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


Reviewed January 2014

What is the official name of the GRM6 gene?

The official name of this gene is “glutamate receptor, metabotropic 6.”

GRM6 is the gene's official symbol. The GRM6 gene is also known by other names, listed below.

What is the normal function of the GRM6 gene?

The GRM6 gene provides instructions for making a protein called metabotropic glutamate receptor 6 (mGluR6). This protein is a glutamate receptor, which is a type of protein that attaches (binds) to the signaling molecule glutamate on the surface of cells. The mGluR6 protein is found within the membrane that surrounds cells called bipolar cells, which are part of the light-sensitive tissue at the back of the eye (retina). Bipolar cells receive visual signals from cells called rods that are used to see in low light. Rod cells release glutamate, which then binds to mGluR6 on bipolar cells. This binding ultimately triggers bipolar cells to transmit the visual signals to other retinal cells and eventually to the brain.

Does the GRM6 gene share characteristics with other genes?

The GRM6 gene belongs to a family of genes called GPCR (G protein-coupled receptors). It also belongs to a family of genes called GR (glutamate 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 GRM6 gene related to health conditions?

autosomal recessive congenital stationary night blindness - caused by mutations in the GRM6 gene

At least 25 mutations in the GRM6 gene have been found to cause autosomal recessive congenital stationary night blindness, which is characterized by the inability to see in low light and other vision problems such as nearsightedness (myopia). Most GRM6 gene mutations impair the function of the mGluR6 protein by changing single protein building blocks (amino acids) in the protein. These mutations prevent the protein from reaching the cell membrane where it is needed to bind to glutamate. Without any mGluR6 protein at the cell surface, the glutamate released from rod cells in low light is not detected by bipolar cells, so visual signals are not transmitted. The brain does not receive the visual information sent by rods, leading to difficulty seeing in low light.

Where is the GRM6 gene located?

Cytogenetic Location: 5q35

Molecular Location on chromosome 5: base pairs 178,978,327 to 178,995,123

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

The GRM6 gene is located on the long (q) arm of chromosome 5 at position 35.

The GRM6 gene is located on the long (q) arm of chromosome 5 at position 35.

More precisely, the GRM6 gene is located from base pair 178,978,327 to base pair 178,995,123 on chromosome 5.

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

Where can I find additional information about GRM6?

You and your healthcare professional may find the following resources about GRM6 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 GRM6 gene or gene products?

  • GPRC1F
  • metabotropic glutamate receptor 6
  • mGlu6
  • MGLUR6

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

What glossary definitions help with understanding GRM6?

acids ; autosomal ; autosomal recessive ; cell ; cell membrane ; congenital ; gene ; molecule ; myopia ; nearsightedness ; photoreceptor ; protein ; receptor ; recessive ; retina ; rods ; tissue

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


  • Beqollari D, Betzenhauser MJ, Kammermeier PJ. Altered G-protein coupling in an mGluR6 point mutant associated with congenital stationary night blindness. Mol Pharmacol. 2009 Nov;76(5):992-7. doi: 10.1124/mol.109.058628. Epub 2009 Aug 7. (
  • Dryja TP, McGee TL, Berson EL, Fishman GA, Sandberg MA, Alexander KR, Derlacki DJ, Rajagopalan AS. Night blindness and abnormal cone electroretinogram ON responses in patients with mutations in the GRM6 gene encoding mGluR6. Proc Natl Acad Sci U S A. 2005 Mar 29;102(13):4884-9. Epub 2005 Mar 21. (
  • NCBI Gene (
  • Sergouniotis PI, Robson AG, Li Z, Devery S, Holder GE, Moore AT, Webster AR. A phenotypic study of congenital stationary night blindness (CSNB) associated with mutations in the GRM6 gene. Acta Ophthalmol. 2012 May;90(3):e192-7. doi: 10.1111/j.1755-3768.2011.02267.x. Epub 2011 Oct 19. (
  • Wang Q, Gao Y, Li S, Guo X, Zhang Q. Mutation screening of TRPM1, GRM6, NYX and CACNA1F genes in patients with congenital stationary night blindness. Int J Mol Med. 2012 Sep;30(3):521-6. doi: 10.3892/ijmm.2012.1039. Epub 2012 Jun 20. (
  • Zeitz C, Forster U, Neidhardt J, Feil S, Kälin S, Leifert D, Flor PJ, Berger W. Night blindness-associated mutations in the ligand-binding, cysteine-rich, and intracellular domains of the metabotropic glutamate receptor 6 abolish protein trafficking. Hum Mutat. 2007 Aug;28(8):771-80. (
  • Zeitz C, van Genderen M, Neidhardt J, Luhmann UF, Hoeben F, Forster U, Wycisk K, Mátyás G, Hoyng CB, Riemslag F, Meire F, Cremers FP, Berger W. Mutations in GRM6 cause autosomal recessive congenital stationary night blindness with a distinctive scotopic 15-Hz flicker electroretinogram. Invest Ophthalmol Vis Sci. 2005 Nov;46(11):4328-35. (


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: January 2014
Published: February 1, 2016