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Stehle IF, Imventarza JA, Woerz F, Hoffmann F, Boldt K, Beyer T, Quinn PM, Ueffing M. Human CRB1 and CRB2 form homo- and heteromeric protein complexes in the retina. Life Sci Alliance 2024; 7:e202302440. [PMID: 38570189 PMCID: PMC10992996 DOI: 10.26508/lsa.202302440] [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: 10/17/2023] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
Crumbs homolog 1 (CRB1) is one of the key genes linked to retinitis pigmentosa and Leber congenital amaurosis, which are characterized by a high clinical heterogeneity. The Crumbs family member CRB2 has a similar protein structure to CRB1, and in zebrafish, Crb2 has been shown to interact through the extracellular domain. Here, we show that CRB1 and CRB2 co-localize in the human retina and human iPSC-derived retinal organoids. In retina-specific pull-downs, CRB1 was enriched in CRB2 samples, supporting a CRB1-CRB2 interaction. Furthermore, novel interactors of the crumbs complex were identified, representing a retina-derived protein interaction network. Using co-immunoprecipitation, we further demonstrate that human canonical CRB1 interacts with CRB1 and CRB2, but not with CRB3, which lacks an extracellular domain. Next, we explored how missense mutations in the extracellular domain affect CRB1-CRB2 interactions. We observed no or a mild loss of CRB1-CRB2 interaction, when interrogating various CRB1 or CRB2 missense mutants in vitro. Taken together, our results show a stable interaction of human canonical CRB2 and CRB1 in the retina.
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Affiliation(s)
- Isabel F Stehle
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Joel A Imventarza
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Franziska Woerz
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Felix Hoffmann
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Karsten Boldt
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Tina Beyer
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Peter Mj Quinn
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Marius Ueffing
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
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2
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Daher A, Banjak M, Noureldine J, Nehme J, El Shamieh S. Genotype-phenotype associations in CRB1 bi-allelic patients: a novel mutation, a systematic review and meta-analysis. BMC Ophthalmol 2024; 24:167. [PMID: 38622537 PMCID: PMC11017593 DOI: 10.1186/s12886-024-03419-4] [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: 07/09/2023] [Accepted: 03/29/2024] [Indexed: 04/17/2024] Open
Abstract
PURPOSE The goal of the study was to search for novel bi-allelic CRB1 mutations, and then to analyze the CRB1 literature at the genotypic and phenotypic levels. APPROACH We screened various variables such as the CRB1 mutation types, domains, exons, and genotypes and their relation with specific ocular phenotypes. An emphasis was given to the bi-allelic missense and nonsense mutations because of their high prevalence compared to other mutation types. Finally, we quantified the effect of various non-modifiable factors over the best-corrected visual acuity oculus uterque (BCVA OU) using multivariate linear regression models and identified genetic interactions. RESULTS A novel bi-allelic missense in the exon 9 of CRB1; c.2936G > A; p.(Gly979Asp) was found to be associated with rod-cone dystrophy (RCD). CRB1 mutation type, exons, domains, and genotype distribution varied significantly according to fundus characteristics, such as peripheral pigmentation and condition, optic disc, vessels, macular condition, and pigmentation (P < 0.05). Of the 154 articles retrieved from PubMed, 96 studies with 439 bi-allelic CRB1 patients were included. Missense mutations were significantly associated with an absence of macular pigments, pale optic disc, and periphery pigmentation, resulting in a higher risk of RCD (P < 0.05). In contrast, homozygous nonsense mutations were associated with macular pigments, periphery pigments, and a high risk of LCA (P < 0.05) and increased BCVA OU levels. We found that age, mutation types, and inherited retinal diseases were critical determinants of BCVA OU as they significantly increased it by 33% 26%, and 38%, respectively (P < 0.05). Loss of function alleles additively increased the risk of LCA, with nonsense having a more profound effect than indels. Finally, our analysis showed that p.(Cys948Tyr) and p.(Lys801Ter) and p.(Lys801Ter); p.(Cys896Ter) might interact to modify BCVA OU levels. CONCLUSION This meta-analysis updated the literature and identified genotype-phenotype associations in bi-allelic CRB1 patients.
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Affiliation(s)
- Ahmad Daher
- Medical Testing Laboratory, Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon
| | - Malak Banjak
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Jinane Noureldine
- Rammal Hassan Rammal Research Laboratory, PhyToxE Research Group, Faculty of Sciences, Lebanese University, Nabatieh, Lebanon
| | - Joseph Nehme
- Faculty of Medicine, Holy Spirit University of Kaslik (USEK), Jounieh, Lebanon
| | - Said El Shamieh
- Medical Testing Laboratory, Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut, Lebanon.
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Peng S, Li JJ, Song W, Li Y, Zeng L, Liang Q, Wen X, Shang H, Liu K, Peng P, Xue W, Zou B, Yang L, Liang J, Zhang Z, Guo S, Chen T, Li W, Jin M, Xing XB, Wan P, Liu C, Lin H, Wei H, Lee RWJ, Zhang F, Wei L. CRB1-associated retinal degeneration is dependent on bacterial translocation from the gut. Cell 2024; 187:1387-1401.e13. [PMID: 38412859 DOI: 10.1016/j.cell.2024.01.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 07/07/2023] [Accepted: 01/25/2024] [Indexed: 02/29/2024]
Abstract
The Crumbs homolog 1 (CRB1) gene is associated with retinal degeneration, most commonly Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Here, we demonstrate that murine retinas bearing the Rd8 mutation of Crb1 are characterized by the presence of intralesional bacteria. While normal CRB1 expression was enriched in the apical junctional complexes of retinal pigment epithelium and colonic enterocytes, Crb1 mutations dampened its expression at both sites. Consequent impairment of the outer blood retinal barrier and colonic intestinal epithelial barrier in Rd8 mice led to the translocation of intestinal bacteria from the lower gastrointestinal (GI) tract to the retina, resulting in secondary retinal degeneration. Either the depletion of bacteria systemically or the reintroduction of normal Crb1 expression colonically rescued Rd8-mutation-associated retinal degeneration without reversing the retinal barrier breach. Our data elucidate the pathogenesis of Crb1-mutation-associated retinal degenerations and suggest that antimicrobial agents have the potential to treat this devastating blinding disease.
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Affiliation(s)
- Shanzhen Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jing Jing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wanying Song
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Ye Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Lei Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Qiaoxing Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiaofeng Wen
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510000, China
| | - Haitao Shang
- Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Keli Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Peiyao Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wei Xue
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Bin Zou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Liu Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Juanran Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhihui Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
| | - Shixin Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Tingting Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wenxuan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Department of Biostatistics, Yale School of Public Health, New Haven, CT 06510, USA
| | - Ming Jin
- Department of Ophthalmology, China-Japan Friendship Hospital, Beijing 10029, China
| | - Xiang-Bin Xing
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510000, China
| | - Pengxia Wan
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510000, China
| | - Chunqiao Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Hong Wei
- Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
| | - Richard W J Lee
- UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| | - Feng Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
| | - Lai Wei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China; The First Affiliated Hospital, Department of Ophthalmology, University of South China, Hengyang 421001, Hunan, China.
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Jin Y, Li S, Jiang Z, Sun L, Huang L, Zhang T, Liu X, Ding X. Genotype-Phenotype of CRB1-Associated Early-Onset Retinal Dystrophy: Novel Insights on Retinal Architecture and Therapeutic Window for Clinical Trials. Invest Ophthalmol Vis Sci 2024; 65:11. [PMID: 38466290 DOI: 10.1167/iovs.65.3.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024] Open
Abstract
Purpose The purpose of this study was to investigate the genotypic and phenotypic characteristics of CRB1-associated early onset retinal dystrophy (CRB1-eoRD) and retinal architecture by swept-source optical coherence tomography (SS-OCT). Methods Eleven probands with CRB1-eoRD were recruited. Clinical information, genetic analysis, and comprehensive ophthalmic examinations including SS-OCT and SS-OCT angiography (SS-OCTA) were conducted. Results A total of 81.8% (9/11) of CRB1-eoRD presented as Leber congenital amaurosis (LCA). Common clinical manifestations included coin-like yellow-white retinal spots (20/22, 90.9%) and para-arteriolar retinal pigment epithelial retention (12/22, 54.5%). Nineteen different CRB1 variants were detected in our case series, including 12 missense, 3 frameshifts, 3 nonsense, and 1 splicing. Of them, 12 variants had been reported, and 7 were novel. SS-OCT showed thinner central macula (the LCA group, P < 0.0001), thicker total retina (P < 0.0001), thinner outer retina (P < 0.05), and thicker inner retina (P < 0.0001) compared with the healthy control. The inner/outer (I/O) retina thickness ratio of CRB1-eoRD was 3.0, higher than the healthy control of 1.2 and other inherited retinal diseases (IRDs) of 2.2 (P < 0.0001 and P = 0.0027, respectively). SS-OCTA revealed an increased vascular density and perfusion area of the superficial vascular complex and deep vascular complex in CRB1-eoRD. Conclusions LCA emerges as a frequently occurring phenotype in CRB1-eoRD. The unique features of SS-OCT and SS-OCTA are illustrated, and the novel biomarker, I/O ratio, may facilitate early diagnosis. The insights gained from this study hold significant value in determining the treatment window for potential forthcoming CRB1 gene therapy.
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Affiliation(s)
- Yili Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Songshan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Zhaoxin Jiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Limei Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Li Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Ting Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Xinyu Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Xiaoyan Ding
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
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5
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Lu Z, Wang L, Ying X, Tan L. Bilateral angle closure glaucoma with retinitis pigmentosa in young patients: case series. BMC Ophthalmol 2023; 23:458. [PMID: 37968604 PMCID: PMC10648655 DOI: 10.1186/s12886-023-03190-y] [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: 05/28/2023] [Accepted: 10/27/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND To report the ocular characteristics and management of three cases of retinitis pigmentosa (RP) concurrent primary angle closure glaucoma (PACG). CASE PRESENTATION Three middle-aged patients presenting with diminished vision, high intraocular pressure (IOP), and typical fundus manifestations of RP were clinically evaluated. The individualized treatment was based on the ocular conditions of each case. A novel genetic alteration in ZNF408 was identified in one patient. Two patients with short-axial eyes received unilateral combined trabeculectomy, cataract surgery, and Irido-zonulo-hyaloid-vitrectomy. One of them had a subluxated lens, managed with a capsular tension ring implantation. Their contralateral eyes, respectively, underwent laser peripheral iridotomy (LPI) and transscleral cyclophotocoagulation. The third patient underwent bilaterally combined laser peripheral iridoplasty, LPI, and medication. Ultimately, all patients achieved the target IOP during a two-year follow-up. CONCLUSION Young patients with RP may have a risk of developing angle closure glaucoma, and conversely, patients with angle closure glaucoma at younger age should be aware of the presence of RP. Therefore, routine gonioscopy and IOP monitoring are required for RP patients, and detailed fundus examinations are warranted for young PACG patients.
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Affiliation(s)
- Ziyang Lu
- Southwest Hospital / Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China
- Department of Ophthalmology, the 958Th Hospital, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Lu Wang
- Southwest Hospital / Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China
| | - Xi Ying
- Southwest Hospital / Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China.
| | - Lian Tan
- Southwest Hospital / Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, 400038, China.
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, 400038, China.
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6
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Rodriguez-Martinez AC, Higgins BE, Tailor-Hamblin V, Malka S, Cheloni R, Collins AM, Bladen J, Henderson R, Moosajee M. Foveal Hypoplasia in CRB1-Related Retinopathies. Int J Mol Sci 2023; 24:13932. [PMID: 37762234 PMCID: PMC10531165 DOI: 10.3390/ijms241813932] [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: 07/25/2023] [Revised: 09/05/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
The CRB1 gene plays a role in retinal development and its maintenance. When disrupted, it gives a range of phenotypes such as early-onset severe retinal dystrophy/Leber congenital amaurosis (EOSRD/LCA), retinitis pigmentosa (RP), cone-rod dystrophy (CORD) and macular dystrophy (MD). Studies in CRB1 retinopathies have shown thickening and coarse lamination of retinal layers resembling an immature retina. Its role in foveal development has not yet been described; however, this retrospective study is the first to report foveal hypoplasia (FH) presence in a CRB1-related retinopathy cohort. Patients with pathogenic biallelic CRB1 variants from Moorfields Eye Hospital, London, UK, were collected. Demographic, clinical data and SD-OCT analyses with FH structural grading were performed. A total of 15 (48%) patients had EOSRD/LCA, 11 (35%) MD, 3 (9%) CORD and 2 (6%) RP. FH was observed in 20 (65%; CI: 0.47-0.79) patients, all of whom were grade 1. A significant difference in BCVA between patients with FH and without was found (p = 0.014). BCVA continued to worsen over time in both groups (p < 0.001), irrespective of FH. This study reports FH in a CRB1 cohort, supporting the role of CRB1 in foveal development. FH was associated with poorer BCVA and abnormal retinal morphology. Nonetheless, its presence did not alter the disease progression.
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Affiliation(s)
- Ana Catalina Rodriguez-Martinez
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 1LE, UK
| | - Bethany Elora Higgins
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Vijay Tailor-Hamblin
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- UCL Experimental Psychology, London WC1H 0AP, UK
| | - Samantha Malka
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Riccardo Cheloni
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
| | - Alexander Mark Collins
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
| | - John Bladen
- King’s College Hospital NHS Foundation Trust, Strand, London WC2R 2LS, UK;
| | - Robert Henderson
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 1LE, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; (A.C.R.-M.); (B.E.H.); (V.T.-H.); (S.M.); (R.C.); (A.M.C.); (R.H.)
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK
- Great Ormond Street Hospital for Children NHS Foundation Trust, London WC1N 1LE, UK
- The Francis Crick Institute, London NW1 1AT, UK
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7
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Kuruvilla SE, Song E, Raoof N, van Bysterveldt K, Oliver VF, Hong SC, Al-Taie R, Wilson G, Vincent AL. Genotypic and phenotypic characterisation of RP2- and RPGR-associated X-linked inherited retinal dystrophy, including female manifestations. Clin Exp Ophthalmol 2023. [PMID: 36882936 DOI: 10.1111/ceo.14220] [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: 08/11/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/09/2023]
Abstract
BACKGROUND With the promise of gene replacement therapy, eligible males and females with X-linked inherited retinal dystrophy (XL-IRD) should be identified. METHODS Retrospective observational cohort study to establish the phenotypic and genotypic spectrum of XL-IRD within New Zealand (NZ). Thirty-two probands, including 9 females, with molecularly proven XL-IRD due to RP2 or RPGR mutations, and 72 family members, of which 43 were affected, were identified from the NZ IRD Database. Comprehensive ophthalmic phenotyping, familial cosegregation, genotyping, and bioinformatics were undertaken. Main outcome measures were: RP2 and RPGR pathogenic variant spectrum, phenotype in males and females (symptoms, age of onset, visual acuity, refraction, electrophysiology, autofluorescence, retinal appearance), and genotype-phenotype correlation. RESULTS For 32 families, 26 unique pathogenic variants were identified; in RP2 (n = 6, 21.9% of all families), RPGR exons 1-14 (n = 10, 43.75%), and RPGR-ORF15 (n = 10, 34.3%). Three RP2 and 8 RPGR exons 1-14 variants are novel, rare, and cosegregate. Thirty-one percent of carrier females were significantly affected, with 18.5% of families initially classified as autosomal dominant. Of five Polynesian families, 80% had novel disease-causing variants. One Māori family showed keratoconus segregating with an ORF15 variant. CONCLUSIONS Significant disease was present in 31% of genetically proven female carriers, often leading to an erroneous presumption of the inheritance pattern. Pathogenic variants in 44% of the families were in exon 1-14 of RPGR, more frequent than usually described, which may inform the gene testing algorithm. Proving cosegregation in families for novel variants and identifying affected females and males translates to optimised clinical care and potential for gene therapy.
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Affiliation(s)
- Shilpa E Kuruvilla
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.,Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
| | - Eileen Song
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Naz Raoof
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.,Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
| | - Katherine van Bysterveldt
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Verity F Oliver
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Sheng Chiong Hong
- Eye Department - Gisborne Hospital, Hauora Tairawhiti, Gisborne, New Zealand
| | - Rasha Al-Taie
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.,Department of Ophthalmology, Manukau Super Clinic, Counties Manukau District Health Board, Manukau, New Zealand
| | - Graham Wilson
- Eye Department - Gisborne Hospital, Hauora Tairawhiti, Gisborne, New Zealand
| | - Andrea L Vincent
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand.,Eye Department, Greenlane Clinical Centre, Auckland District Health Board, Auckland, New Zealand
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8
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Daich Varela M, Georgiou M, Alswaiti Y, Kabbani J, Fujinami K, Fujinami-Yokokawa Y, Khoda S, Mahroo OA, Robson AG, Webster AR, AlTalbishi A, Michaelides M. CRB1-Associated Retinal Dystrophies: Genetics, Clinical Characteristics, and Natural History. Am J Ophthalmol 2023; 246:107-121. [PMID: 36099972 PMCID: PMC10555856 DOI: 10.1016/j.ajo.2022.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 09/02/2022] [Accepted: 09/05/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE To analyze the clinical characteristics, natural history, and genetics of CRB1-associated retinal dystrophies. DESIGN Multicenter international retrospective cohort study. METHODS Review of clinical notes, ophthalmic images, and genetic testing results of 104 patients (91 probands) with disease-causing CRB1 variants. Macular optical coherence tomography (OCT) parameters, visual function, fundus characteristics, and associations between variables were the main outcome measures. RESULTS The mean age of the cohort at the first visit was 19.8 ± 16.1 (median 15) years, with a mean follow-up of 9.6 ± 10 years. Based on history, imaging, and clinical examination, 26 individuals were diagnosed with retinitis pigmentosa (RP; 25%), 54 with early-onset severe retinal dystrophy / Leber congenital amaurosis (EOSRD/LCA; 52%), and 24 with macular dystrophy (MD; 23%). Severe visual impairment was most frequent after 40 years of age for patients with RP and after 20 years of age for EOSRD/LCA. Longitudinal analysis revealed a significant difference between baseline and follow-up best-corrected visual acuity in the 3 subcohorts. Macular thickness decreased in most patients with EOSRD/LCA and MD, whereas the majority of patients with RP had increased perifoveal thickness. CONCLUSIONS A subset of individuals with CRB1 variants present with mild, adult-onset RP. EOSRD/LCA phenotype was significantly associated with null variants, and 167_169 deletion was exclusively present in the MD cohort. The poor OCT lamination may have a degenerative component, as well as being congenital. Disease symmetry and reasonable window for intervention highlight CRB1 retinal dystrophies as a promising target for trials of novel therapeutics.
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Affiliation(s)
- Malena Daich Varela
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom
| | - Michalis Georgiou
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; Jones Eye Institute (M.G.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Yahya Alswaiti
- St John of Jerusalem Eye Hospital group, Jerusalem, Palestine (Y.A., A.A.)
| | - Jamil Kabbani
- Imperial College London (J.K.), London, United Kingdom
| | - Kaoru Fujinami
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center (Y.F.-Y.), Tokyo, Japan
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center (Y.F.-Y.), Tokyo, Japan; Department of Health Policy and Management, School of Medicine, Keio University(Y.F.-Y.), Tokyo, Japan
| | - Shaheeni Khoda
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom
| | - Omar A Mahroo
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom
| | - Anthony G Robson
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom
| | - Alaa AlTalbishi
- St John of Jerusalem Eye Hospital group, Jerusalem, Palestine (Y.A., A.A.)
| | - Michel Michaelides
- Moorfields Eye Hospital (M.D.V., M.G., K.F., S.K., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom; UCL Institute of Ophthalmology, University College London (M.D.V., M.G., K.F., Y.F.-Y., O.A.M., A.G.R., A.R.W., M.M.), London, United Kingdom.
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9
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Non-vasogenic cystoid maculopathies. Prog Retin Eye Res 2022; 91:101092. [PMID: 35927124 DOI: 10.1016/j.preteyeres.2022.101092] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 05/30/2022] [Accepted: 06/01/2022] [Indexed: 11/23/2022]
Abstract
Besides cystoid macular edema due to a blood-retinal barrier breakdown, another type of macular cystoid spaces referred to as non-vasogenic cystoid maculopathies (NVCM) may be detected on optical coherence tomography but not on fluorescein angiography. Various causes may disrupt retinal cell cohesion or impair retinal pigment epithelium (RPE) and Müller cell functions in the maintenance of retinal dehydration, resulting in cystoid spaces formation. Tractional causes include vitreomacular traction, epiretinal membranes and myopic foveoschisis. Surgical treatment does not always allow cystoid space resorption. In inherited retinal dystrophies, cystoid spaces may be part of the disease as in X-linked retinoschisis or enhanced S-cone syndrome, or occur occasionally as in bestrophinopathies, retinitis pigmentosa and allied diseases, congenital microphthalmia, choroideremia, gyrate atrophy and Bietti crystalline dystrophy. In macular telangiectasia type 2, cystoid spaces and cavitations do not depend on the fluid leakage from telangiectasia. Various causes affecting RPE function may result in NVCM such as chronic central serous chorioretinopathy and paraneoplastic syndromes. Non-exudative age macular degeneration may also be complicated by intraretinal cystoid spaces in the absence of fluorescein leakage. In these diseases, cystoid spaces occur in a context of retinal cell loss. Various causes of optic atrophy, including open-angle glaucoma, result in microcystoid spaces in the inner nuclear layer due to a retrograde transsynaptic degeneration. Lastly, drug toxicity may also induce cystoid maculopathy. Identifying NVCM on multimodal imaging, including fluorescein angiography if needed, allows guiding the diagnosis of the causative disease and choosing adequate treatment when available.
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10
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Weatherly SM, Collin GB, Charette JR, Stone L, Damkham N, Hyde LF, Peterson JG, Hicks W, Carter GW, Naggert JK, Krebs MP, Nishina PM. Identification of Arhgef12 and Prkci as genetic modifiers of retinal dysplasia in the Crb1rd8 mouse model. PLoS Genet 2022; 18:e1009798. [PMID: 35675330 PMCID: PMC9212170 DOI: 10.1371/journal.pgen.1009798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 06/21/2022] [Accepted: 05/03/2022] [Indexed: 12/03/2022] Open
Abstract
Mutations in the apicobasal polarity gene CRB1 lead to diverse retinal diseases, such as Leber congenital amaurosis, cone-rod dystrophy, retinitis pigmentosa (with and without Coats-like vasculopathy), foveal retinoschisis, macular dystrophy, and pigmented paravenous chorioretinal atrophy. Limited correlation between disease phenotypes and CRB1 alleles, and evidence that patients sharing the same alleles often present with different disease features, suggest that genetic modifiers contribute to clinical variation. Similarly, the retinal phenotype of mice bearing the Crb1 retinal degeneration 8 (rd8) allele varies with genetic background. Here, we initiated a sensitized chemical mutagenesis screen in B6.Cg-Crb1rd8/Pjn, a strain with a mild clinical presentation, to identify genetic modifiers that cause a more severe disease phenotype. Two models from this screen, Tvrm266 and Tvrm323, exhibited increased retinal dysplasia. Genetic mapping with high-throughput exome and candidate-gene sequencing identified causative mutations in Arhgef12 and Prkci, respectively. Epistasis analysis of both strains indicated that the increased dysplastic phenotype required homozygosity of the Crb1rd8 allele. Retinal dysplastic lesions in Tvrm266 mice were smaller and caused less photoreceptor degeneration than those in Tvrm323 mice, which developed an early, large diffuse lesion phenotype. At one month of age, Müller glia and microglia mislocalization at dysplastic lesions in both modifier strains was similar to that in B6.Cg-Crb1rd8/Pjn mice but photoreceptor cell mislocalization was more extensive. External limiting membrane disruption was comparable in Tvrm266 and B6.Cg-Crb1rd8/Pjn mice but milder in Tvrm323 mice. Immunohistological analysis of mice at postnatal day 0 indicated a normal distribution of mitotic cells in Tvrm266 and Tvrm323 mice, suggesting normal early development. Aberrant electroretinography responses were observed in both models but functional decline was significant only in Tvrm323 mice. These results identify Arhgef12 and Prkci as modifier genes that differentially shape Crb1-associated retinal disease, which may be relevant to understanding clinical variability and underlying disease mechanisms in humans. Inherited eye diseases affect roughly 1:1,000 individuals worldwide. Although these diseases are often linked to variants of a single gene, it is increasingly recognized that a second variant in other genes may modify disease characteristics, including age of onset, severity, and lesion appearance. Identifying such modifier genes in humans is difficult. In this study, two modifiers of a gene associated with retinal damage leading to childhood blindness in humans (CRB1) were identified in mice. Retinal damage caused by Crb1 mutation alone was less severe than in the presence of Arhgef12 or Prkci mutations. Furthermore, the modifier gene mutations caused retinal damage only in the presence of the Crb1 mutation. Our results point to a role of mouse Crb1 and the modifying effects of Arhgef12 and Prkci in a biological network that controls adhesive interactions between cells. The variation in disease severity, lesion appearance, and visual responses in these mice provide a dramatic example of modifier gene influence. This work may lead to an improved understanding of the molecular basis of CRB1-associated retinal disease, with possible relevance to diagnostic and therapeutic intervention in humans.
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Affiliation(s)
| | - Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Wanda Hicks
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | | | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (MPK); (PMN)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (MPK); (PMN)
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11
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Genetic characteristics of 234 Italian patients with macular and cone/cone-rod dystrophy. Sci Rep 2022; 12:3774. [PMID: 35260635 PMCID: PMC8904500 DOI: 10.1038/s41598-022-07618-1] [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: 09/22/2021] [Accepted: 02/16/2022] [Indexed: 01/09/2023] Open
Abstract
Two-hundred and thirty-four Italian patients with a clinical diagnosis of macular, cone and cone-rod dystrophies (MD, CD, and CRD) were examined using next-generation sequencing (NGS) and gene sequencing panels targeting a specific set of genes, Sanger sequencing and—when necessary—multiplex ligation-dependent probe amplification (MLPA) to diagnose the molecular cause of the aforementioned diseases. When possible, segregation analysis was performed in order to confirm unsolved cases. Each patient’s retinal phenotypic characteristics were determined using focal and full-field ERGs, perimetry, spectral domain optical coherence tomography and fundus autofluorescence. We identified 236 potentially causative variants in 136 patients representing the 58.1% of the total cohort, 43 of which were unpublished. After stratifying the patients according to their clinical suspicion, the diagnostic yield was 62.5% and 53.8% for patients with MD and for those with CD/CRD, respectively. The mode of inheritance of all cases confirmed by genetic analysis was 70% autosomal recessive, 26% dominant, and 4% X-linked. The main cause (59%) of both MD and CD/CRD cases was the presence of variants in the ABCA4 gene, followed by variants in PRPH2 (9%) and BEST1 (6%). A careful morpho-functional evaluation of the phenotype, together with genetic counselling, resulted in an acceptable diagnostic yield in a large cohort of Italian patients. Our study emphasizes the role of targeted NGS to diagnose MDs, CDs, and CRDs, as well as the clinical usefulness of segregation analysis for patients with unsolved diagnosis.
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12
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Nahar A, Cho SH. Current perspectives in Leber congenital amaurosis type 8 mouse modeling. Dev Dyn 2022; 251:1094-1106. [PMID: 35150033 DOI: 10.1002/dvdy.462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 02/01/2022] [Accepted: 02/05/2022] [Indexed: 11/11/2022] Open
Abstract
Mutations in the CRB1 (Crumbs homolog 1) cause rare retinal diseases like retinitis pigmentosa type 12 (RP12) and Leber congenital amaurosis type 8 (LCA8). RP12 results in progressively worsening peripheral vision, whereas LCA8 causes severe visual impairment at birth or in early life. While several mouse models have been proposed for RP12, few replicate the full spectrum of human LCA8 pathology, such as disorganized retinal layering, abnormal retinal thickening, pigmentary defects, hyperreflective lesions, and severely attenuated electroretinogram responses at birth. Six models have been proposed utilizing the Cre-loxP system to delete candidate genes in specific retinal cell types and developmental stages. The model ablating Crb1 and its homolog Crb2 (using mRx-Cre) from the beginning of the eye development is the most complete as it shows blindness during the eye-opening stage, pigmentary defects in the RPE, ganglion cell layer heterotopia, disruption of retinal lamination, and acellular patches. LCA8 represents a unique type of retinal dystrophy among LCA subtypes, driven by dysfunctional retinal progenitor cells during eye development. In contrast, other LCA types and RP12 are caused by photoreceptor defects. Therefore, the most accurate LCA8-like mouse model must target both alleles of the Crb1 and Crb2 genes in the optic vesicle or earlier. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ankur Nahar
- Thomas Jefferson University Sidney Kimmel Medical College, 1020 Locust Street, Philadelphia, PA, USA
| | - Seo-Hee Cho
- Center for Translational Medicine, Department of Medicine, Thomas Jefferson University Sidney Kimmel Medical College, 1020 Locust Street, Philadelphia, PA, USA
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13
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Cheng Z, Hagan R, Yeo DCM. Identification of a novel CRB1 variant in a compound heterozygous state in a patient with CRB1-associated maculopathy and foveal retinoschisis. Ophthalmic Genet 2021; 43:253-257. [PMID: 34783605 DOI: 10.1080/13816810.2021.1998551] [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: 10/19/2022]
Abstract
PURPOSE To report a novel CRB1 variant responsible for autosomal recessive foveal retinoschisis and its associated clinical and electrophysiological data. METHODS A case report. RESULTS A 15-year-old boy has foveal retinoschisis similar to those seen in X-linked retinoschisis (XLRS). During follow-up, we observed the co-existence of foveoschitic changes and parafoveal macular atrophy. Molecular genetic testing identified compound heterozygous variants in the CRB1 gene, including a novel variant, c.3878 G > A, predicted to disrupt the normal translation of CRB1 and a previously reported likely pathogenic mutation, c.498_506del. Full-field electroretinograms (ERG) were normal but multifocal ERG showed focal reduced waveform amplitude corresponding to the area of atrophy. CONCLUSIONS A novel missense variant existing in a compound heterozygous state was identified. Biallelic CRB1 mutations can cause anatomical fovea disruption similar to XLRS but have very different electroretinogram findings. This case report enhances our understanding of the spectrum of biallelic CRB1 mutations.
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Affiliation(s)
- Zhihang Cheng
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Richard Hagan
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland.,Clinical Engineering Department, Royal Liverpool University Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
| | - Damien C M Yeo
- Alder Hey Children's Nhs Foundation Trust, Department of Ophthalmology, Alder Hey Children's Hospital, Liverpool, United Kingdom of Great Britain and Northern Ireland
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14
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Roshandel D, Thompson JA, Heath Jeffery RC, Sampson DM, Chelva E, McLaren TL, Lamey TM, De Roach JN, Durkin SR, Chen FK. Multimodal Retinal Imaging and Microperimetry Reveal a Novel Phenotype and Potential Trial End Points in CRB1-Associated Retinopathies. Transl Vis Sci Technol 2021; 10:38. [PMID: 34003923 PMCID: PMC7910635 DOI: 10.1167/tvst.10.2.38] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose Biallelic crumbs cell polarity complex component 1 (CRB1) mutations can present as Leber congenital amaurosis (LCA), retinitis pigmentosa (RP), or cystic maculopathy. This study reports a novel phenotype of asymptomatic fenestrated slit maculopathy (AFSM) and examines macular volume profile and microperimetry as clinical trial end points in CRB1-associated retinopathies. Methods Twelve patients from nine families with CRB1 mutation were recruited. Ultra-widefield (UWF) color fundus photography and autofluorescence (AF), spectral-domain optical coherence tomography (SD-OCT), microperimetry, and adaptive optics (AO) imaging were performed. Macular volume profiles were compared with age-matched healthy controls. Genotyping was performed using APEX genotyping microarrays, targeted next-generation sequencing, and Sanger sequencing. Results We identified one patient with LCA, five patients with RP, and four patients with macular dystrophy (MD) with biallelic CRB1 mutations. Two siblings with compound heterozygote genotype (c.[2843G>A]; [498_506del]) had AFSM characterized by localized outer retinal disruption on SD-OCT and parafoveal cone loss on AO imaging despite normal fundus appearance, visual acuity, and foveal sensitivity. UWF AF demonstrated preserved para-arteriolar retinal pigment epithelium (PPRPE) in all patients with RP. Microperimetry documented preserved central retinal function in six patients. The ratio of perifoveal-to-foveal retinal volume was greater than controls in 89% (8/9) of patients with RP or MD, whereas central subfield and total macular volume were outside normal limits in 67% (6/9). Conclusions AO imaging was helpful in detecting parafoveal cone loss in asymptomatic patients. Macular volume profile and microperimetry parameters may have utility as CRB1 trials end points. Translational Relevance Macular volume and sensitivity can be used as structural and functional end points for trials on CRB1-associated RP and MD.
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Affiliation(s)
- Danial Roshandel
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Rachael C Heath Jeffery
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Danuta M Sampson
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Surrey Biophotonics, Centre for Vision, Speech and Signal Processing and School of Biosciences and Medicine, The University of Surrey, Guildford, UK
| | - Enid Chelva
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Terri L McLaren
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Tina M Lamey
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - John N De Roach
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Shane R Durkin
- Discipline of Ophthalmology and Visual Science, The University of Adelaide, South Australia, Australia.,Department of Ophthalmology, The Royal Adelaide and Queen Elizabeth Hospital, Adelaide, South Australia, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science (incorporating Lions Eye Institute), The University of Western Australia, Australia.,Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.,Department of Ophthalmology, Perth Children's Hospital, Nedlands, Western Australia, Australia
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15
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Maia N, Soares AR, Fortuna AM, Marques I, Gonçalves A, Santos R, Melo Pires M, de Brouwer APM, Jorge P. Usher syndrome and Nebulin-associated myopathy in a single patient due to variants in MYO7A and NEB. Clin Case Rep 2020; 8:2476-2482. [PMID: 33363762 PMCID: PMC7752365 DOI: 10.1002/ccr3.3146] [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: 02/14/2020] [Revised: 06/08/2020] [Accepted: 06/14/2020] [Indexed: 12/02/2022] Open
Abstract
In a patient with Usher syndrome and atypical muscle complaints, we have identified two separate variants in MYO7A andNEB genes by exome sequencing. The homozygous variants in these two recessive genes could explain the full phenotype of our patient.
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Affiliation(s)
- Nuno Maia
- Unidade de Genética MolecularCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
| | - Ana Rita Soares
- Unidade de Genética MédicaCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
| | - Ana Maria Fortuna
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
- Unidade de Genética MédicaCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
| | - Isabel Marques
- Unidade de Genética MolecularCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
| | - Ana Gonçalves
- Unidade de Genética MolecularCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
| | - Rosário Santos
- Unidade de Genética MolecularCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
| | - Manuel Melo Pires
- Serviço de NeuropatologiaCentro Hospitalar e Universitário do Porto (CHUP)PortoPortugal
| | - Arjan P. M. de Brouwer
- Department of Human GeneticsDonders Institute for Brain, Cognition and BehaviourRadboud University NijmegenNijmegenThe Netherlands
| | - Paula Jorge
- Unidade de Genética MolecularCentro de Genética Médica Jacinto de Magalhães (CGM)Centro Hospitalar Universitário do Porto (CHUP)PortoPortugal
- Unidade Multidisciplinar de Investigação Biomédica (UMIB)Instituto de Ciências Biomédicas Abel Salazar (ICBAS)Universidade do PortoPortoPortugal
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16
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Coussa RG, Binkley EM, Wilkinson ME, Andorf JL, Tucker BA, Mullins RF, Sohn EH, Yannuzzi LA, Stone EM, Han IC. Predominance of hyperopia in autosomal dominant Best vitelliform macular dystrophy. Br J Ophthalmol 2020; 106:522-527. [DOI: 10.1136/bjophthalmol-2020-317763] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/05/2020] [Accepted: 11/15/2020] [Indexed: 12/17/2022]
Abstract
Background/AimsPatients with BEST1-associated autosomal dominant Best vitelliform macular dystrophy (AD-BVMD) have been reported to be hyperopic, but the prevalence of refractive error has not been described. This study aimed to characterise the type and degree of refractive error in a large cohort of patients with AD-BVMD compared with an age-similar group with ABCA4-associated Stargardt disease.MethodsThis was a retrospective chart review of consecutive patients with molecularly confirmed AD-BVMD and Stargardt macular dystrophy seen at a single academic centre. Demographic information, including age, gender and genotype were extracted from the chart. The best corrected visual acuity (BCVA), as well as type and degree of refractive error on manifest refraction for each eye on each visit, were recorded and compared.ResultsA total of 178 eyes from 89 patients with AD-BVMD (35 women, 54 men; mean age 36.6 years) and 306 eyes from 153 patients (94 women, 59 men, mean age 30.2 years) with Stargardt disease were included in the study. Mean BCVA was excellent for both AD-BVMD and Stargardt eyes (logMAR 0.23 vs logMAR 0.31, respectively; p=0.55). At initial refraction, 73.0% of AD-BVMD eyes (130/178) were hyperopic, with mean spherical equivalent (SE) +1.38 dioptres (median +0.88) whereas 80.7% of Stargardt eyes (247/306) were myopic, with mean SE of −1.76 dioptres (median −1.19) (p<0.001).ConclusionPatients with AD-BVMD are predominantly hyperopic, whereas those with Stargardt disease are predominantly myopic. The findings provide further evidence of a role for BEST1 in ocular growth and development.
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Prasov L, Guan B, Ullah E, Archer SM, Ayres BM, Besirli CG, Wiinikka-Buesser L, Comer GM, Del Monte MA, Elner SG, Garnai SJ, Huryn LA, Johnson K, Kamat SS, Lieu P, Mian SI, Rygiel CA, Serpen JY, Pawar HS, Brooks BP, Moroi SE, Richards JE, Hufnagel RB. Novel TMEM98, MFRP, PRSS56 variants in a large United States high hyperopia and nanophthalmos cohort. Sci Rep 2020; 10:19986. [PMID: 33203948 PMCID: PMC7672112 DOI: 10.1038/s41598-020-76725-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/26/2020] [Indexed: 12/18/2022] Open
Abstract
Nanophthalmos is a rare condition defined by a small, structurally normal eye with resultant high hyperopia. While six genes have been implicated in this hereditary condition (MFRP, PRSS56, MYRF, TMEM98, CRB1,VMD2/BEST1), the relative contribution of these to nanophthalmos or to less severe high hyperopia (≥ + 5.50 spherical equivalent) has not been fully elucidated. We collected probands and families (n = 56) with high hyperopia or nanophthalmos (≤ 21.0 mm axial length). Of 53 families that passed quality control, plausible genetic diagnoses were identified in 10/53 (18.8%) by high-throughput panel or pooled exome sequencing. These include 1 TMEM98 family (1.9%), 5 MFRP families (9.4%), and 4 PRSS56 families (7.5%), with 4 additional families having single allelic hits in MFRP or PRSS56 (7.5%). A novel deleterious TMEM98 variant (NM_015544.3, c.602G>C, p.(Arg201Pro)) segregated with disease in 4 affected members of a family. Multiple novel missense and frameshift variants in MFRP and PRSS56 were identified. PRSS56 families were more likely to have choroidal folds than other solved families, while MFRP families were more likely to have retinal degeneration. Together, this study defines the prevalence of nanophthalmos gene variants in high hyperopia and nanophthalmos and indicates that a large fraction of cases remain outside of single gene coding sequences.
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Affiliation(s)
- Lev Prasov
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA. .,Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Bin Guan
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Ehsan Ullah
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Steven M Archer
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Bernadete M Ayres
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Cagri G Besirli
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Laurel Wiinikka-Buesser
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Grant M Comer
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Monte A Del Monte
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Susan G Elner
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Sarah J Garnai
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Laryssa A Huryn
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kayla Johnson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Shivani S Kamat
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Philip Lieu
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Shahzad I Mian
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Christine A Rygiel
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Jasmine Y Serpen
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA.,Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.,Case Western Reserve University School of Medicine, Cleveland, OH, 44106, USA
| | - Hemant S Pawar
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Sayoko E Moroi
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA.,Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, 43212, USA
| | - Julia E Richards
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Robert B Hufnagel
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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Nadolski NJ, Balay SD, Wong CXL, Waskiewicz AJ, Hocking JC. Abnormal Cone and Rod Photoreceptor Morphogenesis in gdf6a Mutant Zebrafish. Invest Ophthalmol Vis Sci 2020; 61:9. [PMID: 32293666 PMCID: PMC7401959 DOI: 10.1167/iovs.61.4.9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose Analysis of photoreceptor morphology and gene expression in mispatterned eyes of zebrafish growth differentiation factor 6a (gdf6a) mutants. Methods Rod and cone photoreceptors were compared between gdf6a mutant and control zebrafish from larval to late adult stages using transgenic labels, immunofluorescence, and confocal microscopy, as well as by transmission electron microscopy. To compare transcriptomes between larval gdf6a mutant and control zebrafish, RNA-Seq was performed on isolated eyes. Results Although rod and cone photoreceptors differentiate in gdf6a mutant zebrafish, the cells display aberrant growth and morphology. The cone outer segments, the light-detecting sensory endings, are reduced in size in the mutant larvae and fail to recover to control size at subsequent stages. In contrast, rods form temporarily expanded outer segments. The inner segments, which generate the required energy and proteins for the outer segments, are shortened in both rods and cones at all stages. RNA-Seq analysis provides a set of misregulated genes associated with the observed abnormal photoreceptor morphogenesis. Conclusions GDF6 mutations were previously identified in patients with Leber congenital amaurosis. Here, we reveal a unique photoreceptor phenotype in the gdf6a mutant zebrafish whereby rods and cones undergo abnormal maturation distinct for each cell type. Further, subsequent development shows partial recovery of cell morphology and maintenance of the photoreceptor layer. By conducting a transcriptomic analysis of the gdf6a larval eyes, we identified a collection of genes that are candidate regulators of photoreceptor size and morphology.
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Chan WO, Brennan N, Webster AR, Michaelides M, Muqit MMK. Retinal detachment in retinitis pigmentosa. BMJ Open Ophthalmol 2020; 5:e000454. [PMID: 32671228 PMCID: PMC7351280 DOI: 10.1136/bmjophth-2020-000454] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/23/2020] [Accepted: 06/03/2020] [Indexed: 11/30/2022] Open
Abstract
Objective Retinitis pigmentosa-related retinal detachment (RPRD) is rare, and the full spectrum of retinal complications is not well defined. To describe the types of retinal detachment in patients with retinitis pigmentosa and the surgical outcomes of RPRD. Methods This is a non-comparative, retrospective case series. An electronic database search was performed using Moorfields OpenEyes electronic health records. We identified 90 patients with RPRD between January 2000 and August 2017. Main outcome and measures are visual acuity (VA), surgical outcomes and classification of RPRD. Results Of the 90 patients/detachments, 61 (67.8%) were rhegmatogenous retinal detachment (RRD), 19 (21.1%) were exudative, 3 (3.3%) were tractional retinal detachment (TRD) and 7 (7.8%) had combined. 37.5% (9/24) of patients with exudative retinal detachment were treated with either cryotherapy or laser, and one patient underwent vitrectomy for vitreous haemorrhage. 56/90 patients underwent surgical intervention. Nine patients presented late and were deemed inoperable (two exudative and seven RRD). Of the RRD patients with full operative record, the primary attachment rate was 76.2% (16/21) and final reattachment rate was 85.7% (18/21) over a mean 15.4-year follow-up period. Mean VA for RRD surgery improved from 6/190 (1.51 logMAR) to 6/120 (1.31 logMAR) (p=0.194). In the TRD group, the mean VA was 6/300 (1.66 logMAR) at baseline and improved after surgery to 6/48 (0.90 logMAR) (p=0.421). Conclusions We demonstrated a final reattachment rate of 85.7% with a trend toward better vision following intervention for patients with RPRD. However, the final long-term vision may be poor due to the natural progression of retinitis pigmentosa-associated macular degeneration.
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Affiliation(s)
- Weng Onn Chan
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Nicholas Brennan
- Vitreoretinal Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew R Webster
- Vitreoretinal Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Michel Michaelides
- Vitreoretinal Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Mahiul M K Muqit
- Vitreoretinal Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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20
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Ray TA, Cochran K, Kozlowski C, Wang J, Alexander G, Cady MA, Spencer WJ, Ruzycki PA, Clark BS, Laeremans A, He MX, Wang X, Park E, Hao Y, Iannaccone A, Hu G, Fedrigo O, Skiba NP, Arshavsky VY, Kay JN. Comprehensive identification of mRNA isoforms reveals the diversity of neural cell-surface molecules with roles in retinal development and disease. Nat Commun 2020; 11:3328. [PMID: 32620864 PMCID: PMC7335077 DOI: 10.1038/s41467-020-17009-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 05/30/2020] [Indexed: 02/08/2023] Open
Abstract
Genes encoding cell-surface proteins control nervous system development and are implicated in neurological disorders. These genes produce alternative mRNA isoforms which remain poorly characterized, impeding understanding of how disease-associated mutations cause pathology. Here we introduce a strategy to define complete portfolios of full-length isoforms encoded by individual genes. Applying this approach to neural cell-surface molecules, we identify thousands of unannotated isoforms expressed in retina and brain. By mass spectrometry we confirm expression of newly-discovered proteins on the cell surface in vivo. Remarkably, we discover that the major isoform of a retinal degeneration gene, CRB1, was previously overlooked. This CRB1 isoform is the only one expressed by photoreceptors, the affected cells in CRB1 disease. Using mouse mutants, we identify a function for this isoform at photoreceptor-glial junctions and demonstrate that loss of this isoform accelerates photoreceptor death. Therefore, our isoform identification strategy enables discovery of new gene functions relevant to disease.
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Affiliation(s)
- Thomas A Ray
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Kelly Cochran
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Chris Kozlowski
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Jingjing Wang
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Graham Alexander
- Center for Genomic and Computational Biology, Duke University, Durham, NC, 27710, USA
| | | | | | - Philip A Ruzycki
- John F. Hardesty, M.D. Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, 63110, USA
| | - Brian S Clark
- John F. Hardesty, M.D. Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, 63110, USA
- Department of Developmental Biology, Washington University, St. Louis, MO, 63110, USA
| | | | - Ming-Xiao He
- Advanced Cell Diagnostics, Newark, CA, 94560, USA
| | | | - Emily Park
- Advanced Cell Diagnostics, Newark, CA, 94560, USA
| | - Ying Hao
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Alessandro Iannaccone
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Gary Hu
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Olivier Fedrigo
- Center for Genomic and Computational Biology, Duke University, Durham, NC, 27710, USA
- The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Nikolai P Skiba
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA
| | - Jeremy N Kay
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, 27710, USA.
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC, 27710, USA.
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21
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Ahmed Khan S, Richard Nestel A. CRB1 Gene Mutation Causing Different Phenotypes of Leber Congenital Amaurosis in Siblings. J Ophthalmic Vis Res 2019; 14:518-524. [PMID: 31875109 PMCID: PMC6825708 DOI: 10.18502/jovr.v14i4.5467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 02/10/2019] [Indexed: 12/19/2022] Open
Abstract
Purpose We report a rare case of CRB1gene mutation in two siblings (sisters) affected with the exact same genetic mutation on both CRB1genes resulting in varying phenotypes. Case Report CRB1gene mutation in this case has resulted in causing varying degrees of Leber congenital amaurosis (LCA) in both sisters with a more severe phenotype in the older sibling causing LCA-8 with retinitis pigmentosa spectrum in both eyes and a milder phenotype causing LCA-8 with less severe rod cone dystrophy in the younger sister. Conclusion In summary, the mechanisms of varying phenotypes resulting from CRB1 genetic mutation are still not well understood. We concluded that the presence of different phenotypes associated with identical genotypic mutation of a single gene in siblings or in a family is important especially when dealing with retinal dystrophies.
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22
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Targeted deletion of Crb1/Crb2 in the optic vesicle models key features of leber congenital amaurosis 8. Dev Biol 2019; 453:141-154. [PMID: 31145883 DOI: 10.1016/j.ydbio.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 01/01/2023]
Abstract
The Crb1 and 2 (Crumbs homolog 1 & 2) genes encode large, single-pass transmembrane proteins essential for the apicobasal polarity and adhesion of epithelial cells. Crb1 mutations cause degenerative retinal diseases in humans, including Leber congenital amaurosis type 8 (LCA8) and retinitis pigmentosa type 12 (RP12). In LCA8, impaired photoreceptor development and/or survival is thought to cause blindness during early infancy, whereas, in RP12, progressive photoreceptor degeneration damages peripheral vision later in life. There are multiple animal models of RP12 pathology, but no experimental model of LCA8 recapitulates the full spectrum of its pathological features. To generate a mouse model of LCA8 and identify the functions of Crb1/2 in developing ocular tissues, we used an mRx-Cre driver to generate allelic combinations that enabled conditional gene ablation from the optic vesicle stage. In this series only Crb1/2 double knockout (dKO) mice exhibited characteristics of human LCA8 disease: locally thickened retina with spots devoid of cells, aberrant positioning of retinal cells, severely disrupted lamination, and depigmented retinal-pigmented epithelium. Retinal defects antedated E12.5, which is far earlier than the stage at which photoreceptor cells mainly differentiate. Most remarkably, Crb1/Crb2 dKO showed a severely attenuated electroretinogram at the eye opening stage. These results suggest that human LCA8 can be modeled in the mouse by simultaneously ablating Crb1/2 from the beginning of eye development. Importantly, they also indicate that LCA8 is caused by malfunction of retinal progenitor cells during early ocular development rather than by defective photoreceptor-Muller glial interaction, a mechanism proposed for RP12.
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23
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Zhang X, Zhang D, Chen SC, Lamey T, Thompson JA, McLaren T, De Roach JN, Chen FK, McLenachan S. Establishment of an induced pluripotent stem cell line from a retinitis pigmentosa patient with compound heterozygous CRB1 mutation. Stem Cell Res 2018; 31:147-151. [PMID: 30092450 DOI: 10.1016/j.scr.2018.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 07/19/2018] [Accepted: 08/01/2018] [Indexed: 11/25/2022] Open
Abstract
The human iPSC line LEIi006-A was generated from dermal fibroblasts from a patient with retinitis pigmentosa using episomal plasmids containing OCT4, SOX2, KLF4, L-MYC, LIN28, mir302/367 microRNA and shRNA for p53. The iPSC cells carry compound heterozygous mutations (c.1892A > G and c.2548G > A) in the CRB1 gene. LEIi006-A expressed pluripotent stem cell markers, had a normal karyotype and could be differentiated into endoderm, mesoderm and ectodermal lineages, as well as retinal organoids.
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Affiliation(s)
- Xiao Zhang
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia; Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Dan Zhang
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | | | - Tina Lamey
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Terri McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - John N De Roach
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Fred K Chen
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia; Lions Eye Institute, Nedlands, Western Australia, Australia; Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; Department of Ophthalmology, Royal Perth Hospital, Perth, Western Australia, Australia.
| | - Samuel McLenachan
- Centre for Ophthalmology and Visual Science, The University of Western Australia, Perth, Western Australia, Australia; Lions Eye Institute, Nedlands, Western Australia, Australia
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24
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Fu J, Nagashima M, Guo C, Raymond PA, Wei X. Novel Animal Model of Crumbs-Dependent Progressive Retinal Degeneration That Targets Specific Cone Subtypes. Invest Ophthalmol Vis Sci 2018; 59:505-518. [PMID: 29368007 PMCID: PMC5786287 DOI: 10.1167/iovs.17-22572] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Purpose Human Crb1 is implicated in some forms of retinal degeneration, suggesting a role in photoreceptor maintenance. Multiple Crumbs (Crb) polarity genes are expressed in vertebrate retina, although their functional roles are not well understood. To gain further insight into Crb and photoreceptor maintenance, we compared retinal cell densities between wild-type and Tg(RH2-2:Crb2b-sfEX/RH2-2:GFP)pt108b transgenic zebrafish, in which the extracellular domain of Crb2b-short form (Crb2b-sfEX) is expressed in the retina as a secreted protein, which disrupts the planar organization of RGB cones (red, green, and blue) by interfering with Crb2a/2b-based cone-cone adhesion. Methods We used standard morphometric techniques to assess age-related changes in retinal cell densities in adult zebrafish (3 to 27 months old), and to assess effects of the Crb2b-sfEX transgene on retinal structure and photoreceptor densities. Linear cell densities were measured in all retinal layers in radial sections with JB4-Feulgen histology. Planar (surface) densities of cones were determined in retinal flat-mounts. Cell counts from wild-type and pt108b transgenic fish were compared with both a “photoreceptor maintenance index” and statistical analysis of cell counts. Results Age-related changes in retinal cell linear densities and cone photoreceptor planar densities in wild-type adult zebrafish provided a baseline for analysis. Expression of Crb2b-sfEX caused progressive and selective degeneration of RGB cones, but had no effect on ultraviolet-sensitive (UV) cones, and increased numbers of rod photoreceptors. Conclusions These differential responses of RGB cones, UV cones, and rods to sustained exposure to Crb2b-sfEX suggest that Crb-based photoreceptor maintenance mechanisms are highly selective.
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Affiliation(s)
- Jinling Fu
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, Jilin, China.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Mikiko Nagashima
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan, United States
| | - Chuanyu Guo
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Pamela A Raymond
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan, United States
| | - Xiangyun Wei
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States.,Department of Developmental Biology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States.,Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States.,Louis J. Fox Center for Vision Restoration, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States
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25
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Wood EH, Drenser KA, Hariprasad SM. Genetic Testing for Retina Specialists. Ophthalmic Surg Lasers Imaging Retina 2018; 49:292-295. [DOI: 10.3928/23258160-20180501-01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Khan KN, Robson A, Mahroo OAR, Arno G, Inglehearn CF, Armengol M, Waseem N, Holder GE, Carss KJ, Raymond LF, Webster AR, Moore AT, McKibbin M, van Genderen MM, Poulter JA, Michaelides M. A clinical and molecular characterisation of CRB1-associated maculopathy. Eur J Hum Genet 2018; 26:687-694. [PMID: 29391521 PMCID: PMC5945653 DOI: 10.1038/s41431-017-0082-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/14/2017] [Accepted: 12/05/2017] [Indexed: 12/22/2022] Open
Abstract
To date, over 150 disease-associated variants in CRB1 have been described, resulting in a range of retinal disease phenotypes including Leber congenital amaurosis and retinitis pigmentosa. Despite this, no genotype–phenotype correlations are currently recognised. We performed a retrospective review of electronic patient records to identify patients with macular dystrophy due to bi-allelic variants in CRB1. In total, seven unrelated individuals were identified. The median age at presentation was 21 years, with a median acuity of 0.55 decimalised Snellen units (IQR = 0.43). The follow-up period ranged from 0 to 19 years (median = 2.0 years), with a median final decimalised Snellen acuity of 0.65 (IQR = 0.70). Fundoscopy revealed only a subtly altered foveal reflex, which evolved into a bull’s-eye pattern of outer retinal atrophy. Optical coherence tomography identified structural changes—intraretinal cysts in the early stages of disease, and later outer retinal atrophy. Genetic testing revealed that one rare allele (c.498_506del, p.(Ile167_Gly169del)) was present in all patients, with one patient being homozygous for the variant and six being heterozygous. In trans with this, one variant recurred twice (p.(Cys896Ter)), while the four remaining alleles were each observed once (p.(Pro1381Thr), p.(Ser478ProfsTer24), p.(Cys195Phe) and p.(Arg764Cys)). These findings show that the rare CRB1 variant, c.498_506del, is strongly associated with localised retinal dysfunction. The clinical findings are much milder than those observed with bi-allelic, loss-of-function variants in CRB1, suggesting this in-frame deletion acts as a hypomorphic allele. This is the most prevalent disease-causing CRB1 variant identified in the non-Asian population to date.
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Affiliation(s)
- Kamron N Khan
- University College London Institute of Ophthalmology, University College London, London, UK. .,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK. .,Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK. .,Department of Ophthalmology, St. James's University Teaching Hospital, Leeds, UK.
| | - Anthony Robson
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
| | - Omar A R Mahroo
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Gavin Arno
- University College London Institute of Ophthalmology, University College London, London, UK
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Monica Armengol
- Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Naushin Waseem
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Graham E Holder
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK
| | - Keren J Carss
- NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Department of Haematology, NHS Blood and Transplant Centre, University of Cambridge, Cambridge, CB2 0PT, UK.,Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Lucy F Raymond
- NIHR BioResource - Rare Diseases, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge, UK.,Department of Haematology, NHS Blood and Transplant Centre, University of Cambridge, Cambridge, CB2 0PT, UK.,Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Andrew R Webster
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
| | - Anthony T Moore
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK.,Ophthalmology Department, University of California San Francisco Medical School, San Francisco, CA, USA
| | - Martin McKibbin
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK.,Department of Ophthalmology, St. James's University Teaching Hospital, Leeds, UK
| | - Maria M van Genderen
- Bartiméus Diagnostic Centre for Complex Visual Disorders, Zeist, The Netherlands.,Department of Ophthalmology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - James A Poulter
- Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Michel Michaelides
- University College London Institute of Ophthalmology, University College London, London, UK.,Inherited Eye Disease Service, Moorfields Eye Hospital, London, UK
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27
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CLINICAL PROGRESS IN INHERITED RETINAL DEGENERATIONS: GENE THERAPY CLINICAL TRIALS AND ADVANCES IN GENETIC SEQUENCING. Retina 2017; 37:417-423. [PMID: 27753762 DOI: 10.1097/iae.0000000000001341] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PURPOSE Inherited retinal dystrophies are a significant cause of vision loss and are characterized by the loss of photoreceptors and the retinal pigment epithelium (RPE). Mutations in approximately 250 genes cause inherited retinal degenerations with a high degree of genetic heterogeneity. New techniques in next-generation sequencing are allowing the comprehensive analysis of all retinal disease genes thus changing the approach to the molecular diagnosis of inherited retinal dystrophies. This review serves to analyze clinical progress in genetic diagnostic testing and implications for retinal gene therapy. METHODS A literature search of PubMed and OMIM was conducted to relevant articles in inherited retinal dystrophies. RESULTS Next-generation genetic sequencing allows the simultaneous analysis of all the approximately 250 genes that cause inherited retinal dystrophies. Reported diagnostic rates range are high and range from 51% to 57%. These new sequencing tools are highly accurate with sensitivities of 97.9% and specificities of 100%. Retinal gene therapy clinical trials are underway for multiple genes including RPE65, ABCA4, CHM, RS1, MYO7A, CNGA3, CNGB3, ND4, and MERTK for which a molecular diagnosis may be beneficial for patients. CONCLUSION Comprehensive next-generation genetic sequencing of all retinal dystrophy genes is changing the paradigm for how retinal specialists perform genetic testing for inherited retinal degenerations. Not only are high diagnostic yields obtained, but mutations in genes with novel clinical phenotypes are also identified. In the era of retinal gene therapy clinical trials, identifying specific genetic defects will increasingly be of use to identify patients who may enroll in clinical studies and benefit from novel therapies.
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Motta FL, Salles MV, Costa KA, Filippelli-Silva R, Martin RP, Sallum JMF. The correlation between CRB1 variants and the clinical severity of Brazilian patients with different inherited retinal dystrophy phenotypes. Sci Rep 2017; 7:8654. [PMID: 28819299 PMCID: PMC5561187 DOI: 10.1038/s41598-017-09035-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/20/2017] [Indexed: 12/18/2022] Open
Abstract
Inherited retinal dystrophies are characterized by progressive retina degeneration and mutations in at least 250 genes have been associated as disease-causing. CRB1 is one of many genes analyzed in molecular diagnosis for inherited retinal dystrophy. Crumbs homolog-1 protein encoded by CRB1 is important for cell-to-cell contact, polarization of epithelial cells and the morphogenesis of photoreceptors. Pathogenic variants in CRB1 lead to a huge variety of phenotypes ranging from milder forms of inherited retinal dystrophy, such as retinitis pigmentosa to more severe phenotypes such as Leber congenital amaurosis. In this study, seven novel likely-pathogenic variants were identified: four missense variants (p.Leu479Pro, p.Ala921Pro, p.Cys948Arg and p.Asp1031Asn), two frameshift deletions (c.2536_2542del7 and c.3460_3461delTG) and one frameshift indel variant (c.276_294delinsTGAACACTGTAC). Furthermore, two patients with cone-rod dystrophy due to mutations in CRB1 were reported, supporting previous data, in which mutations in CRB1 can also cause cone-rod dystrophy. Finally, our data suggested there was a direct relation between phenotype severity and the mutation effect on protein functionality in 15 Brazilian CRB1 patients.
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Affiliation(s)
| | | | | | | | - Renan Paulo Martin
- Department of Biophysics, Federal University of Sao Paulo, Sao Paulo, Brazil
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29
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Pellikka M, Tepass U. Unique cell biological profiles of retinal disease-causing missense mutations in the polarity protein Crumbs. J Cell Sci 2017; 130:2147-2158. [PMID: 28515229 DOI: 10.1242/jcs.197178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 05/11/2017] [Indexed: 01/09/2023] Open
Abstract
Mutations in human crumbs 1 (CRB1) are a major cause of retinal diseases that lead to blindness. CRB1 is a transmembrane protein found in the inner segment of photoreceptor cells (PRCs) and the apical membrane of Müller glia. The function of the extracellular region of CRB1 is poorly understood, although more than 80 disease-causing missense mutations have been mapped to it. We have recreated four of these mutations, affecting different extracellular domains, in Drosophila Crumbs (Crb). Crb regulates epithelial polarity and growth, and contributes to PRC differentiation and survival. The mutant Crb isoforms showed a remarkable diversity in protein abundance, subcellular distribution and ability to rescue the lack of endogenous Crb, elicit a gain-of-function phenotype or promote PRC degeneration. Interestingly, although expression of mutant isoforms led to a substantial rescue of the developmental defects seen in crb mutants, they accelerated PRC degeneration compared to that seen in retinas that lacked Crb, indicating that the function of Crb in cellular differentiation and cell survival depends on distinct molecular pathways. Several Crb mutant proteins accumulated abnormally in the rhabdomere and affected rhodopsin trafficking, suggesting that abnormal rhodopsin physiology contributes to Crb/CRB1-associated retinal degeneration.
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Affiliation(s)
- Milena Pellikka
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada
| | - Ulrich Tepass
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, M5S 3G5, Canada
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30
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Ghofrani M, Yahyaei M, Brunner HG, Cremers FP, Movasat M, Imran Khan M, Keramatipour M. Homozygosity Mapping and Targeted Sanger Sequencing Identifies Three Novel CRB1 (Crumbs homologue 1) Mutations in Iranian Retinal Degeneration Families. IRANIAN BIOMEDICAL JOURNAL 2017; 21:294-302. [PMID: 28460491 PMCID: PMC5548961 DOI: 10.18869/acadpub.ibj.21.5.294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background: Inherited retinal diseases (IRDs) are a group of genetic disorders with high degrees of clinical, genetic and allelic heterogeneity. IRDs generally show progressive retinal cell death resulting in gradual vision loss. IRDs constitute a broad spectrum of disorders including retinitis pigmentosa and Leber congenital amaurosis. In this study, we performed genotyping studies to identify the underlying mutations in three Iranian families. Methods: Having employed homozygosity mapping and Sanger sequencing, we identified the underlying mutations in the crumbs homologue 1 gene. The CRB1 protein is a part of a macromolecular complex with a vital role in retinal cell polarity, morphogenesis, and maintenance. Results: We identified a novel homozygous variant (c.1053_1061del; p.Gly352_Cys354del) in one family, a combination of a novel (c.2086T>C; p.Cys696Arg) and a known variant (c.2234C>T, p.Thr745Met) in another family and a homozygous novel variant (c.3090T>A; p.Asn1030Lys) in a third family. Conclusion: This study shows that mutations in CRB1 are relatively common in Iranian non-syndromic IRD patients.
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Affiliation(s)
- Mohammad Ghofrani
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mahin Yahyaei
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Han G. Brunner
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans P.M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Morteza Movasat
- Eye Research Center, Tehran University of Medical Sciences, Farabi Eye Hospital, Tehran, Iran
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
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31
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Barbara R, Turnbull AMJ, Hossain P, Anderson DF, Barbara A. Epidemiology of Keratoconus. KERATOCONUS 2017. [DOI: 10.1007/978-3-319-43881-8_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Verhagen F, Kuiper J, Nierkens S, Imhof SM, Radstake T, de Boer J. Systemic inflammatory immune signatures in a patient with CRB1 linked retinal dystrophy. Expert Rev Clin Immunol 2016; 12:1359-1362. [DOI: 10.1080/1744666x.2016.1241709] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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33
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Srilekha S, Arokiasamy T, Srikrupa NN, Umashankar V, Meenakshi S, Sen P, Kapur S, Soumittra N. Homozygosity Mapping in Leber Congenital Amaurosis and Autosomal Recessive Retinitis Pigmentosa in South Indian Families. PLoS One 2015; 10:e0131679. [PMID: 26147992 PMCID: PMC4493089 DOI: 10.1371/journal.pone.0131679] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 06/04/2015] [Indexed: 11/18/2022] Open
Abstract
Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are retinal degenerative diseases which cause severe retinal dystrophy affecting the photoreceptors. LCA is predominantly inherited as an autosomal recessive trait and contributes to 5% of all retinal dystrophies; whereas RP is inherited by all the Mendelian pattern of inheritance and both are leading causes of visual impairment in children and young adults. Homozygosity mapping is an efficient strategy for mapping both known and novel disease loci in recessive conditions, especially in a consanguineous mating, exploiting the fact that the regions adjacent to the disease locus will also be homozygous by descent in such inbred children. Here we have studied eleven consanguineous LCA and one autosomal recessive RP (arRP) south Indian families to know the prevalence of mutations in known genes and also to know the involvement of novel loci, if any. Complete ophthalmic examination was done for all the affected individuals including electroretinogram, fundus photograph, fundus autofluorescence, and optical coherence tomography. Homozygosity mapping using Affymetrix 250K HMA GeneChip on eleven LCA families followed by screening of candidate gene(s) in the homozygous block identified mutations in ten families; AIPL1 - 3 families, RPE65- 2 families, GUCY2D, CRB1, RDH12, IQCB1 and SPATA7 in one family each, respectively. Six of the ten (60%) mutations identified are novel. Homozygosity mapping using Affymetrix 10K HMA GeneChip on the arRP family identified a novel nonsense mutation in MERTK. The mutations segregated within the family and was absent in 200 control chromosomes screened. In one of the eleven LCA families, the causative gene/mutation was not identified but many homozygous blocks were noted indicating that a possible novel locus/gene might be involved. The genotype and phenotype features, especially the fundus changes for AIPL1, RPE65, CRB1, RDH12 genes were as reported earlier.
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Affiliation(s)
- Sundaramurthy Srilekha
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India
- Ph.D Scholar, Birla Institute of Technology & Science (BITS), Hyderabad, India
| | - Tharigopala Arokiasamy
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India
| | - Natarajan N. Srikrupa
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India
- Ph.D Scholar, Birla Institute of Technology & Science (BITS), Hyderabad, India
| | | | - Swaminathan Meenakshi
- Department of Peadiatric ophthalmology and starbismus, Medical Research Foundation, Chennai, India
| | - Parveen Sen
- Department of Vitreo-Retinal Services, Medical Research Foundation, Chennai, India
| | - Suman Kapur
- Head, Department of Biological Science, Birla Institute of Technology & Science (BITS), Hyderabad, India
| | - Nagasamy Soumittra
- SNONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Chennai, India
- * E-mail: /
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