Clinical Trial: Natural History and Genetic Studies of Usher Syndrome

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Observational

Official Title: Natural History and Genetic Studies of Usher Syndrome

Brief Summary:

This study will explore clinical and genetic aspects of Usher syndrome, an inherited disease causing deafness or impaired hearing, visual problems, and, in some cases, unsteadiness or balance problems. 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. Patients with type 3 disease have progressive hearing loss and balance problems. All patients develop retinitis pigmentosa, an eye disease that causes poor night vision and eventually, blindness.

Patients of any age with Usher syndrome may be eligible for this study. Patients who have had eye and hearing evaluations are asked to send their medical records to the research team at the National Eye Institute (NEI) for review. They are also asked to have a blood sample drawn by a medical professional and sent to NEI for genetic analysis. Finally, they are interviewed about their family histories, particularly about other relative with eye disease. Patients who have not been evaluated previously have the following tests and procedures at NIH:

• Family medical history, especially regarding eye disease. A family tree is drawn.
• Blood draw for genetic studies of Usher syndrome.
• Eye examination to assess visual acuity and eye pressure, and to examine pupils, lens, retina, and eye movements.
• Electroretinogram (ERG) to test the function of visual cells. Wearing eye patches, the patient sits in a dark room for 30 minutes. Electrodes are taped to the forehead and the eye patches are removed. The surface of the eye is numbed with eye drops and contact lenses are placed on the eyes. The patient looks inside a hollow, da
  

  Detailed Summary:

  Background and objectives:

  The Usher syndromes are a group of clinically variable and genetically heterogeneous autosomal recessive syndromes. On the basis of clinical findings, at least three types exist. Patients with Usher type I are born deaf, have vestibular problems, and are thought to perceive night blindness in early childhood. Patients with Usher type II are born with a hearing deficit but are able to develop intelligible speech, do not have balance problems; night vision problems, and visual field changes are noted later. Patients with Usher type III are born with relatively good hearing that deteriorates over a decade or more; they can have progressive balance problems and they report night blindness in childhood or teens. Seven genes have been mapped so far for Usher type I while five of these genes have been identified. For Usher type II, four genes have been mapped and three of these have been identified while there is one cloned gene for Usher type III. Quite a lot of information is still unknown regarding the genetic nature of this syndrome. The picture of the three clinical types of Usher syndrome has also not been well studied up to this point and cross sectional studies seems to be the only source of the information available so far, regarding the natural history of the disease. The aim of this protocol is to better study the natural history of the disease and also make specific genotype-phenotype correlations.

  Study population:

  A total of 200 participants, including patients affected with all three clinical types of Usher syndrome and up to 200 unaffected relatives will be enrolled to the protocol. Unaffected family members, primarily parents and siblings will be enrolled to provide a blood sample when considered helpful for linkage analysis. Family memb
  Sponsor: National Eye Institute (NEI)
  

  Current Primary Outcome: The primary outcomes of interest are the probands genotype and phenotype. [ Time Frame: 1 year ]
  
  

  Original Primary Outcome:
  
  

  Current Secondary Outcome:
  
  

  Original Secondary Outcome:
  
  Information By: National Institutes of Health Clinical Center (CC)
  

  Dates:
  Date Received: March 29, 2005
  Date Started: March 18, 2005
  Date Completion:
  Last Updated: May 9, 2017
  Last Verified: May 3, 2017