Protocol Details

Molecular Genetics of Retinal Degenerations

This study is currently recruiting participants.

Summary | Eligibility | Citations | Contacts

Summary

Number	05-EI-0143
Sponsoring Institute	National Eye Institute (NEI)
Recruitment Detail	Type: Participants currently recruited/enrolled Gender: Male & Female Min Age: 4 Max Age: N/A
Referral Letter Required	No
Population Exclusion(s)	None
Special Instructions	Currently Not Provided
Keywords	Gene; Mutation; Retina; Bietti; Retnitis Pigmentosa; Molecular; Genetics; Retinal; Degeneration; Usher
Recruitment Keyword(s)	Retinal Degeneration; Retinitis Pigmentosa; RP; Usher Syndrome; USH; Bietti Crystalline Dystrophy; BCD
Condition(s)	Retinal Degeneration; Retinitis Pigmentosa
Investigational Drug(s)	None
Investigational Device(s)	None
Intervention(s)	None
Supporting Site	National Eye Institute

This multinational study will investigate the inheritance of genetic retinal degeneration in families of different nationalities and ethnic backgrounds in order to identify the genes that, when altered, cause retinal degeneration. The retina is a light-sensitive membrane lining the back part of the eye. It relays vision signals to the brain, which the brain interprets into sight. When the retina degenerates, vision is altered and possibly lost. The findings of this study should help improve diagnosis and methods of treatment for these disorders. Participating institutions include: the National Institutes for Health in Bethesda, Maryland; the University of Miami in Florida; the Casey Eye Institute in Portland, Oregon; the Byrd Health Sciences Center in Morgantown, West Virginia; the University of Texas Southwestern Medical School in Dallas, Texas; the University of Tennessee Health Sciences Center in Memphis; the Prasad Eye Institute in Hyderabad, India; National Center of Excellence in Molecular Biology in Lahore, Pakistan; and the Jules Gonin Hospital in Lausanne, Switzerland.

Patients with retinitis pigmentosa and closely related diseases such as Usher syndrome, snowflake vitreoretinal dystrophy and Bietti crystalline dystrophy may be eligible for this study. Participants undergo the following tests and procedures:

-Medical and surgical history, including family history of vision problems.

-Examination to clarify the type of retinal degeneration.

-Eye examination, including tests of color vision, field of vision and ability to see in the dark

-Electroretinogram to test the function of visual cells. For this test, the patient sits in a dark room for 30 minutes with his or her eyes patched. Then, a small electrode (silver disk) is taped to the forehead and the eye patches are removed. The surface the eyes is numbed with eye drops, and contact lenses are placed on the eyes. The patient looks inside a large dark globe that emits a series of light flashes. Then a light is turned on inside the globe and more lights flash. The contact lenses sense small electrical signals generated by the retina when the light flashes.

-Hearing tests for patients with a personal or family history of deafness. Tests include an audiogram, ear examination and test of middle ear function. For middle ear function testing, the patient feels a little air pressure change for a moment and hears some tones. Another test requires the patient to sit quietly with electrodes on the head, forehead and earlobes.

-Balance testing, including walking in a straight line, standing with eyes closed in the dark and other tests of coordination, and caloric testing. For the caloric testing, any ear wax in the ear canal is removed before the test begins. Then, electrodes are placed on the skin near the eyes and on the forehead. A small amount of cool (sometimes cold) or warm water is instilled into each ear canal, first one and then the other.

-Blood sample collection for genetic testing.

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Eligibility

INCLUSION CRITERIA:

Patients that meet diagnostic criteria for specific retinal degenerations will be recruited from the NEI and collaborating clinics.

Subjects with the following will be recruited:

1. Individuals or family members of individuals with Retinal degenerations, either congenital, childhood, or age related.

2. Adults must be capable of providing their own consent.

3. All subjects must be able to cooperate with study examination and phlebotomy.

4. Older than 4 years of age.

EXCLUSION CRITERIA:

1. Diseases, infections, or trauma that mimic primary retinal degenerations.

2. Children requiring sedation for study procedures.

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Citations:

Smith RJ, Pelias MZ, Daiger SP, Keats B, Kimberling W, Hejtmancik JF. Clinical variability and genetic heterogeneity within the Acadian Usher population. Am J Med Genet. 1992 Aug 1;43(6):964-9.

Keats BJ, Todorov AA, Atwood LD, Pelias MZ, Hejtmancik JF, Kimberling WJ, Leppert M, Lewis RA, Smith RJ. Linkage studies of Usher syndrome type 1: exclusion results from the Usher syndrome consortium. Genomics. 1992 Nov;14(3):707-14.

Smith RJ, Lee EC, Kimberling WJ, Daiger SP, Pelias MZ, Keats BJ, Jay M, Bird A, Reardon W, Guest M, et al. Localization of two genes for Usher syndrome type I to chromosome 11. Genomics. 1992 Dec;14(4):995-1002.

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Contacts:

Principal Investigator	Referral Contact	For more information:
James F. Hejtmancik, M.D. National Eye Institute (NEI) National Institutes of Health Building 10 Room 10B10 10 Center Drive MSC 1860 Bethesda, Maryland 20892-1860 (301) 435-1598 jh1b@nih.gov	James F. Hejtmancik, M.D. National Eye Institute (NEI) National Institutes of Health Building 10 Room 10B10 10 Center Drive MSC 1860 Bethesda, Maryland 20892-1860 (301) 435-1598 jh1b@nih.gov	Patient Recruitment and Public Liaison Office Building 61 10 Cloister Court Bethesda, Maryland 20892-4754 Toll Free: 1-800-411-1222 TTY: 301-594-9774 (local),1-866-411-1010 (toll free) Fax: 301-480-9793 prpl@mail.cc.nih.gov

Clinical Trials Number:

NCT00231010

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