Genetic diseases of vision.

Among the genetic diseases of vision, retinitis pigmentosa (alone or in combination with systemic afflictions like Usher syndrome, Kearns-Sayre syndrome) deserves special interest because it can be autosomal dominant, autosomal recessive, and X-linked. Leber's hereditary optic neuropathy, the first mitochondrial disease to be defined at the molecular level, manifests at mitochondrial DNA position 11778, but 10 other mutations have recently been found, all residing within mitochondrial DNA-encoded respiratory chain polypeptides. The analysis of Leber's optic neuropathy mutations has provided new important insight into the phenotypic expression of mitochondrial DNA mutations. Some rarer hereditary diseases of vision such as Cone dystrophy, dominant optic atrophy, Leber's congenital amaurosis, Stargardt maculopathy, and choroideremia are discussed.