[Genetic diagnostics of retinal dystrophies : Breakthrough with new methods of DNA sequencing]

Until the mid-2000s, knowledge about the genetic causes of retinal dystrophies was not adequately translated into molecular diagnostics and genetic counselling offered to the patients. Although many genes whose mutations underlie retinal degeneration, e.g., retinitis pigmentosa, Leber congenital amaurosis and cone-rod dystrophies were known, they could not be analyzed on a routine diagnostic basis because DNA sequencing was too expensive and time-consuming. New methods summarized under the term next-generation sequencing (NGS) procedures for high-throughput sequencing have changed this completely. In its initial application in research NGS greatly accelerated the pace of novel disease gene identification: the mutations of most patients with retinal dystrophies can today be found in genes which are known to be associated with the condition. Since approximately 2010, NGS has expanded into routine diagnostics. In most patients, this now enables a genetic diagnosis and therefore specific genetic counselling and medical treatment. Constantly improving bioinformatics and comprehensive databases facilitate the evaluation of the complex NGS data. Nevertheless, profound scientific knowledge regarding the genetics of retinal dystrophies is indispensable to avoid erroneous data interpretation. This is also true for the close interaction between ophthalmologists and medical geneticists.