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Birtel J, Caswell R, De Silva SR, Herrmann P, Rehman S, Lotery AJ, Mahroo OA, Michaelides M, Webster AR, MacLaren RE, Charbel Issa P. IMPG2-Related Maculopathy. Am J Ophthalmol 2024; 258:32-42. [PMID: 37806544 DOI: 10.1016/j.ajo.2023.10.002] [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: 01/16/2023] [Revised: 10/01/2023] [Accepted: 10/01/2023] [Indexed: 10/10/2023]
Abstract
PURPOSE To investigate the phenotype, variability, and penetrance of IMPG2-related maculopathy. DESIGN Retrospective observational case series. METHODS Clinical evaluation, multimodal retinal imaging, genetic testing, and molecular modeling. RESULTS A total of 25 individuals with a mono-allelic IMPG2 variant were included, 5 of whom were relatives of patients with IMPG2-associated retinitis pigmentosa. A distinct maculopathy was present in 17 individuals (median age, 52 years; range, 20-72 years), and included foveal elevation with or without subretinal vitelliform material or focal atrophy of the retinal pigment epithelium. Best-corrected visual acuity (BCVA) was ≥20/50 in the better eye (n = 15), and 5 patients were asymptomatic. Longitudinal observation (n = 8, up to 19 years) demonstrated stable maculopathy (n = 3), partial/complete resorption (n = 4) or increase (n = 1) of the subretinal material, with overall stable vision (n = 6). No manifest maculopathy was observed in 8 individuals (median age, 58 years; range, 43-83 years; BCVA ≥20/25), all were identified through segregation analysis. All 8 individuals were asymptomatic, with minimal foveal changes observed on optical coherence tomography in 3 cases. A total of 18 different variants were detected, 11 of them truncating. Molecular modeling of 5 missense variants [c.727G>C, c.1124C>A, c.2816T>A, c.3047T>C, and c.3193G>A] supported the hypothesis that these have a loss-of-function effect. CONCLUSIONS Mono-allelic IMPG2 variants may result in haploinsufficiency manifesting as a maculopathy with variable penetrance and expressivity. Family members of patients with IMPG2-related retinitis pigmentosa may present with vitelliform lesions. The maculopathy often remains limited to the fovea and is usually associated with moderate visual impairment.
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Affiliation(s)
- Johannes Birtel
- From the Oxford Eye Hospital (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom; Nuffield Laboratory of Ophthalmology (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Ophthalmology (J.B.), University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Department of Ophthalmology (J.B., P.H.), University of Bonn, Bonn, Germany
| | - Richard Caswell
- Exeter Genomics Laboratory (R.C.), Royal Devon University Healthcare NHS Foundation Trust, Exeter, United Kingdom
| | - Samantha R De Silva
- From the Oxford Eye Hospital (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom; Nuffield Laboratory of Ophthalmology (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Moorfields Eye Hospital NHS Foundation Trust (S.R.D.S., O.A.M., M.M., A.R.W.), London, United Kingdom; UCL Institute of Ophthalmology (S.R.D.S., O.A.M., M.M., A.R.W.), University College London, London, United Kingdom
| | - Philipp Herrmann
- Department of Ophthalmology (J.B., P.H.), University of Bonn, Bonn, Germany
| | - Salwah Rehman
- From the Oxford Eye Hospital (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom; Nuffield Laboratory of Ophthalmology (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Andrew J Lotery
- Clinical Neurosciences (A.J.L.), Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom; Southampton Eye Unit (A.J.L.), University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Omar A Mahroo
- Moorfields Eye Hospital NHS Foundation Trust (S.R.D.S., O.A.M., M.M., A.R.W.), London, United Kingdom; UCL Institute of Ophthalmology (S.R.D.S., O.A.M., M.M., A.R.W.), University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust (S.R.D.S., O.A.M., M.M., A.R.W.), London, United Kingdom; UCL Institute of Ophthalmology (S.R.D.S., O.A.M., M.M., A.R.W.), University College London, London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust (S.R.D.S., O.A.M., M.M., A.R.W.), London, United Kingdom; UCL Institute of Ophthalmology (S.R.D.S., O.A.M., M.M., A.R.W.), University College London, London, United Kingdom
| | - Robert E MacLaren
- From the Oxford Eye Hospital (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom; Nuffield Laboratory of Ophthalmology (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Peter Charbel Issa
- From the Oxford Eye Hospital (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Oxford University Hospitals NHS Foundation Trust, Oxford, United Kingdom; Nuffield Laboratory of Ophthalmology (J.B., S.R.D.S., S.R., R.E.M., P.C.I.), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
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Wu S, Yuan Z, Sun Z, Zhu T, Wei X, Zou X, Sui R. A novel tandem duplication of PRDM13 in a Chinese family with North Carolina macular dystrophy. Graefes Arch Clin Exp Ophthalmol 2022; 260:645-653. [PMID: 34427740 DOI: 10.1007/s00417-021-05376-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 07/29/2021] [Accepted: 08/10/2021] [Indexed: 10/20/2022] Open
Abstract
PURPOSES North Carolina macular dystrophy (NCMD) is a rare autosomal dominant inherited disorder characterized by macular impairment with a variety of phenotypic manifestations. The aims of this study were to assess the clinical features of a Chinese family with NCMD and to identify the underlying genetic cause of the disease. METHODS Three patients from a Chinese family were included in this study. Detailed ophthalmological examinations were performed, including best corrected visual acuity (BCVA), slit lamp, dilated indirect ophthalmoscopy, fundus photography, optical coherence tomography (OCT), fundus autofluorescence, full-field electroretinography (ERG), and electrooculography (EOG). Genomic DNA was extracted from peripheral blood samples. Whole-genome sequencing and long-read genome sequencing were applied to detect the pathogenic variants. Sanger sequencing was performed to confirm the breakpoints. RESULTS All three patients had macular involvement ranging from patchy yellowish-white lesions to big-area thinning, which are typical for NCMD. The BCVA ranged from 20/50 to 20/20. OCT revealed varying degrees of macular structure disorganization. The ERG responses were normal, and the Arden ration of the EOG was reduced. A novel 134.6 kb (g.99932464-100067110dup) tandem duplication on chromosome 6 (NC_000006.11) encompassing the entire CCNC and PRDM13 genes and a DNase 1 hypersensitivity site in the MCDR1 locus was identified. CONCLUSION A novel large tandem duplication in MCDR1 locus was confirmed in a Chinese family with NCMD with a variety of macular phenotypes.
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Affiliation(s)
- Shijing Wu
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Zhisheng Yuan
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Zixi Sun
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Tian Zhu
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Xing Wei
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Xuan Zou
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China
| | - Ruifang Sui
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100730, China.
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Green DJ, Lenassi E, Manning CS, McGaughey D, Sharma V, Black GC, Ellingford JM, Sergouniotis PI. North Carolina Macular Dystrophy: Phenotypic Variability and Computational Analysis of Disease-Associated Noncoding Variants. Invest Ophthalmol Vis Sci 2021; 62:16. [PMID: 34125159 PMCID: PMC8212441 DOI: 10.1167/iovs.62.7.16] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Purpose North Carolina macular dystrophy (NCMD) is an autosomal dominant, congenital disorder affecting the central retina. Here, we report clinical and genetic findings in three families segregating NCMD and use epigenomic datasets from human tissues to gain insights into the effect of NCMD-implicated variants. Methods Clinical assessment and genetic testing were performed. Publicly available transcriptomic and epigenomic datasets were analyzed and the activity-by-contact method for scoring enhancer elements and linking them to target genes was used. Results A previously described, heterozygous, noncoding variant upstream of the PRDM13 gene was detected in all six affected study participants (chr6:100,040,987G>C [GRCh37/hg19]). Interfamilial and intrafamilial variability were observed; the visual acuity ranged from 0.0 to 1.6 LogMAR and fundoscopic findings ranged from visually insignificant, confluent, drusen-like macular deposits to coloboma-like macular lesions. Variable degrees of peripheral retinal spots (which were easily detected on widefield retinal imaging) were observed in all study subjects. Notably, a 6-year-old patient developed choroidal neovascularization and required treatment with intravitreal bevacizumab injections. Computational analysis of the five single nucleotide variants that have been implicated in NCMD revealed that these noncoding changes lie within two putative enhancer elements; these elements are predicted to interact with PRDM13 in the developing human retina. PRDM13 was found to be expressed in the fetal retina, with greatest expression in the amacrine precursor cell population. Conclusions We provide further evidence supporting the role of PRDM13 dysregulation in the pathogenesis of NCMD and highlight the usefulness of widefield retinal imaging in individuals suspected to have this condition.
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Affiliation(s)
- David J Green
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Eva Lenassi
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Cerys S Manning
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - David McGaughey
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Vinod Sharma
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Graeme C Black
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Jamie M Ellingford
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Panagiotis I Sergouniotis
- Division of Evolution and Genomic Sciences, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
- Manchester Centre for Genomic Medicine, St Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Manchester Royal Eye Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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