Study of Usher Syndromes, Type 1 and Type 2

Completed

Conditions studied: Retinitis Pigmentosa

In brief

The purpose of this investigation is to gain additional knowledge about what causes type 1 and type 2 Usher syndrome-inherited diseases that can cause balance problems and impaired hearing and vision-and to develop better diagnostic tests. Patients with type 1 Usher syndrome usually are deaf from birth and have speech and balance problems. Patients with type 2 disease generally are hearing impaired but have no balance problems. All patients develop eye problems that cause difficulty seeing in the dark. The development of newer and more sophisticated diagnostic tests may detect subtle differences in signs and symptoms that allow more accurate distinction between the two types of Usher syndrome. This study will use these tests to classify these syndromes and eventually identify the genes responsible for them. Study participants will have a medical and family history taken and a family tree constructed. They will undergo a thorough eye examination, including special tests of color vision, field of vision, and ability to see in the dark. An electroretinogram will be done to measure the function of cells in the retina, and a procedure called fluorescein angiography will be done to look at and photograph the blood vessels in the retina. Special hearing and balance tests will also done. Hearing tests include physical examination of the ears and wearing earphones while listening to tones. Balance and coordination tests require tasks such as walking in a straight line and standing in the dark with eyes closed. A caloric stimulation test will also be done, in which a small amount of water is irrigated into the ear canal. For gene studies, blood samples will be collected from patients and all available family members.

Key facts

Study ID

NCT00001347

Run by

National Eye Institute (NEI)

People needed

200

Starts

1993-06-01

Expected to finish

2002-08-01

Last updated by the study team

2008-03-04

Who can join

Age: any. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• Patients must have documentation of neurosensory hearing loss and retinitis pigmentosa and fulfill the clinical characteristics (Table) as accepted for USH 1 and USH 2.
• The minimal test battery will identify all patients with USH 1 and USH 2 as well as possible subtypes.
• Candidates will be recruited from lists of patients willing to participate in research studies compiled by the R.P. Foundation, and by referral from their private physicians.
• On occasion additional family members will be studied after an initial individual is ascertained as above.
• No patients with intrauterine and childhood infections, and intrauterine and birth complications can result in trauma to both the auditory or visual system and a positive history for these conditions will necessitate exclusion from the study.

Where it is running

• National Eye Institute (NEI) — Bethesda, Maryland, United States

Full record on ClinicalTrials.gov

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