Insights into EYS-associated retinal dystrophies. From disease spectrum towards genetic therapy

Contains fulltext : 201895.pdf (publisher's version ) (Open Access)Radboud University, 11 april 2019Promotores : Collin, R.W.J., Cremers, F.P.M

EYS mutation update: In silico assessment of 271 reported and 26 novel variants in patients with retinitis pigmentosa

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Extending the Spectrum of EYS-Associated Retinal Disease to Macular Dystrophy

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C2orf71a/pcare1 is important for photoreceptor outer segment morphogenesis and visual function in zebrafish.

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Eyes shut homolog is important for the maintenance of photoreceptor morphology and visual function in zebrafish

Contains fulltext : 194442.pdf (publisher's version ) (Open Access

In vitro and in vivo rescue of aberrant splicing in CEP290-associated LCA by antisense oligonucleotide delivery

Leber congenital amaurosis (LCA) is a severe disorder resulting in visual impairment usually starting in the first year of life. The most frequent genetic cause of LCA is an intronic mutation in CEP290 (c.2991 + 1655A > G) that creates a cryptic splice donor site resulting in the insertion of a pseudoexon (exon X) into CEP290 mRNA. Previously, we showed that naked antisense oligonucleotides (AONs) effectively restored normal CEP290 splicing in patient-derived lymphoblastoid cells. We here explore the therapeutic potential of naked and adeno-associated virus (AAV)-packaged AONs in vitro and in vivo In both cases, AON delivery fully restored CEP290 pre-mRNA splicing, significantly increased CEP290 protein levels and rescued a ciliary phenotype present in patient-derived fibroblast cells. Moreover, administration of naked and AAV-packaged AONs to the retina of a humanized mutant Cep290 mouse model, carrying the intronic mutation, showed a statistically significant reduction of exon X-containing Cep290 transcripts, without compromising the retinal structure. Together, our data highlight the tremendous therapeutic prospective of AONs for the treatment of not only CEP290-associated LCA but potentially many other subtypes of retinal dystrophy caused by splicing mutations

Extending the spectrum of EYS-associated retinal disease to macular dystrophy

PURPOSE. To assess the phenotypic variability and natural course of inherited retinal diseases (IRDs) caused by EYS mutations. METHODS. Multiethnic cohort study (N = 30) with biallelic EYS variants from a clinical IRD database (retinitis pigmentosa [RP], N = 27; cone-rod dystrophy [CRD], N = 1; and macular dystrophy, N = 2). In vitro minigene splice assay was performed to determine the effect on EYS pre-mRNA splicing of the c.1299+5_1299+8del variant in macular dystrophy patients. RESULTS. We found 27 different EYS variants in RP patients and 7 were novel. The rate of visual field loss of the V4e isopter area was -0.84 ± 0.44 ln(deg2) per year, and the rate of visual acuity loss was 0.75 Early Treatment Diabetic Retinopathy Study letters per year. Ellipsoid zone width was correlated with area of the hyperautofluorescent ring, with rs = 0.78 and P A), previously identified in RP patients. Two siblings with macular dystrophy carried compound heterozygous EYS variants: c.1299+5_1299+8del and c.6050G>T. The former was novel and shown to result in skipping of exon 8, and the latter was a known RP variant. CONCLUSIONS. We report on EYS-associated macular dystrophy, extending the spectrum of EYSassociated IRDs. We observed heterogeneity between RP patients in age of onset and disease progression. Identical EYS variants were found in cases with RP, CRD, and macular dystrophy. Screening for EYS variants in CRD and macular dystrophy patients might increase the diagnostic yield in previously unsolved cases