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


Reviewed October 2008

What is the official name of the PRPH2 gene?

The official name of this gene is “peripherin 2 (retinal degeneration, slow).”

PRPH2 is the gene's official symbol. The PRPH2 gene is also known by other names, listed below.

What is the normal function of the PRPH2 gene?

The PRPH2 gene (also known as RDS) provides instructions for making a protein called peripherin 2. This protein plays an important role in normal vision. Peripherin 2 is found in the retina, the light-sensitive tissue that lines the back of the eye. This protein is essential for the normal function of specialized cells called photoreceptors that detect light and color. Within these cells, peripherin 2 is involved in the formation and stability of structures that contain light-sensing pigments.

How are changes in the PRPH2 gene related to health conditions?

vitelliform macular dystrophy - caused by mutations in the PRPH2 gene

Mutations in the PRPH2 gene are responsible for some cases of adult-onset vitelliform macular dystrophy. Several mutations have been identified in people with this disorder, most of which change a single protein building block (amino acid) in peripherin 2. These mutations alter the protein's structure or lead to the production of an abnormally short, nonfunctional version of the protein. When peripherin 2 is altered or missing, photoreceptors break down (degenerate) over time. This loss of photoreceptors underlies the retinal abnormalities and progressive vision loss characteristic of vitelliform macular dystrophy. It is unclear why PRPH2 mutations affect only central vision in people with this disorder.

other retinal dystrophies - caused by mutations in the PRPH2 gene

Mutations in the PRPH2 gene cause a variety of other retinal disorders. Each of these conditions involves a slow degeneration of photoreceptor cells, leading to progressive vision loss. A total of more than 100 mutations in the PRPH2 gene have been identified. Many of these mutations cause autosomal dominant retinitis pigmentosa, an eye disease that first disrupts night vision and side (peripheral) vision and eventually may result in blindness. PRPH2 mutations also cause a group of retinal disorders called pattern dystrophies of the retinal pigment epithelium. These disorders typically begin in mid-adulthood and are characterized by an abnormal buildup of pigment in cells underlying the retina.

Some PRPH2 mutations can cause different eye disorders in affected members of the same family. For example, researchers have reported a family with retinitis pigmentosa, pattern dystrophy of the retinal pigment epithelium, and retinitis punctata albescens (an eye disorder similar to retinitis pigmentosa) in different individuals with the same PRPH2 mutation. It is unclear why mutations in this gene cause such a wide range of retinal abnormalities.

Where is the PRPH2 gene located?

Cytogenetic Location: 6p21.1

Molecular Location on chromosome 6: base pairs 42,696,595 to 42,722,989

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

The PRPH2 gene is located on the short (p) arm of chromosome 6 at position 21.1.

The PRPH2 gene is located on the short (p) arm of chromosome 6 at position 21.1.

More precisely, the PRPH2 gene is located from base pair 42,696,595 to base pair 42,722,989 on chromosome 6.

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

Where can I find additional information about PRPH2?

You and your healthcare professional may find the following resources about PRPH2 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 PRPH2 gene or gene products?

  • CACD2
  • peripherin 2, homolog of mouse
  • peripherin, photoreceptor type
  • RDS
  • retinal degeneration, slow
  • retinal degeneration slow protein
  • Tetraspanin-22
  • TSPAN22

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

What glossary definitions help with understanding PRPH2?

amino acid ; autosomal ; autosomal dominant ; epithelium ; gene ; mutation ; peripheral ; photoreceptor ; pigment ; protein ; retina ; tissue

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


  • Boon CJ, den Hollander AI, Hoyng CB, Cremers FP, Klevering BJ, Keunen JE. The spectrum of retinal dystrophies caused by mutations in the peripherin/RDS gene. Prog Retin Eye Res. 2008 Mar;27(2):213-35. doi: 10.1016/j.preteyeres.2008.01.002. Epub 2008 Jan 26. Review. (
  • Chung M, Lotery AJ. Genetics update of macular diseases. Ophthalmol Clin North Am. 2002 Dec;15(4):459-65. Review. (
  • Felbor U, Schilling H, Weber BH. Adult vitelliform macular dystrophy is frequently associated with mutations in the peripherin/RDS gene. Hum Mutat. 1997;10(4):301-9. (
  • Francis PJ, Schultz DW, Gregory AM, Schain MB, Barra R, Majewski J, Ott J, Acott T, Weleber RG, Klein ML. Genetic and phenotypic heterogeneity in pattern dystrophy. Br J Ophthalmol. 2005 Sep;89(9):1115-9. (
  • Michaelides M, Holder GE, Bradshaw K, Hunt DM, Moore AT. Cone-rod dystrophy, intrafamilial variability, and incomplete penetrance associated with the R172W mutation in the peripherin/RDS gene. Ophthalmology. 2005 Sep;112(9):1592-8. (
  • NCBI Gene (
  • Sohocki MM, Daiger SP, Bowne SJ, Rodriquez JA, Northrup H, Heckenlively JR, Birch DG, Mintz-Hittner H, Ruiz RS, Lewis RA, Saperstein DA, Sullivan LS. Prevalence of mutations causing retinitis pigmentosa and other inherited retinopathies. Hum Mutat. 2001;17(1):42-51. (
  • Wang Q, Chen Q, Zhao K, Wang L, Wang L, Traboulsi EI. Update on the molecular genetics of retinitis pigmentosa. Ophthalmic Genet. 2001 Sep;22(3):133-54. Review. (
  • Wells J, Wroblewski J, Keen J, Inglehearn C, Jubb C, Eckstein A, Jay M, Arden G, Bhattacharya S, Fitzke F, et al. Mutations in the human retinal degeneration slow (RDS) gene can cause either retinitis pigmentosa or macular dystrophy. Nat Genet. 1993 Mar;3(3):213-8. (
  • Yang Z, Lin W, Moshfeghi DM, Thirumalaichary S, Li X, Jiang L, Zhang H, Zhang S, Kaiser PK, Traboulsi EI, Zhang K. A novel mutation in the RDS/Peripherin gene causes adult-onset foveomacular dystrophy. Am J Ophthalmol. 2003 Feb;135(2):213-8. (
  • Yang Z, Li Y, Jiang L, Karan G, Moshfeghi D, O'Connor S, Li X, Yu Z, Lewis H, Zack D, Jacobson S, Zhang K. A novel RDS/peripherin gene mutation associated with diverse macular phenotypes. Ophthalmic Genet. 2004 Jun;25(2):133-45. (
  • Zhang K, Garibaldi DC, Li Y, Green WR, Zack DJ. Butterfly-shaped pattern dystrophy: a genetic, clinical, and histopathological report. Arch Ophthalmol. 2002 Apr;120(4):485-90. (


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: October 2008
Published: February 1, 2016