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Reviewed March 2006
What is the official name of the OPN1MW gene?
The official name of this gene is “opsin 1 (cone pigments), medium-wave-sensitive.”
OPN1MW is the gene's official symbol. The OPN1MW gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the OPN1MW gene?
The OPN1MW gene provides instructions for making a protein that is essential for normal color vision. This gene is active in the retina, a light-sensitive tissue at the back of the eye. The retina contains two types of light receptor cells called rods and cones. Rods are responsible for vision in low light. Cones provide vision in bright light, including color vision. Three types of cones each contain a special pigment (a photopigment) that is most sensitive to a particular wavelength of light.
The OPN1MW gene produces a photopigment that is more sensitive to light at the middle of the visible spectrum (yellow/green light). Cones with this pigment are usually called middle-wavelength-sensitive or M cones. In response to light at middle wavelengths, the photopigment triggers a series of chemical reactions within an M cone cell. These reactions ultimately alter the cell's electrical charge, generating a signal that is transmitted to the brain. The brain combines input from all three types of cones to produce normal color vision.
The middle-wavelength-sensitive pigment gene (OPN1MW) and long-wavelength-sensitive pigment gene (OPN1LW) are very similar and are located close together on the X chromosome. Most people have one copy of the OPN1LW gene and one or more copies of the OPN1MW gene. A nearby region of DNA, known as the locus control region (LCR), regulates the activity of these genes. Only the two pigment genes nearest the LCR are active in the retina.
Does the OPN1MW gene share characteristics with other genes?
The OPN1MW gene belongs to a family of genes called GPCR (G protein-coupled receptors).
A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? in the Handbook.
How are changes in the OPN1MW gene related to health conditions?
Where is the OPN1MW gene located?
Cytogenetic Location: Xq28
Molecular Location on the X chromosome: base pairs 154,182,595 to 154,196,860
The OPN1MW gene is located on the long (q) arm of the X chromosome at position 28.
More precisely, the OPN1MW gene is located from base pair 154,182,595 to base pair 154,196,860 on the X chromosome.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about OPN1MW?
You and your healthcare professional may find the following resources about OPN1MW helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the OPN1MW gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding OPN1MW?
alanine ; amino acid ; arginine ; cell ; chromosome ; cone cell ; cones ; cysteine ; deficiency ; deletion ; DNA ; gene ; locus ; mutation ; photopigment ; photoreceptor ; pigment ; polymorphism ; protein ; receptor ; retina ; rods ; serine ; spectrum ; tissue
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (6 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.