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Li S, Jiang Y, Zhang L, Yan W, Wei D, Zhang M, Zhu B, Chen T, Wang X, Zhang Z, Su Y. A New Mouse Model for Usher Syndrome Crossing Kunming Mice with CBA/J Mice. Gene 2024; 922:148562. [PMID: 38754567 DOI: 10.1016/j.gene.2024.148562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 04/06/2024] [Accepted: 05/13/2024] [Indexed: 05/18/2024]
Abstract
BACKGROUND Previously, we discovered a strain of Kunming mice, referred to as the KMush/ush strain, that exhibited notably abnormal electroretinogram (ERG) readings and elevated thresholds for auditory brainstem responses (ABRs), which resembled the characteristics of Usher Syndrome (USH). We successfully identified the pathogenic genes, Pde6b and Adgrv1, after KMush/ush crossbred with CBA/CaJ mice, referred to as CBA-1ush/ush, CBA-2ush/ush or CBA-2ush/ush. In this investigation, we crossbred KMush/ush and CBA/J mice to establish novel recombinant inbred lines and analysed their phenotypic and genotypic characteristics. METHODS ERG readings, ABR testing, fundus morphology, histological examination of the retina and inner ear, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, western blotting, DNA sequence analysis and behavioural experiments were performed to assess the phenotypes and genotypes of the progeny lines. RESULTS No obvious waveforms in the ERG were detected in F1 hybrid mice while normal ABR results were recorded. The F2 hybrids, which were called J1ush/ush or J2ush/ush, exhibited segregated hearing-loss phenotypes. J1ush/ush mice had a retinitis pigmentosa (RP) phenotype with elevated ABR thresholds, whereas J2ush/ush mice exhibited only the RP phenotype. Interestingly, J1ush/ush mice showed significantly higher ABR thresholds than wild-type mice at 28 days post born (P28), and RT-qPCR and DNA-sequencing analysis showed that Adgrv1 gene expression was significantly altered in J1ush/ush mice, but histological analysis showed no significant structural changes in the organ of Corti or spiral ganglia. Further elevation of ABR-related hearing thresholds by P56 manifested only as a reduced density of spiral ganglion cells, which differed significantly from the previous pattern of cochlear alterations in CBA-2ush/ush mice. CONCLUSIONS We successfully introduced the hearing-loss phenotype of inbred mice with USH into CBA/J mice, which provides a good animal model for future studies on the important physiological roles of the Adgrv1 gene in inner-ear structure and for therapeutic studies targeting Adgrv1-mutated USH.
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Affiliation(s)
- Shaoheng Li
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China; Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Air Force Medical University, Xi'an 710032, China
| | - Yihong Jiang
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China
| | - Lei Zhang
- Shaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an 710004, Shaanxi Province, China
| | - Weiming Yan
- The 900th Hospital of Joint Logistic Support Force, PLA, Fuzhou 350000, China
| | - Dongyu Wei
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China
| | - Min Zhang
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China
| | - Bin Zhu
- Outpatient Department, General Hospital of Xizang Military Region, Lhasa 850007, China
| | - Tao Chen
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China; Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi'an 710032, China
| | - Xiaocheng Wang
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China; Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi'an 710032, China.
| | - Zuoming Zhang
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China.
| | - Yuting Su
- Center of Clinical Aerospace Medicine, School of Aerospace Medicine, Air Force Medical University, Xi'an 710032, China; Department of Aviation Medicine, Xijing Hospital, Air Force Medical University, Xi'an 710032, China.
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Heyang M, Warren JL, Ocieczek P, Duncan JL, Moosajee M, Del Priore LV, Shen LL. Long-term natural history of ellipsoid zone width in USH2A-retinopathy. Br J Ophthalmol 2024:bjo-2024-325323. [PMID: 39103200 DOI: 10.1136/bjo-2024-325323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 07/20/2024] [Indexed: 08/07/2024]
Abstract
AIMS To investigate the long-term natural history of ellipsoid zone (EZ) width in USH2A-retinopathy. METHODS EZ width measurements from optical coherence tomography were retrospectively obtained from 110 eyes of 55 participants with molecularly confirmed biallelic USH2A-retinopathy. We used a hierarchical Bayesian method to construct and compare different mathematical models describing the long-term decline of EZ width. RESULTS Compared with linear and quadratic models, exponential decline best represented the long-term loss of EZ width based on the deviance information criterion score. Log-transformed EZ width declined linearly over 30 years of inferred disease duration (median: 0.063 (IQR: 0.040-0.086) log (µm)/year). Compared with the raw EZ width decline rate, the log-transformed EZ width decline rate required 48% fewer patients to achieve an identically powered 1-year trial (38 vs 73 participants). Log EZ width decline rate was uncoupled from baseline EZ width (Spearman ρ=-0.18, p=0.06) and age (ρ=-0.10, p=0.31). Eyes with Usher syndrome exhibited earlier median onset ages of macular EZ width loss (18.8 (IQR: 13.1-24.7) vs 28.1 (IQR: 18.5-35.8) years, p<0.001) but comparable log EZ width decline rates (0.060 (IQR: 0.035-0.100) vs 0.065 (IQR: 0.050-0.079) log (µm)/year; p=0.42). CONCLUSIONS EZ width follows an exponential decline in USH2A-retinopathy. Compared with raw EZ width decline rate, log-transformed EZ width decline rate may be a superior endpoint for clinical trials. Syndromic eyes exhibit an earlier onset of macular EZ width loss but progress at comparable rates to non-syndromic eyes.
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Affiliation(s)
- Michael Heyang
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, Connecticut, USA
| | - Joshua L Warren
- Department of Biostatistics, Yale University School of Public Health, New Haven, Connecticut, USA
| | | | - Jacque L Duncan
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, USA
| | - Mariya Moosajee
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- Institute of Ophthalmology, University College London, London, UK
| | - Lucian V Del Priore
- Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, Connecticut, USA
| | - Liangbo Linus Shen
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, USA
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Donato L, Scimone C, Alibrandi S, Vadalà M, Castellucci M, Bonfiglio VME, Scalinci SZ, Abate G, D'Angelo R, Sidoti A. The genomic mosaic of mitochondrial dysfunction: Decoding nuclear and mitochondrial epigenetic contributions to maternally inherited diabetes and deafness pathogenesis. Heliyon 2024; 10:e34756. [PMID: 39148984 PMCID: PMC11324998 DOI: 10.1016/j.heliyon.2024.e34756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2024] [Revised: 07/16/2024] [Accepted: 07/16/2024] [Indexed: 08/17/2024] Open
Abstract
Aims Maternally inherited diabetes and deafness (MIDD) is a complex disorder characterized by multiorgan clinical manifestations, including diabetes, hearing loss, and ophthalmic complications. This pilot study aimed to elucidate the intricate interplay between nuclear and mitochondrial genetics, epigenetic modifications, and their potential implications in the pathogenesis of MIDD. Main methods A comprehensive genomic approach was employed to analyze a Sicilian family affected by clinically characterized MIDD, negative to the only known causative m.3243 A > G variant, integrating whole-exome sequencing and whole-genome bisulfite sequencing of both nuclear and mitochondrial analyses. Key findings Rare and deleterious variants were identified across multiple nuclear genes involved in retinal homeostasis, mitochondrial function, and epigenetic regulation, while complementary mitochondrial DNA analysis revealed a rich tapestry of genetic diversity across genes encoding components of the electron transport chain and ATP synthesis machinery. Epigenetic analyses uncovered significant differentially methylated regions across the genome and within the mitochondrial genome, suggesting a nuanced landscape of epigenetic modulation. Significance The integration of genetic and epigenetic data highlighted the potential crosstalk between nuclear and mitochondrial regulation, with specific mtDNA variants influencing methylation patterns and potentially impacting the expression and regulation of mitochondrial genes. This pilot study provides valuable insights into the complex molecular mechanisms underlying MIDD, emphasizing the interplay between nucleus and mitochondrion, tracing the way for future research into targeted therapeutic interventions and personalized approaches for disease management.
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Affiliation(s)
- Luigi Donato
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
- Department of Biomolecular Strategies, Genetics and Cutting-edge Therapies, I.E.ME.S.T., Palermo, 90139, Italy
| | - Concetta Scimone
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
- Department of Biomolecular Strategies, Genetics and Cutting-edge Therapies, I.E.ME.S.T., Palermo, 90139, Italy
| | - Simona Alibrandi
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
- Department of Biomolecular Strategies, Genetics and Cutting-edge Therapies, I.E.ME.S.T., Palermo, 90139, Italy
| | - Maria Vadalà
- Department of Biomolecular Strategies, Genetics and Cutting-edge Therapies, I.E.ME.S.T., Palermo, 90139, Italy
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), Ophthalmology Institute, University of Palermo, 90143, Palermo, Italy
| | - Massimo Castellucci
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), Ophthalmology Institute, University of Palermo, 90143, Palermo, Italy
| | - Vincenza Maria Elena Bonfiglio
- Department of Biomedicine, Neuroscience and Advanced Diagnostic (BIND), Ophthalmology Institute, University of Palermo, 90143, Palermo, Italy
| | | | - Giorgia Abate
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
| | - Rosalia D'Angelo
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
| | - Antonina Sidoti
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, Division of Medical Biotechnologies and Preventive Medicine, University of Messina, Messina, 98125, Italy
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Zhuri D, Guler HS, Yalcintepe S, Demir S, Atli E, Atli EI, Gurkan H. Investigation of Targeted Genes and Identification of Novel Variants with Next Generation Sequencing Method in Hearing Loss. J Int Adv Otol 2024; 20:312-324. [PMID: 39161163 PMCID: PMC11363168 DOI: 10.5152/iao.2024.22919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 03/10/2024] [Indexed: 08/21/2024] Open
Abstract
Hearing loss is a widespread condition throughout the world. It may affect patients from newborns to the elderly. There are too many reasons for hearing loss, including congenital hearing loss, virus infections, age-related situations, and traumatic situations, which may be related to the immune-mediated system. Fifty percent of hearing loss is related to genetic mutations and defects; genetic causes are highly heterogeneous, so the analysis of new variants are important for diagnosis. We aimed to describe the importance of detected gene variations by using targeted gene panels in the Next-Generation-Sequencing (NGS) platform. Eighty-one hearing loss targeted genes were investigated using Illumina NextSeq550 technology in 100 participants with hearing loss between 2017 and 2022 in our Genetic Diseases Evaluation Center. Targeted genes were performed on 100 patients with hearing loss diagnosis. The total number of detected variants was 77. Forty-seven cases have likely pathogenic/pathogenic variants. Thirty of them have uncertain clinical significance variants, and from the detected variants, 8 are novel. In this research, we highlighted that earlier detection of hearing loss using molecular genetic methods may help us understand the etiology and orient for a better prognosis. Results detected by using the NGS platform can assist and improve the diagnosis. In this study, the diagnostic rate with targeted genes was detected as 35.29%. It has an important role in clinical practice as the recommendation of cochlear implants. Clarifying the genotype and phenotype correlation helps us figure out the etiology of hearing loss and also the worth of genetic counseling in hereditary hearing loss.
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Affiliation(s)
- Drenushe Zhuri
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Hazal Sezginer Guler
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Sinem Yalcintepe
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Selma Demir
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Engin Atli
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Emine Ikbal Atli
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
| | - Hakan Gurkan
- Department of Medical Genetics, Trakya University Faculty of Medicine, Edirne, Türkiye
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Chandrasekhar S, Lin S, Jurkute N, Oprych K, Estramiana Elorrieta L, Schiff E, Malka S, Wright G, Michaelides M, Mahroo OA, Webster AR, Arno G. Investigating Splice Defects in USH2A Using Targeted Long-Read Sequencing. Cells 2024; 13:1261. [PMID: 39120292 PMCID: PMC11311777 DOI: 10.3390/cells13151261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/17/2024] [Accepted: 07/22/2024] [Indexed: 08/10/2024] Open
Abstract
Biallelic variants in USH2A are associated with retinitis pigmentosa (RP) and Type 2 Usher Syndrome (USH2), leading to impaired vision and, additionally, hearing loss in the latter. Although the introduction of next-generation sequencing into clinical diagnostics has led to a significant uplift in molecular diagnostic rates, many patients remain molecularly unsolved. It is thought that non-coding variants or variants of uncertain significance contribute significantly to this diagnostic gap. This study aims to demonstrate the clinical utility of the reverse transcription-polymerase chain reaction (RT-PCR)-Oxford Nanopore Technology (ONT) sequencing of USH2A mRNA transcripts from nasal epithelial cells to determine the splice-altering effect of candidate variants. Five affected individuals with USH2 or non-syndromic RP who had undergone whole genome sequencing were recruited for further investigation. All individuals had uncertain genotypes in USH2A, including deep intronic rare variants, c.8682-654C>G, c.9055+389G>A, and c.9959-2971C>T; a synonymous variant of uncertain significance, c.2139C>T; p.(Gly713=); and a predicted loss of function duplication spanning an intron/exon boundary, c.3812-3_3837dup p.(Met1280Ter). In silico assessment using SpliceAI provided splice-altering predictions for all candidate variants which were investigated using ONT sequencing. All predictions were found to be accurate; however, in the case of c.3812-3_3837dup, the outcome was a complex cryptic splicing pattern with predominant in-frame exon 18 skipping and a low level of exon 18 inclusion leading to the predicted stop gain. This study detected and functionally characterised simple and complex mis-splicing patterns in USH2A arising from previously unknown deep intronic variants and previously reported variants of uncertain significance, confirming the pathogenicity of the variants.
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Affiliation(s)
| | - Siying Lin
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Neringa Jurkute
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Department of Neuro-Ophthalmology, The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
| | - Kathryn Oprych
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Clinical Genetics, St George’s University Hospitals NHS Foundation Trust, London SW17 0QT, UK
| | - Leire Estramiana Elorrieta
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- Section for Paediatrics, Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London W2 1NY, UK
| | - Elena Schiff
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Samantha Malka
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Genevieve Wright
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Omar A. Mahroo
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Department of Ophthalmology, St Thomas’ Hospital, London SE1 7EH, UK
| | - Andrew R. Webster
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Gavin Arno
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
- National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital and the UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Greenwood Genetic Center, Greenwood, SC 29646, USA
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Liu Y, Zong X, Cao W, Zhang W, Zhang N, Yang N. Gene Therapy for Retinitis Pigmentosa: Current Challenges and New Progress. Biomolecules 2024; 14:903. [PMID: 39199291 DOI: 10.3390/biom14080903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 07/14/2024] [Accepted: 07/23/2024] [Indexed: 09/01/2024] Open
Abstract
Retinitis pigmentosa (RP) poses a significant threat to eye health worldwide, with prevalence rates of 1 in 5000 worldwide. This genetically diverse retinopathy is characterized by the loss of photoreceptor cells and atrophy of the retinal pigment epithelium. Despite the involvement of more than 3000 mutations across approximately 90 genes in its onset, finding an effective treatment has been challenging for a considerable time. However, advancements in scientific research, especially in gene therapy, are significantly expanding treatment options for this most prevalent inherited eye disease, with the discovery of new compounds, gene-editing techniques, and gene loci offering hope for more effective treatments. Gene therapy, a promising technology, utilizes viral or non-viral vectors to correct genetic defects by either replacing or silencing disease-causing genes, potentially leading to complete recovery. In this review, we primarily focus on the latest applications of gene editing research in RP. We delve into the most prevalent genes associated with RP and discuss advancements in genome-editing strategies currently employed to correct various disease-causing mutations.
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Affiliation(s)
- Yuchen Liu
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Xin Zong
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Wenye Cao
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Wenxi Zhang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Ningzhi Zhang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
| | - Ning Yang
- Department of Ophthalmology, Renmin Hospital of Wuhan University, Jiefang Road #238, Wuhan 430060, China
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Lin YW, Huang YS, Lin CY, Lin CW, Wu CC, Yang CH, Yang CM, Chen PL, Chen TC. High prevalence of exon-13 variants in USH2A-related retinal dystrophies in Taiwanese population. Orphanet J Rare Dis 2024; 19:238. [PMID: 38879497 PMCID: PMC11179209 DOI: 10.1186/s13023-024-03238-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 06/04/2024] [Indexed: 06/19/2024] Open
Abstract
BACKGROUND Biallelic pathogenic variants in USH2A lead to Usher syndrome or non-syndromic retinitis pigmentosa, and shown to have geographical and ethnical distribution in previous studies. This study provided a deeper understanding of the detailed clinical features using multimodal imaging, genetic spectrum, and genotype-phenotype correlations of USH2A-related retinal dystrophies in Taiwan. RESULTS In our cohort, the mean age at first visit was 47.66 ± 13.54 years, and the mean age at symptom onset, which was referred to the onset of nyctalopia and/or visual field constriction, was 31.21 ± 15.24 years. Among the variants identified, 23 (50%) were missense, 10 (22%) were splicing variants, 8 (17%) were nonsense, and 5 (11%) were frameshift mutations. The most predominant variant was c.2802T>G, which accounted for 21% of patients, and was located in exon 13. Patients with truncated alleles had significantly earlier symptom onset and seemly poorer disease progression regarding visual acuity, ellipsoid zone line length, and hypofluorescent lesions in the macula than those who had the complete gene. However, the clinical presentation revealed similar progression between patients with and without the c.2802T>G variant. During long-term follow-up, the patients had different ellipsoid zone line progression rates and were almost evenly distributed in the fast, moderate, and slow progression subgroups. Although a younger onset age and a smaller baseline intact macular area was observed in the fast progression subgroup, the results showed no significant difference. CONCLUSIONS This is the first cohort study to provide detailed genetic and longitudinal clinical analyses of patients with USH2A-related retinal dystrophies in Taiwan. The mutated allele frequency in exon 13 was high in Taiwan due to the predominant c.2802T>G variant. Moreover, truncated variants greatly impacted disease progression and determined the length of therapeutic windows. These findings provide insight into the characteristics of candidates for future gene therapies.
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Affiliation(s)
- Yu-Wei Lin
- Department of Medical Education, National Taiwan University Hospital, Taipei, Taiwan
| | - Yu-Shu Huang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan
| | - Chien-Yu Lin
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan
| | - Chao-Wen Lin
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan
| | - Chen-Chi Wu
- Department of Otolaryngology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan
| | - Pei-Lung Chen
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.
- Graduate Institute of Medical Genomics and Proteomics, Medical College, National Taiwan University, No. 2, Xuzhou Road, 5F., Taipei, Taiwan.
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan.
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University Hospital, No 7, Chung-Shan S. Rd, Taipei, Taiwan.
- Center of Frontier Medicine, National Taiwan University Hospital, Taipei, Taiwan.
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Parekh B, Duncan JL, Samarakoon L, Melia M, Abalem MF, Andrews CA, Audo I, Ayala AR, Bradley C, Cheetham JK, Dagnelie G, Durham TA, Huckfeldt RM, Lacy GD, Malbin B, Michaelides M, Musch DC, Peck-Dimit N, Stingl K, Weng CY, Zmejkoski AZ, Jayasundera KT. Self-Reported Functional Vision in USH2A-Associated Retinal Degeneration as Measured by the Michigan Retinal Degeneration Questionnaire. Invest Ophthalmol Vis Sci 2024; 65:5. [PMID: 38833260 PMCID: PMC11156206 DOI: 10.1167/iovs.65.6.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/04/2024] [Indexed: 06/06/2024] Open
Abstract
Purpose The purpose of this study was to evaluate self-reported functional vision (FV) and the impact of vision loss in patients with USH2A-associated retinal degeneration using a patient-reported outcome (PRO) measure, the Michigan Retinal Degeneration Questionnaire (MRDQ), to correlate MRDQ scores with well-established visual function measurements. Design An observational cross-sectional study (n = 93) of participants who had Usher Syndrome Type 2 (USH2, n = 55) or autosomal recessive non-syndromic retinitis pigmentosa (ARRP; n = 38) associated with biallelic variants in the USH2A gene. Methods The study protocol was approved by all ethics boards and informed consent was obtained from each participant. Participants completed the MRDQ at the 48-month study follow-up visit. Disease duration was self-reported by participants. One-way ANOVA was used to compare subgroups (clinical diagnosis, age, disease duration, and full-field stimulus threshold [FST] Blue-Red mediation) on mean scores per domain. Spearman correlation coefficients were used to assess associations between MRDQ domains and visual/retinal function assessments. Results Of the study sample, 58% were female participants and the median disease duration was 13 years. MRDQ domains were sensitive to differences between subgroups of clinical diagnosis, age, disease duration, and FST Blue-Red mediation. MRDQ domains correlated with static perimetry, microperimetry, full-field stimulus testing, and best-corrected visual acuity (BCVA). Conclusions Self-reported FV measured by the MRDQ, when applied to USH2 and ARRP participants, had good distributional characteristics and correlated well with visual function tests. MRDQ adds a new dimension of understanding on vision-related functioning and establishes this PRO tool as an informative measure in evaluating USH2A outcomes.
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Affiliation(s)
- Bela Parekh
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
- University of Michigan, Medical School, Ann Arbor, Michigan, United States
| | - Jacque L Duncan
- University of California, San Francisco, San Francisco, California, United States
| | | | - Michele Melia
- Jaeb Center for Health Research, Tampa, Florida, United States
| | - Maria Fernanda Abalem
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Chris A Andrews
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
- Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, Centre de Référence Maladies Rares REFERET and INSERM-DGOS CIC1423, Paris, France
| | - Allison R Ayala
- Jaeb Center for Health Research, Tampa, Florida, United States
| | - Chris Bradley
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States
| | - Janet K Cheetham
- Foundation Fighting Blindness, Columbia, Maryland, United States
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland, United States
| | - Todd A Durham
- Foundation Fighting Blindness, Columbia, Maryland, United States
| | - Rachel M Huckfeldt
- Massachusetts Eye and Ear Institute, Boston, Massachusetts, United States
| | - Gabrielle D Lacy
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Brett Malbin
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
- Department of Ophthalmology, Kresge Eye Institute, Detroit, Michigan, United States
| | - Michel Michaelides
- Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
| | - David C Musch
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, United States
| | - Nicholas Peck-Dimit
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | | | - Alex Z Zmejkoski
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | - K Thiran Jayasundera
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
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9
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Ashworth KE, Weisbrod J, Ballios BG. Inherited Retinal Diseases and Retinal Organoids as Preclinical Cell Models for Inherited Retinal Disease Research. Genes (Basel) 2024; 15:705. [PMID: 38927641 PMCID: PMC11203130 DOI: 10.3390/genes15060705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/28/2024] Open
Abstract
Inherited retinal diseases (IRDs) are a large group of genetically and clinically diverse blinding eye conditions that result in progressive and irreversible photoreceptor degeneration and vision loss. To date, no cures have been found, although strides toward treatments for specific IRDs have been made in recent years. To accelerate treatment discovery, retinal organoids provide an ideal human IRD model. This review aims to give background on the development and importance of retinal organoids for the human-based in vitro study of the retina and human retinogenesis and retinal pathologies. From there, we explore retinal pathologies in the context of IRDs and the current landscape of IRD treatment discovery. We discuss the usefulness of retinal organoids in this context (as a patient-derived cell model for IRDs) to precisely understand the pathogenesis and potential mechanisms behind a specific IRD-causing variant of interest. Finally, we discuss the importance and promise of retinal organoids in treatment discovery for IRDs, now and in the future.
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Affiliation(s)
- Kristen E. Ashworth
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 3H2, Canada;
- Donald K. Johnson Eye Institute, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada;
| | - Jessica Weisbrod
- Donald K. Johnson Eye Institute, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada;
| | - Brian G. Ballios
- Institute of Medical Science, University of Toronto, Toronto, ON M5S 3H2, Canada;
- Donald K. Johnson Eye Institute, Toronto Western Hospital, Toronto, ON M5T 2S8, Canada;
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
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10
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Bai D, Guo R, Huang D, Ji J, Liu W. Compound heterozygous mutations in GRM6 causing complete Schubert-Bornschein type congenital stationary night blindness. Heliyon 2024; 10:e27039. [PMID: 38434377 PMCID: PMC10907788 DOI: 10.1016/j.heliyon.2024.e27039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/26/2023] [Accepted: 02/22/2024] [Indexed: 03/05/2024] Open
Abstract
Background To explore the genetic defects of a Chinese family with complete Schubert-Bornschein type congenital stationary night blindness (CSNB). Methods A Chinese family with complete Schubert-Bornschein type CSNB was enrolled in this study. The detailed ocular presentations of the patient were recorded. Targeted gene sequencing including 156 genes related to retinal diseases was used to detect the gene mutation. Sanger sequencing was performed to validate the potential pathogenic variants, and segregation analysis was performed on all available family members. Bioinformatics analysis was performed to predict the impact of the mutations. Results By targeted gene sequencing and Sanger sequencing, we identified compound heterozygous mutations in GRM6: c.152G>T (p.Gly51Val) and c.727delG (p.Val243SerfsX21). Segregation analysis demonstrated that the mother of the proband carried the missense mutation (c.152G>T) while her father carried the frameshift mutation (c.727delG), indicating CSNB was autosomal recessively inherited in this family. Several bioinformatics prediction programs revealed the mutations were "Damaging" or "Disease Causing" and conservation analysis showed both the codons Gly51 and Val243 were highly conserved among species, suggesting the changes were pathogenic. Conclusion By targeted gene sequencing and Sanger sequencing, we detected compound heterozygous mutations (c.152G>T, p.Gly51Val and c.727delG, p.Val243SerfsX21) in GRM6. The mutations co-segregated with the phenotype of the family members and are considered to be responsible for complete Schubert-Bornschein type CSNB. However, functional experiments in the future are needed to confirm the pathogenicity of the variants and to elucidate their exact molecular mechanisms causing CSNB.
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Affiliation(s)
- Dong'e Bai
- Department of Ophthalmology, Characteristic Medical Center of Chinese People's Armed Police Force, Tianjin, China
| | - Ruru Guo
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Dandan Huang
- Department of Ophthalmology, Taihe Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Jian Ji
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
| | - Wei Liu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin, 300384, China
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11
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McDonald A, Wijnholds J. Retinal Ciliopathies and Potential Gene Therapies: A Focus on Human iPSC-Derived Organoid Models. Int J Mol Sci 2024; 25:2887. [PMID: 38474133 DOI: 10.3390/ijms25052887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
The human photoreceptor function is dependent on a highly specialised cilium. Perturbation of cilial function can often lead to death of the photoreceptor and loss of vision. Retinal ciliopathies are a genetically diverse range of inherited retinal disorders affecting aspects of the photoreceptor cilium. Despite advances in the understanding of retinal ciliopathies utilising animal disease models, they can often lack the ability to accurately mimic the observed patient phenotype, possibly due to structural and functional deviations from the human retina. Human-induced pluripotent stem cells (hiPSCs) can be utilised to generate an alternative disease model, the 3D retinal organoid, which contains all major retinal cell types including photoreceptors complete with cilial structures. These retinal organoids facilitate the study of disease mechanisms and potential therapies in a human-derived system. Three-dimensional retinal organoids are still a developing technology, and despite impressive progress, several limitations remain. This review will discuss the state of hiPSC-derived retinal organoid technology for accurately modelling prominent retinal ciliopathies related to genes, including RPGR, CEP290, MYO7A, and USH2A. Additionally, we will discuss the development of novel gene therapy approaches targeting retinal ciliopathies, including the delivery of large genes and gene-editing techniques.
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Affiliation(s)
- Andrew McDonald
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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12
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Ye X, Yang S, Tu J, Xu L, Wang Y, Chen H, Yu R, Huang P. Leveraging baseline transcriptional features and information from single-cell data to power the prediction of influenza vaccine response. Front Cell Infect Microbiol 2024; 14:1243586. [PMID: 38384303 PMCID: PMC10879619 DOI: 10.3389/fcimb.2024.1243586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 01/11/2024] [Indexed: 02/23/2024] Open
Abstract
Introduction Vaccination is still the primary means for preventing influenza virus infection, but the protective effects vary greatly among individuals. Identifying individuals at risk of low response to influenza vaccination is important. This study aimed to explore improved strategies for constructing predictive models of influenza vaccine response using gene expression data. Methods We first used gene expression and immune response data from the Immune Signatures Data Resource (IS2) to define influenza vaccine response-related transcriptional expression and alteration features at different time points across vaccination via differential expression analysis. Then, we mapped these features to single-cell resolution using additional published single-cell data to investigate the possible mechanism. Finally, we explored the potential of these identified transcriptional features in predicting influenza vaccine response. We used several modeling strategies and also attempted to leverage the information from single-cell RNA sequencing (scRNA-seq) data to optimize the predictive models. Results The results showed that models based on genes showing differential expression (DEGs) or fold change (DFGs) at day 7 post-vaccination performed the best in internal validation, while models based on DFGs had a better performance in external validation than those based on DEGs. In addition, incorporating baseline predictors could improve the performance of models based on days 1-3, while the model based on the expression profile of plasma cells deconvoluted from the model that used DEGs at day 7 as predictors showed an improved performance in external validation. Conclusion Our study emphasizes the value of using combination modeling strategy and leveraging information from single-cell levels in constructing influenza vaccine response predictive models.
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Affiliation(s)
- Xiangyu Ye
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Sheng Yang
- Department of Biostatistics, National Vaccine Innovation Platform, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Junlan Tu
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Lei Xu
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Yifan Wang
- Department of Infectious Disease, Jurong Hospital Affiliated to Jiangsu University, Jurong, China
| | - Hongbo Chen
- Department of Infectious Disease, Jurong Hospital Affiliated to Jiangsu University, Jurong, China
| | - Rongbin Yu
- Department of Epidemiology, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Peng Huang
- Department of Epidemiology, National Vaccine Innovation Platform, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing, China
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13
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Liu X, Hu F, Zhang D, Li Z, He J, Zhang S, Wang Z, Zhao Y, Wu J, Liu C, Li C, Li X, Wu J. Whole genome sequencing enables new genetic diagnosis for inherited retinal diseases by identifying pathogenic variants. NPJ Genom Med 2024; 9:6. [PMID: 38245557 PMCID: PMC10799956 DOI: 10.1038/s41525-024-00391-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 12/19/2023] [Indexed: 01/22/2024] Open
Abstract
Inherited retinal diseases (IRDs) are a group of common primary retinal degenerative disorders. Conventional genetic testing strategies, such as panel-based sequencing and whole exome sequencing (WES), can only elucidate the genetic etiology in approximately 60% of IRD patients. Studies have suggested that unsolved IRD cases could be attributed to previously undetected structural variants (SVs) and intronic variants in IRD-related genes. The aim of our study was to obtain a definitive genetic diagnosis by employing whole genome sequencing (WGS) in IRD cases where the causative genes were inconclusive following an initial screening by panel sequencing. A total of 271 unresolved IRD patients and their available family members (n = 646) were screened using WGS to identify pathogenic SVs and intronic variants in 792 known ocular disease genes. Overall, 13% (34/271) of IRD patients received a confirmed genetic diagnosis, among which 7% were exclusively attributed to SVs, 4% to a combination of single nucleotide variants (SNVs) and SVs while another 2% were linked to intronic variants. 22 SVs, 3 deep-intronic variants, and 2 non-canonical splice-site variants across 14 IRD genes were identified in the entire cohort. Notably, all of these detected SVs and intronic variants were novel pathogenic variants. Among those, 74% (20/27) of variants were found in genes causally linked to Retinitis Pigmentosa (RP), with the gene EYS being the most frequently affected by SVs. The identification of SVs and intronic variants through WGS enhances the genetic diagnostic yield of IRDs and broadens the mutational spectrum of known IRD-associated genes.
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Affiliation(s)
- Xubing Liu
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Fangyuan Hu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Daowei Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Zhe Li
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jianquan He
- Computer Center, Eye & ENT Hospital, Fudan University, Shanghai, China
| | - Shenghai Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Zhenguo Wang
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yingke Zhao
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Jiawen Wu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Chen Liu
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Chenchen Li
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China
| | - Xin Li
- CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China.
| | - Jihong Wu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.
- NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.
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14
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Cuzzuol BR, Apolonio JS, da Silva Júnior RT, de Carvalho LS, Santos LKDS, Malheiro LH, Silva Luz M, Calmon MS, Crivellaro HDL, Lemos FFB, Freire de Melo F. Usher syndrome: Genetic diagnosis and current therapeutic approaches. World J Otorhinolaryngol 2024; 11:1-17. [DOI: 10.5319/wjo.v11.i1.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 12/21/2023] [Accepted: 01/05/2024] [Indexed: 01/17/2024] Open
Abstract
Usher Syndrome (USH) is the most common deaf-blind syndrome, affecting approximately 1 in 6000 people in the deaf population. This genetic condition is characterized by a combination of hearing loss (HL), retinitis pigmentosa, and, in some cases, vestibular areflexia. Among the subtypes of USH, USH type 1 is considered the most severe form, presenting profound bilateral congenital deafness, vestibular areflexia, and early onset RP. USH type 2 is the most common form, exhibiting congenital moderate to severe HL for low frequencies and severe to profound HL for high frequencies. Conversely, type 3 is the rarest, initially manifesting mild symptoms during childhood that become more prominent in the first decades of life. The dual impact of USH on both visual and auditory senses significantly impairs patients’ quality of life, restricting their daily activities and interactions with society. To date, 9 genes have been confirmed so far for USH: MYO7A, USH1C, CDH23, PCDH15, USH1G, USH2A, ADGRV1, WHRN and CLRN1. These genes are inherited in an autosomal recessive manner and encode proteins expressed in the inner ear and retina, leading to functional loss. Although non-genetic methods can assist in patient triage and disease extension evaluation, genetic and molecular tests play a pivotal role in providing genetic counseling, enabling appropriate gene therapy, and facilitating timely cochlear implantation (CI). The CRISPR/Cas9 system and viral-based gene replacement therapy have recently emerged as highly promising techniques for treating USH. Regarding drug therapy, PTC-124 and Nb54 have been identified as promising drug interventions for genetic HL in USH. Simultaneously, CI has proven to be critical in the restoration of hearing. This review aims to summarize the genetic and molecular diagnosis of USH and highlight the importance of early diagnosis in guiding appropriate treatment strategies and improving patient prognosis.
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Affiliation(s)
- Beatriz Rocha Cuzzuol
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Jonathan Santos Apolonio
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | | | - Lorena Sousa de Carvalho
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Luana Kauany de Sá Santos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Luciano Hasimoto Malheiro
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Marcel Silva Luz
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Mariana Santos Calmon
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Henrique de Lima Crivellaro
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabian Fellipe Bueno Lemos
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
| | - Fabrício Freire de Melo
- Instituto Multidisciplinar em Saúde, Universidade Federal da Bahia, Vitória da Conquista 45029-094, Bahia, Brazil
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15
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Nguyen VP, Hu J, Zhe J, Chen EY, Yang D, Paulus YM. Multimodal photoacoustic microscopy, optical coherence tomography, and fluorescence imaging of USH2A knockout rabbits. Sci Rep 2023; 13:22071. [PMID: 38086867 PMCID: PMC10716268 DOI: 10.1038/s41598-023-48872-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Usher syndrome type 2A (USH2A) is a genetic disorder characterized by retinal degeneration and hearing loss. To better understand the pathogenesis and progression of this syndrome, animal models such as USH2A knockout (USH2AKO) rabbits have been developed. In this study, we employed multimodal imaging techniques, including photoacoustic microscopy (PAM), optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICGA) imaging to evaluate the retinal changes in the USH2AKO rabbit model. Twelve New Zealand White rabbits including USH2AKO and wild type (WT) were used for the experiments. Multimodal imaging was implemented at different time points over a period of 12 months to visualize the progression of retinal changes in USH2AKO rabbits. The results demonstrate that ellipsoid zone (EZ) disruption and degeneration, key features of Usher syndrome, began at the age of 4 months old and persisted up to 12 months. The EZ degeneration areas were clearly observed on the FAF and OCT images. The FAF images revealed retinal pigment epithelium (RPE) degeneration, confirming the presence of the disease phenotype in the USH2AKO rabbits. In addition, PAM images provided high-resolution and high image contrast of the optic nerve and the retinal microvasculature, including retinal vessels, choroidal vessels, and capillaries in three-dimensions. The quantification of EZ fluorescent intensity using FAF and EZ thickness using OCT provided comprehensive quantitative data on the progression of degenerative changes over time. This multimodal imaging approach allowed for a comprehensive and non-invasive assessment of retinal structure, microvasculature, and degenerative changes in the USH2AKO rabbit model. The combination of PAM, OCT, and fluorescent imaging facilitated longitudinal monitoring of disease progression and provided valuable insights into the pathophysiology of USH2A syndrome. These findings contribute to the understanding of USH2A syndrome and may have implications for the development of diagnostic and therapeutic strategies for affected individuals. The multimodal imaging techniques employed in this study offer a promising platform for preclinical evaluation of potential treatments and may pave the way for future clinical applications in patients with Usher syndrome.
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Affiliation(s)
- Van Phuc Nguyen
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Justin Hu
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Josh Zhe
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA
| | - Eugene Y Chen
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan, 2800 Plymouth Rd NCRC B26-355S, Ann Arbor, MI, 48109-2800, USA
| | - Dongshan Yang
- Department of Internal Medicine, Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan, 2800 Plymouth Rd NCRC B26-355S, Ann Arbor, MI, 48109-2800, USA.
| | - Yannis M Paulus
- Department of Ophthalmology and Visual Sciences, University of Michigan, 1000 Wall Street, Ann Arbor, MI, 48105, USA.
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, 48105, USA.
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16
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Daich Varela M, Wong SW, Kiray G, Schlottmann PG, Arno G, Shams ANA, Mahroo OA, Webster AR, AlTalbishi A, Michaelides M. Detailed Clinical, Ophthalmic, and Genetic Characterization of ADGRV1-Associated Usher Syndrome. Am J Ophthalmol 2023; 256:186-195. [PMID: 37422204 PMCID: PMC11139646 DOI: 10.1016/j.ajo.2023.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/10/2023]
Abstract
PURPOSE To present the clinical characteristics, retinal features, natural history, and genetics of ADGRV1-Usher syndrome (USH). DESIGN Multicenter international retrospective cohort study. METHODS Clinical notes, hearing loss history, multimodal retinal imaging, and molecular diagnosis were reviewed. Thirty patients (28 families) with USH type 2 and disease-causing variants in ADGRV1 were identified. Visual function, retinal imaging, and genetics were evaluated and correlated, with retinal features also compared with those of the commonest cause of USH type 2, USH2A-USH. RESULTS The mean age at the first visit was 38.6 ± 12.0 years (range: 19-74 years), and the mean follow-up time was 9.0 ± 7.7 years. Hearing loss was reported in the first decade of life by all patients, 3 (10%) described progressive loss, and 93% had moderate-severe impairment. Visual symptom onset was at 17.0 ± 7.7 years of age (range: 6-32 years), with 13 patients noticing problems before the age of 16. At baseline, 90% of patients had no or mild visual impairment. The most frequent retinal features were a hyperautofluorescent ring at the posterior pole (70%), perimacular patches of decreased autofluorescence (59%), and mild-moderate peripheral bone-spicule-like deposits (63%). Twenty-six (53%) variants were previously unreported, 19 families (68%) had double-null genotypes, and 9 were not-double-null. Longitudinal analysis showed significant differences between baseline and follow-up central macular thickness (-1.25 µm/y), outer nuclear layer thickness (-1.19 µm/y), and ellipsoid zone width (-40.9 µm/y). The rate of visual acuity decline was 0.02 LogMAR (1 letter)/y, and the rate of constriction of the hyperautofluorescent ring was 0.23 mm2/y. CONCLUSIONS ADGRV1-USH is characterized by early-onset, usually non-progressive, mild-to-severe hearing loss and generally good central vision until late adulthood. Perimacular atrophic patches and relatively retained ellipsoid zone and central macular thickness in later adulthood are more often seen in ADGRV1-USH than in USH2A-USH.
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Affiliation(s)
- Malena Daich Varela
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology, University College London (M.D.V., G.A., O.A.M., A.R.W., M.M.), London, UK
| | - Shiao Wei Wong
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK
| | - Gulunay Kiray
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK
| | | | - Gavin Arno
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology, University College London (M.D.V., G.A., O.A.M., A.R.W., M.M.), London, UK
| | - Amjaad N Abu Shams
- St John of Jerusalem Eye Hospital Group, Jerusalem, Palestine (A.N.A.S., A.A.T.)
| | - Omar A Mahroo
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology, University College London (M.D.V., G.A., O.A.M., A.R.W., M.M.), London, UK
| | - Andrew R Webster
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology, University College London (M.D.V., G.A., O.A.M., A.R.W., M.M.), London, UK
| | - Alaa AlTalbishi
- St John of Jerusalem Eye Hospital Group, Jerusalem, Palestine (A.N.A.S., A.A.T.)
| | - Michel Michaelides
- From the Moorfields Eye Hospital (M.D.V., S.W.W., G.K., G.A., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology, University College London (M.D.V., G.A., O.A.M., A.R.W., M.M.), London, UK.
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17
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Bigini F, Lee SH, Sun YJ, Sun Y, Mahajan VB. Unleashing the potential of CRISPR multiplexing: Harnessing Cas12 and Cas13 for precise gene modulation in eye diseases. Vision Res 2023; 213:108317. [PMID: 37722240 PMCID: PMC10685911 DOI: 10.1016/j.visres.2023.108317] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/20/2023]
Abstract
Gene therapy is a flourishing field with the potential to revolutionize the treatment of genetic diseases. The emergence of CRISPR-Cas9 has significantly advanced targeted and efficient genome editing. Although CRISPR-Cas9 has demonstrated promising potential applications in various genetic disorders, it faces limitations in simultaneously targeting multiple genes. Novel CRISPR systems, such as Cas12 and Cas13, have been developed to overcome these challenges, enabling multiplexing and providing unique advantages. Cas13, in particular, targets mRNA instead of genomic DNA, permitting precise gene expression control and mitigating off-target effects. This review investigates the potential of Cas12 and Cas13 in ocular gene therapy applications, such as suppression of inflammation and cell death. In addition, the capabilities of Cas12 and Cas13 are explored in addressing potential targets related with disease mechanisms such as aberrant isoforms, mitochondrial genes, cis-regulatory sequences, modifier genes, and long non-coding RNAs. Anatomical accessibility and relative immune privilege of the eye provide an ideal organ system for evaluating these novel techniques' efficacy and safety. By targeting multiple genes concurrently, CRISPR-Cas12 and Cas13 systems hold promise for treating a range of ocular disorders, including glaucoma, retinal dystrophies, and age-related macular degeneration. Nonetheless, additional refinement is required to ascertain the safety and efficacy of these approaches in ocular disease treatments. Thus, the development of Cas12 and Cas13 systems marks a significant advancement in gene therapy, offering the potential to devise effective treatments for ocular disorders.
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Affiliation(s)
- Fabio Bigini
- Molecular Surgery Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA 94304, USA; Laboratory of Virology, Wageningen University & Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Soo Hyeon Lee
- Molecular Surgery Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA 94304, USA
| | - Young Joo Sun
- Molecular Surgery Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA 94304, USA
| | - Yang Sun
- Molecular Surgery Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA 94304, USA; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; Stanford Maternal & Child Health Research Institute, Palo Alto, CA 94304, USA
| | - Vinit B Mahajan
- Molecular Surgery Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University, Palo Alto, CA 94304, USA; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA.
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18
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Liang Y, Sun X, Duan C, Tang S, Chen J. Application of patient-derived induced pluripotent stem cells and organoids in inherited retinal diseases. Stem Cell Res Ther 2023; 14:340. [PMID: 38012786 PMCID: PMC10683306 DOI: 10.1186/s13287-023-03564-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023] Open
Abstract
Inherited retinal diseases (IRDs) can induce severe sight-threatening retinal degeneration and impose a considerable economic burden on patients and society, making efforts to cure blindness imperative. Transgenic animals mimicking human genetic diseases have long been used as a primary research tool to decipher the underlying pathogenesis, but there are still some obvious limitations. As an alternative strategy, patient-derived induced pluripotent stem cells (iPSCs), particularly three-dimensional (3D) organoid technology, are considered a promising platform for modeling different forms of IRDs, including retinitis pigmentosa, Leber congenital amaurosis, X-linked recessive retinoschisis, Batten disease, achromatopsia, and best vitelliform macular dystrophy. Here, this paper focuses on the status of patient-derived iPSCs and organoids in IRDs in recent years concerning disease modeling and therapeutic exploration, along with potential challenges for translating laboratory research to clinical application. Finally, the importance of human iPSCs and organoids in combination with emerging technologies such as multi-omics integration analysis, 3D bioprinting, or microfluidic chip platform are highlighted. Patient-derived retinal organoids may be a preferred choice for more accurately uncovering the mechanisms of human retinal diseases and will contribute to clinical practice.
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Affiliation(s)
- Yuqin Liang
- Aier Eye Institute, Changsha, 410015, China
- Eye Center of Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Xihao Sun
- Aier Eye Institute, Changsha, 410015, China
- Eye Center of Xiangya Hospital, Central South University, Changsha, 410008, China
| | - Chunwen Duan
- Aier Eye Institute, Changsha, 410015, China
- Changsha Aier Eye Hospital, Changsha, 410015, China
| | - Shibo Tang
- Aier Eye Institute, Changsha, 410015, China.
- Changsha Aier Eye Hospital, Changsha, 410015, China.
| | - Jiansu Chen
- Aier Eye Institute, Changsha, 410015, China.
- Changsha Aier Eye Hospital, Changsha, 410015, China.
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, 510632, China.
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19
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Nam DW, Song YK, Kim JH, Lee EK, Park KH, Cha J, Choi BY, Lee JH, Oh SH, Jo DH, Lee SY. Allelic hierarchy for USH2A influences auditory and visual phenotypes in South Korean patients. Sci Rep 2023; 13:20239. [PMID: 37981655 PMCID: PMC10658080 DOI: 10.1038/s41598-023-47166-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 11/09/2023] [Indexed: 11/21/2023] Open
Abstract
When medical genetic syndromes are influenced by allelic hierarchies, mutant alleles have distinct effects on clinical phenotypes. Genotype-phenotype correlations for Usher syndrome type 2 (USH2) suggest that the USH2A gene exhibits an allelic hierarchy. Here, we analyzed the phenotypes and genotypes of 16 South Korean patients with USH2A biallelic variants to investigate an allelic hierarchy from audiological and ophthalmological perspectives. Using whole exome and genome sequencing, 18 mutant alleles, including 4 novel alleles, were identified and implicated in USH2A-related disorders. Truncated alleles were linked to earlier onset of subjective hearing loss and more severe thresholds; biallelic truncated alleles had more severe effects. Truncated alleles were also associated with retinal structure degeneration and severe functional deterioration. However, younger patients (aged < 16 years) did not exhibit overt retinitis pigmentosa even when they had biallelic truncated alleles, suggesting that USH2A-related USH2 can mimic nonsyndromic hearing loss. For truncated alleles, there was a clear correlation between mean hearing threshold and 30-Hz flicker electroretinography implicit time. This study provides the first evidence of an USH2A-related allelic hierarchy among South Korean patients; our data yield valuable insights concerning the natural courses of clinical phenotypes and how genotype-based therapies may be used.
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Affiliation(s)
- Dong Woo Nam
- Department of Otorhinolaryngology, Chungbuk National University Hospital, Cheongju, Republic of Korea
| | - Yong Keun Song
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jeong Hun Kim
- Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Eun Kyoung Lee
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - JuHyuen Cha
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, Republic of Korea
| | - Jun Ho Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Seung Ha Oh
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea
| | - Dong Hyun Jo
- Department of Anatomy and Cell Biology, Seoul National University College of Medicine, 103, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
| | - Sang-Yeon Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul National University College of Medicine, 101, Daehak-ro, Jongno-gu, Seoul, 03080, Republic of Korea.
- Department of Genomic Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Republic of Korea.
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20
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Crane R, Tebbe L, Mwoyosvi ML, Al-Ubaidi MR, Naash MI. Expression of the human usherin c.2299delG mutation leads to early-onset auditory loss and stereocilia disorganization. Commun Biol 2023; 6:933. [PMID: 37700068 PMCID: PMC10497539 DOI: 10.1038/s42003-023-05296-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness and blindness, with USH2A being the most prevalent form. The mechanisms responsible for this debilitating sensory impairment remain unclear. This study focuses on characterizing the auditory phenotype in a mouse model expressing the c.2290delG mutation in usherin equivalent to human frameshift mutation c.2299delG. Previously we described how this model reproduces patient's retinal phenotypes. Here, we present the cochlear phenotype, showing that the mutant usherin, is expressed during early postnatal stages. The c.2290delG mutation results in a truncated protein that is mislocalized within the cell body of the hair cells. The knock-in model also exhibits congenital hearing loss that remains consistent throughout the animal's lifespan. Structurally, the stereocilia bundles, particularly in regions associated with functional hearing loss, are disorganized. Our findings shed light on the role of usherin in maintaining structural support, specifically in longer inner hair cell stereocilia, during development, which is crucial for proper bundle organization and hair cell function. Overall, we present a genetic mouse model with cochlear defects associated with the c.2290delG mutation, providing insights into the etiology of hearing loss and offering potential avenues for the development of effective therapeutic treatments for USH2A patients.
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Affiliation(s)
- Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Lars Tebbe
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Maggie L Mwoyosvi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
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21
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Toms M, Toualbi L, Almeida PV, Harbottle R, Moosajee M. Successful large gene augmentation of USH2A with non-viral episomal vectors. Mol Ther 2023; 31:2755-2766. [PMID: 37337429 PMCID: PMC10491995 DOI: 10.1016/j.ymthe.2023.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 05/09/2023] [Accepted: 06/14/2023] [Indexed: 06/21/2023] Open
Abstract
USH2A mutations are a common cause of autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, for which there are currently no approved treatments. Gene augmentation is a valuable therapeutic strategy for treating many inherited retinal diseases; however, conventional adeno-associated virus (AAV) gene therapy cannot accommodate cDNAs exceeding 4.7 kb, such as the 15.6-kb-long USH2A coding sequence. In the present study, we adopted an alternative strategy to successfully generate scaffold/matrix attachment region (S/MAR) DNA plasmid vectors containing the full-length human USH2A coding sequence, a GFP reporter gene, and a ubiquitous promoter (CMV or CAG), reaching a size of approximately 23 kb. We assessed the vectors in transfected HEK293 cells and USH2A patient-derived dermal fibroblasts in addition to ush2au507 zebrafish microinjected with the vector at the one-cell stage. pS/MAR-USH2A vectors drove persistent transgene expression in patient fibroblasts with restoration of usherin. Twelve months of GFP expression was detected in the photoreceptor cells, with rescue of Usher 2 complex localization in the photoreceptors of ush2au507 zebrafish retinas injected with pS/MAR-USH2A. To our knowledge, this is the first reported vector that can be used to express full-length usherin with functional rescue. S/MAR DNA vectors have shown promise as a novel non-viral retinal gene therapy, warranting further translational development.
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Affiliation(s)
- Maria Toms
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
| | - Lyes Toualbi
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK
| | - Patrick V Almeida
- DNA Vector Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Richard Harbottle
- DNA Vector Research, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Mariya Moosajee
- Development, Ageing, and Disease, UCL Institute of Ophthalmology, London EC1V 9EL, UK; Ocular Genomics and Therapeutics, The Francis Crick Institute, London NW1 1AT, UK; Department of Genetics, Moorfields Eye Hospital, NHS Foundation Trust, London EC1V 2PD, UK.
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22
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Borrajo J, Javanmardi K, Griffin J, St. Martin SJ, Yao D, Hill K, Blainey PC, Al-Shayeb B. Programmable multi-kilobase RNA editing using CRISPR-mediated trans-splicing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.18.553620. [PMID: 37645763 PMCID: PMC10462116 DOI: 10.1101/2023.08.18.553620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Current gene editing approaches in eukaryotic cells are limited to single base edits or small DNA insertions and deletions, and remain encumbered by unintended permanent effects and significant challenges in the delivery of large DNA cargo. Here we describe Splice Editing, a generalizable platform to correct gene transcripts in situ by programmable insertion or replacement of large RNA segments. By combining CRISPR-mediated RNA targeting with endogenous cellular RNA-splicing machinery, Splice Editing enables efficient, precise, and programmable large-scale editing of gene targets without DNA cleavage or mutagenesis. RNA sequencing and measurement of spliced protein products confirm that Splice Editing achieves efficient and specific targeted RNA and protein correction. We show that Splice Editors based on novel miniature RNA-targeting CRISPR-Cas systems discovered and characterized in this work can be packaged for effective delivery to human cells and affect different types of edits across multiple targets and cell lines. By editing thousands of bases simultaneously in a single reversible step, Splice Editing could expand the treatable disease population for monogenic diseases with large allelic diversity without the permanent unintended effects of DNA editing.
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Affiliation(s)
- Jacob Borrajo
- Amber Bio, Inc., South San Francisco, CA 94080
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
| | | | | | | | - David Yao
- Amber Bio, Inc., South San Francisco, CA 94080
| | - Kaisle Hill
- Amber Bio, Inc., South San Francisco, CA 94080
| | - Paul C. Blainey
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
- Broad Institute of MIT and Harvard, Cambridge, MA 02141
- Koch Institute for Integrative Cancer Research at MIT, Cambridge, MA 02139
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23
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Ordoñez-Labastida V, Chacon-Camacho OF, Lopez-Rodriguez VR, Zenteno JC. USH2A mutational spectrum causing syndromic and non-syndromic retinal dystrophies in a large cohort of Mexican patients. Mol Vis 2023; 29:31-38. [PMID: 37287646 PMCID: PMC10243674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 04/28/2023] [Indexed: 06/09/2023] Open
Abstract
Background Mutations in the USH2A gene are the leading cause of both non-syndromic autosomal recessive retinitis pigmentosa (RP) and Usher syndrome, a syndromic form of RP characterized by retinal dystrophy and sensorineural hearing loss. To contribute to the expansion of the USH2A-related molecular spectrum, the results of genetic screening in a large cohort of Mexican patients are presented. Methods The study population comprised 61 patients with a clinical diagnosis of either non-syndromic RP (n = 30) or Usher syndrome type 2 (USH2; n = 31) who were demonstrated to carry biallelic pathogenic variants in USH2A in a three-year period. Genetic screening was performed either by gene panel sequencing or by exome sequencing. A total of 72 available first- or second-degree relatives were also genotyped for familial segregation of the identified variants. Results The USH2A mutational spectrum in RP patients included 39 distinct pathogenic variants, most of them of the missense type. The most common RP-causing variants were p.Cys759Phe (c.2276G>T), p.Glu767Serfs*21 (c.2299delG), and p.Cys319Tyr (c.956G>A), which together accounted for 25% of all RP variants. Novel USH2A mutations included three nonsense, two missense, two frameshift, and one intragenic deletion. The USH2A mutational spectrum in USH2 patients included 26 distinct pathogenic variants, most of them of the nonsense and frameshift types. The most common Usher syndrome-causing variants were p.Glu767Serfs*21 (c.2299delG), p.Arg334Trp (c.1000C>T), and c.12067-2A>G), which together accounted for 42% of all USH2-related variants. Novel Usher syndrome USH2A mutations included six nonsense, four frameshift, and two missense mutations. The c.2299delG mutation was associated with a common haplotype for SNPs located in exons 2-21 of USH2A, indicating a founder mutation effect. Conclusions Our work expands the USH2A mutational profile by identifying 20 novel pathogenic variants causing syndromic and non-syndromic retinal dystrophy. The prevalent c.2299delG allele is shown to arise from a founder effect. Our results emphasize the usefulness of molecular screening in underrepresented populations for a better characterization of the molecular spectrum of common monogenic diseases.
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Affiliation(s)
- Vianey Ordoñez-Labastida
- Rare Disease Diagnostic Unit, Faculty of Medicine, National Autonomous University of Mexico (UNAM), Mexico City, Mexico
- Department of Genetics, Institute of Ophthalmology “Conde de Valenciana,” Mexico City, Mexico
- Faculty of Medicine, Autonomous University of the State of Morelos (UAEM), Morelos, Mexico
| | - Oscar F. Chacon-Camacho
- Department of Genetics, Institute of Ophthalmology “Conde de Valenciana,” Mexico City, Mexico
- Carrera Médico Cirujano, Facultad de Estudios Superiores Iztacala, UNAM, Mexico City, Mexico
| | | | - Juan C. Zenteno
- Rare Disease Diagnostic Unit, Faculty of Medicine, National Autonomous University of Mexico (UNAM), Mexico City, Mexico
- Department of Genetics, Institute of Ophthalmology “Conde de Valenciana,” Mexico City, Mexico
- Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico
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24
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Major L, McClements ME, MacLaren RE. A Review of CRISPR Tools for Treating Usher Syndrome: Applicability, Safety, Efficiency, and In Vivo Delivery. Int J Mol Sci 2023; 24:ijms24087603. [PMID: 37108761 PMCID: PMC10146473 DOI: 10.3390/ijms24087603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 04/29/2023] Open
Abstract
This review considers research into the treatment of Usher syndrome, a deaf-blindness syndrome inherited in an autosomal recessive manner. Usher syndrome mutations are markedly heterogeneous, involving many different genes, and research grants are limited due to minimal patient populations. Furthermore, gene augmentation therapies are impossible in all but three Usher syndromes as the cDNA sequence exceeds the 4.7 kb AAV packaging limit. It is, therefore, vital to focus research efforts on alternative tools with the broadest applicability. The CRISPR field took off in recent years following the discovery of the DNA editing activity of Cas9 in 2012. New generations of CRISPR tools have succeeded the original CRISPR/Cas9 model to enable more sophisticated genomic amendments such as epigenetic modification and precise sequence alterations. This review will evaluate the most popular CRISPR tools to date: CRISPR/Cas9, base editing, and prime editing. It will consider these tools in terms of applicability (in relation to the ten most prevalent USH2A mutations), safety, efficiency, and in vivo delivery potential with the intention of guiding future research investment.
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Affiliation(s)
- Lauren Major
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Michelle E McClements
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E MacLaren
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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25
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Ukaji T, Takahashi-Shibata M, Arai D, Tsutsumi H, Tajima S, Akamatsu W, Matsumoto F, Ikeda K, Usami SI, Kamiya K. Generation and characterization of a human iPSC line (JUFMDOi007-A) from a patient with Usher syndrome due to mutation in USH2A. Stem Cell Res 2023; 69:103100. [PMID: 37099934 DOI: 10.1016/j.scr.2023.103100] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/13/2023] [Accepted: 04/15/2023] [Indexed: 04/28/2023] Open
Abstract
Usher syndrome type 2A (USH2A) gene mutations have been identified as the most frequent genetic causes of hereditary deafness in Usher syndrome, and an effective treatment has yet to be established. The encoded protein, Usherin, is essential for the ankle link associated with extracellular connections between the stereocilia of inner ear hair cells. We report the generation of a patient-derived USH2A iPSC line with compound mutations c.1907_1912ATGTTT > TCACAG (p.D636V + V637T + C638G) and c.8328_8329delAA (p.L2276fs*12). The iPSC showed the expression of pluripotency markers, the ability to differentiate into three germ layers in vitro, and USH2A mutations with normal karyotype.
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Affiliation(s)
- Takao Ukaji
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan; Division of Experimental Chemotherapy, The Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Tokyo, Japan
| | | | - Daisuke Arai
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Harumi Tsutsumi
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Shori Tajima
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Wado Akamatsu
- Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, Tokyo, Japan
| | - Fumihiko Matsumoto
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Katsuhisa Ikeda
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, Nagano, Japan
| | - Kazusaku Kamiya
- Department of Otorhinolaryngology, Juntendo University Faculty of Medicine, Tokyo, Japan.
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26
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Jung S, Park YC, Lee D, Kim S, Kim SM, Kim Y, Lee D, Hyun J, Koh I, Lee JY. Exome sequencing identified five novel USH2A variants in Korean patients with retinitis pigmentosa. Ophthalmic Genet 2023; 44:163-170. [PMID: 36314366 DOI: 10.1080/13816810.2022.2138456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Retinitis pigmentosa (RP) is an inherited disorder that causes progressive loss of vision. This study aimed to describe the possible causative variants of the USH2A gene in Korean RP families and their associated phenotypes. MATERIALS AND METHODS We recruited 94 RP families (220 subjects, including 94 probands and 126 family members) in a Korean cohort, and analyzed USH2A gene variants through whole-exome sequencing. The pathogenicity of the variants was classified according to American College of Medical Genetics and Genomics and Association for Molecular Pathology guidelines. RESULTS We found 14 USH2A disease-causing variants, including 5 novel variants. Disease causing variants were identified in 10 probands with RP, accounting for 10.6% (10/94) of the Korean RPs in the cohort. To visually represent the structural changes induced by novel variants, we modeled the three-dimensional structures of the wild-type and mutant proteins. CONCLUSIONS This study expands the spectrum of USH2A variants and provides information for future therapeutic strategies for RP.
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Affiliation(s)
- SeungHee Jung
- Department of Biomedical Informatics, Hanyang University, Seoul, Korea
| | - Young Chan Park
- Department of Biomedical Informatics, Hanyang University, Seoul, Korea
- Oneomics Co, Ltd, Gyeonggi-do, Korea
| | - DongHee Lee
- Department of Biomedical Informatics, Hanyang University, Seoul, Korea
- Oneomics Co, Ltd, Gyeonggi-do, Korea
| | - SiYeon Kim
- Department of Biomedical Informatics, Hanyang University, Seoul, Korea
| | | | | | | | | | - InSong Koh
- Department of Biomedical Informatics, Hanyang University, Seoul, Korea
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27
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Natural Disease Course in Usher Syndrome Patients Harboring USH2A Variant p.Cys870* in Exon 13, Amenable to Exon Skipping Therapy. Genes (Basel) 2023; 14:genes14030652. [PMID: 36980924 PMCID: PMC10048357 DOI: 10.3390/genes14030652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/08/2023] [Accepted: 02/13/2023] [Indexed: 03/08/2023] Open
Abstract
The aim of the study was to determine the rate of retinal degeneration in patients with c.2610C>A (p.Cys870*) in USH2A exon 13, amenable to exon skipping therapy. There were nine patients from seven families, three of whom were male (two were homozygous). Seven patients had follow-up data (median of 11 years). Analysis included best corrected visual acuity (BCVA, decimal Snellen), visual field (Goldmann perimetry target II/4), fundus autofluorescence (FAF), optical coherence tomography (OCT), and microperimetry (MP). The median age at the onset of nyctalopia was 20 years (range, 8–35 years of age). At the first exam, at a median age of 42 years, the median BCVA was 0.5 (0.2–1.0), and the median visual field diameter was 23° (5°–114°). Imaging showed a hyperautofluorescent ring delineating preserved foveal photoreceptors in 78% (7/9) of patients, while 22% (2/9) had a hyperautofluorescent patch or atrophy, reflecting advanced disease. Survival analysis predicted that 50% of patients reach legal blindness based on a visual field diameter < 20° at the age of 52 (95% CI, 45–59) and legal blindness based on a BCVA ≤ 0. 1 (20/200) at the age of 55 (95% CI, 46–66). Visual field constriction occurred at the median rate of radial 1.5 deg/year, and hyperautofluorescent ring constriction occurred at the median rate of 34 μm/year. A non-null second allele was found in two patients: p.Thr4315Pro and p.Arg303His; the patient with p.Arg303His had a milder disease. The rates of progression will be useful in the design and execution of clinical trials.
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Perini F, Cendron F, Wu Z, Sevane N, Li Z, Huang C, Smith J, Lasagna E, Cassandro M, Penasa M. Genomics of Dwarfism in Italian Local Chicken Breeds. Genes (Basel) 2023; 14:genes14030633. [PMID: 36980905 PMCID: PMC10047989 DOI: 10.3390/genes14030633] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/27/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023] Open
Abstract
The identification of the dwarf phenotype in chicken is based on body weight, height, and shank length, leaving the differentiation between dwarf and small breeds ambiguous. The aims of the present study were to characterize the sequence variations associated with the dwarf phenotype in three Italian chicken breeds and to investigate the genes associated with their phenotype. Five hundred and forty-one chickens from 23 local breeds (from 20 to 24 animals per breed) were sampled. All animals were genotyped with the 600 K chicken SNP array. Three breeds were described as “dwarf”, namely, Mericanel della Brianza (MERI), Mugellese (MUG), and Pepoi (PPP). We compared MERI, MUG, and PPP with the four heaviest breeds in the dataset by performing genome-wide association studies. Results showed significant SNPs associated with dwarfism in the MERI and MUG breeds, which shared a candidate genomic region on chromosome 1. Due to this similarity, MERI and MUG were analyzed together as a meta-population, observing significant SNPs in the LEMD3 and HMGA2 genes, which were previously reported as being responsible for dwarfism in different species. In conclusion, MERI and MUG breeds seem to share a genetic basis of dwarfism, which differentiates them from the small PPP breed.
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Affiliation(s)
- Francesco Perini
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
| | - Filippo Cendron
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
| | - Zhou Wu
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Natalia Sevane
- Department of Animal Production, Veterinary Faculty, Universidad Complutense de Madrid, Avenida Puerta de Hierro, 28040 Madrid, Spain
| | - Zhiqiang Li
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- College of Animal Science and Technology, Chengdu Campus, Sichuan Agricultural University, Chengdu 611130, China
| | - Chunhua Huang
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- College of Animal Science and Technology, Chengdu Campus, Sichuan Agricultural University, Chengdu 611130, China
| | - Jacqueline Smith
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian EH25 9RG, UK
| | - Emiliano Lasagna
- Department of Agricultural, Food and Environmental Sciences, University of Perugia, 06121 Perugia, Italy
- Correspondence: ; Tel.: +39-075-58517102
| | - Martino Cassandro
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
- Federazione delle Associazioni Nazionali di Razza e Specie, 00187 Roma, Italy
| | - Mauro Penasa
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova, 35020 Legnaro, Italy
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Tebbe L, Mwoyosvi ML, Crane R, Makia MS, Kakakhel M, Cosgrove D, Al-Ubaidi MR, Naash MI. The usherin mutation c.2299delG leads to its mislocalization and disrupts interactions with whirlin and VLGR1. Nat Commun 2023; 14:972. [PMID: 36810733 PMCID: PMC9944904 DOI: 10.1038/s41467-023-36431-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Usher syndrome (USH) is the leading cause of combined deafness-blindness with type 2 A (USH2A) being the most common form. Knockout models of USH proteins, like the Ush2a-/- model that develops a late-onset retinal phenotype, failed to mimic the retinal phenotype observed in patients. Since patient's mutations result in the expression of a mutant protein and to determine the mechanism of USH2A, we generated and evaluated an usherin (USH2A) knock-in mouse expressing the common human disease-mutation, c.2299delG. This mouse exhibits retinal degeneration and expresses a truncated, glycosylated protein which is mislocalized to the photoreceptor inner segment. The degeneration is associated with a decline in retinal function, structural abnormalities in connecting cilium and outer segment and mislocaliztion of the usherin interactors very long G-protein receptor 1 and whirlin. The onset of symptoms is significantly earlier compared to Ush2a-/-, proving expression of mutated protein is required to recapitulate the patients' retinal phenotype.
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Affiliation(s)
- Lars Tebbe
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Maggie L Mwoyosvi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
- Department of Microbiology & Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Ryan Crane
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mustafa S Makia
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | - Mashal Kakakhel
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA
| | | | - Muayyad R Al-Ubaidi
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
| | - Muna I Naash
- Department of Biomedical Engineering, University of Houston, Houston, TX, 77204, USA.
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Genetic characteristics of suspected retinitis pigmentosa in a cohort of Chinese patients. Gene 2023; 853:147087. [PMID: 36464167 DOI: 10.1016/j.gene.2022.147087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
The study aimed to screen for the causative variants in Chinese patients with suspected retinitis pigmentosa (RP). A cohort of 75 unrelated Chinese patients with a clinical diagnosis of RP and their available family members were enrolled in this study. Genomic DNA of all subjects was extracted and whole-exome sequencing (WES) was applied. Candidate variants were identified, and minigene assays were conducted to evaluate the pathogenicity of novel splicing variants. Totally, the diagnostic yield was 44 % (33/75) and 16 novel variants that had not been reported previously were found. Among the genetically solved 33 cases, 31 patients were identified as carrying causative variants of RP and 2 patients carried pathogenic variants implicated in other retinal diseases. USH2A, CYP4V2, and RPGR were the most common causative genes, accounting for about half of the genetically solved cases. Moreover, minigene assays validated that the novel splicing variants were detrimental. Additionally, 9 patients carried a single deleterious heterozygous variant in 6 genes with autosomal recessive hereditary patterns, and no corresponding copy number variants (CNVs) was detected. The findings of this study revealed the genetic landscape of RP in China and provided guidance for clinicians.
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Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction. HGG ADVANCES 2023; 4:100181. [PMID: 36785559 PMCID: PMC9918427 DOI: 10.1016/j.xhgg.2023.100181] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 01/12/2023] [Indexed: 01/19/2023] Open
Abstract
A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.
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Xing D, Yu R, Wang L, Hu L, Yang Y, Li C, Li Z, Li X. Novel mutations of the USH2A gene cause Usher syndrome in five Chinese families. BMC Ophthalmol 2022; 22:317. [PMID: 35870892 PMCID: PMC9308926 DOI: 10.1186/s12886-022-02532-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 07/11/2022] [Indexed: 11/18/2022] Open
Abstract
Background Usher syndrome (USH) is a leading disorder of deaf–blindness. The phenotypic and genetic heterogeneity of USH makes the diagnosis of this disorder difficult. However, diagnosis can be facilitated by employing molecular approaches, especially for diseases without pronounced pathognomonic symptoms. Therefore, this study aimed to reveal the genetic defects in five USH patients using clinical targeted exome sequencing (TES). Methods USH patients and their family members from five unrelated Chinese USH families were recruited and subjected to TES. Ophthalmic information was obtained for all patients to ensure a meaningful interpretation. The TES data were analysed using an established bioinformatics pipeline to identify causative mutations. Further verification by Sanger sequencing and cosegregation analysis were performed on available family members. Results We identified genetic mutations in five USH patients using TES. Seven mutations, four of which were novel, were identified in the USH2A gene. One proband (F1-II-3) was found to have a homozygous mutation inherited from nonconsanguineous parents, and another proband (F5-III-1) was found to carry three USH2A gene mutations. Conclusion In conclusion, the study revealed the importance of TES in the clinical diagnosis of USH patients with variable phenotypes. The correlation between USH2A gene mutations and clinical phenotypes will help to refine the clinical diagnosis of USH. Supplementary Information The online version contains supplementary material available at 10.1186/s12886-022-02532-6.
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Whole-Exome Sequencing Revealed New Candidate Genes for Human Dilated Cardiomyopathy. Diagnostics (Basel) 2022; 12:diagnostics12102411. [PMID: 36292100 PMCID: PMC9600457 DOI: 10.3390/diagnostics12102411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/29/2022] [Accepted: 10/02/2022] [Indexed: 11/17/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is a complex disease affecting young adults. It is a pathological condition impairing myocardium activity that leads to heart failure and, in the most severe cases, transplantation, which is currently the only possible therapy for the disease. DCM can be attributed to many genetic determinants interacting with environmental factors, resulting in a highly variable phenotype. Due to this complexity, the early identification of causative gene mutations is an important goal to provide a genetic diagnosis, implement pre-symptomatic interventions, and predict prognosis. The advent of next-generation sequencing (NGS) has opened a new path for mutation screening, and exome sequencing provides a promising approach for identifying causal variants in known genes and novel disease-associated candidates. We analyzed the whole-exome sequencing (WES) of 15 patients affected by DCM without overloading (hypertension, valvular, or congenital heart disease) or chronic ischemic conditions. We identified 70 pathogenic or likely pathogenic variants and 1240 variants of uncertain clinical significance. Gene ontology enrichment analysis was performed to assess the potential connections between affected genes and biological or molecular function, identifying genes directly related to extracellular matrix organization, transcellular movement through the solute carrier and ATP-binding cassette transporter, and vitamin B12 metabolism. We found variants in genes implicated to a different extent in cardiac function that may represent new players in the complex genetic scenario of DCM.
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Major L, McClements ME, MacLaren RE. New CRISPR Tools to Correct Pathogenic Mutations in Usher Syndrome. Int J Mol Sci 2022; 23:ijms231911669. [PMID: 36232969 PMCID: PMC9569511 DOI: 10.3390/ijms231911669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/28/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022] Open
Abstract
Inherited retinal degenerations are a leading cause of blindness in the UK. Significant advances have been made to tackle this issue in recent years, with a pioneering FDA approved gene therapy treatment (Luxturna®), which targets a loss of function mutation in the RPE65 gene. However, there remain notable shortcomings to this form of gene replacement therapy. In particular, the lack of viability for gene sequences exceeding the 4.7 kb adeno-associated virus (AAV) packaging limit or for toxic gain of function mutations. The USH2A gene at ~15.7 kb for instance is too large for AAV delivery: a safe and effective vehicle capable of transducing photoreceptor cells for gene replacement therapy. Usher Syndrome is a clinically and genetically heterogenous deaf-blindness syndrome with autosomal recessive inheritance. The USH2A gene encodes the protein usherin, which localises to the photoreceptor cilium and cochlear hair cells. Mutations in the USH2A gene cause Usher Syndrome type II (USH2), which is the most common subtype of Usher Syndrome and the focus of this review. To date, researchers have been unable to create an efficient, safe editing tool that is small enough to fit inside a single AAV vector for delivery into human cells. This article reviews the potential of CRISPR technology, derived from bacterial defence mechanisms, to overcome these challenges; delivering tools to precisely edit and correct small insertions, deletions and base transitions in USH2A without the need to deliver the full-length gene. Such an ultra-compact therapy could make strides in combating a significant cause of blindness in young people.
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Affiliation(s)
- Lauren Major
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
| | - Michelle E. McClements
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
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Su T, Liang L, Zhang L, Wang J, Chen L, Su C, Cao J, Yu Q, Deng S, Chan HF, Tang S, Guo Y, Chen J. Retinal organoids and microfluidic chip-based approaches to explore the retinitis pigmentosa with USH2A mutations. Front Bioeng Biotechnol 2022; 10:939774. [PMID: 36185441 PMCID: PMC9524156 DOI: 10.3389/fbioe.2022.939774] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 08/23/2022] [Indexed: 11/19/2022] Open
Abstract
Retinitis pigmentosa (RP) is a leading cause of vision impairment and blindness worldwide, with limited medical treatment options. USH2A mutations are one of the most common causes of non-syndromic RP. In this study, we developed retinal organoids (ROs) and retinal pigment epithelium (RPE) cells from induced pluripotent stem cells (iPSCs) of RP patient to establish a sustainable in vitro RP disease model. RT-qPCR, western blot, and immunofluorescent staining assessments showed that USH2A mutations induced apoptosis of iPSCs and ROs, and deficiency of the extracellular matrix (ECM) components. Transcriptomics and proteomics findings suggested that abnormal ECM-receptor interactions could result in apoptosis of ROs with USH2A mutations via the PI3K-Akt pathway. To optimize the culture conditions of ROs, we fabricated a microfluidic chip to co-culture the ROs with RPE cells. Our results showed that this perfusion system could efficiently improve the survival rate of ROs. Further, ECM components such as laminin and collagen IV of ROs in the RP group were upregulated compared with those maintained in static culture. These findings illustrate the potential of microfluidic chip combined with ROs technology in disease modelling for RP.
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Affiliation(s)
- Ting Su
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Liying Liang
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Lan Zhang
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jianing Wang
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
| | - Luyin Chen
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
| | - Caiying Su
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Jixing Cao
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
| | - Quan Yu
- Centric Laboratory, Medical College, Jinan University, Guangzhou, China
| | - Shuai Deng
- Institute for Tissue Engineering and Regenerative Medicine, Chinese University of Hong Kong, Hong Kong, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | - Hon Fai Chan
- Institute for Tissue Engineering and Regenerative Medicine, Chinese University of Hong Kong, Hong Kong, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education of China, Ministry of Education of China, School of Biomedical Sciences, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong, China
| | | | - Yonglong Guo
- Department of Ophthalmology, First Affiliated Hospital of Jinan University, Jinan University, Guangzhou, China
- College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
- *Correspondence: Jiansu Chen, ; Yonglong Guo,
| | - Jiansu Chen
- Key Laboratory for Regenerative Medicine, Ministry of Education, Jinan University, Guangzhou, China
- Aier Eye Institute, Changsha, China
- Institute of Ophthalmology, Medical College, Jinan University, Guangzhou, China
- *Correspondence: Jiansu Chen, ; Yonglong Guo,
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Li W, Jiang XS, Han DM, Gao JY, Yang ZT, Jiang L, Zhang Q, Zhang SH, Gao Y, Wu JH, Li JK. Genetic Characteristics and Variation Spectrum of USH2A-Related Retinitis Pigmentosa and Usher Syndrome. Front Genet 2022; 13:900548. [PMID: 36110214 PMCID: PMC9468824 DOI: 10.3389/fgene.2022.900548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/10/2022] [Indexed: 11/13/2022] Open
Abstract
Purposes: We aimed to characterize the USH2A genotypic spectrum in a Chinese cohort and provide a detailed genetic profile for Chinese patients with USH2A-IRD.Methods: We designed a retrospective study wherein a total of 1,334 patients diagnosed with IRD were included as a study cohort, namely 1,278 RP and 56 USH patients, as well as other types of IEDs patients and healthy family members as a control cohort. The genotype-phenotype correlation of all participants with USH2A variant was evaluated.Results: Etiological mutations in USH2A, the most common cause of RP and USH, were found in 16.34% (n = 218) genetically solved IRD patients, with prevalences of 14.87% (190/1,278) and 50% (28/56). After bioinformatics and QC processing, 768 distinct USH2A variants were detected in all participants, including 136 disease-causing mutations present in 665 alleles, distributed in 5.81% of all participants. Of these 136 mutations, 43 were novel, nine were founder mutations, and two hot spot mutations with allele count ≥10. Furthermore, 38.5% (84/218) of genetically solved USH2A-IRD patients were caused by at least one of both c.2802T>G and c.8559–2 A>G mutations, and 36.9% and 69.6% of the alleles in the RP and USH groups were truncating, respectively.Conclusion: USH2A-related East Asian-specific founder and hot spot mutations were the major causes for Chinese RP and USH patients. Our study systematically delineated the genotype spectrum of USH2A-IRD, enabled accurate genetic diagnosis, and provided East Asian and other ethnicities with baseline data of a Chinese origin, which would better serve genetic counseling and therapeutic targets selection.
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Affiliation(s)
- Wei Li
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Xiao-Sen Jiang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Dong-Ming Han
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Jia-Yu Gao
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Zheng-Tao Yang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Li Jiang
- Department of Ophthalmology, Laizhou City People’s Hospital, Yantai, China
| | - Qian Zhang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- BGI-Shenzhen, Shenzhen, China
| | - Sheng-Hai Zhang
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
| | - Ya Gao
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Ji-Hong Wu
- Eye Institute, Eye and ENT Hospital, College of Medicine, Fudan University, Shanghai, China
- Shanghai Key Laboratory of Visual Impairment and Restoration, Science and Technology Commission of Shanghai Municipality, Shanghai, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
| | - Jian-Kang Li
- BGI-Shenzhen, Shenzhen, China
- *Correspondence: Wei Li, ; Ya Gao, ; Ji-Hong Wu, ; Jian-Kang Li,
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Santos DF, Molina Thurin LJ, Gustavo Vargas J, Izquierdo NJ, Oliver A. A Genotype-Phenotype Analysis of Usher Syndrome in Puerto Rico: A Case Series. Cureus 2022; 14:e28213. [PMID: 36003347 PMCID: PMC9392863 DOI: 10.7759/cureus.28213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2022] [Indexed: 11/15/2022] Open
Abstract
Introduction Patients with Usher syndrome (USH) have retinitis pigmentosa (RP) and hearing loss inherited as an autosomal recessive (ar) trait. Mutations in the USH2A gene are the most common cause of Usher syndrome. We report the genotype-phenotype correlation in 10 patients with Usher syndrome from Puerto Rico (PR). This is the first genotype-phenotype analysis of patients with the syndrome in PR. Methods We conducted a chart review of patients who carried an Usher syndrome diagnosis. They underwent a comprehensive ophthalmic evaluation by at least one of the authors. This included best corrected visual acuity (BCVA), visual field mean deviation (VF MD), pattern standard deviation (PSD), and macular optical coherence tomography (mOCT) average volume and thickness. Genotyping was done using the Invitae Inherited Retinal Disease (IRD) Panel. Results Three patients had a logMAR BCVA of 1.0 or worse. The median VF MD was -29.7 dB and -29.2 dB in the OD and OS, respectively. The median PSD was 5.5 dB and 5.7 dB in the OD and OS, respectively. Upon macular OCT, patients had a median volume of 8.4 μm3 and 8 μm3 in the OD and OS, respectively. The median thickness was 235 μm and 223 μm in the OD and OS, respectively. All patients had pathogenic USH2A variants, and eight of these were compound heterozygotes. The most common variants were p.Cys575Tyr and p.Glu767Serfs*21, each present in four patients. Patients with the p.Cys759Phe variant had the worst phenotype with the worst BCVA, largest VF MD, and slimmer macular thickness. Conclusion Our findings are compatible with previously reported pathogenic mutations in the USH2A gene. However, the p.Cys759Phe variant has previously been correlated with a mild phenotype. In our study, the p.Cys759Phe variant correlated with the most severe phenotype. This variant has a high prevalence in the Spanish population, and PR was a Spanish colony for 400 years. The presence of this variant could be traced back to Spain. Genotyping patients with Usher syndrome is of utmost importance. Further studies to evaluate the common founder effect of patients with the syndrome in PR are warranted.
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Feenstra HM, Al-Khuzaei S, Shah M, Broadgate S, Shanks M, Kamath A, Yu J, Jolly JK, MacLaren RE, Clouston P, Halford S, Downes SM. Phenotypic and Genetic Characteristics in a Cohort of Patients with Usher Genes. Genes (Basel) 2022; 13:genes13081423. [PMID: 36011334 PMCID: PMC9407802 DOI: 10.3390/genes13081423] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/28/2022] [Accepted: 08/08/2022] [Indexed: 11/24/2022] Open
Abstract
Background: This study aimed to compare phenotype−genotype correlation in patients with Usher syndrome (USH) to those with autosomal recessive retinitis pigmentosa (NS-ARRP) caused by genes associated with Usher syndrome. Methods: Case notes of patients with USH or NS-ARRP and a molecularly confirmed diagnosis in genes associated with Usher syndrome were reviewed. Phenotypic information, including the age of ocular symptoms, hearing impairment, visual acuity, Goldmann visual fields, fundus autofluorescence (FAF) imaging and spectral domain optical coherence tomography (OCT) imaging, was reviewed. The patients were divided into three genotype groups based on variant severity for genotype-phenotype correlations. Results: 39 patients with Usher syndrome and 33 patients with NS-ARRP and a molecular diagnosis in an Usher syndrome-related gene were identified. In the 39 patients diagnosed with Usher syndrome, a molecular diagnosis was confirmed as follows: USH2A (28), MYO7A (4), CDH23 (2), USH1C (2), GPR98/VLGR1 (2) and PCDH15 (1). All 33 patients with NS-ARRP had variants in USH2A. Further analysis was performed on the patients with USH2A variants. USH2A patients with syndromic features had an earlier mean age of symptom onset (17.9 vs. 31.7 years, p < 0.001), had more advanced changes on FAF imaging (p = 0.040) and were more likely to have cystoid macular oedema (p = 0.021) when compared to USH2A patients presenting with non-syndromic NS-ARRP. Self-reported late-onset hearing loss was identified in 33.3% of patients with NS-ARRP. Having a syndromic phenotype was associated with more severe USH2A variants (p < 0.001). Eighteen novel variants in genes associated with Usher syndrome were identified in this cohort. Conclusions: Patients with Usher syndrome, whatever the associated gene in this cohort, tended to have an earlier onset of retinal disease (other than GPR98/VLGR1) when compared to patients presenting with NS-ARRP. Analysis of genetic variants in USH2A, the commonest gene in our cohort, showed that patients with a more severe genotype were more likely to be diagnosed with USH compared to NS-ARRP. USH2A patients with syndromic features have an earlier onset of symptoms and more severe features on FAF and OCT imaging. However, a third of patients diagnosed with NS-ARRP developed later onset hearing loss. Eighteen novel variants in genes associated with Usher syndrome were identified in this cohort, thus expanding the genetic spectrum of known pathogenic variants. An accurate molecular diagnosis is important for diagnosis and prognosis and has become particularly relevant with the advent of potential therapies for Usher-related gene
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Affiliation(s)
- Helena M. Feenstra
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Saoud Al-Khuzaei
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Mital Shah
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Morag Shanks
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7LE, UK
| | - Archith Kamath
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Jing Yu
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Wellcome Centre for Human Genetics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 7BN, UK
| | - Jasleen K. Jolly
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Vision and Eye Research Institute, Anglia Ruskin University, Cambridge CB1 1PT, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
| | - Penny Clouston
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7LE, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Susan M. Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 9DU, UK
- Correspondence:
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39
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Cross N, van Steen C, Zegaoui Y, Satherley A, Angelillo L. Current and Future Treatment of Retinitis Pigmentosa. Clin Ophthalmol 2022; 16:2909-2921. [PMID: 36071725 PMCID: PMC9441588 DOI: 10.2147/opth.s370032] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 07/14/2022] [Indexed: 12/16/2022] Open
Abstract
Retinitis Pigmentosa (RP) is a group of inherited retinal dystrophies (IRDs) characterised by progressive vision loss. Patients with RP experience a significant impact on daily activities, social interactions, and employment, reducing their quality of life. Frequent delays in referrals and no standard treatment for most patients also contribute to the high unmet need for RP. This paper aims to describe the evolving therapeutic landscape for RP including the rationale for advanced therapy medicinal products (ATMPs). A review of available data was conducted in three stages: (1) a search of publicly available literature; (2) qualitative research with physicians treating RP patients in France, Germany, Italy, Spain, and the UK; and (3) a review of leading candidates in the RP pipeline. Globally, there are currently over 100 drugs in development for RP; 50% of which are ATMPs. Amongst the 15 cell and gene therapies in late-stage development, 5 leading candidates have been selected to profile based on the development stage, drug target and geography: gene therapies AGN-151597, GS-030 and VMCO-1 and human stem cell therapies jCell and ReN-003. Hereditary retinal diseases are suitable for treatment with cell and gene therapies due to the accessibility of the retina and its immune privilege and compartmentalisation. Therapeutic approaches that aim to rescue photoreceptors (eg gene therapies) require that non-functional target cells are still present, whereas other therapies (eg cell therapies) are not reliant on the presence of viable photoreceptors. Gene therapies may be attractive as their fundamental goal is to restore vision; however, cell therapies will likely have a broader application and do not rely on genetic testing, which can delay treatment. Ensuring effective therapeutic options for RP patients across disease stages requires the continued diversification and advancement of the development pipeline, and sustained efforts to promote early patient identification and timely diagnosis.
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Affiliation(s)
| | - Cécile van Steen
- Market Access, Health Technology Assessment & Health Economics and Outcome Research, Europe, the Middle East and Africa, Santen GmbH, Munich, Bavaria, Germany
| | - Yasmina Zegaoui
- Market Access, Lightning Health, London, UK
- Correspondence: Yasmina Zegaoui, Market Access, Lightning Health, 8 Devonshire Square, London, EC2M 4PL, UK, Tel +44 7770918748, Email
| | | | - Luigi Angelillo
- Market Access, Health Technology Assessment & Health Economics and Outcome Research, Europe, the Middle East and Africa, Santen GmbH, Munich, Bavaria, Germany
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40
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Li MM, Tayoun AA, DiStefano M, Pandya A, Rehm HL, Robin NH, Schaefer AM, Yoshinaga-Itano C. Clinical evaluation and etiologic diagnosis of hearing loss: A clinical practice resource of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2022; 24:1392-1406. [PMID: 35802133 DOI: 10.1016/j.gim.2022.03.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 03/28/2022] [Indexed: 11/26/2022] Open
Abstract
Hearing loss is a common and complex condition that can occur at any age, can be inherited or acquired, and is associated with a remarkably wide array of etiologies. The diverse causes of hearing loss, combined with the highly variable and often overlapping presentations of different forms of hearing loss, challenge the ability of traditional clinical evaluations to arrive at an etiologic diagnosis for many deaf and hard-of-hearing individuals. However, identifying the etiology of hearing loss may affect clinical management, improve prognostic accuracy, and refine genetic counseling and assessment of the likelihood of recurrence for relatives of deaf and hard-of-hearing individuals. Linguistic and cultural identities associated with being deaf or hard-of-hearing can complicate access to and the effectiveness of clinical care. These concerns can be minimized when genetic and other health care services are provided in a linguistically and culturally sensitive manner. This clinical practice resource offers information about the frequency, causes, and presentations of hearing loss and suggests approaches to the clinical and genetic evaluation of deaf and hard-of-hearing individuals aimed at identifying an etiologic diagnosis and providing informative and effective patient education and genetic counseling.
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Affiliation(s)
- Marilyn M Li
- Department of Pathology and Laboratory Medicine, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Ahmad Abou Tayoun
- Al Jalila Genomics Center, Al Jalila Children's Specialty Hospital, Mohammed Bin Rashid University, Dubai, United Arab Emirates
| | | | - Arti Pandya
- Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC
| | - Heidi L Rehm
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA
| | - Nathaniel H Robin
- Departments of Genetics and Pediatrics, University of Alabama at Birmingham, Birmingham, AL
| | - Amanda M Schaefer
- Department of Otolaryngology-Head & Neck Surgery, Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA
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41
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Bhardwaj A, Yadav A, Yadav M, Tanwar M. Genetic dissection of non-syndromic retinitis pigmentosa. Indian J Ophthalmol 2022; 70:2355-2385. [PMID: 35791117 PMCID: PMC9426071 DOI: 10.4103/ijo.ijo_46_22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Retinitis pigmentosa (RP) belongs to a group of pigmentary retinopathies. It is the most common form of inherited retinal dystrophy, characterized by progressive degradation of photoreceptors that leads to nyctalopia, and ultimately, complete vision loss. RP is distinguished by the continuous retinal degeneration that progresses from the mid-periphery to the central and peripheral retina. RP was first described and named by Franciscus Cornelius Donders in the year 1857. It is one of the leading causes of bilateral blindness in adults, with an incidence of 1 in 3000 people worldwide. In this review, we are going to focus on the genetic heterogeneity of this disease, which is provided by various inheritance patterns, numerosity of variations and inter-/intra-familial variations based upon penetrance and expressivity. Although over 90 genes have been identified in RP patients, the genetic cause of approximately 50% of RP cases remains unknown. Heterogeneity of RP makes it an extremely complicated ocular impairment. It is so complicated that it is known as “fever of unknown origin”. For prognosis and proper management of the disease, it is necessary to understand its genetic heterogeneity so that each phenotype related to the various genetic variations could be treated.
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Affiliation(s)
- Aarti Bhardwaj
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Anshu Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Manoj Yadav
- Department of Genetics, M. D. University, Rohtak, Haryana, India
| | - Mukesh Tanwar
- Department of Genetics, M. D. University, Rohtak, Haryana, India
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42
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Scrutinizing pathogenicity of the USH2A c.2276 G > T; p.(Cys759Phe) variant. NPJ Genom Med 2022; 7:37. [PMID: 35672333 PMCID: PMC9174243 DOI: 10.1038/s41525-022-00306-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/10/2022] [Indexed: 11/23/2022] Open
Abstract
The USH2A variant c.2276 G > T (p.(Cys759Phe)) has been described by many authors as a frequent cause of autosomal recessive retinitis pigmentosa (arRP). However, this is in contrast with the description of two asymptomatic individuals homozygous for this variant. We therefore assessed pathogenicity of the USH2A c.2276 G > T variant using extensive genetic and functional analyses. Whole genome sequencing and optical genome mapping were performed for three arRP cases homozygous for USH2A c.2276 G > T to exclude alternative genetic causes. A minigene splice assay was designed to investigate the effect of c.2276 G > T on pre-mRNA splicing, in presence or absence of the nearby c.2256 T > C variant. Moreover, an ush2ap.(Cys771Phe) zebrafish knock-in model mimicking human p.(Cys759Phe) was generated and characterized using functional and immunohistochemical analyses. Besides the homozygous c.2276 G > T USH2A variant, no alternative genetic causes were identified. Evaluation of the ush2ap.(Cys771Phe) zebrafish model revealed strongly reduced levels of usherin expression at the photoreceptor periciliary membrane, increased levels of rhodopsin localization in the photoreceptor cell body and decreased electroretinogram (ERG) b-wave amplitudes compared to wildtype controls. In conclusion, we confirmed pathogenicity of USH2A c.2276 G > T (p.(Cys759Phe)). Consequently, cases homozygous for c.2276 G > T can now receive a definite genetic diagnosis and can be considered eligible for receiving future QR-421a-mediated exon 13 skipping therapy.
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43
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Jaffal L, Akhdar H, Joumaa H, Ibrahim M, Chhouri Z, Assi A, Helou C, Lee H, Seo GH, Joumaa WH, El Shamieh S. Novel Missense and Splice Site Mutations in USH2A, CDH23, PCDH15, and ADGRV1 Are Associated With Usher Syndrome in Lebanon. Front Genet 2022; 13:864228. [PMID: 35651951 PMCID: PMC9149366 DOI: 10.3389/fgene.2022.864228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/28/2022] [Indexed: 01/02/2023] Open
Abstract
The purpose of this study was to expand the mutation spectrum by searching the causative mutations in nine Lebanese families with Usher syndrome (USH) using whole-exome sequencing. The pathogenicity of candidate mutations was first evaluated according to their frequency, conservation, and in silico prediction tools. Then, it was confirmed via Sanger sequencing, followed by segregation analysis. Finally, a meta-analysis was conducted to calculate the prevalence of USH genes in the Lebanese population. Three missense mutations, two splice site mutations, and one insertion/deletion were detected in eight of the families. Four of these variants were novel: c.5535C > A; p.(Asn1845Lys) in exon 41 of CDH23, c.7130G > A; p.(Arg2377Gln) in exon 32 of ADGRV1, c.11390-1G > A in USH2A, and c.3999–6A > G in PCDH15. All the identified mutations were shown to be likely disease-causing through our bioinformatics analysis and co-segregated with the USH phenotype. The mutations were classified according to the ACMG standards. Finally, our meta-analysis showed that the mutations in ADGRV1, USH2A, and CLRN1 are the most prevalent and responsible for approximately 75% of USH cases in Lebanon. Of note, the frequency USH type 3 showed a relatively high incidence (23%) compared to the worldwide prevalence, which is around 2–4%. In conclusion, our study has broadened the mutational spectrum of USH and showed a high heterogeneity of this disease in the Lebanese population.
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Affiliation(s)
- Lama Jaffal
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon.,Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon
| | - Hanane Akhdar
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon.,Department of Biological and Chemical Sciences, School of Arts and Sciences, Lebanese International University, Beirut, Lebanon
| | - Hawraa Joumaa
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Mariam Ibrahim
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Zahraa Chhouri
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Alexandre Assi
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut, Lebanon
| | - Charles Helou
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut, Lebanon
| | - Hane Lee
- Rare Genetic Disease Research Center, 3billion Inc, Seoul, South Korea
| | - Go Hun Seo
- Rare Genetic Disease Research Center, 3billion Inc, Seoul, South Korea
| | - Wissam H Joumaa
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Said El Shamieh
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon.,Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
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Abstract
Inherited retinal dystrophies (IRDs) are a heterogeneous group of diseases that affect more than 2 million people worldwide. Gene therapy (GT) has emerged as an exciting treatment modality with the potential to provide long-term benefit to patients. Today, gene addition is the most straightforward GT for autosomal recessive IRDs. However, there are three scenarios where this approach falls short. First, in autosomal dominant diseases caused by gain-of-function or dominant-negative mutations, the toxic mutated protein needs to be silenced. Second, a number of IRD genes exceed the limited carrying capacity of adeno-associated virus vectors. Third, there are still about 30% of patients with unknown mutations. In the first two contexts, precise editing tools, such as CRISPR-Cas9, base editors, or prime editors, are emerging as potential GT solutions for the treatment of IRDs. Here, we review gene editing tools based on CRISPR-Cas9 technology that have been used in vivo and the recent first-in-human application of CRISPR-Cas9 in an IRD.
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Affiliation(s)
- Juliette Pulman
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - José-Alain Sahel
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.,Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,CHNO des Quinze-Vingts, INSERM-DGOS CIC 1423, Paris, France.,Fondation Ophtalmologique Rothschild, Paris, France
| | - Deniz Dalkara
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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45
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Gill JS, Theofylaktopoulos V, Mitsios A, Houston S, Hagag AM, Dubis AM, Moosajee M. Investigating Biomarkers for USH2A Retinopathy Using Multimodal Retinal Imaging. Int J Mol Sci 2022; 23:ijms23084198. [PMID: 35457016 PMCID: PMC9024786 DOI: 10.3390/ijms23084198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/03/2022] [Accepted: 04/06/2022] [Indexed: 12/13/2022] Open
Abstract
Pathogenic mutations in USH2A are a leading cause of visual loss secondary to non-syndromic or Usher syndrome-associated retinitis pigmentosa (RP). With an increasing number of RP-targeted clinical trials in progress, we sought to evaluate the photoreceptor topography underlying patterns of loss observed on clinical retinal imaging to guide surrogate endpoint selection in USH2A retinopathy. In this prospective cross-sectional study, twenty-five patients with molecularly confirmed USH2A-RP underwent fundus autofluorescence (FAF), spectral-domain optical coherence tomography (SD-OCT) and adaptive optics scanning laser ophthalmoscopy (AOSLO) retinal imaging. Analysis comprised measurement of FAF horizontal inner (IR) and outer (OR) hyperautofluorescent ring diameter; SD-OCT ellipsoid zone (EZ) and external limiting membrane (ELM) width, normalised EZ reflectance; AOSLO foveal cone density and intact macular photoreceptor mosaic (IMPM) diameter. Thirty-two eyes from 16 patients (mean age ± SD, 36.0 ± 14.2 years) with USH2A-associated Usher syndrome type 2 (n = 14) or non-syndromic RP (n = 2) met the inclusion criteria. Spatial alignment was observed between IR-EZ and OR-ELM diameters/widths (p < 0.001). The IMPM border occurred just lateral to EZ loss (p < 0.001), although sparser intact photoreceptor inner segments were detected until ELM disruption. EZ width and IR diameter displayed a biphasic relationship with cone density whereby slow cone loss occurred until retinal degeneration reached ~1350 μm from the fovea, beyond which greater reduction in cone density followed. Normalised EZ reflectance and cone density were significantly associated (p < 0.001). As the strongest correlate of cone density (p < 0.001) and best-corrected visual acuity (p < 0.001), EZ width is the most sensitive biomarker of structural and functional decline in USH2A retinopathy, rendering it a promising trial endpoint.
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Affiliation(s)
- Jasdeep S. Gill
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
| | - Vasileios Theofylaktopoulos
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
| | - Andreas Mitsios
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Sarah Houston
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
| | - Ahmed M. Hagag
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Adam M. Dubis
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Global Business School for Health, University College London, London WC1E 6BT, UK
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK; (J.S.G.); (V.T.); (A.M.); (S.H.); (A.M.H.); (A.M.D.)
- NIHR Moorfields Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 3JH, UK
- Correspondence: ; Tel.: +44-207-608-6971
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The genetic and phenotypic landscapes of Usher syndrome: from disease mechanisms to a new classification. Hum Genet 2022; 141:709-735. [PMID: 35353227 PMCID: PMC9034986 DOI: 10.1007/s00439-022-02448-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/04/2022] [Indexed: 12/16/2022]
Abstract
Usher syndrome (USH) is the most common cause of deaf–blindness in humans, with a prevalence of about 1/10,000 (~ 400,000 people worldwide). Cochlear implants are currently used to reduce the burden of hearing loss in severe-to-profoundly deaf patients, but many promising treatments including gene, cell, and drug therapies to restore the native function of the inner ear and retinal sensory cells are under investigation. The traditional clinical classification of Usher syndrome defines three major subtypes—USH1, 2 and 3—according to hearing loss severity and onset, the presence or absence of vestibular dysfunction, and age at onset of retinitis pigmentosa. Pathogenic variants of nine USH genes have been initially reported: MYO7A, USH1C, PCDH15, CDH23, and USH1G for USH1, USH2A, ADGRV1, and WHRN for USH2, and CLRN1 for USH3. Based on the co-occurrence of hearing and vision deficits, the list of USH genes has been extended to few other genes, but with limited supporting information. A consensus on combined criteria for Usher syndrome is crucial for the development of accurate diagnosis and to improve patient management. In recent years, a wealth of information has been obtained concerning the properties of the Usher proteins, related molecular networks, potential genotype–phenotype correlations, and the pathogenic mechanisms underlying the impairment or loss of hearing, balance and vision. The advent of precision medicine calls for a clear and more precise diagnosis of Usher syndrome, exploiting all the existing data to develop a combined clinical/genetic/network/functional classification for Usher syndrome.
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47
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Meunier A, Zanlonghi X, Roux AF, Fils JF, Caspers L, Migeotte I, Abramowicz M, Meunier I. Natural history of Usher type 2 with the c.2299delG mutation of USH2A in a large cohort. Ophthalmic Genet 2022; 43:470-475. [PMID: 35345973 DOI: 10.1080/13816810.2022.2051191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND The c.2299delG mutation is prevalent and accounts for 24.5% USH2A pathogenic variants, with promising prospects for customized gene therapy. MATERIALS AND METHODS We compared the ocular and auditory phenotypes in a retrospective cohort of 169 Usher type 2 patients, with and without the c.2299delG allele, including visual acuity, slit-lamp examination, optical coherence tomography, kinetic perimetry, and audiometric assessment to define the hearing disability. Statistical methods used were covariate balancing propensity score and adjusted survival curves log-rank test for the analysis of visual acuity. RESULTS We compare 54 Usher patients (31%) carrying at least one c.2299delG allele to 109 patients without this variant. The mean ages at onset of night blindness (14 years) and onset of peripheral vision deficiency (24 years) were similar in both groups, as was the severity of hearing loss (p = 0.731), even in homozygotes (p = 0.136). Based on the covariate balancing propensity score, the c.2299delG carrier patients developed cataract and reached a BCVA of 20/63 earlier than patients without this mutation (mean age 36 versus 42 y.o.; and 52.2 versus 55.1 y.o., respectively). Using adjusted survival curves and a log-rank test based on inverse probability weighting, patients with the c.2299delG variant reach blindness (BCVA <20/400) at 42.3 years old instead of 79.8 years for other USH2A pathogenic variants. CONCLUSIONS We conclude that c.2299delG is associated with a more severe phenotype of the Usher type 2, in homozygotes and in compound heterozygotes.
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Affiliation(s)
- Audrey Meunier
- Department of Ophthalmology, University Hospital Saint-Pierre, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Xavier Zanlonghi
- Centre de compétence Maladies rares, Jules Verne Clinic, Nantes, France
| | - Anne-Françoise Roux
- Laboratory of Molecular Genetics, University of Montpellier, Montpellier University Hospital, Montpellier, France.,Institute for Neurosciences of Montpellier, INSERM, University of Montpellier, Montpellier, France
| | | | - Laure Caspers
- Department of Ophthalmology, University Hospital Saint-Pierre, Université Libre de Bruxelles (ULB), Bruxelles, Belgium
| | - Isabelle Migeotte
- Genetic department, IRIBHM, Université Libre de Bruxelles, Bruxelles, Belgium
| | - Marc Abramowicz
- Genetic department, IRIBHM, Université Libre de Bruxelles, Bruxelles, Belgium.,Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier, INSERM, University of Montpellier, Montpellier, France.,National center in rare diseases Maolya, Genetics of Sensory Diseases, University Hospital, Sensgene Care Network, Montpellier, France
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48
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Eintracht J, Harding P, Lima Cunha D, Moosajee M. Efficient embryoid-based method to improve generation of optic vesicles from human induced pluripotent stem cells. F1000Res 2022; 11:324. [PMID: 35811797 PMCID: PMC9218590 DOI: 10.12688/f1000research.108829.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/08/2022] [Indexed: 01/02/2023] Open
Abstract
Animal models have provided many insights into ocular development and disease, but they remain suboptimal for understanding human oculogenesis. Eye development requires spatiotemporal gene expression patterns and disease phenotypes can differ significantly between humans and animal models, with patient-associated mutations causing embryonic lethality reported in some animal models. The emergence of human induced pluripotent stem cell (hiPSC) technology has provided a new resource for dissecting the complex nature of early eye morphogenesis through the generation of three-dimensional (3D) cellular models. By using patient-specific hiPSCs to generate in vitro optic vesicle-like models, we can enhance the understanding of early developmental eye disorders and provide a pre-clinical platform for disease modelling and therapeutics testing. A major challenge of in vitro optic vesicle generation is the low efficiency of differentiation in 3D cultures. To address this, we adapted a previously published protocol of retinal organoid differentiation to improve embryoid body formation using a microwell plate. Established morphology, upregulated transcript levels of known early eye-field transcription factors and protein expression of standard retinal progenitor markers confirmed the optic vesicle/presumptive optic cup identity of in vitro models between day 20 and 50 of culture. This adapted protocol is relevant to researchers seeking a physiologically relevant model of early human ocular development and disease with a view to replacing animal models.
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Affiliation(s)
- Jonathan Eintracht
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Philippa Harding
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Dulce Lima Cunha
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Mariya Moosajee
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
- The Francis Crick Institute, London, NW1 1AT, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
- Great Ormond Street Hospital for Children, London, WC1N 3JH, UK
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49
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Fenner BJ, Tan TE, Barathi AV, Tun SBB, Yeo SW, Tsai ASH, Lee SY, Cheung CMG, Chan CM, Mehta JS, Teo KYC. Gene-Based Therapeutics for Inherited Retinal Diseases. Front Genet 2022; 12:794805. [PMID: 35069693 PMCID: PMC8782148 DOI: 10.3389/fgene.2021.794805] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Inherited retinal diseases (IRDs) are a heterogenous group of orphan eye diseases that typically result from monogenic mutations and are considered attractive targets for gene-based therapeutics. Following the approval of an IRD gene replacement therapy for Leber's congenital amaurosis due to RPE65 mutations, there has been an intensive international research effort to identify the optimal gene therapy approaches for a range of IRDs and many are now undergoing clinical trials. In this review we explore therapeutic challenges posed by IRDs and review current and future approaches that may be applicable to different subsets of IRD mutations. Emphasis is placed on five distinct approaches to gene-based therapy that have potential to treat the full spectrum of IRDs: 1) gene replacement using adeno-associated virus (AAV) and nonviral delivery vectors, 2) genome editing via the CRISPR/Cas9 system, 3) RNA editing by endogenous and exogenous ADAR, 4) mRNA targeting with antisense oligonucleotides for gene knockdown and splicing modification, and 5) optogenetic approaches that aim to replace the function of native retinal photoreceptors by engineering other retinal cell types to become capable of phototransduction.
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Affiliation(s)
- Beau J Fenner
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Tien-En Tan
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | | | - Sai Bo Bo Tun
- Singapore Eye Research Institute, Singapore, Singapore
| | - Sia Wey Yeo
- Singapore Eye Research Institute, Singapore, Singapore
| | - Andrew S H Tsai
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Shu Yen Lee
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Chui Ming Gemmy Cheung
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Choi Mun Chan
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
| | - Jodhbir S Mehta
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore.,School of Material Science and Engineering, Nanyang Technological University, Singapore, Singapore.,Yong Loo Lin School of Medicine, Department of Ophthalmology, National University of Singapore, Singapore, Singapore
| | - Kelvin Y C Teo
- Singapore National Eye Centre, Singapore, Singapore.,Singapore Eye Research Institute, Singapore, Singapore.,Duke-NUS Graduate Medical School, Ophthalmology and Visual Sciences Academic Clinical Programme, Singapore, Singapore
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50
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Girach A, Audo I, Birch DG, Huckfeldt RM, Lam BL, Leroy BP, Michaelides M, Russell SR, Sallum JM, Stingl K, Tsang SH, Yang P. RNA-based therapies in inherited retinal diseases. Ther Adv Ophthalmol 2022; 14:25158414221134602. [PMID: 36388727 PMCID: PMC9643766 DOI: 10.1177/25158414221134602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 10/05/2022] [Indexed: 11/10/2023] Open
Abstract
Inherited retinal diseases (IRDs) are a genetically and phenotypically heterogeneous group of genetic eye disorders. There are more than 300 disease entities, and together this group of disorders affects millions of people globally and is a frequent cause of blindness or low-vision certification. However, each type is rare or ultra-rare. Characteristically, the impaired vision in IRDs is due to retinal photoreceptor dysfunction and loss resulting from mutation in a gene that codes for a retinal protein. Historically, IRDs have been considered incurable and individuals living with these blinding conditions could be offered only supportive care. However, the treatment landscape for IRDs is beginning to evolve. Progress is being made, driven by improvements in understanding of genotype-phenotype relationships, through advances in molecular genetic testing and retinal imaging. Alongside this expanding knowledge of IRDs, the current era of precision medicine is fueling a growth in targeted therapies. This has resulted in the first treatment for an IRD being approved. Several other therapies are currently in development in the IRD space, including RNA-based therapies, gene-based therapies (such as augmentation therapy and gene editing), cell therapy, visual prosthetics, and optogenetics. RNA-based therapies are a novel approach within precision medicine that have demonstrated success, particularly in rare diseases. Three antisense oligonucleotides (AONs) are currently in development for the treatment of specific IRD subtypes. These RNA-based therapies bring several key advantages in the setting of IRDs, and the potential to bring meaningful vision benefit to individuals living with inherited blinding disorders. This review will examine the increasing breadth and relevance of RNA-based therapies in clinical medicine, explore the key features that make AONs suitable for treating genetic eye diseases, and provide an overview of the three-leading investigational AONs in clinical trials.
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Affiliation(s)
- Aniz Girach
- ProQR Therapeutics, Zernikedreef 9, 2333 CK
Leiden, the Netherlands
| | - Isabelle Audo
- Centre Hospitalier National d’Ophtalmologie des
Quinze-Vingts, Centre de référence maladies rares REFERET and INSERM-DHOS
CIC 1423, CHNO des Quinze-Vingts, Paris, France
- Institute of Ophthalmology, University College
London, London, UK
- Sorbonne Université, INSERM, CNRS, Institut de
la Vision, Paris, France
| | | | - Rachel M. Huckfeldt
- Department of Ophthalmology, Harvard Medical
School, Massachusetts Eye and Ear Infirmary, Boston, MA, USA
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of
Miami Miller School of Medicine, Miami, FL, USA
| | - Bart P. Leroy
- Department of Ophthalmology & Center for
Medical Genetics, Ghent University Hospital & Ghent University, Ghent,
Belgium
- Division of Ophthalmology & Center for
Cellular & Molecular Therapeutics, The Children’s Hospital of
Philadelphia, Philadelphia, PA, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University
College London and Moorfields Eye Hospital, London, UK
| | - Stephen R. Russell
- The University of Iowa Institute for Vision
Research, University of Iowa, Iowa City, IA, USA
| | - Juliana M.F. Sallum
- Department of Ophthalmology, Universidade
Federal de São Paulo, São Paulo, Brazil
- Instituto de Genética Ocular, São Paulo,
Brazil
| | - Katarina Stingl
- Center for Ophthalmology, University Eye
Hospital, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of
Tübingen, Tübingen, Germany
| | - Stephen H. Tsang
- Jonas Children’s Vision Care and Bernard and
Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Vagelos
College of Physicians and Surgeons, Columbia University, New York, NY,
USA
- Edward S. Harkness Eye Institute, New
York-Presbyterian Hospital, New York, NY, USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health &
Science University, Portland, OR, USA
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