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 heterogeneou s group of disorders characterized by preferential loss of macular function and consequently loss of central and color vision. The primary causes lead ing to the degenerative processes are largely unknown although recent progr ess in human molecular genetics is most promising in providing novel insigh ts into the basic biochemical mechanisms of these dystrophies. To date, the disease loci of more than 20 maculopathies including cone and cone-rod dys trophies have been mapped to specific chromosomal regions of which seven di sease genes have already been identified, As the goals nf the Human Genome Initiative approach completion, the cloning of the genes involved in the et iology of human retinopathies will be greatly simplified providing the basi s for a more comprehensive understanding of retinal function and dysfunctio n, In addition, these advances will facilitate the identification of indivi duals at risk at a presymptomatic or initial stage of disease, thus creatin g a unique opportunity to devise novel therapeutic strategies that will pri marily be aimed at an early intervention with the potential to either delay or even prevent the development of disease pathology.