The following are health and medical definitions of terms that appear in the Usher Syndrome article.
American Sign Language: Abbreviated ASL. A complete, complex language that employs signs made with the hands and other movements, including facial expressions and postures of the body, used primarily by people in North America who are deaf.
Autosomal: Pertaining to a chromosome that is not a sex chromosome; relating to any one of the chromosomes save the sex chromosomes. See the entire definition of Autosomal
Autosomal recessive: A genetic condition that appears only in individuals who have received two copies of an autosomal gene, one copy from each parent. The gene is on an autosome, a nonsex chromosome. The parents are carriers who have only one copy of the gene and do not exhibit the trait because the gene is recessive to its normal counterpart gene. See the entire definition of Autosomal recessive
Bilateral: Having, or relating to, two sides. Bilateral is as opposed, for example, to unilateral (which means having, or relating to, one side).
Blind:1. Unable to see. Without part or all of the sense of sight. 2. In a clinical trial, not to know the treatment given or received. The participant is not told whether they are in the experimental or control arm of the study. Also called masked.
Blindness: Loss of useful sight. Blindness can be temporary or permanent. Damage to any portion of the eye, the optic nerve, or the area of the brain responsible for vision can lead to blindness. There are numerous (actually, innumerable) causes of blindness. The current politically correct terms for blindness include visually handicapped and visually challenged.
Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
Cell: The basic structural and functional unit in people and all living things. Each cell is a small container of chemicals and water wrapped in a membrane. See the entire definition of Cell
Central vision: Straight-ahead vision. Central vision is the work of the macula, a small area in the center of the retina that contains a rich collection of cones. (The retina is made up of two types of cells, the cones and the rods. Millions of cones are packed into the macula. The cones are nerve cells sensitive to light, fine detail, and color.) Central vision permits a person to read, drive, and perform other activities that require fine, sharp, straight-ahead vision. As opposed to peripheral vision.
Chromosome: A visible carrier of the genetic information. See the entire definition of Chromosome
Chromosomes: The microscopically visible carriers of the genetic material. They are composed of deoxyribonucleic acid (DNA) and proteins and, under a microscope, look like little rods. See the entire definition of Chromosomes
Clinical trials: Trials to evaluate the effectiveness and safety of medications or medical devices by monitoring their effects on large groups of people. See the entire definition of Clinical trials
Cochlear: Pertaining to the cochlea, the organ of hearing.
Cure:1. To heal, to make well, to restore to good health. Cures are easy to claim and, all too often, difficult to confirm. 2. A time without recurrence of a disease so that the risk of recurrence is small, as in the 5-year cure rate for malignant melanoma. 3. Particularly in the past, a course of treatment. For example, take a cure at a spa. See the entire definition of Cure
Deafness:Deafness is defined by partial or complete hearing loss. Levels of hearing impairment vary from a mild but important loss of sensitivity to a total loss of hearing. Older adults suffer most often from hearing loss. Age-related hearing loss affects 30 to 35 percent of the population between the ages of 65 and 75 years, and 40 percent of the population over the age of 75. The most common cause of hearing loss in children is otitis media, a disorder that affects predominantly infants and young children. A substantial number of hearing impairments are caused by environmental factors such as noise, drugs, and toxins. Many sensorineural hearing losses result from a genetic predisposition.
Diagnosis:1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV. See the entire definition of Diagnosis
Electronystagmogram: A recording of the eye movements, usually done to confirm the presence of nystagmus. Electronystagmogram may be done in cases of vertigo (dizziness) to determine if there is damage to the vestibular portion of the acousticnerve. The test may be done in cases of possible acoustic neuroma, Meniere disease, positional vertigo, and labyrinthitis. Abbreviated ENG.
Electroretinogram: Abbreviated ERG. An electroretinographic recording. See: Electroretinography.
Family history: The family structure and relationships within the family, including information about diseases in family members. See the entire definition of Family history
Gene: The basic biological unit of heredity. A segment of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Gene
Genes: The basic biological units of heredity. Segments of deoxyribonucleic acid (DNA) needed to contribute to a function. See the entire definition of Genes
Genetic: Having to do with genes and genetic information.
Genetic counseling: An educational counseling process for individuals and families who have a genetic disease or who are at risk for such a disease. Genetic counseling is designed to provide patients and their families with information about their condition and help them make informed decisions. See the entire definition of Genetic counseling
Genetic testing: Tests done for clinical genetic purposes. Genetic tests may be done for diverse purposes pertaining to clinical genetics, including the diagnosis of genetic disease in children and adults; the identification of future disease risks; the prediction of drug responses; and the detection of risks of disease to future children.
Intervention: The act of intervening, interfering or interceding with the intent of modifying the outcome. In medicine, an intervention is usually undertaken to help treat or cure a condition. For example, early intervention may help children with autism to speak. "Acupuncture as a therapeutic intervention is widely practiced in the United States," according to the National Institutes of Health. From the Latin intervenire, to come between.
Involuntary: Done other than in accordance with the conscious will of the individual. The opposite of voluntary. See the entire definition of Involuntary
Laboratory: A place for doing tests and research procedures and preparing chemicals, etc. Although "laboratory" looks very like the Latin "laboratorium" (a place to labor, a work place), the word "laboratory" came from the Latin "elaborare" (to work out, as a problem, and with great pains), as evidenced by the Old English spelling "elaboratory" designating "a place where learned effort was applied to the solution of scientific problems."
Mutation: A permanent change, a structural alteration, in the DNA or RNA. In humans and many other organisms, mutations occur in DNA. However, in retroviruses like HIV, mutations occur in RNA which is the genetic material of retroviruses. See the entire definition of Mutation
Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.
NIDCD: Stands for National Institute on Deafness and Other Communication Disorders, one of the US National Institutes of Health (the NIH). See the entire definition of NIDCD
Onset: In medicine, the first appearance of the signs or symptoms of an illness as, for example, the onset of rheumatoid arthritis. There is always an onset to a disease but never to the return to good health. The default setting is good health. See the entire definition of Onset
Optic: Having to do with vision.
Optic nerve: The optic nerve connects the eye to the brain. The optic nerve carries the impulses formed by the retina, the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images. Using an ophthalmoscope, the head of the optic nerve can be easily seen. It can be viewed as the only visible part of the brain (or extension of it). See the entire definition of Optic nerve
Palmitate: An antioxidant and a vitamin A compound that is added to low-fat and fat-free milk to replace the vitamin content lost through the removal of milk fat. Palmitate (more formally known as retinyl palmitate) contains palmitic acid, a 16-carbon saturated fatty acid, which is the major fatty acid found in palm oil. The palmitic acid is attached to the alcohol form of vitamin A, called retinol, to make vitamin A stable in milk. The name "palmitate" comes from the French "palmitique" from palmite, the pith of the palm tree.
Peripheral: Situated away from the center, as opposed to centrally located. See the entire definition of Peripheral
Peripheral vision: Side vision. The ability to see objects and movement outside of the direct line of vision. Peripheral vision is the work of the rods, nerve cells located largely outside the macula (the center) of the retina. The rods are also responsible for night vision and low-light vision but are insensitive to color. As opposed to central vision.
Pigment: A substance that gives color to tissue. Pigments are responsible for the color of skin, eyes, and hair.
Pregnancy: The state of carrying a developing embryo or fetus within the female body. This condition can be indicated by positive results on an over-the-counter urine test, and confirmed through a blood test, ultrasound, detection of fetal heartbeat, or an X-ray. Pregnancy lasts for about nine months, measured from the date of the woman's last menstrual period (LMP). It is conventionally divided into three trimesters, each roughly three months long. See the entire definition of Pregnancy
Pregnant: The state of carrying a developing fetus within the body. See the entire definition of Pregnant
Progressive: Increasing in scope or severity. Advancing. Going forward. In medicine, a disease that is progressive is going from bad to worse.
Puberty: A complex biologic and psychologic process involving sexual development, accelerated growth, and adrenal maturation heralded by the secretion of gonadotropin releasing hormone (GnRH) from a part of the brain called the hypothalamus. This event is the first known step in the reproductive cascade. It initiates the pulsatile release of gonadotropins, gonadal secretion of sex steroids, pubertal development, and gametogenesis (the production of sperm and ova). See the entire definition of Puberty
Recessive: A condition that appears only in individuals who have received two copies of a mutant gene, one copy from each parent. The individuals with a double dose of the mutated gene are called homozygotes. Their parents, each with a single dose of the mutated gene, appear normal and are called heterozygotes, or gene carriers. See the entire definition of Recessive
Retina: The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain. There is a small area, called the macula, in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly. See the entire definition of Retina
Retinal: Pertaining to the retina, the extraordinary layer of neurons (nerve cells) that line the back of the eye, which can sense light and create impulses capable of voyaging through the optic nerve to the brain where the impulses are recognized as an image. See the entire definition of Retinal
Retinitis pigmentosa: Any one of a large group of inherited disorders in which abnormalities of the photoreceptors (the rods and cones) in the retina lead to progressive visual loss. People with retinitis pigmentosa (RP) first experience defective dark adaptation ("night blindness"), then constriction of the visual field ("tunnel vision") and eventually loss of central vision. See the entire definition of Retinitis pigmentosa
Sign language: A language that employs signs made with the hands and other movements, including facial expressions and postures of the body, used primarily by people who are deaf. There are many different sign languages as, for example, British and American sign languages. British sign language (BSL) is not easily intelligible to users of American sign language (ASL). Unlike ASL, BSL uses a two-handed alphabet. In developing countries, deaf people may use the sign language of educators and missionaries from elsewhere in the world. For example, some deaf individuals in Madagascar use Norwegian sign language. By contrast, deaf children in Nicaragua have created their own sign language. Study of the emerging Nicaruagan sign language (NSL) has revealed that children naturally possess learning abilities capable of giving language its fundamental structure. See also: American sign language.
Symptom: Any subjective evidence of disease. Anxiety, lower back pain, and fatigue are all symptoms. They are sensations only the patient can perceive. In contrast, a sign is objective evidence of disease. A bloody nose is a sign. It is evident to the patient, doctor, nurse and other observers.
Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease. See the entire definition of Syndrome
Trait: In genetics, a trait refers to any genetically determined characteristic. In technical terms, a genetic trait is amenable to segregation analysis rather than quantitative analysis. See the entire definition of Trait
Usher syndrome: A genetic disorder characterized by hearing impairment and an eye disorder called retinitis pigmentosa in which vision worsens over time. Some people with Usher syndrome also have balance problems. See the entire definition of Usher syndrome
Vestibular: 1) Having to do with a structure that is a vestibule (entrance), such as the vestibule of the ear. 2) Having to do with the body's system for maintaining equilibrium.
Visual field: The entire area that can be seen when the eye is directed forward, including that which is seen with peripheral vision. See the entire definition of Visual field
Visual field test: A test which measures the extent and distribution of the field of vision. See the entire definition of Visual field test
Vitamin A: Vitamin A is retinol. Carotene compounds (found, for example, in egg yolk, butter and cream) are gradually converted by the body to vitamin A (retinol). A form of vitamin A called retinal is responsible for transmitting light sensation in the retina of the eye. See the entire definition of Vitamin A
Vitamin E: Alpha-tocopherol, an antioxidant vitamin which binds oxygen free radicals that can cause tissue damage. Deficiency of vitamin E can lead to anemia. Vitamin E may play a possible role in preventing heart disease and cancer of the lung and prostate. See the entire definition of Vitamin E
Genetic disease is a disorder or condition caused by abnormalities in a person's genome. Types of genetic inheritance include single inheritance (for example, cystic fibrosis, sickle cell anemia, Marfan syndrome, and hemochromatosis), multifactoral inheritance, chromosome abnormalities (for example, Turner syndrome, and Klinefelter syndrome), and mitochondrial inheritance (for example, epilepsy and dementia).
Retinitis pigmentosa (RP) is a genetic condition that causes retinal degeneration and eventual vision loss. Symptoms include night blindness and tunnel vision. Visual field testing and electrophysiological testing are essential in diagnosing RP. Though there is no cure for RP, vitamin A therapy and an omega-3-rich diet may be recommended for patients to slow disease progression.
Noise-induced hearing loss may be an acoustic trauma (temporary hearing loss), or permanent due to an acute acoustic trauma. Experts agree that continual exposure to more then 85 dBs (decibels) is dangerous to the ears. Ear plugs and ear muffs can help prevent noise-induced hearing loss as well as decreasing exposure to loud noises.
Hearing loss (deafness) may be present at birth or it may manifest later in life. Deafness may be genetic or due to damage from noise. Treatment of deafness depends upon its cause.
Your health care provider may refer you to a genetic professional. Universities and medical centers also often have affiliated genetic professionals, or can provide referrals to a genetic professional or genetics clinic. Genetic counseling provides patients and family members the tools to make the right choice in regard to test for a disease or condition.
What is the importance of noise-induced hearing loss?
The industrial and technological revolution may have
propelled society to higher levels of achievement, but this progress has also
made the world a noisier place in which to live. In fact, noise pollution is a
growing health hazard and can be found almost everywhere. Car alarms, leaf
blowers, gunshots, boom boxes, and traffic congestion fill our cities with decibels (the measure of sound intensity). Escaping to the country may not provide a quiet refuge, and even farmers are at high risk for exposure to noise from their farm machinery.
What's more, potentially harmful noise is not necessarily unpleasant or unwanted. For example, the music at a concert and the pounding of a jackhammer on the street can be equally damaging to the inner ear. The reason for this is that any sounds (acoustic energies) delivered with equal intensity, regardless of their source, are equally dangerous. Eventually, continued ...
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