Many eye diseases have a genetic basis, and most can be caused by mutations in many different genes (extensive genetic heterogeneity). The retinal dystrophies are a good example: More than 200 genes have been identified for the isolated forms (Leber’s congenital amaurosis, retinitis pigmentosa, cone-rod dystrophy, congenital stationary night blindness), and for syndromes that comprise additional dysfunctions or malformations of extraocular tissues and organs. Selecting genes for diagnostic testing has been difficult, and their analysis with the hitherto predominant DNA sequencing method (Sanger sequencing) has been extremely laborious: The phenotype rarely indicates the affected gene, and the contributions of the particular genes to the disease (e.g., to LCA) were largely unknown. Consequently, comprehensive genetic analyses were impossible in most cases. In the recent years, high-throughput sequencing technologies, summarized as next-generation sequencing (NGS), have revolutionized genetic research and, subsequently, genetic diagnostics. The latter has far-reaching implications for the individual management of patients with genetic eye diseases and their families.
Georg Thieme Verlag KG Stuttgart · New York.