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Usher syndrome

Reviewed February 2007

What is Usher syndrome?

Usher syndrome is a condition characterized by hearing loss or deafness and progressive vision loss. The loss of vision is caused by an eye disease called retinitis pigmentosa (RP), which affects the layer of light-sensitive tissue at the back of the eye (the retina). Vision loss occurs as the light-sensing cells of the retina gradually deteriorate. Night vision loss begins first, followed by blind spots that develop in the side (peripheral) vision. Over time, these blind spots enlarge and merge to produce tunnel vision. In some cases of Usher syndrome, vision is further impaired by clouding of the lens of the eye (cataracts). Many people with retinitis pigmentosa retain some central vision throughout their lives, however.

Researchers have identified three major types of Usher syndrome, designated as types I, II, and III. These types are distinguished by their severity and the age when signs and symptoms appear. Type I is further divided into seven distinct subtypes, designated as types IA through IG. Usher syndrome type II has at least three described subtypes, designated as types IIA, IIB, and IIC.

Individuals with Usher syndrome type I are typically born completely deaf or lose most of their hearing within the first year of life. Progressive vision loss caused by retinitis pigmentosa becomes apparent in childhood. This type of Usher syndrome also includes problems with the inner ear that affect balance. As a result, children with the condition begin sitting independently and walking later than usual.

Usher syndrome type II is characterized by hearing loss from birth and progressive vision loss that begins in adolescence or adulthood. The hearing loss associated with this form of Usher syndrome ranges from mild to severe and mainly affects high tones. Affected children have problems hearing high, soft speech sounds, such as those of the letters d and t. The degree of hearing loss varies within and among families with this condition. Unlike other forms of Usher syndrome, people with type II do not have difficulties with balance caused by inner ear problems.

People with Usher syndrome type III experience progressive hearing loss and vision loss beginning in the first few decades of life. Unlike the other forms of Usher syndrome, infants with Usher syndrome type III are usually born with normal hearing. Hearing loss typically begins during late childhood or adolescence, after the development of speech, and progresses over time. By middle age, most affected individuals are profoundly deaf. Vision loss caused by retinitis pigmentosa also develops in late childhood or adolescence. People with Usher syndrome type III may also experience difficulties with balance due to inner ear problems. These problems vary among affected individuals, however.

How common is Usher syndrome?

Usher syndrome is thought to be responsible for 3 percent to 6 percent of all childhood deafness and about 50 percent of deaf-blindness in adults. Usher syndrome type I is estimated to occur in at least 4 per 100,000 people. It may be more common in certain ethnic populations, such as people with Ashkenazi (central and eastern European) Jewish ancestry and the Acadian population in Louisiana. Type II is thought to be the most common form of Usher syndrome, although the frequency of this type is unknown. Type III Usher syndrome accounts for only a small percentage of all Usher syndrome cases in most populations. This form of the condition is more common in the Finnish population, however, where it accounts for about 40 percent of all cases.

What genes are related to Usher syndrome?

Mutations in the CDH23, CLRN1, GPR98, MYO7A, PCDH15, USH1C, USH1G, and USH2A genes cause Usher syndrome.

The genes related to Usher syndrome provide instructions for making proteins that play important roles in normal hearing, balance, and vision. They function in the development and maintenance of hair cells, which are sensory cells in the inner ear that help transmit sound and motion signals to the brain. In the retina, these genes are also involved in determining the structure and function of light-sensing cells called rods and cones. In some cases, the exact role of these genes in hearing and vision is unknown. Most of the mutations responsible for Usher syndrome lead to a loss of hair cells in the inner ear and a gradual loss of rods and cones in the retina. Degeneration of these sensory cells causes hearing loss, balance problems, and vision loss characteristic of this condition.

Usher syndrome type I can result from mutations in the CDH23, MYO7A, PCDH15, USH1C, or USH1G gene. At least two other unidentified genes also cause this form of Usher syndrome.

Usher syndrome type II is caused by mutations in at least four genes. Only two of these genes, USH2A and GPR98 (also called VLGR1), have been identified.

Mutations in at least two genes are responsible for Usher syndrome type III; however, CLRN1 is the only gene that has been identified.

Related Gene(s)

Changes in these genes are associated with Usher syndrome.

  • CDH23
  • CLRN1
  • GPR98
  • MYO7A
  • PCDH15
  • USH1C
  • USH1G
  • USH2A

How do people inherit Usher syndrome?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of Usher syndrome?

These resources address the diagnosis or management of Usher syndrome and may include treatment providers.

  • Gene Review: Usher Syndrome Type I (http://www.ncbi.nlm.nih.gov/books/NBK1265)
  • Gene Review: Usher Syndrome Type I (http://www.ncbi.nlm.nih.gov/books/NBK1265)
  • Gene Review: Usher Syndrome Type II (http://www.ncbi.nlm.nih.gov/books/NBK1341)
  • Gene Review: Usher Syndrome Type II (http://www.ncbi.nlm.nih.gov/books/NBK1341)
  • Genetic Testing Registry: Retinitis pigmentosa-deafness syndrome (http://www.ncbi.nlm.nih.gov/gtr/conditions/C0271097)
  • Genetic Testing Registry: Usher syndrome, type 1 (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1568247)
  • Genetic Testing Registry: Usher syndrome, type 1C (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1848604)
  • Genetic Testing Registry: Usher syndrome, type 1D (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1832845)
  • Genetic Testing Registry: Usher syndrome, type 1E (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1865865)
  • Genetic Testing Registry: Usher syndrome, type 1F (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1865885)
  • Genetic Testing Registry: Usher syndrome, type 1G (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1847089)
  • Genetic Testing Registry: Usher syndrome, type 2A (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1848634)
  • Genetic Testing Registry: Usher syndrome, type 2C (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1854237)
  • Genetic Testing Registry: Usher syndrome, type 3 (http://www.ncbi.nlm.nih.gov/gtr/conditions/C1568248)
  • Genetic Testing Registry: Usher syndrome type ID/F, CDH23/PCDH15, digenic (http://www.ncbi.nlm.nih.gov/gtr/conditions/CN121478)
  • MedlinePlus Encyclopedia: Retinitis pigmentosa (http://www.nlm.nih.gov/medlineplus/ency/article/001029.htm)

You might also find information on the diagnosis or management of Usher syndrome in Educational resources (http://www.ghr.nlm.nih.gov/condition/usher-syndrome/show/Educational+resources) and Patient support (http://www.ghr.nlm.nih.gov/condition/usher-syndrome/show/Patient+support).

General information about the diagnosis (http://ghr.nlm.nih.gov/handbook/consult/diagnosis) and management (http://ghr.nlm.nih.gov/handbook/consult/treatment) of genetic conditions is available in the Handbook. Read more about genetic testing (http://ghr.nlm.nih.gov/handbook/testing), particularly the difference between clinical tests and research tests (http://ghr.nlm.nih.gov/handbook/testing/researchtesting).

To locate a healthcare provider, see How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

Where can I find additional information about Usher syndrome?

You may find the following resources about Usher syndrome helpful. These materials are written for the general public.

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for Usher syndrome?

  • Deafness-retinitis pigmentosa syndrome
  • dystrophia retinae pigmentosa-dysostosis syndrome
  • Graefe-Usher syndrome
  • Hallgren syndrome
  • Retinitis pigmentosa-deafness syndrome
  • Usher's syndrome

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines (http://ghr.nlm.nih.gov/ConditionNameGuide) and How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about Usher syndrome?

Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).

What glossary definitions help with understanding Usher syndrome?

autosomal ; autosomal recessive ; cell ; cones ; gene ; hair cells ; inherited ; loss of hair ; peripheral ; population ; recessive ; retina ; rods ; sensory cells ; syndrome ; tissue

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Adato A, Vreugde S, Joensuu T, Avidan N, Hamalainen R, Belenkiy O, Olender T, Bonne-Tamir B, Ben-Asher E, Espinos C, Millán JM, Lehesjoki AE, Flannery JG, Avraham KB, Pietrokovski S, Sankila EM, Beckmann JS, Lancet D. USH3A transcripts encode clarin-1, a four-transmembrane-domain protein with a possible role in sensory synapses. Eur J Hum Genet. 2002 Jun;10(6):339-50. (http://www.ncbi.nlm.nih.gov/pubmed/12080385?dopt=Abstract)
  • Ahmed ZM, Riazuddin S, Riazuddin S, Wilcox ER. The molecular genetics of Usher syndrome. Clin Genet. 2003 Jun;63(6):431-44. Review. (http://www.ncbi.nlm.nih.gov/pubmed/12786748?dopt=Abstract)
  • Astuto LM, Weston MD, Carney CA, Hoover DM, Cremers CW, Wagenaar M, Moller C, Smith RJ, Pieke-Dahl S, Greenberg J, Ramesar R, Jacobson SG, Ayuso C, Heckenlively JR, Tamayo M, Gorin MB, Reardon W, Kimberling WJ. Genetic heterogeneity of Usher syndrome: analysis of 151 families with Usher type I. Am J Hum Genet. 2000 Dec;67(6):1569-74. Epub 2000 Nov 1. (http://www.ncbi.nlm.nih.gov/pubmed/11060213?dopt=Abstract)
  • Boëda B, El-Amraoui A, Bahloul A, Goodyear R, Daviet L, Blanchard S, Perfettini I, Fath KR, Shorte S, Reiners J, Houdusse A, Legrain P, Wolfrum U, Richardson G, Petit C. Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle. EMBO J. 2002 Dec 16;21(24):6689-99. (http://www.ncbi.nlm.nih.gov/pubmed/12485990?dopt=Abstract)
  • Eudy JD, Sumegi J. Molecular genetics of Usher syndrome. Cell Mol Life Sci. 1999 Oct 15;56(3-4):258-67. Review. (http://www.ncbi.nlm.nih.gov/pubmed/11212353?dopt=Abstract)
  • Friedman TB, Schultz JM, Ahmed ZM. Usher syndrome type 1: genotype-phenotype relationships. Retina. 2005 Dec;25(8 Suppl):S40-S42. Review. (http://www.ncbi.nlm.nih.gov/pubmed/16374329?dopt=Abstract)
  • Gene Review: Usher Syndrome Type I (http://www.ncbi.nlm.nih.gov/books/NBK1265)
  • Gene Review: Usher Syndrome Type II (http://www.ncbi.nlm.nih.gov/books/NBK1341)
  • Hmani-Aifa M, Ben Arab S, Kharrat K, Orten DJ, Boulila-Elgaied A, Drira M, Hachicha S, Kimberling WJ, Ayadi H. Distinctive audiometric features between USH2A and USH2B subtypes of Usher syndrome. J Med Genet. 2002 Apr;39(4):281-3. (http://www.ncbi.nlm.nih.gov/pubmed/11950859?dopt=Abstract)
  • Keats BJ, Savas S. Genetic heterogeneity in Usher syndrome. Am J Med Genet A. 2004 Sep 15;130A(1):13-6. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15368488?dopt=Abstract)
  • Leroy BP, Aragon-Martin JA, Weston MD, Bessant DA, Willis C, Webster AR, Bird AC, Kimberling WJ, Payne AM, Bhattacharya SS. Spectrum of mutations in USH2A in British patients with Usher syndrome type II. Exp Eye Res. 2001 May;72(5):503-9. (http://www.ncbi.nlm.nih.gov/pubmed/11311042?dopt=Abstract)
  • Pennings RJ, Fields RR, Huygen PL, Deutman AF, Kimberling WJ, Cremers CW. Usher syndrome type III can mimic other types of Usher syndrome. Ann Otol Rhinol Laryngol. 2003 Jun;112(6):525-30. (http://www.ncbi.nlm.nih.gov/pubmed/12834121?dopt=Abstract)
  • Petit C. Usher syndrome: from genetics to pathogenesis. Annu Rev Genomics Hum Genet. 2001;2:271-97. Review. (http://www.ncbi.nlm.nih.gov/pubmed/11701652?dopt=Abstract)
  • Reiners J, Nagel-Wolfrum K, Jürgens K, Märker T, Wolfrum U. Molecular basis of human Usher syndrome: deciphering the meshes of the Usher protein network provides insights into the pathomechanisms of the Usher disease. Exp Eye Res. 2006 Jul;83(1):97-119. Epub 2006 Mar 20. Review. (http://www.ncbi.nlm.nih.gov/pubmed/16545802?dopt=Abstract)
  • Reisser CF, Kimberling WJ, Otterstedde CR. Hearing loss in Usher syndrome type II is nonprogressive. Ann Otol Rhinol Laryngol. 2002 Dec;111(12 Pt 1):1108-11. (http://www.ncbi.nlm.nih.gov/pubmed/12498372?dopt=Abstract)
  • Seeliger M, Pfister M, Gendo K, Paasch S, Apfelstedt-Sylla E, Plinkert P, Zenner HP, Zrenner E. Comparative study of visual, auditory, and olfactory function in Usher syndrome. Graefes Arch Clin Exp Ophthalmol. 1999 Apr;237(4):301-7. (http://www.ncbi.nlm.nih.gov/pubmed/10208263?dopt=Abstract)
  • Weston MD, Eudy JD, Fujita S, Yao S, Usami S, Cremers C, Greenberg J, Ramesar R, Martini A, Moller C, Smith RJ, Sumegi J, Kimberling WJ. Genomic structure and identification of novel mutations in usherin, the gene responsible for Usher syndrome type IIa. Am J Hum Genet. 2000 Apr;66(4):1199-210. Epub 2000 Mar 22. Erratum in: Am J Hum Genet 2000 Jun;66(6):2020. Greenburg J [corrected to Greenberg J]. (http://www.ncbi.nlm.nih.gov/pubmed/10729113?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: February 2007
Published: October 27, 2014