[Genetics of retinal dystrophies--an overview]

Vision requires complex retinal functions, involving multiple genes with different functions. Retinal degeneration results from disturbance of retina-specific processes such as the visual transduction cascade, but also from defects in basic functions such as pre-mRNA splicing and nucleotide synthesis. As a consequence, the retinal dystrophies are genetically extremely heterogeneous (as shown in the table). Thanks to the Human Genome Project, the identification of retinal disease genes and additional loci has skyrocketed. Today, a typical search for the causative gene in a disease-linked genomic interval starts at the computer. Genes from a particular region can be displayed, and multiple gene-specific data such as expression patterns are immediately accessible. Candidate genes can then be investigated in DNA from affected individuals.