Recent advances in the molecular genetics of hereditary retinal dystrophies with primary involvement of the macula.

Hereditary dystrophies of the central retina and choroid are a heterogeneous group of disorders characterized by preferential loss of macular function and consequently loss of central and color vision. The primary causes leading to the degenerative processes are largely unknown although recent progress in human molecular genetics is most promising in providing novel insights into the basic biochemical mechanisms of these dystrophies. To date, the disease loci of more than 20 maculopathies including cone and cone-rod dystrophies have been mapped to specific chromosomal regions of which seven disease genes have already been identified. As the goals of the Human Genome Initiative approach completion, the cloning of the genes involved in the etiology of human retinopathies will be greatly simplified providing the basis for a more comprehensive understanding of retinal function and dysfunction. In addition, these advances will facilitate the identification of individuals at risk at a presymptomatic or initial stage of disease, thus creating a unique opportunity to devise novel therapeutic strategies that will primarily be aimed at an early intervention with the potential to either delay or even prevent the development of disease pathology.