A Novel Pair of Compound Heterozygous Mutation of EYS in a Han Chinese Family with Retinitis Pigmentosa.

Background: Retinitis pigmentosa (RP) is a complex inherited and progressive degenerative retinal disease. The eyes shut homolog (EYS) is frequently associated with RP is surprisingly high. Exploring the function of EYS is quite difficult due to the unique gene size and species specificity. Gene therapy may provide a breakthrough to treat this disease. Therefore, exploring and clarifying pathogenic mutations of EYS-associated RP has important guiding significance for clinical treatment. Methods: Clinical and molecular genetic data for EYS-associated RP were retrospectively analyzed. Sanger sequencing was applied to identify novel mutations in these patients. Candidate pathogenic variants were subsequently evaluated using bioinformatic tools. Results: A novel pair of compound heterozygous mutations was identified: a novel stop-gain mutation c.2439C>A (p.C813fsX) and a frameshift deletion mutation c.6714delT (p. P2238fsX) of the EYS gene in the RP family. Both of these mutations were rare or absent in the 1000 Genomes Project, dbSNP, and Genome Aggregation Database (gnomAD). These two mutations would result in a lack of multiple functionally important epidermal growth factor-like and Laminin G-like coding regions in EYS. Conclusions: A novel compound heterozygote of the EYS gene in a Chinese family with an autosomal inheritance pattern of RP was identified. Identifying more pathogenic mutations and expanding the mutation spectrum of the EYS gene will contribute to a more comprehensive understanding of the molecular pathogenesis of RP disease that could be gained in the future. It also could provide an important basis for the diagnosis, clinical management, and genetic counseling of the disease.