Recent advances in the molecular genetics of retinitis pigmentosa.

In recent years a rapid development in gene cloning techniques has been seen which has, in part, been responsible for the elucidation of the molecular mechanisms involved in many hereditary diseases. Most noteworthy is the rapid detection of mutations in various genes Most noteworthy is the rapid detection of mutations in various genes associated with various retinal degenerations and disorders. There is an increasing need for ophthalmologists to keep abreast with these new developments to better understand disease processes and recognize new opportunities for the diagnosis and treatment of these conditions. In addition, more recent discoveries in molecular genetics have revealed previously unrecognized associations between different clinical entities that share common gene mutations (gene sharing), as well as distinctly different molecular alterations within the spectrum of what traditionally was believed to be the same disease (locus heterogeneity). These findings will most likely, in the future, invoke the need to redefine disease categories at the molecular level. This article reviews basic molecular genetics useful to ophthalmologists and examines in detail these concepts with regard to one representative hereditary retinal disease--retinitis pigmentosa.