- Deafness-retinitis pigmentosa syndrome
- Dystrophia retinae pigmentosa-dysostosis syndrome
- Graefe-Usher syndrome
- Hallgren syndrome
- Retinitis pigmentosa - deafness
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People 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 occurs 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 have 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 the first two decades of life, after the development of speech, and progresses over time. By middle age, most affected individuals are profoundly deaf. Vision loss caused by retinitis pigmentosa develops in late childhood or adolescence. People with Usher syndrome type III may also have problems with balance due to inner ear problems. These problems vary among affected individuals.
The Human Phenotype Ontology provides the following list of signs and symptoms for Usher syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.
The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.
The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.
Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
- Usher syndrome. Genetics Home Reference (GHR). February 2007; http://ghr.nlm.nih.gov/condition/usher-syndrome. Accessed 9/20/2011.