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Usher Syndromes
Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes resulting in a combination of hearing loss and visual impairment. It is a major cause of deafblindness and is at present incurable. Usher syndrome is classed into three subtypes (I, II and III) according to the genes responsible and the onset of deafness. All three subtypes are caused by mutations in genes involved in the function of the inner ear and retina. These mutations are inherited in an autosomal recessive pattern. The occurrence of Usher syndrome varies across the world and across the different syndrome types, with rates as high as 1 in 12,500 in Germany to as low as 1 in 28,000 in Norway. Type I is most common in Ashkenazi Jewish and Acadian populations, and type III is rarely found outside Ashkenazi Jewish and Finnish populat ... [...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 effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive. This state of having 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 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 copy of the Y chromosome, Y-linked traits cannot be dominant or recessive. Additionally, there are other forms of dominance such as incomplete d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCDH15
Protocadherin-15 is a protein that in humans is encoded by the ''PCDH15'' gene. Function This gene is a member of the cadherin superfamily. Family members encode integral membrane proteins that mediate calcium-dependent cell-cell adhesion. The protein product of this gene consists of a signal peptide, 11 extracellular calcium-binding domains, a transmembrane domain and a unique cytoplasmic domain. It plays an essential role in maintenance of normal retinal and cochlear function. It is thought to interact with CDH23 to form tip-link filaments. Clinical significance Mutations in this gene have been associated with hearing loss, which is consistent with its location at the Usher syndrome Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes result ... type 1F (USH1F) critical region on chrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birmingham, UK
Birmingham ( ) is a city and metropolitan borough in the metropolitan county of West Midlands in England. It is the second-largest city in the United Kingdom with a population of 1.145 million in the city proper, 2.92 million in the West Midlands metropolitan county, and approximately 4.3 million in the wider metropolitan area. It is the largest UK metropolitan area outside of London. Birmingham is known as the second city of the United Kingdom. Located in the West Midlands region of England, approximately from London, Birmingham is considered to be the social, cultural, financial and commercial centre of the Midlands. Distinctively, Birmingham only has small rivers flowing through it, mainly the River Tame and its tributaries River Rea and River Cole – one of the closest main rivers is the Severn, approximately west of the city centre. Historically a market town in Warwickshire in the medieval period, Birmingham grew during the 18th century during the Midlands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finns
Finns or Finnish people ( fi, suomalaiset, ) are a Baltic Finnic ethnic group native to Finland. Finns are traditionally divided into smaller regional groups that span several countries adjacent to Finland, both those who are native to these countries as well as those who have resettled. Some of these may be classified as separate ethnic groups, rather than subgroups of Finns. These include the Kvens and Forest Finns in Norway, the Tornedalians in Sweden, and the Ingrian Finns in Russia. Finnish, the language spoken by Finns, is closely related to other Balto-Finnic languages, e.g. Estonian and Karelian. The Finnic languages are a subgroup of the larger Uralic family of languages, which also includes Hungarian. These languages are markedly different from most other languages spoken in Europe, which belong to the Indo-European family of languages. Native Finns can also be divided according to dialect into subgroups sometimes called ''heimo'' (lit. ''tribe''), although suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CLRN1
Clarin-1 is a protein that in humans is encoded by the ''CLRN1'' gene. Function This gene encodes a protein that contains a cytosolic N-terminus, multiple helical transmembrane domains, and an endoplasmic reticulum membrane retention signal, TKGH, in the C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is .... The encoded protein may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome type IIIa. Multiple transcript variants encoding distinct isoforms have been identified for this gene. References Further reading * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Retinitis Pigmentosa Overview * {{gene-3-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DFNB31
Whirlin is a protein that in humans is encoded by the ''DFNB31'' gene. In rat brain, WHRN interacts with a calmodulin-dependent serine kinase, CASK, and may be involved in the formation of scaffolding protein complexes that facilitate synaptic transmission in the central nervous system (CNS). Mutations in this gene, also known as WHRN, cause autosomal recessive deafness. Model organisms Model organisms have been used in the study of WHRN function. A conditional knockout mouse line, called ''Whrntm1a(EUCOMM)Wtsi'' was generated as part of the International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Twenty tests were carried out on mutant mice and two significant abnormalities were observed. ''Whrntm1a(EUCOMM)Wtsi'' homozygote mice show a moderate to severe hearing l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GPR98
ADGRV1, also known as G protein-coupled receptor 98 (GPR98) or Very Large G-protein coupled receptor 1 (VLGR1), is a protein that in humans is encoded by the ''GPR98'' gene. Several alternatively spliced transcripts have been described. The adhesion GPCR VLGR1 is the largest GPCR known, with a size of 6300 amino acids and consisting of 90 exons. There are 8 splice variants of VlgR1, named VlgR1a-1e and Mass1.1-1.3. The N-terminus consists of 5800 amino acids containing 35 Calx-beta domains, one pentraxin domain, and one epilepsy associated repeat. Mutations of VlgR1 have been shown to result in Usher's syndrome. Knockouts of Vlgr1 in mice have been shown to phenocopy Usher's syndrome and lead to audiogenic seizures. Function This gene encodes a member of the adhesion-GPCR family of receptors. The protein binds calcium and is expressed in the central nervous system. It is also known as ''very large G-protein coupled receptor 1'' because it is 6300 residues long. It contains ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USH2A
Usherin is a protein that in humans is encoded by the ''USH2A'' gene. This gene encodes the protein Usherin that contains laminin EGF motifs, a pentraxin domain, and many fibronectin type III motifs. The encoded basement membrane-associated protein may be important in development and homeostasis of the inner ear and retina. Mutations within this gene have been associated with Usher syndrome Usher syndrome, also known as Hallgren syndrome, Usher–Hallgren syndrome, retinitis pigmentosa–dysacusis syndrome or dystrophia retinae dysacusis syndrome, is a rare genetic disorder caused by a mutation in any one of at least 11 genes result ... type IIa. Alternatively spliced transcript variants that encode different isoforms have been described. References Further reading * * * * * * * * * * * * * * * * * * * External links GeneReviews/NCBI/NIH/UW entry on Usher Syndrome Type II {{gene-1-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hard-of-hearing
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spoken language, and in adults it can create difficulties with social interaction and at work. Hearing loss can be temporary or permanent. Hearing loss related to age usually affects both ears and is due to cochlear hair cell loss. In some people, particularly older people, hearing loss can result in loneliness. Deaf people usually have little to no hearing. Hearing loss may be caused by a number of factors, including: genetics, ageing, exposure to noise, some infections, birth complications, trauma to the ear, and certain medications or toxins. A common condition that results in hearing loss is chronic ear infections. Certain infections during pregnancy, such as cytomegalovirus, syphilis and rubella, may also cause hearing loss in the child. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashkenazi Jewish
Ashkenazi Jews ( ; he, יְהוּדֵי אַשְׁכְּנַז, translit=Yehudei Ashkenaz, ; yi, אַשכּנזישע ייִדן, Ashkenazishe Yidn), also known as Ashkenazic Jews or ''Ashkenazim'',, Ashkenazi Hebrew pronunciation: , singular: , Modern Hebrew: are a Jewish diaspora population who coalesced in the Holy Roman Empire around the end of the first millennium CE. Their traditional diaspora language is Yiddish (a West Germanic language with Jewish linguistic elements, including the Hebrew alphabet), which developed during the Middle Ages after they had moved from Germany and France into Northern Europe and Eastern Europe. For centuries, Ashkenazim in Europe used Hebrew only as a sacred language until the revival of Hebrew as a common language in 20th-century Israel. Throughout their numerous centuries living in Europe, Ashkenazim have made many important contributions to its philosophy, scholarship, literature, art, music, and science. The rabbinical term '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinitis Pigmentosa
Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may experience "tunnel vision". Complete blindness is uncommon. Onset of symptoms is generally gradual and often begins in childhood. Retinitis pigmentosa is generally inherited from one or both parents or rarely it can be caused by a miscoding during DNA division. It is caused by genetic miscoding of proteins in one of more than 300 genes involved. The underlying mechanism involves the progressive loss of rod photoreceptor cells that line the retina of the eyeball. The rod cells secrete a neuroprotective substance (Rod-derived cone viability factor, RdCVF) that protects the cone cells from apoptosis (cell death). However, when the rod cells die, this substance is no longer provided. This is generally followed by the loss of cone photorecept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinal Pigmented Epithelium
The pigmented layer of retina or retinal pigment epithelium (RPE) is the pigmented cell layer just outside the neurosensory retina that nourishes retinal visual cells, and is firmly attached to the underlying choroid and overlying retinal visual cells. History The RPE was known in the 18th and 19th centuries as the pigmentum nigrum, referring to the observation that the RPE is dark (black in many animals, brown in humans); and as the tapetum nigrum, referring to the observation that in animals with a tapetum lucidum, in the region of the tapetum lucidum the RPE is not pigmented. Anatomy The RPE is composed of a single layer of hexagonal cells that are densely packed with pigment granules. When viewed from the outer surface, these cells are smooth and hexagonal in shape. When seen in section, each cell consists of an outer non-pigmented part containing a large oval nucleus and an inner pigmented portion which extends as a series of straight thread-like processes between the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
