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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed July 2007

What is the official name of the GPR143 gene?

The official name of this gene is “G protein-coupled receptor 143.”

GPR143 is the gene's official symbol. The GPR143 gene is also known by other names, listed below.

What is the normal function of the GPR143 gene?

The GPR143 gene, also known as OA1, provides instructions for making a protein that is involved in the coloring (pigmentation) of the eyes and skin. This protein is made in the light-sensitive tissue at the back of the eye (the retina) and in skin cells. The GPR143 protein is part of a signaling pathway that controls the growth and maturation of melanosomes, which are cellular structures that produce and store a pigment called melanin. Melanin is the substance that gives skin, hair, and eyes their color. In the retina, this pigment also plays a critical role in normal vision.

Does the GPR143 gene share characteristics with other genes?

The GPR143 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 GPR143 gene related to health conditions?

ocular albinism - caused by mutations in the GPR143 gene

More than 60 GPR143 mutations have been identified in people with the most common form of ocular albinism, which is called the Nettleship-Falls type or type 1. Most mutations alter the size or shape of the GPR143 protein. These genetic changes often prevent the abnormal protein from ever reaching melanosomes, where it is needed to control the growth of these pigment-containing structures. In other cases, the GPR143 protein reaches melanosomes normally but mutations prevent the protein from interacting with other molecules in its signaling pathway. Without functional GPR143 protein, melanosomes in skin cells and the retina can grow abnormally large. It is unclear how these giant melanosomes (macromelanosomes) are related to vision loss and other eye abnormalities in people with ocular albinism.

Most forms of albinism result from a reduced amount of melanin pigment within cells. Researchers continue to study why ocular albinism occurs when cells in the retina appear to contain a substantial amount of melanin. It is possible that this pigment is concentrated into a few abnormal macromelanosomes instead of being evenly distributed among many normal-sized melanosomes within the cell. Additional studies may help clarify the relationship between melanosomes, melanin distribution, and the reduced levels of pigmentation that are characteristic of ocular albinism.

Where is the GPR143 gene located?

Cytogenetic Location: Xp22.3

Molecular Location on the X chromosome: base pairs 9,725,413 to 9,765,965

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The GPR143 gene is located on the short (p) arm of the X chromosome at position 22.3.

The GPR143 gene is located on the short (p) arm of the X chromosome at position 22.3.

More precisely, the GPR143 gene is located from base pair 9,725,413 to base pair 9,765,965 on the X chromosome.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about GPR143?

You and your healthcare professional may find the following resources about GPR143 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 GPR143 gene or gene products?

  • GP143_HUMAN
  • OA1
  • ocular albinism 1 (Nettleship-Falls)
  • ocular albinism type 1 protein

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding GPR143?

albinism ; cell ; epithelium ; gene ; melanin ; pigment ; pigmentation ; protein ; receptor ; retina ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Camand O, Boutboul S, Arbogast L, Roche O, Sternberg C, Sutherland J, Levin A, Héon E, Menasche M, Dufier J, Abitbol M. Mutational analysis of the OA1 gene in ocular albinism. Ophthalmic Genet. 2003 Sep;24(3):167-73. (
  • Cortese K, Giordano F, Surace EM, Venturi C, Ballabio A, Tacchetti C, Marigo V. The ocular albinism type 1 (OA1) gene controls melanosome maturation and size. Invest Ophthalmol Vis Sci. 2005 Dec;46(12):4358-64. (
  • Gene Review: Ocular Albinism, X-Linked (
  • Innamorati G, Piccirillo R, Bagnato P, Palmisano I, Schiaffino MV. The melanosomal/lysosomal protein OA1 has properties of a G protein-coupled receptor. Pigment Cell Res. 2006 Apr;19(2):125-35. (
  • Mayeur H, Roche O, Vêtu C, Jaliffa C, Marchant D, Dollfus H, Bonneau D, Munier FL, Schorderet DF, Levin AV, Héon E, Sutherland J, Lacombe D, Said E, Mezer E, Kaplan J, Dufier JL, Marsac C, Menasche M, Abitbol M. Eight previously unidentified mutations found in the OA1 ocular albinism gene. BMC Med Genet. 2006 Apr 28;7:41. (
  • NCBI Gene (
  • Oetting WS. New insights into ocular albinism type 1 (OA1): Mutations and polymorphisms of the OA1 gene. Hum Mutat. 2002 Feb;19(2):85-92. Review. (
  • Schiaffino MV, Tacchetti C. The ocular albinism type 1 (OA1) protein and the evidence for an intracellular signal transduction system involved in melanosome biogenesis. Pigment Cell Res. 2005 Aug;18(4):227-33. Review. (
  • Shen B, Samaraweera P, Rosenberg B, Orlow SJ. Ocular albinism type 1: more than meets the eye. Pigment Cell Res. 2001 Aug;14(4):243-8. Review. (


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.

Reviewed: July 2007
Published: February 8, 2016