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Ichthyosis
Ichthyosis is a family of genetic skin disorders characterized by dry, thickened, scaly skin. The more than 20 types of ichthyosis range in severity of symptoms, outward appearance, underlying genetic cause and mode of inheritance (e.g., dominant, recessive, autosomal or X-linked). Ichthyosis comes from the Greek ἰχθύς ''ichthys'', literally "fish", since dry, scaly skin is the defining feature of all forms of ichthyosis. The severity of symptoms can vary enormously, from the mildest, most common, types such as ichthyosis vulgaris, which may be mistaken for normal dry skin, up to life-threatening conditions such as harlequin-type ichthyosis. Ichthyosis vulgaris accounts for more than 95% of cases. Types Many types of ichthyoses exist, and an exact diagnosis may be difficult. Types of ichthyoses are classified by their appearance, if they are syndromic or not, and by mode of inheritance. For example, non-syndromic ichthyoses that are inherited recessively come under the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harlequin-type Ichthyosis
Harlequin-type ichthyosis is a genetic disorder that results in thickened skin over nearly the entire body at birth. The skin forms large, diamond/trapezoid/rectangle-shaped plates that are separated by deep cracks. These affect the shape of the eyelids, nose, mouth, and ears and limit movement of the arms and legs. Restricted movement of the chest can lead to breathing difficulties. These plates fall off over several weeks. Other complications can include premature birth, infection, problems with body temperature, and dehydration. The condition is the most severe form of ichthyosis, a group of genetic disorders characterised by scaly skin. Harlequin-type ichthyosis is caused by mutations in the ''ABCA12'' gene. This gene codes for a protein necessary for transporting lipids out of cells in the outermost layer of skin. The disorder is autosomal recessive and inherited from parents who are carriers. Diagnosis is often based on appearance at birth and confirmed by genetic testin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harlequin-type Ichthyosis
Harlequin-type ichthyosis is a genetic disorder that results in thickened skin over nearly the entire body at birth. The skin forms large, diamond/trapezoid/rectangle-shaped plates that are separated by deep cracks. These affect the shape of the eyelids, nose, mouth, and ears and limit movement of the arms and legs. Restricted movement of the chest can lead to breathing difficulties. These plates fall off over several weeks. Other complications can include premature birth, infection, problems with body temperature, and dehydration. The condition is the most severe form of ichthyosis, a group of genetic disorders characterised by scaly skin. Harlequin-type ichthyosis is caused by mutations in the ''ABCA12'' gene. This gene codes for a protein necessary for transporting lipids out of cells in the outermost layer of skin. The disorder is autosomal recessive and inherited from parents who are carriers. Diagnosis is often based on appearance at birth and confirmed by genetic testin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-linked Recessive Ichthyosis
X-linked ichthyosis (abbreviated ''XLI'') is a skin condition caused by the hereditary deficiency of the steroid sulfatase (STS) enzyme that affects 1 in 2000 to 1 in 6000 males. XLI manifests with dry, scaly skin and is due to deletions or mutations in the ''STS'' gene. XLI can also occur in the context of larger deletions causing contiguous gene syndromes. Treatment is largely aimed at alleviating the skin symptoms.: Treatment Section The term is from the Ancient Greek 'ichthys' meaning 'fish'. Signs and symptoms The major symptoms of XLI include scaling of the skin, particularly on the neck, trunk, and lower extremities. The extensor surfaces are typically the most severely affected areas. The >4 mm diameter scales adhere to the underlying skin and can be dark brown or gray in color. Symptoms may subside during the summer. Associated medical conditions Aside from the skin scaling, XLI is not typically associated with other major medical problems. Atrial fibr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosis Vulgaris
Ichthyosis vulgaris (also known as "autosomal dominant ichthyosis" and "Ichthyosis simplex") is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis,Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . affecting around 1 in 250 people. For this reason it is known as common ichthyosis. It is usually an autosomal dominant inherited disease (often associated with filaggrin), although a rare non-heritable version called acquired ichthyosis exists.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . Presentation The symptoms of the inherited form of ichthyosis vulgaris are not usually present at birth but generally develop between three months and five years of age.''Ichthy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABCA12
ATP-binding cassette sub-family A member 12 also known as ATP-binding cassette transporter 12 is a protein that in humans is encoded by the ''ABCA12'' gene. ABCA12 belongs to a group of genes called the ATP-binding cassette family, which makes proteins that transport molecules across cell membranes. The ABCA12 gene is active in some types of skin cells and in several other tissues, such as testis, placenta, lung, stomach, and fetal brain and liver. This protein appears to be essential for normal development of the skin, which provides a barrier between the body and its surrounding environment. It transports epidermoside, a glucosylceramide, out of the keratinocytes of the stratum corneum of the epidermis. The ABCA12 gene is located on the long (q) arm of chromosome 2 between positions 34 and 35, from base pair 215,621,772 to base pair 215,828,656. Clinical significance Harlequin-type ichthyosis Several mutations in the ABCA12 gene are known to cause harlequin-type i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosis Vulgaris
Ichthyosis vulgaris (also known as "autosomal dominant ichthyosis" and "Ichthyosis simplex") is a skin disorder causing dry, scaly skin. It is the most common form of ichthyosis,Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . affecting around 1 in 250 people. For this reason it is known as common ichthyosis. It is usually an autosomal dominant inherited disease (often associated with filaggrin), although a rare non-heritable version called acquired ichthyosis exists.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . Presentation The symptoms of the inherited form of ichthyosis vulgaris are not usually present at birth but generally develop between three months and five years of age.''Ichthy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyosis Bullosa Of Siemens
Ichthyosis bullosa of Siemens is a type of familial, autosomal dominant ichthyosis, a rare skin disorder.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . It is also known as bullous congenital ichthyosiform erythroderma of Siemens or ichthyosis exfoliativa. It is a genetic disorder with no known cure which is estimated to affect about 1 in 500,000 people.Caputo, Ruggero and Tadini, Gianluca''Atlas of Genodermatoses'' Page 19, Published by Taylor & Francis, 2005, Symptoms and signs Ichthyosis bullosa of Siemens has symptoms very similar to epidermolytic hyperkeratosis but is generally milder. Ichthyosis bullosa of Siemens affects only the upper layers of the epidermis whilst epidermolytic hyperkeratosis affects the suprabasal layer which is deeper in the skin.Harper, John; Oranje, Arnold P. and Prose, Neil S.''Textbook of Pediatric Dermatology'' Page 1110, Published by Blackwell Science, 2000, At birth the baby's skin has a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamellar Ichthyosis
Lamellar ichthyosis, also known as ichthyosis lamellaris and nonbullous congenital ichthyosis, is a rare inherited skin disorder, affecting around 1 in 600,000 people. Presentation Affected babies are born in a collodion membrane, a shiny, waxy-appearing outer layer to the skin. This is shed 10–14 days after birth, revealing the main symptom of the disease, extensive scaling of the skin caused by hyperkeratosis. With increasing age, the scaling tends to be concentrated around joints in areas such as the groin, the armpits, the inside of the elbow and the neck. The scales often tile the skin and may resemble fish scales. Collodion baby In medicine, the term collodion baby applies to newborns who appear to have an extra layer of skin (known as a ''collodion membrane'') that has a collodion-like quality. It is a descriptive term, not a specific diagnosis or disorder (as such, it is a syndrome). Appearance and treatment at birth The appearance is often described as a shiny f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STS (gene)
Steroid sulfatase (STS), or steryl-sulfatase (EC 3.1.6.2), formerly known as arylsulfatase C, is a sulfatase enzyme involved in the metabolism of steroids. It is encoded by the ''STS'' gene. Reactions This enzyme catalyses the following chemical reaction : 3β-hydroxyandrost-5-en-17-one 3-sulfate + H2O \rightleftharpoons 3β-hydroxyandrost-5-en-17-one + sulfate Also acts on some related steryl sulfates. Function The protein encoded by this gene catalyzes the conversion of sulfated steroid precursors to the free steroid. This includes DHEA sulfate, estrone sulfate, pregnenolone sulfate, and cholesterol sulfate, all to their unconjugated forms (DHEA, estrone, pregnenolone, and cholesterol, respectively). The encoded protein is found in the endoplasmic reticulum, where it is present as a homodimer. Clinical significance A congenital deficiency in the enzyme is associated with X-linked ichthyosis, a scaly-skin disease affecting roughly 1 in every 2,000 to 6,000 males. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KRT2
Keratin 2A also known as keratin 2E or keratin 2 is a protein that in humans is encoded by the ''KRT2A'' gene. Keratin 2A is a type II cytokeratin. It is found largely in the upper spinous layer of epidermal keratinocytes and mutations in the gene encoding this protein have been associated with ichthyosis bullosa of Siemens Ichthyosis bullosa of Siemens is a type of familial, autosomal dominant ichthyosis, a rare skin disorder.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . It is also known as bullous congenital .... References Further reading * * * * * * * * * * * * * * * * * * * External links * Keratins {{gene-12-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidermolytic Hyperkeratosis
Epidermolytic ichthyosis (EI), also known as bullous epidermis ichthyosis (BEI), epidermolytic hyperkeratosis (EHK), bullous congenital ichthyosiform erythroderma (BCIE), bullous ichthyosiform erythrodermaFreedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. . or bullous congenital ichthyosiform erythroderma Brocq, is a rare and severe form of ichthyosis that affects around 1 in 300,000 people. It is caused by a genetic mutation, and thus cannot be completely cured without some form of gene therapy. While some research has been done into possible gene therapy treatments, the work hasn't yet been successfully developed to the stage where it can be routinely given to patients. The condition involves the clumping of keratin filaments.James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . Presentation Epidermolytic hyperkeratosis is a skin disorder that is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TGM1
Protein-glutamine gamma-glutamyltransferase K is a transglutaminase enzyme that in humans is encoded by the ''TGM1'' gene. Function Keratinocyte transglutaminase enzymes serve to specifically catalyze the development of the cornified cell envelope, a defining characteristic of epidermal keratinocytes that have undergone the termination of differentiation. The specific cross linkages formed by keratinocyte transglutaminase are between n^ε-(γ-glutamyl)lysine residues which develop into isopeptide protein-protein linkages that adds to the stabilization of the cornified cell envelope. In terminally differentiated stratified squamous epithelia, the cornified cell envelope protein linkages allow for a structurally fortified, yet flexible (15 nm thick) layer to the place of the cell membrane, acting as a highly insoluble barrier. The expression of the enzyme is most highly exhibited along the biological membrane of these fully formed epithelial cells, preventing the cell from under ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
