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URL of this page: https://medlineplus.gov/genetics/gene/nyx/

NYX gene

nyctalopin

Normal Function

The NYX gene provides instructions for making a protein called nyctalopin, which plays an important role in a specialized tissue at the back of the eye called the retina. Within the retina, nyctalopin is located on cells called bipolar cells, which relay signals to other retinal cells. The retina contains two types of photoreceptors: rods and cones. Rods are needed for vision in low light. Cones are needed for vision in bright light, including color vision.

Nyctalopin plays a critical role in normal vision. Studies suggest the protein helps relay visual signals from rods and cones to bipolar cells. This signaling is an essential step in the transmission of visual information from the eyes to the brain.

Health Conditions Related to Genetic Changes

X-linked congenital stationary night blindness

Variants (also called mutations) in the NYX gene have been identified in people with X-linked congenital stationary night blindness. NYX gene variants are responsible for the complete form of the disorder, which is characterized by difficulty seeing in low light (night blindness), loss of sharpness (reduced visual acuity), severe nearsightedness (high myopia), involuntary movements of the eyes (nystagmus), and eyes that do not look in the same direction (strabismus).

Many NYX gene variants change single protein building blocks (amino acids) in nyctalopin. NYX gene variants can change the size or shape of the protein or prevent it from attaching to the surface of bipolar cells. A loss of functional nyctalopin disrupts the ability of photoreceptor cells to transmit visual signals to bipolar cells, which impairs vision in people with X-linked congenital stationary night blindness. The rod pathway is severely disrupted, while the function of cones is only mildly affected.

More About This Health Condition

Other disorders

Variants in the NYX gene have been found to cause high myopia without the other vision problems that are characteristic of X-linked congenital stationary night blindness. The variants responsible for high myopia each change a single amino acid in nyctalopin, which produces an unstable protein and leads to vision problems.

Other Names for This Gene

  • CLRP
  • NYX_HUMAN

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases

References

  • Bech-Hansen NT, Naylor MJ, Maybaum TA, Sparkes RL, Koop B, Birch DG, Bergen AA, Prinsen CF, Polomeno RC, Gal A, Drack AV, Musarella MA, Jacobson SG, Young RS, Weleber RG. Mutations in NYX, encoding the leucine-rich proteoglycan nyctalopin, cause X-linked complete congenital stationary night blindness. Nat Genet. 2000 Nov;26(3):319-23. doi: 10.1038/81619. Citation on PubMed
  • Jacobi FK, Andreasson S, Langrova H, Meindl A, Zrenner E, Apfelstedt-Sylla E, Pusch CM. Phenotypic expression of the complete type of X-linked congenital stationary night blindness in patients with different mutations in the NYX gene. Graefes Arch Clin Exp Ophthalmol. 2002 Oct;240(10):822-8. doi: 10.1007/s00417-002-0562-z. Epub 2002 Sep 21. Citation on PubMed
  • Kim AH, Liu PK, Chang YH, Kang EY, Wang HH, Chen N, Tseng YJ, Seo GH, Lee H, Liu L, Chao AN, Chen KJ, Hwang YS, Wu WC, Lai CC, Tsang SH, Hsiao MC, Wang NK. Congenital Stationary Night Blindness: Clinical and Genetic Features. Int J Mol Sci. 2022 Nov 29;23(23):14965. doi: 10.3390/ijms232314965. Citation on PubMed
  • Leroy BP, Budde BS, Wittmer M, De Baere E, Berger W, Zeitz C. A common NYX mutation in Flemish patients with X linked CSNB. Br J Ophthalmol. 2009 May;93(5):692-6. doi: 10.1136/bjo.2008.143727. Epub 2008 Jul 10. Citation on PubMed
  • MacDonald IM, Hoang S, Tuupanen S. X-Linked Congenital Stationary Night Blindness. 2008 Jan 16 [updated 2019 Jul 3]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from http://www.ncbi.nlm.nih.gov/books/NBK1245/ Citation on PubMed
  • Poopalasundaram S, Erskine L, Cheetham ME, Hardcastle AJ. Focus on molecules: nyctalopin. Exp Eye Res. 2005 Dec;81(6):627-8. doi: 10.1016/j.exer.2005.07.017. Epub 2005 Sep 12. No abstract available. Citation on PubMed
  • Pusch CM, Zeitz C, Brandau O, Pesch K, Achatz H, Feil S, Scharfe C, Maurer J, Jacobi FK, Pinckers A, Andreasson S, Hardcastle A, Wissinger B, Berger W, Meindl A. The complete form of X-linked congenital stationary night blindness is caused by mutations in a gene encoding a leucine-rich repeat protein. Nat Genet. 2000 Nov;26(3):324-7. doi: 10.1038/81627. Citation on PubMed
  • Xiao X, Jia X, Guo X, Li S, Yang Z, Zhang Q. CSNB1 in Chinese families associated with novel mutations in NYX. J Hum Genet. 2006;51(7):634-40. doi: 10.1007/s10038-006-0406-5. Epub 2006 May 3. Citation on PubMed
  • Zeitz C, Robson AG, Audo I. Congenital stationary night blindness: an analysis and update of genotype-phenotype correlations and pathogenic mechanisms. Prog Retin Eye Res. 2015 Mar;45:58-110. doi: 10.1016/j.preteyeres.2014.09.001. Epub 2014 Oct 13. Citation on PubMed
  • Zhang Q, Xiao X, Li S, Jia X, Yang Z, Huang S, Caruso RC, Guan T, Sergeev Y, Guo X, Hejtmancik JF. Mutations in NYX of individuals with high myopia, but without night blindness. Mol Vis. 2007 Mar 1;13:330-6. Citation on PubMed or Free article on PubMed Central
  • Zhou L, Li T, Song X, Li Y, Li H, Dan H. NYX mutations in four families with high myopia with or without CSNB1. Mol Vis. 2015 Mar 5;21:213-23. eCollection 2015. Citation on PubMed

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.