Usher syndrome type 2A
Other Names for this Disease
- Usher syndrome type 2
Usher syndrome type 2A is a genetic condition characterized by hearing loss from birth and progressive vision loss that begins in adolescence or adulthood. Vision loss is due to retinitis pigmentosa. 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, vision is further impaired by clouding of the front surface of the eye (cataracts). Hearing loss ranges from mild to severe and mainly affects high tones. The degree of hearing loss varies within and among families with this condition. Unlike other forms of Usher syndrome, people with type 2A do not have difficulties with balance caused by inner ear problems. Usher syndrome type 2A is caused by mutations the USH2A gene and is inherited in an autosomal recessive manner.
Last updated: 9/20/2011
- Usher syndrome. Genetics Home Reference (GHR). February 2007; http://ghr.nlm.nih.gov/condition/usher-syndrome. Accessed 9/20/2011.
- Keats BJB & Lentz J. Usher Syndrome Type II. GeneReviews. December 2010; http://www.ncbi.nlm.nih.gov/books/NBK1341/. Accessed 9/20/2011.
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- Genetics Home Reference (GHR) contains information on Usher syndrome type 2A. This website is maintained by the National Library of Medicine.
- The National Organization for Rare Disorders (NORD) is a federation of more than 130 nonprofit voluntary health organizations serving people with rare disorders. Click on the link to view information on this topic.
- The National Institutes of Health (NIH) has developed an information page on Usher syndrome. To view this information, click on the link above.
- Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
- Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
- PubMed is a searchable database of medical literature and lists journal articles that discuss Usher syndrome type 2A. Click on the link to view a sample search on this topic.