Choroideremia: An X chromosome-linked abnormality characterized by atrophy of the choroid and degeneration of the retinal pigment epithelium causing night blindness.Uveal Diseases: Diseases of the uvea.Chromosome Walking: A technique with which an unknown region of a chromosome can be explored. It is generally used to isolate a locus of interest for which no probe is available but that is known to be linked to a gene which has been identified and cloned. A fragment containing a known gene is selected and used as a probe to identify other overlapping fragments which contain the same gene. The nucleotide sequences of these fragments can then be characterized. This process continues for the length of the chromosome.Alkyl and Aryl Transferases: A somewhat heterogeneous class of enzymes that catalyze the transfer of alkyl or related groups (excluding methyl groups). EC 2.5.Stapes: One of the three ossicles of the middle ear. It transmits sound vibrations from the INCUS to the internal ear (Ear, Internal see LABYRINTH).rab GTP-Binding Proteins: A large family of MONOMERIC GTP-BINDING PROTEINS that play a key role in cellular secretory and endocytic pathways. EC 3.6.1.-.X Chromosome: The female sex chromosome, being the differential sex chromosome carried by half the male gametes and all female gametes in human and other male-heterogametic species.Protein Prenylation: A post-translational modification of proteins by the attachment of an isoprenoid to the C-terminal cysteine residue. The isoprenoids used, farnesyl diphosphate or geranylgeranyl diphosphate, are derived from the same biochemical pathway that produces cholesterol.Hypohidrosis: Abnormally diminished or absent perspiration. Both generalized and segmented (reduced or absent sweating in circumscribed locations) forms of the disease are usually associated with other underlying conditions.Adaptor Proteins, Signal Transducing: A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymesChoroid: The thin, highly vascular membrane covering most of the posterior of the eye between the RETINA and SCLERA.Retinal Degeneration: A retrogressive pathological change in the retina, focal or generalized, caused by genetic defects, inflammation, trauma, vascular disease, or aging. Degeneration affecting predominantly the macula lutea of the retina is MACULAR DEGENERATION. (Newell, Ophthalmology: Principles and Concepts, 7th ed, p304)Fundus Oculi: The concave interior of the eye, consisting of the retina, the choroid, the sclera, the optic disk, and blood vessels, seen by means of the ophthalmoscope. (Cline et al., Dictionary of Visual Science, 4th ed)Visual Acuity: Clarity or sharpness of OCULAR VISION or the ability of the eye to see fine details. Visual acuity depends on the functions of RETINA, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast.Night Vision: Function of the human eye that is used in dim illumination (scotopic intensities) or at nighttime. Scotopic vision is performed by RETINAL ROD PHOTORECEPTORS with high sensitivity to light and peak absorption wavelength at 507 nm near the blue end of the spectrum.Sensory Aids: Devices that help people with impaired sensory responses.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Night Blindness: Failure or imperfection of vision at night or in dim light, with good vision only on bright days. (Dorland, 27th ed)Motion Pictures as Topic: The art, technique, or business of producing motion pictures for entertainment, propaganda, or instruction.Gene Duplication: Processes occurring in various organisms by which new genes are copied. Gene duplication may result in a MULTIGENE FAMILY; supergenes or PSEUDOGENES.Nucleic Acid Amplification Techniques: Laboratory techniques that involve the in-vitro synthesis of many copies of DNA or RNA from one original template.DNA Copy Number Variations: Stretches of genomic DNA that exist in different multiples between individuals. Many copy number variations have been associated with susceptibility or resistance to disease.Multiplex Polymerase Chain Reaction: Methods for using more than one primer set in a polymerase chain reaction to amplify more than one segment of the target DNA sequence in a single reaction.Gene Dosage: The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Neurosciences: The scientific disciplines concerned with the embryology, anatomy, physiology, biochemistry, pharmacology, etc., of the nervous system.Electroretinography: Recording of electric potentials in the retina after stimulation by light.Visual Fields: The total area or space visible in a person's peripheral vision with the eye looking straightforward.Genes, Recessive: Genes that influence the PHENOTYPE only in the homozygous state.Tomography, Optical Coherence: An imaging method using LASERS that is used for mapping subsurface structure. When a reflective site in the sample is at the same optical path length (coherence) as the reference mirror, the detector observes interference fringes.Foundations: Organizations established by endowments with provision for future maintenance.Genetic Therapy: Techniques and strategies which include the use of coding sequences and other conventional or radical means to transform or modify cells for the purpose of treating or reversing disease conditions.Nuclear Warfare: Warfare involving the use of NUCLEAR WEAPONS.Pigment Epithelium of Eye: The layer of pigment-containing epithelial cells in the RETINA; the CILIARY BODY; and the IRIS in the eye.Retina: The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.Retinal Pigment Epithelium: The single layer of pigment-containing epithelial cells in the RETINA, situated closely to the tips (outer segments) of the RETINAL PHOTORECEPTOR CELLS. These epithelial cells are macroglia that perform essential functions for the photoreceptor cells, such as in nutrient transport, phagocytosis of the shed photoreceptor membranes, and ensuring retinal attachment.Photoreceptor Cells, Vertebrate: Specialized PHOTOTRANSDUCTION neurons in the vertebrates, such as the RETINAL ROD CELLS and the RETINAL CONE CELLS. Non-visual photoreceptor neurons have been reported in the deep brain, the PINEAL GLAND and organs of the circadian system.Macula Lutea: An oval area in the retina, 3 to 5 mm in diameter, usually located temporal to the posterior pole of the eye and slightly below the level of the optic disk. It is characterized by the presence of a yellow pigment diffusely permeating the inner layers, contains the fovea centralis in its center, and provides the best phototropic visual acuity. It is devoid of retinal blood vessels, except in its periphery, and receives nourishment from the choriocapillaris of the choroid. (From Cline et al., Dictionary of Visual Science, 4th ed)Fluorescein Angiography: Visualization of a vascular system after intravenous injection of a fluorescein solution. The images may be photographed or televised. It is used especially in studying the retinal and uveal vasculature.Ophthalmoscopy: Examination of the interior of the eye with an ophthalmoscope.Lens Nucleus, Crystalline: The core of the crystalline lens, surrounded by the cortex.Dosage Compensation, Genetic: Genetic mechanisms that allow GENES to be expressed at a similar level irrespective of their GENE DOSAGE. This term is usually used in discussing genes that lie on the SEX CHROMOSOMES. Because the sex chromosomes are only partially homologous, there is a different copy number, i.e., dosage, of these genes in males vs. females. In DROSOPHILA, dosage compensation is accomplished by hypertranscription of genes located on the X CHROMOSOME. In mammals, dosage compensation of X chromosome genes is accomplished by random X CHROMOSOME INACTIVATION of one of the two X chromosomes in the female.X Chromosome Inactivation: A dosage compensation process occurring at an early embryonic stage in mammalian development whereby, at random, one X CHROMOSOME of the pair is repressed in the somatic cells of females.Scleral Diseases: General disorders of the sclera or white of the eye. They may include anatomic, embryologic, degenerative, or pigmentation defects.Bibliography of Medicine: A list of works, documents, and other publications on medical subjects and topics of interest to the field of medicine.Lenses: Pieces of glass or other transparent materials used for magnification or increased visual acuity.History, 19th Century: Time period from 1801 through 1900 of the common era.Facial NeoplasmsSearch Engine: Software used to locate data or information stored in machine-readable form locally or at a distance such as an INTERNET site.Deafness: A general term for the complete loss of the ability to hear from both ears.Databases, Genetic: Databases devoted to knowledge about specific genes and gene products.Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Intellectual Disability: Subnormal intellectual functioning which originates during the developmental period. This has multiple potential etiologies, including genetic defects and perinatal insults. Intelligence quotient (IQ) scores are commonly used to determine whether an individual has an intellectual disability. IQ scores between 70 and 79 are in the borderline range. Scores below 67 are in the disabled range. (from Joynt, Clinical Neurology, 1992, Ch55, p28)Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.