedia.org)
- Primary: These include conditions that affect the basement membrane of the corneal epithelium. (entokey.com)
- Very often areas of EBMD changes, loose epithelium, epithelial detachment and intraepithelial cysts present as "negative fluorescein staining. (entokey.com)
- A frank erosion or epithelial defect (staining positively with fluorescein) is often surrounded by an area of negative staining, which indicates the full extent of the defective epithelium. (entokey.com)
Flecks1
- Both eyes exhibited small, dot-like, white flecks scattered throughout all layers of the corneal stroma, which corresponds to the typical FCD phenotype. (molvis.org)
Erosions2
- Patient remains asymptomatic until epithelial erosions precipitate acute episodes of ocular hyperemia, pain, and photophobia. (wikipedia.org)
- For example, intraepithelial cysts, deposits in basal epithelial cells, subbasal microfolds, reduplicated basement membrane, damaged subbasal nerves, and altered morphology of anterior stroma can be seen in MD without erosions. (entokey.com)
Superficial2
- Symmetrical reticular opacities form in the superficial central cornea of both eyes at about 4-5 years of age in Reis-Bücklers corneal dystrophy. (wikipedia.org)
- Visual acuity eventually becomes reduced during the second and third decades of life following a progressive superficial haze and an irregular corneal surface. (wikipedia.org)
Inheritance1
- Fleck corneal dystrophy (FCD, Online Mendelian Inheritance in Man (OMIM) #121850) was first reported in 1957 by Francois and Neetens [ 9 ], and is one of the hereditary corneal dystrophies in which the causative genes have already been identified. (molvis.org)
Patient2
- The purpose of this study is to report a novel mutation of the PIKFYVE gene in a Japanese patient with fleck corneal dystrophy. (molvis.org)
- The patient had no obvious vision loss or any complaints related to this corneal dystrophy, and the appropriateness of our identified mutation as a causative one for FCD is theoretically discussed. (molvis.org)
Occur1
- As clinical manifestations widely vary with the different entities, corneal dystrophies should be suspected when corneal transparency is lost or corneal opacities occur spontaneously, particularly in both corneas, and especially in the presence of a positive family history or in the offspring of consanguineous parents. (wikipedia.org)
Accumulation2
- The hallmark of Schnyder corneal dystrophy is the accumulation of crystals within the corneal stroma which cause corneal clouding typically in a ring-shaped fashion. (wikipedia.org)
- Abnormal basement membrane, abnormal or deficient hemidesmosomes, defective anchoring system, and accumulation of collagenous debris between and beneath epithelial cells result in easy slippage or tearing of the basal cells from the underlying connective tissue. (entokey.com)
Significantly1
- Corneal dystrophy may not significantly affect vision in the early stages. (wikipedia.org)
Episodes1
- Other dystrophies may cause repeated episodes of pain without leading to permanent loss of vision. (wikipedia.org)
Disorders1
- Corneal dystrophy is a group of rare hereditary disorders characterised by bilateral abnormal deposition of substances in the transparent front part of the eye called the cornea. (wikipedia.org)
Surface1
- Secondary: Trauma to the corneal surface with organic matter such as twigs, leaves, paper and finger nails is the commonest cause of RCES. (entokey.com)
Affect2
- citation needed] There are over 20 corneal dystrophies that affect all parts of the cornea. (wikipedia.org)
- Corneal dystrophies affect vision in widely differing ways. (wikipedia.org)
Japanese1
- To the best of our knowledge, this is the first study to show that a novel mutation (p.Glu1389AspfsX16) causing the truncation of the PIKFYVE protein causes fleck corneal dystrophy in the Japanese population. (molvis.org)
Layers1
- Most usually begin in one of the five corneal layers and may later spread to nearby layers. (wikipedia.org)