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Leber's Congenital Amaurosis
Leber congenital amaurosis (LCA) is a rare inherited eye disease that appears at birth or in the first few months of life. It affects about 1 in 40,000 newborns. LCA was first described by Theodor Leber in the 19th century. It should not be confused with Leber's hereditary optic neuropathy, which is a different disease also described by Theodor Leber. One form of LCA was successfully treated with gene therapy in 2008. Signs and symptoms LCA symptoms typically begin in the first few months of life, most commonly with involuntary twitching of the eye (nystagmus). Affected infants may show misaligned eyes when looking at something (strabismus), aversion to light (photophobia), and poke or rub at their eyes (Franceschetti’s oculodigital sign). Those with LCA invariably experience vision problems. Affected infants show decreased visual response to objects. Loss of visual acuity is severe, with affected individuals' vision ranging from 20/200 to 20/400. Around a third of thos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinians, Augustinian friar working in the 19th century in Brno, was the first to study genetics scientifically. Mendel studied "trait inheritance", patterns in the way traits are handed down from parents to offspring over time. He observed that organisms (pea plants) inherit traits by way of discrete "units of inheritance". This term, still used today, is a somewhat ambiguous definition of what is referred to as a gene. Phenotypic trait, Trait inheritance and Molecular genetics, molecular inheritance mechanisms of genes are still primary principles of genetics in the 21st century, but modern genetics has expanded to study the function and behavior of genes. Gene structure and function, variation, and distribution are studied within the context of the Cell (bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retinal Exam
An eye examination, commonly known as an eye test, is a series of tests performed to assess Visual acuity, vision and ability to Focus (optics), focus on and discern objects. It also includes other tests and examinations of the human eye, eyes. Eye examinations are primarily performed by an optometrist, ophthalmologist, or an orthoptist. Health care professionals often recommend that all people should have periodic and thorough eye examinations as part of routine primary care, especially since many eye diseases are asymptomatic. Typically, a healthy individual who otherwise has no concerns with their eyes receives an eye exam once in their 20s and twice in their 30s. Eye examinations may detect potentially treatable blindness, blinding eye diseases, ocular manifestation of systemic disease, ocular manifestations of systemic disease, or signs of tumour, tumors or other anomalies of the Human brain, brain. A full eye examination consists of a comprehensive evaluation of medical h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CCT2 (gene)
T-complex protein 1 subunit beta is a protein that in humans is encoded by the ''CCT2'' gene. Function This gene encodes a molecular chaperone that is member of the TRiC complex. This complex consists of two identical stacked rings, each containing eight different proteins. Unfolded polypeptides enter the central cavity of the complex and are folded in an ATP-dependent manner. The complex folds various proteins, including actin and tubulin. Alternate transcriptional splice variants of the gene described in this record have been observed but have not been thoroughly characterized. Interactions CCT2 (gene) has been shown to interact with PPP4C Serine/threonine-protein phosphatase 4 catalytic subunit is an enzyme that in humans is encoded by the ''PPP4C'' gene. Interactions PPP4C has been shown to interact with: * CCDC6, * CCT2, * CCT3, * CCT4, * CCT5, * CCT6A, * CCT7, .... References External links * * Further reading * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ALMS1
Alstrom syndrome 1 also known as ALMS1 is a protein which in humans is encoded by the ''ALMS1'' gene. Gene The gene is located on the short arm of chromosome 2 (2p13.2) on the plus (Watson) strand. It is 224,161 bases in length organised into 23 exons. The encoded protein has 4,167 amino acids and molecular weight of 460,937 Da. Three isoforms are known. Mutations associated with disease are usually found in exons 8, 10 and 16. Tissue and subcellular distribution The gene is expressed in fetal tissues including the aorta, brain, eye, kidney, liver, lung, olfactory bulb, pancreas, skeletal muscle, spleen and testis. The protein is found in the cytoplasm, centrosome, cell projections and cilium basal body. During mitosis it localizes to both spindle poles. Structure The protein has a large tandem-repeat domain comprising 34 imperfect repetitions of 47 amino acids as well as additional low complexity regions. Function The encoded protein functions in microtubule organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Phototransduction
Visual phototransduction is the sensory transduction process of the visual system by which light is detected by photoreceptor cells ( rods and cones) in the vertebrate retina. A photon is absorbed by a retinal chromophore (each bound to an opsin), which initiates a signal cascade through several intermediate cells, then through the retinal ganglion cells (RGCs) comprising the optic nerve. Overview Light enters the eye, passes through the optical media, then the inner neural layers of the retina before finally reaching the photoreceptor cells in the outer layer of the retina. The light may be absorbed by a chromophore bound to an opsin, which photoisomerizes the chromophore, initiating both the visual cycle, which "resets" the chromophore, and the phototransduction cascade, which transmits the visual signal to the brain. The cascade begins with graded polarisation (an analog signal) of the excited photoreceptor cell, as its membrane potential increases from a resting po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GUCY2D
Retinal guanylyl cyclase 1 also known as guanylate cyclase 2D, retinal is an enzyme that in humans is encoded by the GUCY2D (guanylate cyclase 2D) gene. Function This gene encodes a retina-specific guanylate cyclase, which is a member of the membrane guanylyl cyclase family. Like other membrane guanylyl cyclases, this enzyme has a hydrophobic amino-terminal signal sequence followed by a large extracellular domain, a single membrane spanning domain, a kinase homology domain, and a guanylyl cyclase catalytic domain. In contrast to other membrane guanylyl cyclases, this enzyme is not activated by natriuretic peptides. The nomenclature for members of the Gucy2 gene family is not consistent across species. In many mammals, including mice and rats, the Gucy2d gene encodes a related protein – GC-D – that is specifically expressed in a subpopulation of olfactory sensory neurons. This gene is a pseudogene in humans and most other primates. In rodents, the corresponding (orthologous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIPL1
Aryl-hydrocarbon-interacting protein-like 1 is a protein that in humans is encoded by the ''AIPL1'' gene. The protein is a member of FKBP prolyl isomerase family. Function Leber congenital amaurosis (LCA) accounts for at least 5% of all inherited retinal disease and is the most severe inherited retinopathy with the earliest age of onset. Individuals affected with LCA are diagnosed at birth or in the first few months of life with severely impaired vision or blindness, nystagmus and an abnormal or flat electroretinogram. The photoreceptor/pineal -expressed gene, AIPL1, encoding aryl-hydrocarbon interacting protein-like 1, was mapped within the LCA4 candidate region. The protein contains three tetratricopeptide motifs, consistent with nuclear transport or chaperone activity. AIPL1 mutations may cause approximately 20% of recessive LCA. Interactions AIPL1 has been shown to interact with NUB1. See also * Aryl hydrocarbon * Aryl hydrocarbon receptor * AH receptor-inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoreceptor Cell
A photoreceptor cell is a specialized type of neuroepithelial cell found in the retina that is capable of visual phototransduction. The great biological importance of photoreceptors is that they convert light (visible electromagnetic radiation) into signals that can stimulate biological processes. To be more specific, photoreceptor proteins in the cell absorb photons, triggering a change in the cell's membrane potential. There are currently three known types of photoreceptor cells in mammalian eyes: rod cell, rods, cone cell, cones, and intrinsically photosensitive retinal ganglion cells. The two classic photoreceptor cells are rods and cones, each contributing information used by the visual system to form an image of the environment, Visual perception, sight. Rods primarily mediate scotopic vision (dim conditions) whereas cones primarily mediate photopic vision (bright conditions), but the processes in each that supports phototransduction is similar. The intrinsically photosen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PRPH2
Peripherin-2 is a protein, that in humans is encoded by the ''PRPH2'' gene. Peripherin-2 is found in the rod and cone cells of the retina of the eye. Defects in this protein result in one form of retinitis pigmentosa, an incurable blindness. Mutations in the PRPH2 gene are associated with Vitelliform macular dystrophy. Function The protein encoded by this gene is a member of the transmembrane 4 superfamily, also known as the tetraspanin family. Most of these members are cell-surface proteins that are characterized by the presence of four transmembrane helices. Tetraspanins mediate signal transduction events that play a role in the regulation of cell development, activation, growth and motility. Peripherin 2 (sometimes referred to as peripherin/RDS or simply RDS) is a cell surface glycoprotein found in the outer segment of both rod and cone photoreceptor cells. It is located in the rim regions of the flattened disks that contain rhodopsin, which is the protein that is responsi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GDF6
Growth differentiation factor 6 (GDF6) is a protein that in humans is encoded by the ''GDF6'' gene. Function GDF6 belongs to the transforming growth factor beta superfamily and may regulate patterning of the ectoderm by interacting with bone morphogenetic proteins, and control eye development. Growth differentiation factor 6 (GDF6) is a regulatory protein associated with growth and differentiation of developing embryos. GDF6 is encoded by the GDF6 gene. It is a member the transforming growth factor beta superfamily which is a group of proteins involved in early regulation of cell growth and development. GDF6 has been shown to play an important role in the patterning of the epidermis and bone and joint formation. GDF6 induces genes related to the development of the epidermis and can bind directly to noggin, a gene that controls neural development, to block its effect. GDF6 interacts with bone morphogenetic proteins (BMPs) to form heterodimers that may work to regulate neural in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRB1
Crumbs homolog 1 is a protein that in humans is encoded by the ''CRB1'' gene. This gene encodes a protein which is similar to the Drosophila ''crumbs'' protein and localizes to the inner segment of mammalian photoreceptors. In Drosophila, crumbs localizes to the stalk of the fly photoreceptor and may be a component of the molecular scaffold that controls proper development of polarity in the eye. Mutations in this gene are associated with a severe form of retinitis pigmentosa, RP12, and with Leber congenital amaurosis. Alternatively spliced transcript variants have been observed but their full-length nature has yet to be determined. One small study suggests that mutations in this gene are associated with keratoconus Keratoconus is an eye disorder in which the cornea, the transparent front part of the eye, gradually thins and bulges outward into a cone shape. This causes distorted vision, including blurry vision, double vision, increased nearsightedness, ... in patients t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autosomal Dominant
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] |
