New insights into genetic eye disease.

Most human genetic abnormalities affecting the eye are clinically detectable but, until recently, our knowledge of the genes concerned was sparse. Several genes capable of causing progressive degeneration of the mammalian retina have now been identified by a combination of 'positional cloning' and 'candidate gene' approaches. One of these genes codes for the visual pigment rhodopsin. The identification of two genes (rd and rds) capable of causing retinal degeneration in the mouse has provided candidate genes for similar human disorders.