Evaluating allele-specific invalidation therapies for autosomal dominant CRX mutations
Carriers of dominant CRX pathogenic missense variants can present with different clinical phenotypes: Leber Congenital Amaurosis (LCA), cone-rod dystrophy (CRD) and retinitis pigmentosa (RP). Moreover, individuals with pathogenic variants can be asymptomatic (non-penetrance). Based on preliminary data, we hypothesise that this may be due to aberrant splicing even in the case of missense variants not localized at canonical splice sites. To test this hypothesis, the PhD student (DC10) will develop a CRX minigene assay to investigate the effect on splicing of selected CRX missense variants. In parallel, DC10 will validate splicing effects in iPSC-derived retinal organoids from asymptomatic and symptomatic patients within the same family. Furthermore, DC10 will assay the effect of mutant allele-specific knockdown using CRISPR-Cas9-mediated genome editing and/or ASO-mediated exon skipping to further validate these results and as a potential therapeutic strategy. The work performed by DC10 could provide a prognostic tool for testing the pathogenicity of CRX variants and lead to the development of innovative therapeutics.