Clinical Implication of Retinitis Pigmentosa Molecular Diagnostic Using High Throughput Sequencing.

The retinitis pigmentosa (RP) are genetic conditions that cause retinal degeneration leading to severe low vision and is the leading cause of consultation in reference centers dedicated to the ophthalmic genetics. These rare diseases are characterized by a triple heterogeneity (clinical, genetic and molecular), which made them unreachable by traditional molecular diagnostic sequencing technology by the large number of genes to be tested (> 190).

The advent of high-throughput sequencing (NGS) and targeted capture has opened unexpected possibilities of investigation and ultimately to improve the care of patients. This project aims to study the genetic and molecular epidemiology of an interregional french (grand EST) cohort of patients. Patients receive a detailed retinal phenotype (visual acuity, visual field, photographs of the fundus and ERG). Their DNA will be analyzed by NGS targets the 190 known genes (https://sph.uth.edu/retnet/).

This research will provide a molecular epidemiological cohort study compared to prior publications on the frequency of genes involved. The benefit for patients is important to: establish a mode of transmission of the disease and optimize genetic counseling (currently very empirical); establish phenotype-genotype correlations in the French population (very few studies to date) and from the data of international literature; identify patients likely to be included in future therapeutic protocols of research; identify patients with significant potential for future projects to identify new genes.

The primary purpose of the protocol is to use high throughput sequencing to identify pathogenic variants in genes involved in RP.

The secondary purposes will be the following:

• Determining the diagnostic yield
• Study the genotype-phenotype correlation.

The secondary purposes will be the following:

• Determining the diagnostic yield
• Study the genotype-phenotype correlation