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Abstract Age‐related macular degeneration (AMD) is a leading cause of blindness. Vision loss is caused by the retinal pigment epithelium (RPE) and photoreceptors atrophy and/or retinal and choroidal angiogenesis. Here we use AMD patient‐specific RPE cells with the Complement Factor H Y402H high‐risk polymorphism to perform a comprehensive analysis of extracellular vesicles (EVs), their cargo and role in disease pathology. We show that AMD RPE is characterised by enhanced polarised EV secretion. Multi‐omics analyses demonstrate that AMD RPE EVs carry RNA, proteins and lipids, which mediate key AMD features including oxidative stress, cytoskeletal dysfunction, angiogenesis and drusen accumulation. Moreover, AMD RPE EVs induce amyloid fibril formation, revealing their role in drusen formation. We demonstrate that exposure of control RPE to AMD RPE apical EVs leads to the acquisition of AMD features such as stress vacuoles, cytoskeletal destabilization and abnormalities in the morphology of the nucleus. Retinal organoid treatment with apical AMD RPE EVs leads to disrupted neuroepithelium and the appearance of cytoprotective alpha B crystallin immunopositive cells, with some co‐expressing retinal progenitor cell markers Pax6/Vsx2, suggesting injury‐induced regenerative pathways activation. These findings indicate that AMD RPE EVs are potent inducers of AMD phenotype in the neighbouring RPE and retinal cells.

Background: Religion/spirituality plays a vital role in most aspects of Muslims' lives. However, there has been little research on the part of religion/spirituality in health professionals' clinical experience with patients with genetic disorders, including long QT syndrome. Methods: This qualitative study explored health professionals' views working in Saudi Arabia concerning the role of Islam in their clinical practice. Semi-structured interviews were undertaken with 12 health professionals from two cardiogenetic centers in Saudi Arabia. Results: The participants included clinical geneticists (4/12), genetic counselor (1/12), molecular geneticists (2/12), cardiologists (3/12), and patient coordinators (2/12). The data were analyzed using thematic analysis, and three main themes were identified: (1) the value attributed to religion/spirituality in the context of genetic counseling, (2) professional and patient-level barriers to formal religious assessment and conversations in the context of genetic counseling, and (3) incorporating religion/spirituality into genetic counseling sessions. Conclusion: The study sheds light on the advantages of using informal religious language to establish rapport and build trust between patients and health professionals in genetic counseling. It also draws attention to the importance of exploring patients' willingness to discuss religious issues. Participants identified a lack of appropriate training as a significant barrier to attending to patients' religious/spiritual needs during genetic counseling. [JBCGenetics 2020; 3(2.000): 60-70]

Abstract Introduction Mutations in pre‐mRNA processing factor 31 (PRPF31), a core protein of the spliceosomal tri‐snRNP complex, cause autosomal‐dominant retinitis pigmentosa (adRP). It has remained an enigma why mutations in ubiquitously expressed tri‐snRNP proteins result in retina‐specific disorders, and so far, the underlying mechanism of splicing factors‐related RP is poorly understood. Methods We used the induced pluripotent stem cell (iPSC) technology to generate retinal organoids and RPE models from four patients with severe and very severe PRPF31‐adRP, unaffected individuals and a CRISPR/Cas9 isogenic control. Results To fully assess the impacts of PRPF31 mutations, quantitative proteomics analyses of retinal organoids and RPE cells were carried out showing RNA splicing, autophagy and lysosome, unfolded protein response (UPR) and visual cycle‐related pathways to be significantly affected. Strikingly, the patient‐derived RPE and retinal cells were characterised by the presence of large amounts of cytoplasmic aggregates containing the mutant PRPF31 and misfolded, ubiquitin‐conjugated proteins including key visual cycle and other RP‐linked tri‐snRNP proteins, which accumulated progressively with time. The mutant PRPF31 variant was not incorporated into splicing complexes, but reduction of PRPF31 wild‐type levels led to tri‐snRNP assembly defects in Cajal bodies of PRPF31 patient retinal cells, altered morphology of nuclear speckles and reduced formation of active spliceosomes giving rise to global splicing dysregulation. Moreover, the impaired waste disposal mechanisms further exacerbated aggregate formation, and targeting these by activating the autophagy pathway using Rapamycin reduced cytoplasmic aggregates, leading to improved cell survival. Conclusions Our data demonstrate that it is the progressive aggregate accumulation that overburdens the waste disposal machinery rather than direct PRPF31‐initiated mis‐splicing, and thus relieving the RPE cells from insoluble cytoplasmic aggregates presents a novel therapeutic strategy that can be combined with gene therapy studies to fully restore RPE and retinal cell function in PRPF31‐adRP patients.

Retinitis pigmentosa (RP) is the most common inherited retinal disease characterized by progressive degeneration of photoreceptors and/or retinal pigment epithelium that eventually results in blindness. Mutations in pre-mRNA processing factors (PRPF3, 4, 6, 8, 31, SNRNP200, and RP9) have been linked to 15–20% of autosomal dominant RP (adRP) cases. Current evidence indicates that PRPF mutations cause retinal specific global spliceosome dysregulation, leading to mis-splicing of numerous genes that are involved in a variety of retina-specific functions and/or general biological processes, including phototransduction, retinol metabolism, photoreceptor disk morphogenesis, retinal cell polarity, ciliogenesis, cytoskeleton and tight junction organization, waste disposal, inflammation, and apoptosis. Importantly, additional PRPF functions beyond RNA splicing have been documented recently, suggesting a more complex mechanism underlying PRPF-RPs driven disease pathogenesis. The current review focuses on the key RP-PRPF genes, depicting the current understanding of their roles in RNA splicing, impact of their mutations on retinal cell’s transcriptome and phenome, discussed in the context of model species including yeast, zebrafish, and mice. Importantly, information on PRPF functions beyond RNA splicing are discussed, aiming at a holistic investigation of PRPF-RP pathogenesis. Finally, work performed in human patient-specific lab models and developing gene and cell-based replacement therapies for the treatment of PRPF-RPs are thoroughly discussed to allow the reader to get a deeper understanding of the disease mechanisms, which we believe will facilitate the establishment of novel and better therapeutic strategies for PRPF-RP patients.

A large-scale DNA-based assay, namely SNaPshot, was developed and validated for the determination of allelic polymorphisms of genes associated with type II diabetes (T2D) mellitus disease in Saudi patients. The new approach is alternative to phenotyping and physiological diagnosis. The assay includes single nucleotide polymorphisms (SNPs) of seven most common genes namely, GNB-3, GCK, SLC30A, KNJ11, TCF7L2, CDKN2A/B and HNF4A. The study proved that the new genotyping assay is rapid, easy to perform and robust for screening of high risk T2D family members. The new assay can be applied in genetic testing as an important tool for identifying significant genetic factors that help in predicting diabetes at early stages of life to avoid subsequent complications. This assay can also be used to evaluate the gene risk variants in populations of other geographic origins.

Mutations in pre-mRNA processing factors cause autosomal dominant retinitis pigmentosa. Here the authors provide insights into the pathophysiological mechanisms underlying non-syndromic retinal disease caused by heterozygous mutations in genes encoding ubiquitously expressed splicing factors.