Molecular genetics and prospects for therapy of the inherited retinal dystrophies.

More than 60 genes responsible for human retinal dystrophies have been identified. Those recently isolated include the transcription factor genes NRL and NR2E3, RDH5 (retinol dehydrogenase), EFEMP1 (which encodes an extracellular matrix protein), CRB1, PROML1, RP1, AIPL1 and USH1C (harmonin). The ABCR protein has been identified as a critical transporter in the recycling of retinal (vitamin A). At present, a number of novel therapeutic strategies are being evaluated including pharmacological treatments, cell transplantation and gene therapy. The progress made with such approaches now offers hope to patients with these incurable forms of blindness.