Studies of Families With Hereditary Cataracts

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00001609
Recruitment Status : Completed
First Posted : November 4, 1999
Last Update Posted : March 4, 2008
Information provided by:
National Institutes of Health Clinical Center (CC)

Brief Summary:

The objective of this study is to discover the genes responsible for the development of hereditary cataracts in families. A cataract is clouding of the lens of the eye that obstructs the passage of light and may impair vision. Information from this study may provide a better understanding of why hereditary cataracts form and perhaps lead to the development of a test that can predict who will likely be affected and to what degree.

Patients or family members of patients with inherited cataracts who participate in this study will be asked questions about their family history, especially concerning eye disease or cataracts, and a family tree will be drawn. They will undergo a complete eye examination, including photographs to document the clarity or opacity of the lens. In addition, a small blood sample will be drawn for use in gene mapping studies of inherited cataract.

Condition or disease
Cataract Congenital Anomaly

Detailed Description:
Although the etiology of some secondary cataracts is becoming better understood and certain animal models have the promise to elucidate the relationships between lens crystallin and hereditary cataract, little is known about the causes of congenital cataracts in humans. Even the classification of different types of cataracts is cumbersome and imperfect. A better understanding of cataractogenesis will come through an understanding of the molecular components of the lens of the eye and the ways in which lesions of these components are manifested structurally and functionally as opacity of the lens. It is well known that cataracts exhibit marked genetic heterogeneity. In mice and humans, hereditary cataracts have been shown to result from lesions at many distinct loci and those cataracts corresponding to one locus can be morphologically heterogeneous, implying that environmental factors may modify the phenotype of the cataract which a molecular lesion causes. Nonetheless, molecular biological characterization of cataracts in the mouse and guinea pig has suggested that alterations in lens crystallins can cause hereditary cataracts making them reasonable candidate genes for causing hereditary cataracts in humans. In addition, it is apparent that hereditary lesions which mimic or contribute additively to environmental stresses known to cause cataracts might be candidate genes for causing hereditary cataracts. This knowledge increases the feasibility of genetic linkage studies and provides a rationale basis on which to begin the molecular analysis of naturally occurring hereditary cataracts. Therefore, it is the purpose of this protocol to concentrate upon hereditary cataracts.

Study Type : Observational
Enrollment : 1200 participants
Official Title: Clinical and Molecular Studies in Families With Congenital or Hereditary Cataracts
Study Start Date : October 1996
Study Completion Date : March 2003

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Cataract

Information from the National Library of Medicine

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Ages Eligible for Study:   Child, Adult, Older Adult
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

The proband must have documentation of congenital or hereditary cataract.

Patients with cataract due to radiation, steroid, or associated with other ocular diseases such as uveitis, retinitis pigmentosa etc. and age-related cataracts will be excluded.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00001609

United States, Maryland
National Eye Institute (NEI)
Bethesda, Maryland, United States, 20892
Sponsors and Collaborators
National Eye Institute (NEI)

Publications: Identifier: NCT00001609     History of Changes
Other Study ID Numbers: 970009
First Posted: November 4, 1999    Key Record Dates
Last Update Posted: March 4, 2008
Last Verified: March 2003

Keywords provided by National Institutes of Health Clinical Center (CC):
Genetic Analysis
Linkage Analysis
Genomic DNA
Risk Prediction
Pedigree Analysis
Congenital Cataracts
Hereditary Cataracts

Additional relevant MeSH terms:
Congenital Abnormalities
Lens Diseases
Eye Diseases