Clinical and Genetic Studies in Families With Myopia and Related Diseases

Myopia

Myopia, Nearsightedness

This study will examine the inheritance of myopia in families of various nationalities and ethnic backgrounds to identify gene changes that cause myopia or similar diseases and to better understand these conditions. In patients with myopia, the eye does not focus light accurately on the retina (tissue that lines the back of the eye), so that objects at a distance appear blurry. Myopia may occur alone, with other vision problems such as retinal dislocations, cataract or glaucoma, or with other problems such as joint or skin problems. People with myopia (usually those from families with several affected members) and control subjects with normal vision may be eligible for this study. Each participant undergoes the following procedures: * Blood draw for genetic testing related to the disorders under study * Medical and family history, including drawing a family tree to explore vision problems in the family * Complete eye examination, including refraction (pupil dilation) and visual acuity testing, photographs of the retina and possibly lens, and specialized tests to measure field of vision, color vision and ability to see in the dark

Objective: This project, Clinical and Molecular Studies in Families with Myopia and Related Diseases will study the inheritance of myopia in families of many nationalities and ethnic backgrounds in order to identify the genes that, when mutated, cause myopia, high myopia, or similar diseases and the pathophysiology through which they act. Study Population: The number of subjects to be enrolled has no logical upper limit, but will be at least 250 and not more than 2000 during the next 5 years. The study consists of ascertaining individuals and especially families with multiple individuals, affected by myopia or related ocular diseases. Design: These patients and their families will undergo detailed ophthalmological examinations and, where indicated, additional non-investigational examinations to characterize disease in their families and determine their affectation status. A blood sample will be collected from each individual for isolation of DNA and in some individual s biochemical studies or for lymphoblastoid transformation to establish a renewable source of DNA. Linkage analysis, physical mapping, and mutational screening will be carried out to identify the specific the gene and the mutations in it that are associated with myopia in this family. If necessary, the gene product or blood sample will be characterized biochemically. The study will enroll subjects at the NEI and at collaborating centers including the Zhongshan Ophthalmic Center of Sun Yat-Sen University, Guangzhou, China. Outcome Measures: Linkage will be determined using the lod score method and mutations in specific genes will be assessed using a combination of residue conservation, blosum score, and molecular modeling. Biochemical, metabolic, and physiological effects will be individualized to the specific assay.

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China, United States