Hereditary degenerative retinopathies: Optimism for somatic gene therapy

Retinitis pigmentosa comprises a large and exceptionally heterogeneous grou p of hereditary disorders of the retina, iis a result of an extensive inves tigation around the world, primary genetic lesions have been described in m any genes, Some of these genes encode enzymes that are involved in the sign al transduction pathway. On the basis of in vitro functional assays and sta ndard transgenic and knock-out experiments, it has been proposed that norma l cell functions are disrupted because of an abnormal protein-folding and m etabolic errors or structural defects in the membrane. This ultimately lead s to a gene-mediated cell death known as apoptosis, Various gene transfer a pproaches using mouse models further suggest that the degeneration can be r escued to some extent. Although many questions remain to be answered, inves tigations during the last 10 years have enormously increased our understand ing of this exceptionally heterogeneous disorder and give hope for an effec tive gene therapy and a possible cure.