The genetic diagnosis of inherited retinal dystrophies has been deeply hampered by the extreme genetic and allelic heterogeneity of this group of disorders, with most families bearing rare or private pathogenic variants. Clinicians, patients, and the affected families are becoming aware of the benefits of a reliable molecular diagnosis: it facilitates genetic counseling and prenatal screening, improves the clinical diagnosis – providing prognostic information as genotype–phenotype correlations are being drawn, opens new venues for basic research, and guides therapy as the current clinical trials for retinal disorders are mainly gene-specific. The wide range of high-throughput techniques, now increasingly available and affordable for most laboratories, poses new questions to the clinical geneticists concerning the best approach to accurate genotyping on the basis of efficiency and cost-effectiveness. The comparison between available molecular diagnosis methodologies, in this rapidly moving field, leads to the conclusion that there is not an obvious preferential approach, but a combination of prioritized strategies is at present the optimal choice.
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We would like to acknowledge the generous support from the patients, their families, and patient’s associations, particularly to Andrés Mayor (Fundaluce, Hospital Central de Asturias). E. P. is under contract by CIBERER. This study was supported by grants SAF2009-08079 (Ministerio de Ciencia e Innovación, Gobierno de España) and SGR2009-1427 (Generalitat de Catalunya), CIBERER (U718), Fundaluce and ONCE to R.G.-D. We apologize to all the colleagues whose contributions to the genetic testing of retinal dystrophies could not be quoted due to space limitations.
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