Update on ophthalmic molecular genetics

Abstract

Abstract Purpose To provide an overview of the recent technological advances in human molecular genetics that can be applied in ophthalmic genetics. Methods Since the finalization of the Human Genome Project many novel genomic technologies emerged that led to significant advances in gene identification and genetic testing of hereditary eye disorders: (1) genomewide copy number screening (array CGH); (2) genomewide SNP genotyping; (3) next‐generation sequencing. Results (1) Microarray comparative genomic hybridisation or array CGH allows genomewide discovery of submicroscopic deletions and duplications in a single experiment. This technique is applied in routine molecular cytogenetic testing. Using array CGH a causal genomic defect can be found in at least 10% of all cases with mental retardation and/or multiple congenital anomalies. In ophthalmic genetics array CGH is mainly useful in the context of developmental eye disorders, with chorioretinal coloboma and anterior segment dysgenesis as an example. (2) Genomewide chip‐based SNP genotyping can be used for homozygosity mapping in inbred and outbred pedigrees. Recent successes in gene identification using this approach are illustrated. (3) Next‐generation sequencing or NGS. The application of this technology in gene identification and genetic testing of genetically heterogeneous conditions (with LCA as a paradigm) is discussed. Conclusion The rapid progress of genomic technologies such as array CGH, SNP chip analysis and next‐generation sequencing lead to a boost in gene identification and genetic testing of both developmental and retinal eye disease.