Molecular genetics is revolutionizing our understanding of ophthalmic disease

PURPOSE: To inform ophthalmologists of the extraordinary progress in molecular generics that is revolutionizing our understanding of ophthalmic disease and of the crucial role of the clinician in facilitating genetic discovery. METHOD: Review of relevant: articles. RESULTS: Genes for many mendelian-inherited eye diseases have been localized and some identified using three general approaches: positional cloning, which requires no knowledge of underlying pathophysiology; a candidate gene approach, which examines genes based on their likely function; and a positional. candidate approach, which uses map location as well as candidate genes in the linked region to isolate a gene. In positional cloning, once linkage is obtained, the gene can eventually be isolated, cloned, and sequenced and mutations identified, Techniques in molecular biology and other disciplines can then be used to unravel the pathophysiology of a disease. CONCLUSIONS: Molecular genetics is advancing our understanding of the classification and pathophysiology of ophthalmic diseases, The present classification syst em,based largely on clinical description of disease, is being replaced with a more rational classification based on genetic causes.