Aniridia is a rare congenital condition characterized by the underdevelopment of the eye's iris. This usually occurs in both eyes. It is associated with poor development of the retina at the back of the eye resulting in visual loss. The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... // Q00-Q99 - Congenital malformations, deformations and chromosomal abnormalities (Q00-Q07) Congenital malformations of the nervous system (Q00) Anencephaly and similar malformations (Q01) Encephalocele (Q02) Microcephaly (Q03) Congenital hydrocephalus (Q04) Other congenital malformations of brain (Q05) Spina bifida (Q06) Other congenital malformations of spinal cord (Q07) Other congenital malformations of nervous... The International Statistical Classification of Diseases and Related Health Problems (commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... A congenital disorder is a medical condition or defect that is present at or before birth (for example, congenital heart disease). ... A human eye. ... The human iris The iris is the green/grey/brown area. ... Human eye cross-sectional view. ... Visual loss results in the absence of vision where it existed before, which can happen either acutely or over a long period of time. ...

Eyes of a Scandinavian male wherein the iris is not present due to aniridia. Notice the lack of common eye color as the eye appears to be one large pupil.

Image File history File links BlackEyesAniridia. ... Image File history File links BlackEyesAniridia. ... Eye color is a polygenic trait and is determined primarily by the amount and type of pigments present in the eyes iris. ...

Signs and symptoms

Clinical presentation: ocular

• Stumps of iris usually apparent
• Some patients have partial aniridia with relatively preserved vision
• Corneal findings; Limbal stem cell deficiency = aniridic keratopathy
• Corneal pannus usually presents in early childhood with radial vessels at 6 and 12 o’clock, developing circumferential grayish haze which advances centrally
• Corneal epithelium may harbor ectopic conjunctival goblet cells, and inflammatory cells are usually present
• Microcornea is very common in aniridia
• Initial fine lens opacities in infants
• Visually significant cataract often acquired by 2nd-3rd decade
• Multiple cataract types described: anterior polar, pyramidal, nuclear, lamellar, and cortical
• Lens subluxation / ectopia lentis
• Nystagmus
• Sensory strabismus
• Glaucoma onset usually by 2nd decade
• Gradually increasing angle obstruction, though open angle also possible
• Possible glaucoma mechanism: Contractile membrane covering angle, with increase in iridocorneal processes; iris stump may become totally adherent to posterior corneal surface
• Foveal hypoplasia, which may be complete or very subtle; Fluorescein angiography may be needed to demonstrate lack of foveal avascular zone
• Optic nerve hypoplasia to some degree is present in up to 75% of aniridia patients

Iris has three main meanings, related by their derivation from the Greek word for rainbow: Iris (mythology), a messenger of the gods in Greek mythology, identified with the rainbow Iris (anatomy), the sphincter around the pupil of the eye, named after the colors in human and animal eyes Iris (plant... The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... Mouse embryonic stem cells with fluorescent marker. ... Keratopathy can refer to: Florida keratopathy Thygesons superficial punctate keratopathy Category: ... Pannus is a medical term for a hanging flap of skin. ... Types of epithelium This article discusses the epithelium, an animal anatomical structure. ... The conjunctiva is a membrane that covers the sclera (white part of the eye) and lines the inside of the eyelids. ... Goblet cells are glandular epithelial cells that are specifically designed to secrete mucus. ... Look up lens in Wiktionary, the free dictionary. ... A cataract is an opacity that develops in the crystalline lens of the eye or in its envelope. ... A cataract is an opacity that develops in the crystalline lens of the eye or in its envelope. ... Anterior lens luxation Ectopia lentis is a displacement or malposition of the eyes crystalline lens from its normal location. ... Nystagmus is rapid involuntary rhythmic eye movement, with the eyes moving quickly in one direction (quick phase), and then slowly in the other (slow phase). ... For the protein Strabismus, see Strabismus (protein) Strabismus, also known as heterotropia, squint, crossed eye, cockeyed, wandering eye, or wall eyed, is a condition in which the eyes are not properly aligned with each other. ... Fluorescein angiography, or fluorescent angiography, is a technique for examining the circulation of the retina. ... The fovea, a part of the eye, is a spot located in the center of the macula. ... Optic nerve hypoplasia is a medical condition that results in underdevelopment of the optic nerves. ...

Clinical presentation: non-ocular

• Dysosmia / dysnomia = hypoplastic olfactory bulbs
• Glucose intolerance / diabetes mellitus
• Reduced size of corpus callosum and anterior commissure
• Absent pineal gland: abnormal sleep due to melatonin abnormalities
• Unilateral polymicrogyria
• WAGR syndrome (Wilms tumour, aniridia, genitourinary abnormality, mental retardation)
• Wilms tumor occurs in 30-50% of cases
• External genital anomalies occur only in males, often delaying recognition of WAGR in females
• Late onset nephropathy is a well-recognized feature of this syndrome

Dysnomia is a marked difficulty in remembering names or recalling words needed for oral or written language. ... Vesalius Fabrica, 1543. ... Glucose (Glc), a monosaccharide (or simple sugar), is the most important carbohydrate in biology. ... For the disease characterized by excretion of large amounts of severely diluted urine, see diabetes insipidus. ... The corpus callosum is a structure in the mammalian brain that connects the left and right cerebral hemispheres. ... Diagram of pituitary and pineal glands. ... Sleep is the state of natural rest observed in most mammals, birds, fish, as well as invertebrates such as the fruitfly Drosophila. ... Melatonin, 5-methoxy-N-acetyltryptamine, is a hormone found in all living creatures from algae[1] to humans, at levels that vary in a diurnal cycle. ... Polymicrogyria is a neuronal developmental disorder. ... WAGR syndrome (also called WAGR complex) is a rare genetic syndrome in which affected children are predisposed to develop Wilms tumor (a tumor of the kidneys), Aniridia (absence of the colored part of the eye, the iris), Genitourinary anomalies, and mental Retardation. ... This page is a candidate to be moved to Wiktionary. ... Mental retardation is a term for a pattern of persistently slow learning of basic motor and language skills (milestones) during childhood, and a significantly below-normal global intellectual capacity as an adult. ... Wilms tumor is a neoplasm of the kidneys that typically occurs in children. ... Nephropathy refers to damage to or disease of the kidney. ...

Treatment

Due to the high risk of glaucoma and cataract formation, aniridia patients should be under the care of an ophthalmologist familiar with the condition. The risk of progressive glaucoma persists from childhood into adulthood, necessitating long-term follow-up. Optometrists and low vision specialists are often valuable in maximizing visual and social functioning, prescribing glasses, and amelioriating light sensitivity (photophobia).

The iris functions to restrict the amount of light entering the eye, so if it is absent, most individuals with aniridia are sensitive to bright outdoor light and their eyes may need protecting. This can be done with tinted glasses, or with a contact lens which has an artificial iris painted onto it. This article does not cite its references or sources. ... A pair of contact lenses when not inserted in the eye. ...

Aniridia is often associated with other health and developmental problems, as well as complicating eye conditions such as: foveal hypoplasia, nystagmus, glaucoma, corneal disease, cataract, lens subluxation and optic nerve disease. Nystagmus is rapid involuntary rhythmic eye movement, with the eyes moving quickly in one direction (quick phase), and then slowly in the other (slow phase). ... The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber, providing most of an eyes optical power [1]. Together with the lens, the cornea refracts light and, as a result, helps the eye to focus. ... A cataract is an opacity that develops in the crystalline lens of the eye or in its envelope. ... In medicine, a subluxation is an incomplete or partial dislocation of a joint or organ [1]. A dislocation of any joint would usually need medical attention to help relocate the joint, however with a subluxation the patient will report of a joint dislocating which then relocates by itself. ...

Types

Aniridia may be broadly divided into hereditary and sporadic forms. Hereditary aniridia is usually transmited in an autosomal dominant manner (50% of offspring affected), although rarer autosomal recessive forms (such as Gillespie syndrome) have also been reported. Sporadic aniridia mutations may affect the WT1 region adjacent to the AN2 aniridia region, causing a kidney cancer called nephroblastoma (Wilms tumor). These patients often also have genitourinary abnormalities and mental retardation (WAGR syndrome). An autosomal dominant gene is one that occurs on an autosomal (non-sex determining) chromosome. ... In genetics, the term recessive gene refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele). ... This article is about mutation in biology, for other meanings see: mutation (disambiguation). ... Wilms tumor is a neoplasm of the kidneys that typically occurs in children. ... Wilms tumor is a neoplasm of the kidneys that typically occurs in children. ... Mental retardation is a term for a pattern of persistently slow learning of basic motor and language skills (milestones) during childhood, and a significantly below-normal global intellectual capacity as an adult. ... WAGR syndrome (also called WAGR complex) is a rare genetic syndrome in which affected children are predisposed to develop Wilms tumor (a tumor of the kidneys), Aniridia (absence of the colored part of the eye, the iris), Genitourinary anomalies, and mental Retardation. ...

The AN2 region of the short arm of chromosome 11 (11p13) includes the PAX6 gene (named for its PAired boX status), whose gene product helps regulate a cascade of other genetic processes involved in the development of the eye (as well as other nonocular structures). This PAX6 gene is around 95% similar to the pax gene found in zebrafish, a creature which diverged from the human ancestry around 400 million years ago. Thus, the PAX6 gene constitutes an important evolutionary link to mankind's distant ancestors. Chromosome 11 is one of the 23 pairs of chromosomes in humans. ... // Introduction Paired box (Pax) genes are a family of tissue specific transcription factors containing a PAIRED domain and usually a partial or complete homeodomain. ... The name zebrafish applies to several different kinds of fish with striped bodies considered to resemble a zebra: Brachydanio rerio, also called Danio rerio or the Zebra Danio, is a commonly used model organism in studies of biological development. ... This article is about evolution in biology. ...

Defects in the PAX6 gene cause aniridia-like ocular defects in mice (as well as Drosophilia = fruit flies). Aniridia is a heterozygotic disease, meaning that only one of the two chromosome 11 copies is affected. When both copies are altered (homozgous condition), the result is a uniformly fatal condition with near complete failure of entire eye formation. Mice may refer to: An abbreviation of Meetings, Incentives, Conferencing, Exhibitions. ... Type species Drosophila (Musca) funebris Fabricius, 1787 Drosophila is a genus of small flies whose members are often called small fruit flies, or more appropriately vinegar flies, wine flies, pomace flies, grape flies, and picked fruit-flies. ... Chromosome 11 is one of the 23 pairs of chromosomes in humans. ...

Several different mutations may affect the PAX6 gene. Some mutations appear to inhibit gene function more than others, with subsequent variability in the severity of the disease. Thus, some aniridic individuals are only missing a relatively small amount of iris, do not have foveal hypoplasia, and retain relatively normal vision. Presumably, the genetic defect in these individuals causes less "heterozygous insufficiency," meaning they retain enough gene function to yield a milder phenotype. This article or section does not cite its references or sources. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ...

• Mendelian Inheritance in Man (OMIM) 106200 AN1
• Mendelian Inheritance in Man (OMIM) 106210 AN2
• Mendelian Inheritance in Man (OMIM) 106220 Aniridia and absent patella
• Mendelian Inheritance in Man (OMIM) 106230 Aniridia, microcornea, and spontaneously reabsorbed cataract
• Mendelian Inheritance in Man (OMIM) 206700 Aniridia, cerebellar ataxia, and mental deficiency (Gillespie syndrome)

The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ...

External links

• Aniridia - Geneva Foundation for Medical Education and Research
• The Aniridia Network
• eMedicine

See also

• WAGR syndrome
• Scleral lenses