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Disease Profile

Usher syndrome type 2A

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
1-9 / 100 000

3,310 - 29,790

US Estimated

1-9 / 100 000

5,135 - 46,215

Europe Estimated

Age of onset

Infancy

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ICD-10

H35.5

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

USH2A; USH2; US2

Categories

Congenital and Genetic Diseases; Ear, Nose, and Throat Diseases; Eye diseases

Summary

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.[1][2]

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal electroretinogram
0000512
Hemianopia
0012377
Iris hypopigmentation
Light eye color
0007730
Nyctalopia
Night blindness
Night-blindness
Poor night vision

[ more ]

0000662
Scotoma
0000575
Sensorineural hearing impairment
0000407
Visual loss
Loss of vision
Vision loss

[ more ]

0000572
30%-79% of people have these symptoms
Cataract
Clouding of the lens of the eye
Cloudy lens

[ more ]

0000518
Myopia
Close sighted
Near sighted
Near sightedness
Nearsightedness

[ more ]

0000545
5%-29% of people have these symptoms
Abnormality of dental color
Abnormality of tooth color
Abnormality of tooth shade

[ more ]

0011073
Abnormality of dental enamel
Abnormal tooth enamel
Enamel abnormalities
Enamel abnormality

[ more ]

0000682
Anxiety
Excessive, persistent worry and fear
0000739
Aplasia/Hypoplasia of the cerebellum
Absent/small cerebellum
Absent/underdeveloped cerebellum

[ more ]

0007360
Ataxia
0001251
Carious teeth
Dental cavities
Tooth cavities
Tooth decay

[ more ]

0000670
Cerebral cortical atrophy
Decrease in size of the outer layer of the brain due to loss of brain cells
0002120
Depressivity
Depression
0000716
Hallucinations
Hallucination
Sensory hallucination

[ more ]

0000738
Microdontia
Decreased width of tooth
0000691
Nystagmus
Involuntary, rapid, rhythmic eye movements
0000639
Schizophrenia
0100753
Subcortical cerebral atrophy
0012157
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance
0000007
Congenital sensorineural hearing impairment
0008527
Rod-cone dystrophy
0000510

Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

        In-Depth Information

        • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • 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.

          References

          1. Usher syndrome. Genetics Home Reference (GHR). 2016; https://ghr.nlm.nih.gov/condition/usher-syndrome.
          2. Keats BJB & Lentz J. Usher Syndrome Type II. GeneReviews. 2016; https://www.ncbi.nlm.nih.gov/books/NBK1341/.

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