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Wu PL, Lin PH, Lee W, Wang EHH, Kang EYC, Liu L, Wang NK. A GUCY2D variant associated cone-rod dystrophy with electronegative ERG: A case report and review. Am J Ophthalmol Case Rep 2024; 36:102094. [PMID: 39100576 PMCID: PMC11294699 DOI: 10.1016/j.ajoc.2024.102094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 06/10/2024] [Accepted: 06/17/2024] [Indexed: 08/06/2024] Open
Abstract
Purpose Cone-rod dystrophies (CORD) are inherited retinal dystrophies characterized by primary cone degeneration with secondary rod involvement. We report two patients from the same family with a dominant variant in the guanylate cyclase 2D (GUCY2D) gene with different phenotypes in the electroretinogram (ERG). Observations A 21-year-old lady (Patient 1) was referred due to experiencing blurry vision and color vision impairment. Visual field testing revealed a central scotoma. Spectral-domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF) documented macula dysfunction. Reduced amplitude was observed in the photopic responses of ERG. Her 54-year-old father (Patient 2) had similar issues with blurry vision. A dilated fundus examination displayed bilateral macular atrophy. Loss of the ellipsoid zone line and collapse of the outer nuclear segment were noted on the SD-OCT. Photopic ERG responses were extinguished, and an electronegative ERG was observed in the dark-adapted 3.0 ERG. The gene report revealed a c.2512C > T (p.Arg838Cys) variant in GUCY2D for both patients. They were respectively diagnosed as cone dystrophy (COD) and cone-rod dystrophy (CORD). Conclusions We report two different clinical phenotypes in GUCY2D-associated COD despite sharing the same variant. A dysfunction in the synaptic junction between the photoreceptor and the secondary neuron was proposed to explain the electronegative ERG. This explanation might extend to other gene-related cases of CORD with electronegative ERG.
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Affiliation(s)
- Pei-Liang Wu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
- College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Pei-Hsuan Lin
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
- Department of Ophthalmology, National Taiwan University Yunlin Branch, Yunlin, Taiwan
| | - Winston Lee
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
| | - Ethan Hung-Hsi Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
- College of Arts and Sciences, University of Miami, Coral Gables, FL, USA
| | - Eugene Yu-Chuan Kang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Laura Liu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- School of Traditional Chinese Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Nan-Kai Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University, New York, NY, USA
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- Vagelos College of Physicians and Surgeons, Columbia University, New York, USA
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Hahn LC, van der Veen I, Georgiou M, van Schooneveld MJ, Ten Brink JB, Florijn RJ, Mahroo OA, de Carvalho ER, Webster AR, Bergen AA, Michaelides M, Boon CJF. Clinical, Genetic, and Histopathological Characteristics of CRX-associated Retinal Dystrophies. Ophthalmol Retina 2024:S2468-6530(24)00365-8. [PMID: 39128788 DOI: 10.1016/j.oret.2024.08.003] [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: 02/25/2024] [Revised: 08/04/2024] [Accepted: 08/05/2024] [Indexed: 08/13/2024]
Abstract
PURPOSE To describe phenotypic, genotypic, and histopathological features of inherited retinal dystrophies associated with the CRX gene (CRX-RDs). DESIGN Retrospective multicenter cohort study including histopathology. SUBJECTS Thirty-nine patients from 31 families with pathogenic variants in the CRX gene. METHODS Clinical data of 152 visits were collected from medical records. The median follow-up time was 9.1 years (interquartile range (IQR), 3.3-15.3 years; range, 0.0-48.8 years). Histopathologic examination of the eye of a 17-year-old patient with advanced early-onset CRX-RD was performed. MAIN OUTCOME MEASURES Visual acuity, retinal imaging, electroretinography, genotype-phenotype correlation, and histopathological examination were evaluated. RESULTS The age at onset ranged from birth to the eighth decade of life. Median visual acuity was 1.00 logarithm of the minimum angle of resolution (logMAR) (IQR, 0.69-1.48 logMAR; range, 0.06-3.00 logMAR) at a mean age of 52.0 ± 19.9 years (range, 4.6-81.9 years). Sufficient imaging was available for 36 out of 39 patients (92.3%), and all showed degeneration of at least the macula. Of these 36 patients, 22 (61.1%) had only macular dystrophy. Another 10 patients (27.8%) had additional degeneration beyond the vascular arcades, and 4 patients (11.1%) panretinal degeneration. Two patients (5.1%) had Leber congenital amaurosis. In total, 21 different disease-associated heterozygous CRX variants were identified (10 frameshift, 7 missense, 2 deletion, 1 nonsense, 1 deletion-insertion variants). Missense variants in the CRX homeodomain and 2 variants deleting all functional domains, thus causing haploinsufficiency, generally tended to cause milder late-onset phenotypes. Histopathologic examination of the eye of a 17-year-old patient with advanced early-onset retinal dystrophy due to a heterozygous deletion of exons 3 and 4 of the CRX gene revealed loss of laminar integrity and widespread photoreceptor degeneration especially in the central retina, with extensive loss of photoreceptor nuclei and outer segments. CONCLUSIONS This study illustrates the large clinical and genetic heterogenic spectrum of CRX-RDs, ranging from Leber congenital amaurosis to mild late-onset maculopathy resembling occult macular dystrophy. Haploinsufficiency and missense variants tended to be associated with milder phenotypes. Patients showed degeneration predominantly affecting the central retina on imaging. The histopathological findings also mirror these clinical findings and features similar to previously reported animal models of CRX-RDs. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Leo C Hahn
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Isa van der Veen
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Michalis Georgiou
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Department of Ophthalmology, Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Mary J van Schooneveld
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, St Thomas' Hospital, London, United Kingdom
| | - Jacoline B Ten Brink
- Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Ralph J Florijn
- Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands
| | - Omar A Mahroo
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Department of Ophthalmology, St Thomas' Hospital, London, United Kingdom; Section of Ophthalmology, King's College London, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | | | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Arthur A Bergen
- Department of Human Genetics, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; The Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.
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3
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Fujinami K, Nishiguchi KM, Oishi A, Akiyama M, Ikeda Y. Specification of variant interpretation guidelines for inherited retinal dystrophy in Japan. Jpn J Ophthalmol 2024; 68:389-399. [PMID: 39078460 DOI: 10.1007/s10384-024-01063-5] [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: 10/23/2023] [Accepted: 12/12/2023] [Indexed: 07/31/2024]
Abstract
Accurate interpretation of sequence variants in inherited retinal dystrophy (IRD) is vital given the significant genetic heterogeneity observed in this disorder. To achieve consistent and accurate diagnoses, establishment of standardized guidelines for variant interpretation is essential. The American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines for variant interpretation serve as the global "cross-disease" standard for classifying variants in Mendelian hereditary disorders. These guidelines propose a systematic approach for categorizing variants into 5 classes based on various types of evidence, such as population data, computational data, functional data, and segregation data. However, for clinical genetic diagnosis and to ensure standardized diagnosis and treatment criteria, additional specifications based on features associated with each disorder are necessary. In this context, we present a comprehensive framework outlining the newly specified ACMG/AMP rules tailored explicitly to IRD in the Japanese population on behalf of the Research Group on Rare and Intractable Diseases (Ministry of Health, Labour and Welfare of Japan). These guidelines consider disease frequencies, allele frequencies, and both the phenotypic and the genotypic characteristics unique to IRD in the Japanese population. Adjustments and modifications have been incorporated to reflect the specific requirements of the population. By incorporating these IRD-specific factors and refining the existing ACMG/AMP guidelines, we aim to enhance the accuracy and consistency of variant interpretation in IRD cases, particularly in the Japanese population. These guidelines serve as a valuable resource for ophthalmologists and clinical geneticists involved in the diagnosis and treatment of IRD, providing them with a standardized framework to assess and classify genetic variants.
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Affiliation(s)
- Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo, 152-8902, Japan
| | - Koji M Nishiguchi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya, 466-8550, Japan.
| | - Akio Oishi
- Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, 852-8501, Japan
| | - Masato Akiyama
- Department of Ocular Pathology and Imaging Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
| | - Yasuhiro Ikeda
- Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Miyazaki, 889-1692, Japan
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Shepherdson JL, Friedman RZ, Zheng Y, Sun C, Oh IY, Granas DM, Cohen BA, Chen S, White MA. Pathogenic variants in CRX have distinct cis-regulatory effects on enhancers and silencers in photoreceptors. Genome Res 2024; 34:243-255. [PMID: 38355306 PMCID: PMC10984388 DOI: 10.1101/gr.278133.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Dozens of variants in the gene for the homeodomain transcription factor (TF) cone-rod homeobox (CRX) are linked with human blinding diseases that vary in their severity and age of onset. How different variants in this single TF alter its function in ways that lead to a range of phenotypes is unclear. We characterized the effects of human disease-causing variants on CRX cis-regulatory function by deploying massively parallel reporter assays (MPRAs) in mouse retina explants carrying knock-ins of two variants, one in the DNA-binding domain (p.R90W) and the other in the transcriptional effector domain (p.E168d2). The degree of reporter gene dysregulation in these mutant Crx retinas corresponds with their phenotypic severity. The two variants affect similar sets of enhancers, and p.E168d2 has distinct effects on silencers. Cis-regulatory elements (CREs) near cone photoreceptor genes are enriched for silencers that are derepressed in the presence of p.E168d2. Chromatin environments of CRX-bound loci are partially predictive of episomal MPRA activity, and distal elements whose accessibility increases later in retinal development are enriched for CREs with silencer activity. We identified a set of potentially pleiotropic regulatory elements that convert from silencers to enhancers in retinas that lack a functional CRX effector domain. Our findings show that phenotypically distinct variants in different domains of CRX have partially overlapping effects on its cis-regulatory function, leading to misregulation of similar sets of enhancers while having a qualitatively different impact on silencers.
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Affiliation(s)
- James L Shepherdson
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
- Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Ryan Z Friedman
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
- Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Yiqiao Zheng
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Inez Y Oh
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - David M Granas
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
- Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Barak A Cohen
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
- Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA;
- Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
| | - Michael A White
- Department of Genetics, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA;
- Edison Family Center for Genome Sciences & Systems Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri 63110, USA
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Georgiou M, Fujinami K, Robson AG, Fujinami-Yokokawa Y, Shakarchi AF, Ji MH, Uwaydat SH, Kim A, Kolesnikova M, Arno G, Pontikos N, Mahroo OA, Tsang SH, Webster AR, Michaelides M. RBP3-Retinopathy-Inherited High Myopia and Retinal Dystrophy: Genetic Characterization, Natural History, and Deep Phenotyping. Am J Ophthalmol 2024; 258:119-129. [PMID: 37806543 PMCID: PMC11139644 DOI: 10.1016/j.ajo.2023.09.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 09/26/2023] [Accepted: 09/26/2023] [Indexed: 10/10/2023]
Abstract
PURPOSE To examine the genetic and clinical features and the natural history of RBP3-associated retinopathy. DESIGN Multi-center international, retrospective, case series of adults and children, with moleculraly confirmed RBP3-asociated retinopathy. METHODS The genetic, clinical, and retinal imaging findings, including optical coherence tomography (OCT) and fundus autofluorescence (FAF), were investigated both cross-sectionally and longitudinally. The results of international standard full-field electroretinography (ERG) and pattern electroretinography (PERG) were reviewed. RESULTS We ascertained 12 patients (5 female and 7 male) from 10 families (4 patients previously reported). Ten novel disease-causing RBP3 variants were identified. Ten patients were homozygous. The mean age (±SD, range) of the group was 21.4 years (±19.1, 2.9-60.5 years) at baseline evaluation. All 12 patients were highly myopic, with a mean spherical equivalent of -16.0D (range, -7.0D to -33.0D). Visual acuity was not significantly different between eyes, and no significant anisometropia was observed. Mean best-corrected visual acuity (BCVA) was 0.48 logMAR (SD, ±0.29; range, 0.2-1.35 logMAR); at baseline. Eleven patients had longitudinal BCVA assessment, with a mean BCVA of 0.46 logMAR after a mean follow-up of 12.6 years. All patients were symptomatic with reduced VA and myopia by the age of 7 years old. All patients had myopic fundi and features in keeping with high myopia on OCT, including choroidal thinning. The 4 youngest patients had no fundus pigmentary changes, with the rest of the patients presenting with a variable degree of mid-peripheral pigmentation and macular changes. FAF showed variable phenotypes, ranging from areas of increased signal to advanced atrophy in older patients. OCT showed cystoid macular edema at presentation in 3 patients, which persisted during follow-up in 2 patients and resolved to atrophy in the third patient. The ERGs were abnormal in 9 of 9 cases, revealing variable relative involvement of rod and cone photoreceptors with additional milder dysfunction post-phototransduction in some. All but 1 patient had PERG evidence of macular dysfunction, which was severe in most cases. CONCLUSIONS This study details the clinical and functional phenotype of RBP3-retinopathy in the largest cohort reported to date. RBP3-retinopathy is a disease characterized by early onset, slow progression over decades, and high myopia. The phenotypic spectrum and natural history as described herein has prognostic and counseling implications. RBP3-related disease should be considered in children with high myopia and retinal dystrophy.
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Affiliation(s)
- Michalis Georgiou
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK; Jones Eye Institute (M.G., A.F.S., M.H.J., S.H.U.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Kaoru Fujinami
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK; Laboratory of Visual Physiology (K.F., Y.F.-Y.), Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Anthony G Robson
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK
| | - Yu Fujinami-Yokokawa
- Laboratory of Visual Physiology (K.F., Y.F.-Y.), Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management (Y.F.-Y.), Keio University School of Medicine, Tokyo, Japan
| | - Ahmed F Shakarchi
- Jones Eye Institute (M.G., A.F.S., M.H.J., S.H.U.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marco H Ji
- Jones Eye Institute (M.G., A.F.S., M.H.J., S.H.U.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Sami H Uwaydat
- Jones Eye Institute (M.G., A.F.S., M.H.J., S.H.U.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Angela Kim
- Jonas Children's Vision Care (A.K., M.K., S.H.T.), Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Columbia University, and Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Masha Kolesnikova
- Jonas Children's Vision Care (A.K., M.K., S.H.T.), Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Columbia University, and Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Gavin Arno
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK
| | - Nikolas Pontikos
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK
| | - Omar A Mahroo
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK
| | - Stephen H Tsang
- Jonas Children's Vision Care (A.K., M.K., S.H.T.), Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Columbia University, and Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA
| | - Andrew R Webster
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK
| | - Michel Michaelides
- From Moorfields Eye Hospital (M.G., K.F., A.G.R., G.A., N.P., O.A.M., A.R.W., M.M.), London, UK; UCL Institute of Ophthalmology (M.G., K.F., A.G.R.m G.A., N.P., O.A.M., A.R.W., M.M.), University College London, London, UK.
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Occelli LM, Jones BW, Cervantes TJ, Petersen-Jones SM. Metabolic changes and retinal remodeling in Heterozygous CRX mutant cats (CRX RDY/+). Exp Eye Res 2023; 235:109630. [PMID: 37625575 DOI: 10.1016/j.exer.2023.109630] [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: 05/26/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023]
Abstract
CRX is a transcription factor essential for normal photoreceptor development and survival. The CRXRdy cat has a naturally occurring truncating mutation in CRX and is a large animal model for dominant Leber congenital amaurosis. This study investigated retinal remodeling that occurs as photoreceptors degenerate. CRXRdy/+ cats from 6 weeks to 10 years of age were investigated. In vivo structural changes of retinas were analyzed by fundus examination, confocal scanning laser ophthalmoscopy and spectral domain optical coherence tomography. Histologic analyses included immunohistochemistry for computational molecular phenotyping with macromolecules and small molecules. Affected cats had a cone-led photoreceptor degeneration starting in the area centralis. Initially there was preservation of inner retinal cells such as bipolar, amacrine and horizontal cells but with time migration of the deafferented neurons occurred. Early in the process of degeneration glial activation occurs ultimately resulting in formation of a glial seal. With progression the macula-equivalent area centralis developed severe atrophy including loss of retinal pigmentary epithelium. Microneuroma formation occured in advanced stages as more marked retinal remodeling occurred. This study indicates that retinal degeneration in the CrxRdy/+ cat retina follows the progressive, phased revision of retina that have been previously described for retinal remodeling. These findings suggest that therapy dependent on targeting inner retinal cells may be useful in young adults with preserved inner retinas prior to advanced stages of retinal remodeling and neuronal cell loss.
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Affiliation(s)
- Laurence M Occelli
- Small Animal Clinical Sciences, Michigan State University, 736 Wilson Road, East Lansing, MI, USA.
| | - Bryan W Jones
- Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, UT, USA.
| | - Taylor J Cervantes
- Small Animal Clinical Sciences, Michigan State University, 736 Wilson Road, East Lansing, MI, USA.
| | - Simon M Petersen-Jones
- Small Animal Clinical Sciences, Michigan State University, 736 Wilson Road, East Lansing, MI, USA.
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7
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Fujinami-Yokokawa Y, Yang L, Joo K, Tsunoda K, Liu X, Kondo M, Ahn SJ, Li H, Park KH, Tachimori H, Miyata H, Woo SJ, Sui R, Fujinami K. Occult Macular Dysfunction Syndrome: Identification of Multiple Pathologies in a Clinical Spectrum of Macular Dysfunction with Normal Fundus in East Asian Patients: EAOMD Report No. 5. Genes (Basel) 2023; 14:1869. [PMID: 37895218 PMCID: PMC10606510 DOI: 10.3390/genes14101869] [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: 08/13/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 10/29/2023] Open
Abstract
Occult macular dystrophy (OMD) is the most prevalent form of macular dystrophy in East Asia. Beyond RP1L1, causative genes and mechanisms remain largely uncharacterised. This study aimed to delineate the clinical and genetic characteristics of OMD syndrome (OMDS). Patients clinically diagnosed with OMDS in Japan, South Korea, and China were enrolled. The inclusion criteria were as follows: (1) macular dysfunction and (2) normal fundus appearance. Comprehensive clinical evaluation and genetic assessment were performed to identify the disease-causing variants. Clinical parameters were compared among the genotype groups. Seventy-two patients with OMDS from fifty families were included. The causative genes were RP1L1 in forty-seven patients from thirty families (30/50, 60.0%), CRX in two patients from one family (1/50, 2.0%), GUCY2D in two patients from two families (2/50, 4.0%), and no genes were identified in twenty-one patients from seventeen families (17/50, 34.0%). Different severities were observed in terms of disease onset and the prognosis of visual acuity reduction. This multicentre large cohort study furthers our understanding of the phenotypic and genotypic spectra of patients with macular dystrophy and normal fundus. Evidently, OMDS encompasses multiple Mendelian retinal disorders, each representing unique pathologies that dictate their respective severity and prognostic patterns.
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Affiliation(s)
- Yu Fujinami-Yokokawa
- Department of Health Policy and Management, Keio University School of Medicine, Tokyo 160-8582, Japan; (Y.F.-Y.)
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo 152-8902, Japan
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Division of Public Health, Yokokawa Clinic, Suita 564-0083, Japan
| | - Lizhu Yang
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13620, Republic of Korea
| | - Kazushige Tsunoda
- Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo 152-8902, Japan
| | - Xiao Liu
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo 152-8902, Japan
- Southwest Hospital, Army Medical University, Chongqing 400715, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing 400715, China
| | - Mineo Kondo
- Department of Ophthalmology, Mie University Graduate School of Medicine, Mie 514-8507, Japan
| | - Seong Joon Ahn
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul 04763, Republic of Korea
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Hospital, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Hisateru Tachimori
- Endowed Course for Health System Innovation, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Hiroaki Miyata
- Department of Health Policy and Management, Keio University School of Medicine, Tokyo 160-8582, Japan; (Y.F.-Y.)
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam 13620, Republic of Korea
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China
| | - Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, NHO Tokyo Medical Center, Tokyo 152-8902, Japan
- UCL Institute of Ophthalmology, London EC1V 9EL, UK
- Moorfields Eye Hospital, London EC1V 2PD, UK
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Yang TH, Kang EYC, Lin PH, Wu PL, Sachs JA, Wang NK. The Value of Electroretinography in Identifying Candidate Genes for Inherited Retinal Dystrophies: A Diagnostic Guide. Diagnostics (Basel) 2023; 13:3041. [PMID: 37835784 PMCID: PMC10572658 DOI: 10.3390/diagnostics13193041] [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: 08/20/2023] [Revised: 09/08/2023] [Accepted: 09/13/2023] [Indexed: 10/15/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are a group of heterogeneous diseases caused by genetic mutations that specifically affect the function of the rod, cone, or bipolar cells in the retina. Electroretinography (ERG) is a diagnostic tool that measures the electrical activity of the retina in response to light stimuli, and it can help to determine the function of these cells. A normal ERG response consists of two waves, the a-wave and the b-wave, which reflect the activity of the photoreceptor cells and the bipolar and Muller cells, respectively. Despite the growing availability of next-generation sequencing (NGS) technology, identifying the precise genetic mutation causing an IRD can be challenging and costly. However, certain types of IRDs present with unique ERG features that can help guide genetic testing. By combining these ERG findings with other clinical information, such as on family history and retinal imaging, physicians can effectively narrow down the list of candidate genes to be sequenced, thereby reducing the cost of genetic testing. This review article focuses on certain types of IRDs with unique ERG features. We will discuss the pathophysiology and clinical presentation of, and ERG findings on, these disorders, emphasizing the unique role ERG plays in their diagnosis and genetic testing.
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Affiliation(s)
- Tsai-Hsuan Yang
- Department of Education, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, National Yang Ming Chiao Tung University, Taipei 11217, Taiwan
| | - Eugene Yu-Chuan Kang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Pei-Hsuan Lin
- National Taiwan University Hospital, Yunlin 640203, Taiwan;
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-L.W.); (J.A.S.)
| | - Pei-Liang Wu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-L.W.); (J.A.S.)
- Department of Medicine, National Taiwan University, Taipei 10617, Taiwan
| | - Jacob Aaron Sachs
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-L.W.); (J.A.S.)
- College of Arts and Sciences, University of Miami, Coral Gables, FL 33146, USA
| | - Nan-Kai Wang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan 33305, Taiwan;
- College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, NY 10032, USA; (P.-L.W.); (J.A.S.)
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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Kim DG, Joo K, Han J, Choi M, Kim SW, Park KH, Park SJ, Lee CS, Byeon SH, Woo SJ. Genotypic Profile and Clinical Characteristics of CRX-Associated Retinopathy in Koreans. Genes (Basel) 2023; 14:genes14051057. [PMID: 37239417 DOI: 10.3390/genes14051057] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/26/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023] Open
Abstract
This study aimed to investigate the clinical characteristics of Korean patients with retinal dystrophy associated with pathogenic variants of cone rod homeobox-containing gene (CRX). We retrospectively enrolled Korean patients with CRX-associated retinal dystrophy (CRX-RD) who visited two tertiary referral hospitals. Pathogenic variants were identified using targeted panel sequencing or whole-exome sequencing. We analyzed clinical features and phenotypic spectra according to genotype. Eleven patients with CRX-RD were included in this study. Six patients with cone-rod dystrophy (CORD), two with macular dystrophy (MD), two with Leber congenital amaurosis (LCA), and one with retinitis pigmentosa (RP) were included. One patient (9.1%) had autosomal recessive inheritance, and the other ten patients (90.9%) had autosomal dominant inheritance. Six patients (54.5%) were male, and the mean age of symptom onset was 27.0 ± 17.9 years. At the first presentation, the mean age was 39.4 ± 20.6 years, and best-corrected visual acuity (BCVA) (logMAR) was 0.76 ± 0.90 in the better eye. Negative electroretinography (ERG) was observed in seven (63.6%) patients. Nine pathogenic variants were identified, including two novel variants, c.101-1G>A and c.898T>C:p.(*300Glnext*118). Taken together with the variants reported in prior studies, all variants within the homeodomain are missense variants, whereas most variants downstream of the homeodomain are truncating variants (88%). The clinical features of pathogenic variants within the homeodomain are either CORD or MD with bull's eye maculopathy, whereas variants downstream of the homeodomain cause more diverse phenotypes, with CORD and MD in 36%, LCA in 40%, and RP in 24%. This is the first case series in Korea to investigate the CRX-RD genotype-phenotype correlation. Pathogenic variants downstream of the homeodomain of the CRX gene are present as RP, LCA, and CORD, whereas pathogenic variants within the homeodomain are mainly present as CORD or MD with bull's eye maculopathy. This trend was similar to previous genotype-phenotype analyses of CRX-RD. Further molecular biologic research on this correlation is required.
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Affiliation(s)
- Dong Geun Kim
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
- Department of Ophthalmology, Inje University College of Medicine, Busan Paik Hospital, Busan 47392, Republic of Korea
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Severance Hospital, Seoul 06273, Republic of Korea
| | - Mihyun Choi
- Department of Ophthalmology, Guro Hospital, Korea University College of Medicine, Seoul 08308, Republic of Korea
| | - Seong-Woo Kim
- Department of Ophthalmology, Guro Hospital, Korea University College of Medicine, Seoul 08308, Republic of Korea
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Sang Jun Park
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Christopher Seungkyu Lee
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Severance Hospital, Seoul 06273, Republic of Korea
| | - Suk Ho Byeon
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Severance Hospital, Seoul 06273, Republic of Korea
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
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Jiang X, Mahroo OA. Negative electroretinograms: genetic and acquired causes, diagnostic approaches and physiological insights. Eye (Lond) 2021; 35:2419-2437. [PMID: 34127841 PMCID: PMC8377097 DOI: 10.1038/s41433-021-01604-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/05/2021] [Accepted: 05/10/2021] [Indexed: 02/07/2023] Open
Abstract
The dark-adapted human electroretinogram (ERG) response to a standard bright flash includes a negative-going a-wave followed by a positive-going b-wave that crosses the baseline. An electronegative waveform (or negative ERG) results when the b-wave is selectively reduced such that the ERG fails to cross the baseline following the a-wave. In the context of a normally sized a-wave, it indicates a site of retinal dysfunction occurring after phototransduction (commonly at the photoreceptor to bipolar cell synapse). This is an important finding. In genetic disease, the pattern of ERG abnormality can point to variants in a small group of genes (frequently those associated with congenital stationary night blindness and X-linked retinoschisis, but negative ERGs can also be seen in other conditions including syndromic disease). In acquired disease, there are numerous causes, but specific features may point to melanoma-associated retinopathy (MAR). In some cases, the visual symptoms precede the diagnosis of the melanoma and so the ERG findings can initiate investigations facilitating early detection and treatment. Negative ERGs can occur in other paraneoplastic conditions, and in a range of other diseases. This review will outline the physiological basis for the negative ERG, report prevalences in the literature from different cohorts, discuss the range of causes, displaying examples of a number of ERG phenotypes, highlight features of a clinical approach to patients, and briefly discuss further insights relating to current flows shaping the a-wave trough and from single-cell transcriptome analysis.
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Affiliation(s)
- Xiaofan Jiang
- grid.83440.3b0000000121901201Institute of Ophthalmology, University College London, London, UK ,grid.439257.e0000 0000 8726 5837Retinal and Genetics Services, Moorfields Eye Hospital, London, UK ,grid.425213.3Section of Ophthalmology and Department of Twin Research and Genetic Epidemiology, King’s College London, St Thomas’ Hospital Campus, London, UK
| | - Omar A. Mahroo
- grid.83440.3b0000000121901201Institute of Ophthalmology, University College London, London, UK ,grid.439257.e0000 0000 8726 5837Retinal and Genetics Services, Moorfields Eye Hospital, London, UK ,grid.425213.3Section of Ophthalmology and Department of Twin Research and Genetic Epidemiology, King’s College London, St Thomas’ Hospital Campus, London, UK ,grid.5335.00000000121885934Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
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11
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Al-Khuzaei S, Hudspith KAZ, Broadgate S, Shanks ME, Clouston P, Németh AH, Halford S, Downes SM. Targeted next generation sequencing and family survey enable correct genetic diagnosis in CRX associated macular dystrophy - a case report. BMC Ophthalmol 2021; 21:168. [PMID: 33836713 PMCID: PMC8034119 DOI: 10.1186/s12886-021-01919-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 03/23/2021] [Indexed: 02/05/2023] Open
Abstract
Background We present 3 members of a family with macular dystrophy, originally diagnosed as Stargardt disease, with a significantly variable age at onset, caused by a heterozygous mutation in CRX. Case presentation A 43-year-old female with bull’s eye maculopathy, whose sister was diagnosed with Stargardt disease previously at another centre, was found to have a single ABCA4 variant. Further examination of the family revealed that the asymptomatic father was also affected, indicating a dominant pattern of inheritance. In addition, the ABCA4 variant was not identified in the sister originally diagnosed with Stargardt disease. Next generation sequencing identified a heterozygous c.121C > T, p.R41W missense mutation in CRX in all 3 affected members. Conclusions We describe a common phenotype, but with variable age at onset, with autosomal dominant inheritance and reduced penetrance in a family found to have a pathogenic sequence variant in CRX. This illustrates the importance of panel based molecular genetic testing accompanied by family studies to establish a definitive diagnosis.
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Affiliation(s)
- Saoud Al-Khuzaei
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Oxford Eye Hospital, John Radcliffe Hospital, Headley Way, Oxford, OX9 3DU, UK
| | - Karl A Z Hudspith
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Morag E Shanks
- Oxford Medical Genetics Laboratory, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Penny Clouston
- Oxford Medical Genetics Laboratory, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Andrea H Németh
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Susan M Downes
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK. .,Oxford Eye Hospital, John Radcliffe Hospital, Headley Way, Oxford, OX9 3DU, UK.
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