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Georgiou M, Robson AG, Uwaydat SH, Ji MH, Shakarchi AF, Pontikos N, Mahroo OA, Cheetham ME, Webster AR, Hardcastle AJ, Michaelides M. RP2-Associated X-linked Retinopathy: Clinical Findings, Molecular Genetics, and Natural History in a Large Cohort of Female Carriers. Am J Ophthalmol 2024; 261:112-120. [PMID: 37977507 DOI: 10.1016/j.ajo.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/25/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE RP2-associated retinopathy typically causes severe early onset retinitis pigmentosa (RP) in affected males. However, there is a scarcity of reports describing the clinical phenotype of female carriers. We tested the hypothesis that RP2 variants manifest in female carriers with a range of functional and anatomic characteristics. DESIGN Retrospective case series. METHODS Females with disease-causing variants in RP2 were identified from investigation of pedigrees affected by RP2 retinopathy. All case notes and results of molecular genetic testing, retinal imaging (fundus autofluorescence imaging, optical coherence tomography (OCT)), and electrophysiology were reviewed. RESULTS Forty pedigrees were investigated. Twenty-nine pedigrees had obligate carriers or molecularly confirmed female members with recorded relevant history and/or examination. For 8 pedigrees, data were available only from history, with patients reporting affected female relatives with RP in 4 cases and unaffected female relatives in the other 4 cases. Twenty-seven females from 21 pedigrees were examined by a retinal genetics specialist. Twenty-three patients (85%) reported no complaints and had normal vision and 4 patients had RP-associated complaints (15%). Eight patients had normal fundus examination (30%), 10 had a tapetal-like reflex (TLR; 37%), 5 had scattered peripheral pigmentation (19%), and the 4 symptomatic patients had fundus findings compatible with RP (15%). All asymptomatic patients with normal fundus, TLR, or asymptomatic pigmentary changes had a continuous ellipsoid zone on OCT when available. The electroretinograms revealed mild to severe photoreceptor dysfunction in 9 of 11 subjects, often asymmetrical, including 5 with pattern electroretinogram evidence of symmetrical (n = 4) or unilateral (n = 1 subject) macular dysfunction. CONCLUSIONS Most carriers were asymptomatic, exhibiting subclinical characteristics such as TLR and pigmentary changes. However, female carriers of RP2 variants can manifest RP. Family history of affected females with RP does not exclude X-linked disease. The phenotypic spectrum as described herein has prognostic and counselling implications for RP2 carriers and patients.
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Affiliation(s)
- Michalis Georgiou
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom; Jones Eye Institute (M.G., S.H.U., M.H.J., A.F.S.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Anthony G Robson
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Sami H Uwaydat
- Jones Eye Institute (M.G., S.H.U., M.H.J., A.F.S.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marco H Ji
- Jones Eye Institute (M.G., S.H.U., M.H.J., A.F.S.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ahmed F Shakarchi
- Jones Eye Institute (M.G., S.H.U., M.H.J., A.F.S.), University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Nikolas Pontikos
- University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Omar A Mahroo
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Michael E Cheetham
- University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Andrew R Webster
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Alison J Hardcastle
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom
| | - Michel Michaelides
- From the Moorfields Eye Hospital (M.G., A.G.R., N.P., O.A.M., A.R.W., M.M.), London, United Kingdeom; University College London Institute of Ophthalmology (M.G., A.G.R., N.P., O.A.M., M.E.C., A.R.W., A.J.H., M.M.), University College London, London, United Kingdom.
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Georgiou M, Robson AG, Jovanovic K, Guimarães TACD, Ali N, Pontikos N, Uwaydat SH, Mahroo OA, Cheetham ME, Webster AR, Hardcastle AJ, Michaelides M. RP2-Associated X-linked Retinopathy: Clinical Findings, Molecular Genetics, and Natural History. Ophthalmology 2023; 130:413-422. [PMID: 36423731 PMCID: PMC10567581 DOI: 10.1016/j.ophtha.2022.11.015] [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: 09/21/2022] [Revised: 11/10/2022] [Accepted: 11/10/2022] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To review and describe in detail the clinical course, functional and anatomic characteristics of RP2-associated retinal degeneration. DESIGN Retrospective case series. PARTICIPANTS Male participants with disease-causing variants in the RP2 gene. METHODS Review of all case notes and results of molecular genetic testing, retinal imaging (fundus autofluorescence [FAF] imaging, OCT), and electrophysiology assessment. MAIN OUTCOME MEASURES Molecular genetic testing, clinical findings including best-corrected visual acuity (BCVA), qualitative and quantitative retinal imaging analysis, and electrophysiology parameters. RESULTS Fifty-four molecularly confirmed patients were identified from 38 pedigrees. Twenty-eight disease-causing variants were identified, with 20 not previously clinically characterized. Fifty-three patients (98.1%) presented with retinitis pigmentosa. The mean age of onset (range ± standard deviation [SD]) was 9.6 years (1-57 ± 9.2 years). Forty-four patients (91.7%) had childhood-onset disease, with mean age of onset of 7.6 years. The most common first symptom was night blindness (68.8%). Mean BCVA (range ± SD) was 0.91 logarithm of the minimum angle of resolution (logMAR) (0-2.7 ± 0.80) and 0.94 logMAR (0-2.7 ± 0.78) for right and left eyes, respectively. On the basis of the World Health Organization visual impairment criteria, 18 patients (34%) had low vision. The majority (17/22) showed electroretinogram (ERG) evidence of a rod-cone dystrophy. Pattern ERG P50 was undetectable in all but 2 patients. A range of FAF findings was observed, from normal to advanced atrophy. There were no statistically significant differences between right and left eyes for ellipsoid zone width (EZW) and outer nuclear layer (ONL) thickness. The mean annual rate of EZW loss was 219 μm/year, and the mean annual decrease in ONL thickness was 4.93 μm/year. No patient with childhood-onset disease had an identifiable ellipsoid zone (EZ) after the age of 26 years at baseline or follow-up. Four patients had adulthood-onset disease and a less severe phenotype. CONCLUSIONS This study details the clinical phenotype of RP2 retinopathy in a large cohort. The majority presented with early-onset severe retinal degeneration, with early macular involvement and complete loss of the foveal photoreceptor layer by the third decade of life. Full-field ERGs revealed rod-cone dystrophy in the vast majority, but with generalized (peripheral) cone system involvement of widely varying severity in the first 2 decades of life. FINANCIAL DISCLOSURE(S) Proprietary or commercial disclosure may be found after the references.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Katarina Jovanovic
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Naser Ali
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Sami H Uwaydat
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michael E Cheetham
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Alison J Hardcastle
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Liu X, Jia R, Meng X, Wang L, Yang L. Analysis of RPGR gene mutations in 41 Chinese families affected by X-linked inherited retinal dystrophy. Front Genet 2022; 13:999695. [PMID: 36276946 PMCID: PMC9582779 DOI: 10.3389/fgene.2022.999695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/12/2022] [Indexed: 11/13/2022] Open
Abstract
Background: This study analyzed the phenotypes and genotypes of 41 Chinese families with inherited retinal dystrophy (IRD) and RPGR gene mutations.Methods: This retrospective analysis evaluated a cohort of 41 patients who were subjected to a specific Hereditary Eye Disease Enrichment Panel (HEDEP) analysis. All (likely) pathogenic variants were determined by Sanger sequencing, and co-segregation analyses were performed on the available family members. All cases were subjected to Sanger sequencing for RPGR open reading frame 15 (ORF15) mutations.Results: A total of 41 probands from different families with a clinical diagnosis of retinitis pigmentosa (RP; 34 cases) and cone-rod dystrophy (CORD; 7 cases) were included in this cohort. According to clinical information, 2, 18, and 21 cases were first assigned as autosomal dominant (AD), sporadic, and X-linked (XL) inheritance, respectively. Several cases of affected females who presented with a male phenotype have been described, posing challenges at diagnosis related to the apparent family history of AD. Mutations were located in RPGR exons or introns 1–14 and in ORF15 of 12 of 41 (29.3%) and 29 of 41 (70.7%) subjects, respectively. Thirty-four (likely) pathogenic mutations were identified. Frameshifts were the most frequently observed variants, followed by nonsense, splice, and missense mutations. Herein, a detailed description of four RP patients carrying RPGR intronic mutations is reported, and in vitro splice assays were performed to confirm the pathogenicity of these intronic mutations.Conclusion: Our findings provide useful insights for the genetic and clinical counseling of patients with XL IRD, which will be useful for ongoing and future gene therapy trials.
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Affiliation(s)
- Xiaozhen Liu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Ruixuan Jia
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xiang Meng
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Likun Wang
- Institute of Systems Biomedicine, Department of Pathology, School of Basic Medical Sciences, Beijing Key Laboratory of Tumor Systems Biology, Peking-Tsinghua Center of Life Sciences, Peking University Health Science Center, Beijing, China
- *Correspondence: Likun Wang, ; Liping Yang,
| | - Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
- *Correspondence: Likun Wang, ; Liping Yang,
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Yang J, Zhou L, Ouyang J, Xiao X, Sun W, Li S, Zhang Q. Genotype-Phenotype Analysis of RPGR Variations: Reporting of 62 Chinese Families and a Literature Review. Front Genet 2021; 12:600210. [PMID: 34745198 PMCID: PMC8565807 DOI: 10.3389/fgene.2021.600210] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 04/27/2021] [Indexed: 02/05/2023] Open
Abstract
Purpose RPGR is the most common cause of X-linked retinitis pigmentosa (RP), of which female carriers are also frequently affected. The aim of the current study was to explore the RPGR variation spectrum and associated phenotype based on the data from our lab and previous studies. Methods Variants in RPGR were selected from exome sequencing data of 7,092 probands with different eye conditions. The probands and their available family members underwent comprehensive ocular examinations. Similar data were collected from previous reports through searches in PubMed, Web of Science, and Google Scholar. Systematic analyses of genotypes, phenotypes and their correlations were performed. Results A total of 46 likely pathogenic variants, including nine missense and one in-frame variants in RCC1-like domain and 36 truncation variants, in RPGR were detected in 62 unrelated families in our in-house cohort. In addition, a total of 585 variants, including 491 (83.9%) truncation variants, were identified from the literature. Systematic analysis of variants from our in-house dataset, literature, and gnomAD suggested that most of the pathogenic variants of RPGR were truncation variants while pathogenic missense and in-frame variants were enriched in the RCC1-like domain. Phenotypic variations were present between males and female carriers, including more severe refractive error but better best corrected visual acuity (BCVA) in female carriers than those in males. The male patients showed a significant reduction of BCVA with increase of age and males with exon1-14 variants presented a better BCVA than those with ORF15 variants. For female carriers, the BCVA also showed significant reduction with increase of age, but BCVA in females with exon1-14 variants was not significant difference compared with those with ORF15 variants. Conclusion Most pathogenic variants of RPGR are truncations. Missense and in-frame variants located outside of the RCC1-like domain might be benign and the pathogenicity criteria for these variants should be considered with greater caution. The BCVA and refractive error are different between males and female carriers. Increase of age and location of variants in ORF15 contribute to the reduction of BCVA in males. These results are valuable for understanding genotypes and phenotypes of RPGR.
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Affiliation(s)
- Junxing Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Lin Zhou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, China
| | - Jiamin Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Di Iorio V, Karali M, Melillo P, Testa F, Brunetti-Pierri R, Musacchia F, Condroyer C, Neidhardt J, Audo I, Zeitz C, Banfi S, Simonelli F. Spectrum of Disease Severity in Patients With X-Linked Retinitis Pigmentosa Due to RPGR Mutations. Invest Ophthalmol Vis Sci 2021; 61:36. [PMID: 33372982 PMCID: PMC7774109 DOI: 10.1167/iovs.61.14.36] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose The purpose of this study was to perform a detailed longitudinal phenotyping of X-linked retinitis pigmentosa (RP) caused by mutations in the RPGR gene during a long follow-up period. Methods An Italian cohort of 48 male patients (from 31 unrelated families) with RPGR-associated RP was clinically assessed at a single center (mean follow-up = 6.5 years), including measurements of best-corrected visual acuity (BCVA), Goldmann visual field (GVF), optical coherence tomography (OCT), fundus autofluorescence (FAF), microperimetry, and full-field electroretinography (ERG). Results Patients (29.6 ± 15.2 years) showed a mean BCVA of 0.6 ± 0.7 logMAR, mostly with myopic refraction (79.2%). Thirty patients (62.5%) presented a typical RP fundus, while the remaining sine pigmento RP. Over the follow-up, BCVA significantly declined at a mean rate of 0.025 logMAR/year. Typical RP and high myopia were associated with a significantly faster decline of BCVA. Blindness was driven primarily by GVF loss. ERG responses with a rod-cone pattern of dysfunction were detectable in patients (50%) that were significantly younger and more frequently presented sine pigmento RP. Thirteen patients (27.1%) had macular abnormalities without cystoid macular edema. Patients (50%) with a perimacular hyper-FAF ring were significantly younger, had a higher BCVA and a better-preserved ellipsoid zone band than those with markedly decreased FAF. Patients harboring pathogenic variants in exons 1 to 14 showed a milder phenotype compared to those with ORF15 mutations. Conclusions Our monocentric, longitudinal retrospective study revealed a spectrum disease progression in male patients with RPGR-associated RP. Slow disease progression correlated with sine pigmento RP, absence of high myopia, and mutations in RPGR exons 1 to 14.
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Affiliation(s)
- Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy.,Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | | | | | - John Neidhardt
- Human Genetics, Faculty of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, University Oldenburg, Oldenburg, Germany
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France.,CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC, France.,Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania "Luigi Vanvitelli," Naples, Italy
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A novel missense variant c.G644A (p.G215E) of the RPGR gene in a Chinese family causes X-linked retinitis pigmentosa. Biosci Rep 2020; 39:220828. [PMID: 31652454 PMCID: PMC6822503 DOI: 10.1042/bsr20192235] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/11/2019] [Accepted: 09/24/2019] [Indexed: 01/01/2023] Open
Abstract
The mutations in patients with X-linked retinitis pigmentosa (xlRP) have not been well described in the Chinese population. In the present study, a five-generation Chinese retinitis pigmentosa (RP) family was recruited; targeted next-generation sequencing (TGS) was used to identify causative genes and Sanger sequencing for co-segregation. RNA-seq data analysis and revere transcriptional-polymerase chain reaction (RT-PCR) were applied to investigate gene expression patterns of RP GTPase regulator (RPGR) in human and Rpgr in mouse. A novel, hemizygous, deleterious and missense variant: c.G644A (p.G215E) in the RPGR gene (NM_000328.2) exon 7 of X-chromosome was identified in the proband, which was co-segregated with the clinical phenotypes in this family. RNA-seq data showed that RPGR is ubiquitously expressed in 27 human tissues with testis in highest, but no eye tissues data. Then the expressions for Rpgr mRNA in mice including eye tissues were conducted and showed that Rpgr transcript is ubiquitously expressed very highly in retina and testis, and highly in other eye tissues including lens, sclera, and cornea; and expressed highly in the six different developmental times of retinal tissue. Ubiquitous expression in different tissues from eye and very high expression in the retina indicated that RPGR plays a vital role in eye functions, particularly in retina. In conclusion, our study is the first to indicate that the novel missense variant c.G644A (p.G215E) in the RPGR gene might be the disease-causing mutation in this xlRP family, expanding mutation spectrum. These findings facilitate better understanding of the molecular pathogenesis of this disease; provide new insights for genetic counseling and healthcare.
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Zou X, Fang S, Wu S, Li H, Sun Z, Zhu T, Wei X, Sui R. Detailed comparison of phenotype between male patients carrying variants in exons 1-14 and ORF15 of RPGR. Exp Eye Res 2020; 198:108147. [PMID: 32702353 DOI: 10.1016/j.exer.2020.108147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/05/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE To compare disease severity in detail between patients carrying variants in exons 1-14 and ORF15 of retinitis pigmentosa GTPase regulator (RPGR). METHODS Systematic next-generation sequencing data analysis, Sanger sequencing validation and segregation analysis were utilised to identify the pathogenic variants. Detailed ophthalmic examinations, including electroretinograms, fundus photography, fundus autofluorescence and optical coherence tomography were performed. Statistical analysis, including age adjustment and comparison, were performed based on cross-sectional level to compare disease severity between variants in the two RPGR variant groups. RESULTS Sixty-two variants were identified in RPGR in 86 patients from 77 unrelated families. Twenty-nine (37.7%) had variants in RPGR-exons 1-14 (group 1) and 48 (62.3%) in RPGR-ORF15 (group 2). Eighty-four patients were diagnosed with X-linked retinitis pigmentosa and only two patients with cone-rod dystrophy. LogMAR visual acuity increased 0.035 and 0.022 each year on average in group 1 and group 2, respectively. Group 2 patients had better visual acuity with a mean logMAR difference of 0.4378, which is significant after age adjustment (P < 0.01). Neither the value of log (ellipsoid zone width) nor central retinal thickness was significantly correlated with variant grouping after considering the effect of the age variable (P = 0.56 and 0.40, respectively). Spherical refractive error did not differ significantly between the two variant groups (P = 0.17). Patterns of autofluorescence included a hyperfluorescent ring at the posterior pole, diffuse hyperfluorescence in the macular area, and dark macular autofluorescence with or without fovea hyperfluorescence. The age and proportion of fundus autofluorescence patterns between the two variant groups were significantly different (P < 0.01). CONCLUSIONS Patients with variants in exons 1-14 retained less visual acuity than patients with ORF15 variants and deteriorated faster. However, the ellipsoid zone widths, central retinal thickness and refractions were comparable between the two groups. Autofluorescence pattern relates to the age and the variant grouping.
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Affiliation(s)
- Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Sha Fang
- School of Statistics, Capital University of Economics and Business, Beijing, 100070, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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Chiang JPW, Lamey TM, Wang NK, Duan J, Zhou W, McLaren TL, Thompson JA, Ruddle J, De Roach JN. Development of High-Throughput Clinical Testing of RPGR ORF15 Using a Large Inherited Retinal Dystrophy Cohort. Invest Ophthalmol Vis Sci 2019; 59:4434-4440. [PMID: 30193314 DOI: 10.1167/iovs.18-24555] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Mutations in the ORF15 region of RPGR account for approximately half of all X-linked retinitis pigmentosa cases. However, a robust high-throughput method for the detection of ORF15 mutations has yet to be validated. We set out to develop the first clinically validated next-generation sequencing (NGS) method for the detection of mutations in this difficult-to-sequence region, including test accuracy and coverage data. Methods As part of a blind-test, 145 research samples, previously tested by Sanger sequencing, and 81 clinical samples were evaluated using NGS of long-range PCR products fragmented with Illumina's Nextera library preparation kit (method 1), or with Centrillion's OneTube technology, supplemented with duplication analysis using an ORF15-specific in-silico array (method 2). DNA fragments were analyzed using Agilent's DNA 1000 assay, and sequencing was done on Illumina's MiSeq 2×150 or HiSeq2500 2×100. NextGENe by SoftGenetics was used for data analysis and variant calling. Results The Nextera library preparation method produced 24 cases of discordance due to (in order of decreasing occurrence) false-negatives, incorrectly called variants, and a false-positive. Subsequent use of a new, OneTube NGS library preparation method, supplemented with duplication analyses, resolved discordance between Sanger and NGS data in all cases. This improvement in variant detection accuracy was largely attributed to improvement in random fragmentation offered by the enzymatic OneTube method, resulting in more complete coverage of the highly repetitive ORF15 region. Minimum coverage was roughly 320 reads for Nextera and 6800 reads for OneTube (normalized for total read counts). Conclusions This paper documents the first clinically validated NGS method for reliable, high-throughput sequencing of RPGR ORF15. Sensitivity and specificity of the new method were 100%, with the caveat of unclear zygosity calling for one large duplication case. These findings demonstrate a reliable and practical implementation for NGS-based diagnosis of RPGR ORF15 mutations. They also provide the foundation for targeted, high-coverage sequencing of any other repetitive regions within the genome.
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Affiliation(s)
- John P W Chiang
- Molecular Vision Laboratory, Hillsboro, Oregon, United States
| | - Tina M Lamey
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia
| | - Nicholas K Wang
- Molecular Vision Laboratory, Hillsboro, Oregon, United States
| | - Jie Duan
- Molecular Vision Laboratory, Hillsboro, Oregon, United States
| | - Wei Zhou
- Centrillion Technologies, Palo Alto, California, United States
| | - Terri L McLaren
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Jennifer A Thompson
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | | | - John N De Roach
- Australian Inherited Retinal Disease Registry and DNA Bank, Department of Medical Technology and Physics, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia.,Centre for Ophthalmology and Visual Science, The University of Western Australia, Crawley, Western Australia, Australia
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9
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Disruption of RPGR protein interaction network is the common feature of RPGR missense variations that cause XLRP. Proc Natl Acad Sci U S A 2019; 116:1353-1360. [PMID: 30622176 DOI: 10.1073/pnas.1817639116] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal degenerative disease with severe vision impairment leading to blindness. About 10-15% of RP cases are caused by mutations in the RPGR gene, with RPGR mutations accounting for 70% of X-linked RP cases. The mechanism by which RPGR mutations cause photoreceptor cell dysfunction is not well understood. In this study, we show that the two isoforms of RPGR (RPGR1-19 and RPGRORF15) interact with endogenous PDE6D, INPP5E, and RPGRIP1L. The RPGR1-19 isoform contains two PDE6D binding sites with the C-terminal prenylation site being the predominant PDE6D binding site. The C terminus of RPGR1-19 that contains the prenylation site regulates its interaction with PDE6D, INPP5E, and RPGRIP1L. Only the RPGR1-19 isoform localizes to cilia in cultured RPE1 cells. Missense variations found in RPGR patients disrupt the interaction between RPGR isoforms and their endogenous interactors INPP5E, PDE6D, and RPGRIP1L. We evaluated a RPGR missense variation (M58K) found in a family with X-linked retinitis pigmentosa (XLRP) and show that this missense variation disrupts the interaction of RPGR isoforms with their endogenous interactors. The M58K variation also disrupts the ciliary localization of the RPGR1-19 isoform. Using this assay, we also show that some of the RPGR missense variants reported in the literature might not actually be disease causing. Our data establishes an in vitro assay that can be used to validate the potential pathogenicity of RPGR missense variants.
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10
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Analysis of RP2 and RPGR Mutations in Five X-Linked Chinese Families with Retinitis Pigmentosa. Sci Rep 2017; 7:44465. [PMID: 28294154 PMCID: PMC5353642 DOI: 10.1038/srep44465] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
Mutations in RP2 and RPGR genes are responsible for the X-linked retinitis pigmentosa (XLRP). In this study, we analyzed the RP2 and RPGR gene mutations in five Han Chinese families with XLRP. An approximately 17Kb large deletion including the exon 4 and exon 5 of RP2 gene was found in an XLRP family. In addition, four frameshift mutations including three novel mutations of c.1059 + 1 G > T, c.2002dupC and c.2236_2237del CT, as well as a previously reported mutation of c.2899delG were detected in the RPGR gene in the other four families. Our study further expands the mutation spectrum of RP2 and RPGR, and will be helpful for further study molecular pathogenesis of XLRP.
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11
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Ullah I, Kabir F, Iqbal M, Gottsch CBS, Naeem MA, Assir MZ, Khan SN, Akram J, Riazuddin S, Ayyagari R, Hejtmancik JF, Riazuddin SA. Pathogenic mutations in TULP1 responsible for retinitis pigmentosa identified in consanguineous familial cases. Mol Vis 2016; 22:797-815. [PMID: 27440997 PMCID: PMC4947966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 07/14/2016] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To identify pathogenic mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous familial cases. METHODS Seven large familial cases with multiple individuals diagnosed with retinitis pigmentosa were included in the study. Affected individuals in these families underwent ophthalmic examinations to document the symptoms and confirm the initial diagnosis. Blood samples were collected from all participating members, and genomic DNA was extracted. An exclusion analysis with microsatellite markers spanning the TULP1 locus on chromosome 6p was performed, and two-point logarithm of odds (LOD) scores were calculated. All coding exons along with the exon-intron boundaries of TULP1 were sequenced bidirectionally. We constructed a single nucleotide polymorphism (SNP) haplotype for the four familial cases harboring the K489R allele and estimated the likelihood of a founder effect. RESULTS The ophthalmic examinations of the affected individuals in these familial cases were suggestive of RP. Exclusion analyses confirmed linkage to chromosome 6p harboring TULP1 with positive two-point LOD scores. Subsequent Sanger sequencing identified the single base pair substitution in exon14, c.1466A>G (p.K489R), in four families. Additionally, we identified a two-base deletion in exon 4, c.286_287delGA (p.E96Gfs77*); a homozygous splice site variant in intron 14, c.1495+4A>C; and a novel missense variation in exon 15, c.1561C>T (p.P521S). All mutations segregated with the disease phenotype in the respective families and were absent in ethnically matched control chromosomes. Haplotype analysis suggested (p<10(-6)) that affected individuals inherited the causal mutation from a common ancestor. CONCLUSIONS Pathogenic mutations in TULP1 are responsible for the RP phenotype in seven familial cases with a common ancestral mutation responsible for the disease phenotype in four of the seven families.
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Affiliation(s)
- Inayat Ullah
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Muhammad Iqbal
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | | | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Muhammad Zaman Assir
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Radha Ayyagari
- Shiley Eye Institute, University of California, San Diego, CA
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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12
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Kabir F, Ullah I, Ali S, Gottsch AD, Naeem MA, Assir MZ, Khan SN, Akram J, Riazuddin S, Ayyagari R, Hejtmancik JF, Riazuddin SA. Loss of function mutations in RP1 are responsible for retinitis pigmentosa in consanguineous familial cases. Mol Vis 2016; 22:610-25. [PMID: 27307693 PMCID: PMC4901054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 06/08/2016] [Indexed: 10/31/2022] Open
Abstract
PURPOSE This study was undertaken to identify causal mutations responsible for autosomal recessive retinitis pigmentosa (arRP) in consanguineous families. METHODS Large consanguineous families were ascertained from the Punjab province of Pakistan. An ophthalmic examination consisting of a fundus evaluation and electroretinography (ERG) was completed, and small aliquots of blood were collected from all participating individuals. Genomic DNA was extracted from white blood cells, and a genome-wide linkage or a locus-specific exclusion analysis was completed with polymorphic short tandem repeats (STRs). Two-point logarithm of odds (LOD) scores were calculated, and all coding exons and exon-intron boundaries of RP1 were sequenced to identify the causal mutation. RESULTS The ophthalmic examination showed that affected individuals in all families manifest cardinal symptoms of RP. Genome-wide scans localized the disease phenotype to chromosome 8q, a region harboring RP1, a gene previously implicated in the pathogenesis of RP. Sanger sequencing identified a homozygous single base deletion in exon 4: c.3697delT (p.S1233Pfs22*), a single base substitution in intron 3: c.787+1G>A (p.I263Nfs8*), a 2 bp duplication in exon 2: c.551_552dupTA (p.Q185Yfs4*) and an 11,117 bp deletion that removes all three coding exons of RP1. These variations segregated with the disease phenotype within the respective families and were not present in ethnically matched control samples. CONCLUSIONS These results strongly suggest that these mutations in RP1 are responsible for the retinal phenotype in affected individuals of all four consanguineous families.
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Affiliation(s)
- Firoz Kabir
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Inayat Ullah
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Shahbaz Ali
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | | | - Muhammad Asif Naeem
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Muhammad Zaman Assir
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Shaheen N. Khan
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Javed Akram
- Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Sheikh Riazuddin
- National Centre of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan,Allama Iqbal Medical College, University of Health Sciences, Lahore, Pakistan,National Centre for Genetic Diseases, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Radha Ayyagari
- Shiley Eye Institute, University of California, San Diego, CA
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
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13
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Schwarz N, Carr AJ, Lane A, Moeller F, Chen LL, Aguilà M, Nommiste B, Muthiah MN, Kanuga N, Wolfrum U, Nagel-Wolfrum K, da Cruz L, Coffey PJ, Cheetham ME, Hardcastle AJ. Translational read-through of the RP2 Arg120stop mutation in patient iPSC-derived retinal pigment epithelium cells. Hum Mol Genet 2015; 24:972-86. [PMID: 25292197 PMCID: PMC4986549 DOI: 10.1093/hmg/ddu509] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 09/29/2014] [Indexed: 01/08/2023] Open
Abstract
Mutations in the RP2 gene lead to a severe form of X-linked retinitis pigmentosa. RP2 patients frequently present with nonsense mutations and no treatments are currently available to restore RP2 function. In this study, we reprogrammed fibroblasts from an RP2 patient carrying the nonsense mutation c.519C>T (p.R120X) into induced pluripotent stem cells (iPSC), and differentiated these cells into retinal pigment epithelial cells (RPE) to study the mechanisms of disease and test potential therapies. RP2 protein was undetectable in the RP2 R120X patient cells, suggesting a disease mechanism caused by complete lack of RP2 protein. The RP2 patient fibroblasts and iPSC-derived RPE cells showed phenotypic defects in IFT20 localization, Golgi cohesion and Gβ1 trafficking. These phenotypes were corrected by over-expressing GFP-tagged RP2. Using the translational read-through inducing drugs (TRIDs) G418 and PTC124 (Ataluren), we were able to restore up to 20% of endogenous, full-length RP2 protein in R120X cells. This level of restored RP2 was sufficient to reverse the cellular phenotypic defects observed in both the R120X patient fibroblasts and iPSC-RPE cells. This is the first proof-of-concept study to demonstrate successful read-through and restoration of RP2 function for the R120X nonsense mutation. The ability of the restored RP2 protein level to reverse the observed cellular phenotypes in cells lacking RP2 indicates that translational read-through could be clinically beneficial for patients.
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Affiliation(s)
- Nele Schwarz
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Amanda-Jayne Carr
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Amelia Lane
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Fabian Moeller
- Johannes Gutenberg-University Muellerweg 6, 55099 Mainz, Germany and
| | - Li Li Chen
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Mònica Aguilà
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Britta Nommiste
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Manickam N Muthiah
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK
| | - Naheed Kanuga
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| | - Uwe Wolfrum
- Johannes Gutenberg-University Muellerweg 6, 55099 Mainz, Germany and
| | | | - Lyndon da Cruz
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK
| | - Peter J Coffey
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
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Mutations of 60 known causative genes in 157 families with retinitis pigmentosa based on exome sequencing. Hum Genet 2014; 133:1255-71. [DOI: 10.1007/s00439-014-1460-2] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 06/03/2014] [Indexed: 12/01/2022]
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15
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Zahid S, Khan N, Branham K, Othman M, Karoukis AJ, Sharma N, Moncrief A, Mahmood MN, Sieving PA, Swaroop A, Heckenlively JR, Jayasundera T. Phenotypic conservation in patients with X-linked retinitis pigmentosa caused by RPGR mutations. JAMA Ophthalmol 2013; 131:1016-25. [PMID: 23681342 DOI: 10.1001/jamaophthalmol.2013.120] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IMPORTANCE For patients with X-linked retinitis pigmentosa and clinicians alike, phenotypic variability can be challenging because it complicates counseling regarding patients' likely visual prognosis. OBJECTIVE To evaluate the clinical findings from patients with X-linked retinitis pigmentosa with 13 distinct RPGR mutations and assess for phenotypic concordance or variability. DESIGN Retrospective medical record review of data collected from 1985 to 2011. SETTING Kellogg Eye Center, University of Michigan. PATIENTS A total of 42 patients with X-linked retinitis pigmentosa with mutations in RPGR. Age at first visit ranged from 4 to 53 years, with follow-up ranging from 1 to 11 visits (median follow-up time, 5.5 years; range, 1.4-32.7 years, for 23 patients with >1 visit). MAIN OUTCOMES AND MEASURES Clinical data assessed for concordance included visual acuity (VA), Goldmann visual fields (GVFs), and full-field electroretinography (ERG). Electroretinography phenotype (cone-rod vs rod-cone dysfunction) was defined by the extent of photopic vs scotopic abnormality. Qualitative GVF phenotype was determined by the GVF pattern, where central or peripheral loss suggested cone or rod dysfunction, respectively. Goldmann visual fields were also quantified and compared among patients. RESULTS Each mutation was detected in 2 or more related or unrelated patients. Five mutations in 11 patients displayed strong concordance of VA, while 4 mutations in 16 patients revealed moderate concordance of VA. A definitive cone-rod or rod-cone ERG pattern consistent among patients was found in 6 of 13 mutations (46.2%); the remaining mutations were characterized by patients demonstrating both phenotypes or who had limited data or nonrecordable ERG values. Concordant GVF phenotypes (7 rod-cone pattern vs 4 cone-rod pattern) were seen in 11 of 13 mutations (84.6%). All 6 mutations displaying a constant ERG pattern within the mutation group revealed a GVF phenotype consistent with the ERG findings. CONCLUSIONS AND RELEVANCE While VA and ERG phenotypes are concordant in only some patients carrying identical mutations, assessment of GVF phenotypes revealed stronger phenotypic conservation. Phenotypic concordance is important for establishing proper counseling of patients diagnosed as having X-linked retinitis pigmentosa, as well as for establishing accurate patient selection and efficacy monitoring in therapeutic trials.
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Affiliation(s)
- Sarwar Zahid
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, MI 48105, USA
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16
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Churchill JD, Bowne SJ, Sullivan LS, Lewis RA, Wheaton DK, Birch DG, Branham KE, Heckenlively JR, Daiger SP. Mutations in the X-linked retinitis pigmentosa genes RPGR and RP2 found in 8.5% of families with a provisional diagnosis of autosomal dominant retinitis pigmentosa. Invest Ophthalmol Vis Sci 2013; 54:1411-6. [PMID: 23372056 DOI: 10.1167/iovs.12-11541] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE We determined the fraction of families in a well-characterized cohort with a provisional diagnosis of autosomal dominant retinitis pigmentosa (adRP) that have disease-causing mutations in the X-linked retinitis pigmentosa GTPase regulator (RPGR) gene or the retinitis pigmentosa 2 (RP2) gene. METHODS Families with a provisional clinical diagnosis of adRP, and a pedigree consistent with adRP but no male-to-male transmission were selected from a cohort of 258 families, and tested for mutations in the RPGR and RP2 genes with di-deoxy sequencing. To facilitate testing of RPGR in "adRP" families that had no male members available for testing, the repetitive and purine-rich ORF15 of RPGR was subcloned and sequenced in heterozygous female subjects from 16 unrelated families. RESULTS Direct sequencing of RPGR and RP2 allowed for identification of a disease-causing mutation in 21 families. Of these "adRP" families 19 had RPGR mutations, and two had RP2 mutations. Subcloning and sequencing of ORF15 of RPGR in female subjects identified one additional RPGR mutation. Of the 22 mutations identified, 15 have been reported previously. CONCLUSIONS These data show that 8.5% (22 in 258) of families thought to have adRP truly have X-linked retinitis pigmentosa (XLRP). These results have substantive implications for calculation of recurrence risk, genetic counseling, and potential treatment options, and illustrate the importance of screening families with a provisional diagnosis of autosomal inheritance and no male-to-male transmission for mutations in X-linked genes. Mutations in RPGR are one of the most common causes of all forms of retinitis pigmentosa.
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Affiliation(s)
- Jennifer D Churchill
- Human Genetics Center, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA
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17
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18
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Branham K, Othman M, Brumm M, Karoukis AJ, Atmaca-Sonmez P, Yashar BM, Schwartz SB, Stover NB, Trzupek K, Wheaton D, Jennings B, Ciccarelli ML, Jayasundera KT, Lewis RA, Birch D, Bennett J, Sieving PA, Andreasson S, Duncan JL, Fishman GA, Iannaccone A, Weleber RG, Jacobson SG, Heckenlively JR, Swaroop A. Mutations in RPGR and RP2 account for 15% of males with simplex retinal degenerative disease. Invest Ophthalmol Vis Sci 2012; 53:8232-7. [PMID: 23150612 DOI: 10.1167/iovs.12-11025] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
PURPOSE To determine the proportion of male patients presenting simplex retinal degenerative disease (RD: retinitis pigmentosa [RP] or cone/cone-rod dystrophy [COD/CORD]) with mutations in the X-linked retinal degeneration genes RPGR and RP2. METHODS Simplex males were defined as patients with no known affected family members. Patients were excluded if they had a family history of parental consanguinity. Blood samples from a total of 214 simplex males with a diagnosis of retinal degeneration were collected for genetic analysis. The patients were screened for mutations in RPGR and RP2 by direct sequencing of PCR-amplified genomic DNA. RESULTS We identified pathogenic mutations in 32 of the 214 patients screened (15%). Of the 29 patients with a diagnosis of COD/CORD, four mutations were identified in the ORF15 mutational hotspot of the RPGR gene. Of the 185 RP patients, three patients had mutations in RP2 and 25 had RPGR mutations (including 12 in the ORF15 region). CONCLUSIONS This study represents mutation screening of RPGR and RP2 in the largest cohort, to date, of simplex males affected with RP or COD/CORD. Our results demonstrate a substantial contribution of RPGR mutations to retinal degenerations, and in particular, to simplex RP. Based on our findings, we suggest that RPGR should be considered as a first tier gene for screening isolated males with retinal degeneration.
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Affiliation(s)
- Kari Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Kellogg Eye Center, Ann Arbor, Michigan 48105, USA
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19
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Allelic heterogeneity and genetic modifier loci contribute to clinical variation in males with X-linked retinitis pigmentosa due to RPGR mutations. PLoS One 2011; 6:e23021. [PMID: 21857984 PMCID: PMC3155520 DOI: 10.1371/journal.pone.0023021] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 07/07/2011] [Indexed: 11/23/2022] Open
Abstract
Mutations in RPGR account for over 70% of X-linked retinitis pigmentosa (XlRP), characterized by retinal degeneration and eventual blindness. The clinical consequences of RPGR mutations are highly varied, even among individuals with the same mutation: males demonstrate a wide range of clinical severity, and female carriers may or may not be affected. This study describes the phenotypic diversity in a cohort of 98 affected males from 56 families with RPGR mutations, and demonstrates the contribution of genetic factors (i.e., allelic heterogeneity and genetic modifiers) to this diversity. Patients were categorized as grade 1 (mild), 2 (moderate) or 3 (severe) according to specific clinical criteria. Patient DNAs were genotyped for coding SNPs in 4 candidate modifier genes with products known to interact with RPGR protein: RPGRIP1, RPGRIP1L, CEP290, and IQCB1. Family-based association testing was performed using PLINK. A wide range of clinical severity was observed both between and within families. Patients with mutations in exons 1–14 were more severely affected than those with ORF15 mutations, and patients with predicted null alleles were more severely affected than those predicted to make RPGR protein. Two SNPs showed association with severe disease: the minor allele (N) of I393N in IQCB1 (p = 0.044) and the common allele (R) of R744Q in RPGRIP1L (p = 0.049). These data demonstrate that allelic heterogeneity contributes to phenotypic diversity in XlRP and suggest that this may depend on the presence or absence of RPGR protein. In addition, common variants in 2 proteins known to interact with RPGR are associated with severe disease in this cohort.
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Murga-Zamalloa C, Swaroop A, Khanna H. Multiprotein complexes of Retinitis Pigmentosa GTPase regulator (RPGR), a ciliary protein mutated in X-linked Retinitis Pigmentosa (XLRP). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 664:105-14. [PMID: 20238008 DOI: 10.1007/978-1-4419-1399-9_13] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mutations in Retinitis Pigmentosa GTPase Regulator (RPGR) are a frequent cause of X-linked Retinitis Pigmentosa (XLRP). The RPGR gene undergoes extensive alternative splicing and encodes for distinct protein isoforms in the retina. Extensive studies using isoform-specific antibodies and mouse mutants have revealed that RPGR predominantly localizes to the transition zone to primary cilia and associates with selected ciliary and microtubule-associated assemblies in photoreceptors. In this chapter, we have summarized recent advances on understanding the role of RPGR in photoreceptor protein trafficking. We also provide new evidence that suggests the existence of discrete RPGR multiprotein complexes in photoreceptors. Piecing together the RPGR-interactome in different subcellular compartments should provide critical insights into the role of alternative RPGR isoforms in associated orphan and syndromic retinal degenerative diseases.
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Affiliation(s)
- Carlos Murga-Zamalloa
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, Ann Arbor, MI 48105, USA
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21
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Guédard-Méreuze SL, Vaché C, Molinari N, Vaudaine J, Claustres M, Roux AF, Tuffery-Giraud S. Sequence contexts that determine the pathogenicity of base substitutions at position +3 of donor splice-sites. Hum Mutat 2009; 30:1329-39. [DOI: 10.1002/humu.21070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Beaufrère L, Rieu S, Hache JC, Dumur V, Claustres M, Tuffery S. Altered rep-1 expression due to substitution at position +3 of the IVS13 splice-donor site of the choroideremia (CHM) gene. Curr Eye Res 2009. [DOI: 10.1080/02713689808951249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Aleman TS, Cideciyan AV, Sumaroka A, Schwartz SB, Roman AJ, Windsor EAM, Steinberg JD, Branham K, Othman M, Swaroop A, Jacobson SG. Inner retinal abnormalities in X-linked retinitis pigmentosa with RPGR mutations. Invest Ophthalmol Vis Sci 2007; 48:4759-65. [PMID: 17898302 PMCID: PMC3178894 DOI: 10.1167/iovs.07-0453] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To investigate in vivo the retinal microstructure in X-linked retinitis pigmentosa (XLRP) caused by RPGR mutations as a prelude to treatment initiatives for this common form of RP. METHODS Patients with RPGR-XLRP (n = 12; age range, 10-56 years) were studied by optical coherence tomography (OCT) in a wide region of central retina. Overall retinal thickness and outer nuclear layer (ONL) and inner retinal parameters across horizontal and vertical meridians were analyzed and compared. RESULTS Retinal architecture of all patients with RPGR mutations was abnormal. At the fovea in younger patients, the ONL could be normal; but, at increasing eccentricities, there was a loss of photoreceptor laminar structure, even at the youngest ages studied. At later ages and advanced disease stages, the ONL was thin and reduced in extent. Inner retinal thickness, in contrast, was normal or hyperthick. Inner retinal thickening was detectable at all ages studied and was strongly associated with ONL loss. CONCLUSIONS Inner retinal laminar abnormalities in RPGR-XLRP are likely to reflect a neuronal-glial retinal remodeling response to photoreceptor loss and are detectable relatively early in the disease course. These results should be factored into emerging therapeutic strategies for this form of RP.
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Affiliation(s)
- Tomas S Aleman
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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He S, Parapuram SK, Hurd TW, Behnam B, Margolis B, Swaroop A, Khanna H. Retinitis Pigmentosa GTPase Regulator (RPGR) protein isoforms in mammalian retina: insights into X-linked Retinitis Pigmentosa and associated ciliopathies. Vision Res 2007; 48:366-76. [PMID: 17904189 PMCID: PMC2267686 DOI: 10.1016/j.visres.2007.08.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 08/03/2007] [Accepted: 08/06/2007] [Indexed: 12/01/2022]
Abstract
Mutations in the cilia-centrosomal protein Retinitis Pigmentosa GTPase Regulator (RPGR) are a frequent cause of retinal degeneration. The RPGR gene undergoes complex alternative splicing and encodes multiple protein isoforms. To elucidate the function of major RPGR isoforms (RPGR 1-19 and RPGR ORF15), we have generated isoform-specific antibodies and examined their expression and localization in the retina. Using sucrose-gradient centrifugation, immunofluorescence and co-immunoprecipitation methods, we show that RPGR isoforms localize to distinct sub-cellular compartments in mammalian photoreceptors and associate with a number of cilia-centrosomal proteins. The RCC1-like domain of RPGR, which is present in all major RPGR isoforms, is sufficient to target it to the cilia and centrosomes in cultured cells. Our findings indicate that multiple isotypes of RPGR may perform overlapping yet somewhat distinct transport-related functions in photoreceptors.
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Affiliation(s)
- Shirley He
- Department of Ophthalmology and Visual Sciences, University of Michigan, W. K. Kellogg Eye Center, 1000 Wall Street, Ann Arbor, MI 48105, USA
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Zangerl B, Johnson JL, Acland GM, Aguirre GD. Independent origin and restricted distribution of RPGR deletions causing XLPRA. ACTA ACUST UNITED AC 2007; 98:526-30. [PMID: 17646274 DOI: 10.1093/jhered/esm060] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Canine X-linked progressive retinal atrophy (XLPRA) is an inherited blinding disorder caused by mutations in the ORF15 of the RPGR gene and homolog to human retinitis pigmentosa 3 (RP3). The disease is observed in 2 variations, XLPRA1 in Siberian husky and samoyed and XLPRA2 derived from mongrel dogs. A third, neutral, deletion has been described in red wolves. Haplotype analysis of the 633-kbp RP3 interval in 6 different canidae confirmed the same decent for the XLPRA1 mutation in both affected breeds but suggests a recent and independent origin for both forms of XLPRA. The RP3 interval was excluded from causative associations with blindness in the red wolf and akita, a breed closely related to Nordic sled dogs. Overall, these data suggest a limited distribution of the affected haplotypes and indicate that mutations in the ORF15 are likely to be limited to the described dog breeds.
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Affiliation(s)
- Barbara Zangerl
- Section of Ophthalmology, Department of Clinical Studies-Philadelphia, University of Pennsylvania, Philadelphia, USA.
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Jin ZB, Hayakawa M, Murakami A, Nao-i N. RCC1-like domain and ORF15: essentials in RPGR gene. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 572:29-33. [PMID: 17249551 DOI: 10.1007/0-387-32442-9_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Clinical research into mutations of the RPGR gene showed that lack of either the RCC1-like domain of the ORF15 causes X-linked retinitis pigmentosa. Thus, the ORF15 and RCC1-like domain play a crucial role in the human retina. Further sudies on the role of the RCC1-like domain in the visual Cascade and additional findings of related proteins in the retina or even other organs, will give us a more precise understanding of this protein.
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Affiliation(s)
- Zi-Bing Jin
- Department of Ophthalmology, Miyazaki Medical College, University of Miyazaki, Japan
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Pelletier V, Jambou M, Delphin N, Zinovieva E, Stum M, Gigarel N, Dollfus H, Hamel C, Toutain A, Dufier JL, Roche O, Munnich A, Bonnefont JP, Kaplan J, Rozet JM. Comprehensive survey of mutations in RP2 and RPGR in patients affected with distinct retinal dystrophies: genotype-phenotype correlations and impact on genetic counseling. Hum Mutat 2007; 28:81-91. [PMID: 16969763 DOI: 10.1002/humu.20417] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
X-linked forms of retinitis pigmentosa (RP) (XLRP) account for 10 to 20% of families with RP and are mainly accounted for by mutations in the RP2 or RP GTPase regulator (RPGR) genes. We report the screening of these genes in a cohort of 127 French family comprising: 1) 93 familial cases of RP suggesting X-linked inheritance, including 48 out of 93 families with expression in females but no male to male transmission; 2) seven male sibships of RP; 3) 25 sporadic male cases of RP; and 4) two cone dystrophies (COD). A total of 5 out of the 93 RP families excluded linkage to the RP2 and RP3 loci and were removed form the cohort. A total of 14 RP2 mutations, 12 of which are novel, were identified in 14 out of 88 familial cases of RP and 1 out of 25 sporadic male case (4%). In 13 out of 14 of the familial cases, no expression of the disease was noted in females, while in 1 out of 14 families one woman developed RP in the third decade. A total of 42 RPGR mutations, 26 of which were novel, were identified in 80 families, including: 69 out of 88 familial cases (78.4%); 2 out of 7 male sibship (28.6%); 8 out of 25 sporadic male cases (32.0%); and 1 out of 2 COD. No expression of the disease was noted in females in 41 out of 69 familial cases (59.4%), while at least one severely affected woman was recognized in 28 out of 69 families (40.6%). The frequency of RP2 and RPGR mutations in familial cases of RP suggestive of X-linked transmission are in accordance to that reported elsewhere (RP2: 15.9% vs. 6-20%; RPGR: 78.4% vs. 55-90%). Interestingly, about 30% of male sporadic cases and 30% of male sibships of RP carried RP2 or RPGR mutations, confirming the pertinence of the genetic screening of XLRP genes in male patients affected with RP commencing in the first decade and leading to profound visual impairment before the age of 30 years.
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Affiliation(s)
- Valérie Pelletier
- Unité de Recherches Génétique et Epigénétique des Maladies Métaboliques, Neurosensorielles et du Développement, Institut Nationale de la Santé et de la Recherche Médicale (INSERM) U781, Hôpital Necker-Enfants Malades, Paris, France
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Karra D, Jacobi FK, Broghammer M, Blin N, Pusch CM. Population haplotypes of exon ORF15 of the retinitis pigmentosa GTPase regulator gene in Germany : implications for screening for inherited retinal disorders. Mol Diagn Ther 2006; 10:115-23. [PMID: 16669610 DOI: 10.1007/bf03256451] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Mutations in exon ORF15 of the retinitis pigmentosa GTPase regulator gene (RPGR) within chromosomal region Xp21.1 are a significant cause of a number of retinal disorders. The high mutation rate is ascribed to the highly repetitive, purine-rich tracts within the exon ORF15 sequence. Importantly, all exon ORF15 mutations observed to date represent protein-truncating mutations (nonsense and frameshift mutations). Because of its repetitive motifs, mutation screening of the hot-spot region by direct DNA sequencing is a technically challenging task. METHODS We devised a screening strategy for exon ORF15 mutations that reserves DNA sequencing for precise sizing and base-order assessment of detected mutations. The screening strategy is based on a PCR/restriction fragment length polymorphism (RFLP) analysis of exon ORF15 and comparison with population-specific RFLP haplotypes. The latter were constructed from PCR/RFLP analysis of DNA samples from 100 healthy German male individuals. Mutational alterations of normal RFLP haplotype patterns were predicted. RESULTS Six distinct RFLP haplotypes (founder alleles H1-H6) were observed with frequencies ranging from 2% to 63%. All natural variations of exon ORF15 were in-frame alterations ranging in size between 3bp and 36bp. Prediction of mutation-specific RFLP patterns indicated a high detection rate of mutations. CONCLUSION A new strategy has been developed using routine protocols for mutation screening of difficult-to-sequence, highly repetitive exon ORF15 of the RPGR gene in a German population.
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Affiliation(s)
- Daniela Karra
- Division of Molecular Genetics, Institute of Anthropology and Human Genetics, University of Tübingen, Tübingen, Germany
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Melamud A, Shen GQ, Chung D, Xi Q, Simpson E, Li L, Peachey NS, Zegarra H, Hagstrom SA, Wang QK, Traboulsi EI. Mapping a new genetic locus for X linked retinitis pigmentosa to Xq28. J Med Genet 2006; 43:e27. [PMID: 16740911 PMCID: PMC2593026 DOI: 10.1136/jmg.2005.031518] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have defined a new genetic locus for an X linked form of retinitis pigmentosa (RP) on chromosome Xq28. We examined 15 members of a family in which RP appeared to be transmitted in an X linked manner. Ocular examinations were performed, and fundus photographs and electroretinograms were obtained for selected patients. Blood samples were obtained from all patients and an additional seven family members who were not given examinations. Visual acuity in four affected individuals ranged from 20/40 to 20/80+. Patients described the onset of night blindness and colour vision defects in the second decade of life, with the earliest at 13 years of age. Examined affected individuals had constricted visual fields and retinal findings compatible with RP. Based on full field electroretinography, cone function was more severely reduced than rod function. Female carriers had no ocular signs or symptoms and slightly reduced cone electroretinographic responses. Affected and non-affected family members were genotyped for 20 polymorphic markers on the X-chromosome spaced at 10 cM intervals. Genotyping data were analysed using GeneMapper software. Genotyping and linkage analyses identified significant linkage to markers DXS8061, DXS1073, and DXS1108 with two point LOD scores of 2.06, 2.17, and 2.20, respectively. Haplotype analysis revealed segregation of the disease phenotype with markers at Xq28.
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Andréasson S. Developments in molecular genetics and electrophysiology in inherited retinal disorders. ACTA ACUST UNITED AC 2006; 84:161-8. [PMID: 16637830 DOI: 10.1111/j.1600-0420.2006.00657.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Retinitis pigmentosa is said to be the most frequent reason for severe visual handicap among young people in Scandinavia today. Developments in the fields of electrophysiology and molecular genetics have increased our understanding of the pathophysiology of these disorders and have also improved our clinical competence, leading to a better understanding of the patient's visual handicap and his or her prognosis. This represents the first step towards fulfilling our plan for the future, which is ultimately to cure blindness caused by the different forms of hereditary retinal degeneration. This review is based on 20 years of research at the Department of Ophthalmology in Lund.
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Affiliation(s)
- Sten Andréasson
- Department of Ophthalmology, University Hospital of Lund, Lund, Sweden.
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31
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Weleber RG, Gregory-Evans K. Retinitis Pigmentosa and Allied Disorders. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50023-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Madsen PP, Kibaek M, Roca X, Sachidanandam R, Krainer AR, Christensen E, Steiner RD, Gibson KM, Corydon TJ, Knudsen I, Wanders RJA, Ruiter JPN, Gregersen N, Andresen BS. Short/branched-chain acyl-CoA dehydrogenase deficiency due to an IVS3+3A>G mutation that causes exon skipping. Hum Genet 2005; 118:680-90. [PMID: 16317551 DOI: 10.1007/s00439-005-0070-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 08/31/2005] [Indexed: 12/23/2022]
Abstract
Short/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD) is an autosomal recessive disorder of L: -isoleucine catabolism. Little is known about the clinical presentation associated with this enzyme defect, as it has been reported in only a limited number of patients. Because the presence of C5-carnitine in blood may indicate SBCADD, the disorder may be detected by MS/MS-based routine newborn screening. It is, therefore, important to gain more knowledge about the clinical presentation and the mutational spectrum of SBCADD. In the present study, we have studied two unrelated families with SBCADD, both with seizures and psychomotor delay as the main clinical features. One family illustrates the fact that affected individuals may also remain asymptomatic. In addition, the normal level of newborn blood spot C5-acylcarnitine in one patient underscores the fact that newborn screening by MS/MS currently lacks sensitivity in detecting SBCADD. Until now, seven mutations in the SBCAD gene have been reported, but only three have been tested experimentally. Here, we identify and characterize an IVS3+3A>G mutation (c.303+3A>G) in the SBCAD gene, and provide evidence that this mutation is disease-causing in both families. Using a minigene approach, we show that the IVS3+3A>G mutation causes exon 3 skipping, despite the fact that it does not appear to disrupt the consensus sequence of the 5' splice site. Based on these results and numerous literature examples, we suggest that this type of mutation (IVS+3A>G) induces missplicing only when in the context of non-consensus (weak) 5' splice sites. Statistical analysis of the sequences shows that the wild-type versions of 5' splice sites in which +3A>G mutations cause exon skipping and disease are weaker on average than a random set of 5' splice sites. This finding is relevant to the interpretation of the functional consequences of this type of mutation in other disease genes.
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Affiliation(s)
- Pia Pinholt Madsen
- Research Unit for Molecular Medicine, Aarhus University Hospital and Faculty of Health Science, Skejby Sygehus, Aarhus, Denmark
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Moore A, Escudier E, Roger G, Tamalet A, Pelosse B, Marlin S, Clément A, Geremek M, Delaisi B, Bridoux AM, Coste A, Witt M, Duriez B, Amselem S. RPGR is mutated in patients with a complex X linked phenotype combining primary ciliary dyskinesia and retinitis pigmentosa. J Med Genet 2005; 43:326-33. [PMID: 16055928 PMCID: PMC2563225 DOI: 10.1136/jmg.2005.034868] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Primary ciliary dyskinesia (PCD) is a rare disease classically transmitted as an autosomal recessive trait and characterised by recurrent airway infections due to abnormal ciliary structure and function. To date, only two autosomal genes, DNAI1 and DNAH5 encoding axonemal dynein chains, have been shown to cause PCD with defective outer dynein arms. Here, we investigated one non-consanguineous family in which a woman with retinitis pigmentosa (RP) gave birth to two boys with a complex phenotype combining PCD, discovered in early childhood and characterised by partial dynein arm defects, and RP that occurred secondarily. The family history prompted us to search for an X linked gene that could account for both conditions. RESULTS We found perfect segregation of the disease phenotype with RP3 associated markers (Xp21.1). Analysis of the retinitis pigmentosa GTPase regulator gene (RPGR) located at this locus revealed a mutation (631_IVS6+9del) in the two boys and their mother. As shown by study of RPGR transcripts expressed in nasal epithelial cells, this intragenic deletion, which leads to activation of a cryptic donor splice site, predicts a severely truncated protein. CONCLUSION These data provide the first clear demonstration of X linked transmission of PCD. This unusual mode of inheritance of PCD in patients with particular phenotypic features (that is, partial dynein arm defects and association with RP), which should modify the current management of families affected by PCD or RP, unveils the importance of RPGR in the proper development of both respiratory ciliary structures and connecting cilia of photoreceptors.
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Affiliation(s)
- A Moore
- Institut National de la Santé et de la Recherche Médicale U. 654, Hôpital Henri-Mondor, Créteil, France
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Khanna H, Hurd TW, Lillo C, Shu X, Parapuram SK, He S, Akimoto M, Wright AF, Margolis B, Williams DS, Swaroop A. RPGR-ORF15, which is mutated in retinitis pigmentosa, associates with SMC1, SMC3, and microtubule transport proteins. J Biol Chem 2005; 280:33580-7. [PMID: 16043481 PMCID: PMC1249479 DOI: 10.1074/jbc.m505827200] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene account for almost 20% of patients with retinitis pigmentosa. Most mutations are detected in alternatively spliced RPGR-ORF15 isoform(s), which are primarily but not exclusively expressed in the retina. We show that, in addition to the axoneme, the RPGR-ORF15 protein is localized to the basal bodies of photoreceptor connecting cilium and to the tip and axoneme of sperm flagella. Mass spectrometric analysis of proteins that were immunoprecipitated from the retinal axoneme-enriched fraction using an anti-ORF15 antibody identified two chromosome-associated proteins, structural maintenance of chromosomes (SMC) 1 and SMC3. Using pulldown assays, we demonstrate that the interaction of RPGR with SMC1 and SMC3 is mediated, at least in part, by the RCC1-like domain of RPGR. This interaction was not observed with phosphorylation-deficient mutants of SMC1. Both SMC1 and SMC3 localized to the cilia of retinal photoreceptors and Madin-Darby canine kidney cells, suggesting a broader physiological relevance of this interaction. Additional immunoprecipitation studies revealed the association of RPGR-ORF15 isoform(s) with the intraflagellar transport polypeptide IFT88 as well as microtubule motor proteins, including KIF3A, p150Glued, and p50-dynamitin. Inhibition of dynein function by overexpressing p50 abrogated the localization of RPGR-ORF15 to basal bodies. Taken together, these results provide novel evidence for the possible involvement of RPGR-ORF15 in microtubule organization and regulation of transport in primary cilia.
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Affiliation(s)
| | - Toby W. Hurd
- Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, MI
| | - Concepcion Lillo
- Departments of Pharmacology and Neurosciences, School of Medicine, University of California at San Diego, La Jolla, CA
| | - Xinhua Shu
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, EH4 2XU, UK
| | | | - Shirley He
- Departments of Ophthalmology & Visual Sciences and
| | - Masayuki Akimoto
- Translational Research Center, Kyoto University Hospital, Sakyo-ku, Kyoto, Japan
| | - Alan F. Wright
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, EH4 2XU, UK
| | - Ben Margolis
- Howard Hughes Medical Institute, University of Michigan Medical School, Ann Arbor, MI
| | - David S. Williams
- Departments of Pharmacology and Neurosciences, School of Medicine, University of California at San Diego, La Jolla, CA
| | - Anand Swaroop
- Departments of Ophthalmology & Visual Sciences and
- Human Genetics, University of Michigan, Ann Arbor, MI
- To whom correspondence should be addressed: Department of Ophthalmology and Visual Sciences, University of Michigan, W.K. Kellogg Eye Center, 1000 Wall St., Ann Arbor, MI-48105. Tel: 734-763-3731; Fax: 734-647-0228. E. mail:
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Freund M, Asang C, Kammler S, Konermann C, Krummheuer J, Hipp M, Meyer I, Gierling W, Theiss S, Preuss T, Schindler D, Kjems J, Schaal H. A novel approach to describe a U1 snRNA binding site. Nucleic Acids Res 2004; 31:6963-75. [PMID: 14627829 PMCID: PMC290269 DOI: 10.1093/nar/gkg901] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RNA duplex formation between U1 snRNA and a splice donor (SD) site can protect pre-mRNA from degradation prior to splicing and initiates formation of the spliceosome. This process was monitored, using sub-genomic HIV-1 expression vectors, by expression analysis of the glycoprotein env, whose formation critically depends on functional SD4. We systematically derived a hydrogen bond model for the complementarity between the free 5' end of U1 snRNA and 5' splice sites and numerous mutations following transient transfection of HeLa-T4+ cells with 5' splice site mutated vectors. The resulting model takes into account number, interdependence and neighborhood relationships of predicted hydrogen bond formation in a region spanning the three most 3' base pairs of the exon (-3 to -1) and the eight most 5' base pairs of the intron (+1 to +8). The model is represented by an algorithm classifying U1 snRNA binding sites which can or cannot functionally substitute SD4 with respect to Rev-mediated env expression. In a data set of 5' splice site mutations of the human ATM gene we found a significant correlation between the algorithmic classification and exon skipping (P = 0.018, chi2-test), showing that the applicability of the proposed model reaches far beyond HIV-1 splicing. However, the algorithmic classification must not be taken as an absolute measure of SD usage as it may be modified by upstream sequence elements. Upstream to SD4 we identified a fragment supporting ASF/SF2 binding. Mutating GAR nucleotide repeats within this site decreased the SD4-dependent Rev-mediated env expression, which could be balanced simply by artificially increasing the complementarity of SD4.
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Affiliation(s)
- Marcel Freund
- Institut für Virologie, Heinrich-Heine-Universität Düsseldorf, Geb. 22.21, Universitätsstrasse 1, D-40225 Düsseldorf, Germany
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Dandekar SS, Ebenezer ND, Grayson C, Chapple JP, Egan CA, Holder GE, Jenkins SA, Fitzke FW, Cheetham ME, Webster AR, Hardcastle AJ. An atypical phenotype of macular and peripapillary retinal atrophy caused by a mutation in the RP2 gene. Br J Ophthalmol 2004; 88:528-32. [PMID: 15031171 PMCID: PMC1772091 DOI: 10.1136/bjo.2003.027979] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To determine the molecular basis and describe the phenotype of an atypical retinal dystrophy in a family presenting with bilateral, progressive central visual loss. METHODS Family members were examined. Investigations included Goldman perimetry, electrophysiology, and autofluorescence imaging. Candidate gene screening was performed using SSCP and sequence analysis. The proband's lymphoblastoid cells were examined for protein expression. RESULTS Fundal examination of the proband, his mother, and brother revealed peripapillary and macular atrophy. Autosomal dominant retinal dystrophy was suspected, but less severe disease in the mother led to screening for mutations in X linked genes. A 4 bp microdeletion in exon 3 of the RP2 gene, segregating with disease, was identified. No RP2 protein expression was detected. CONCLUSION The distinct phenotype in this family, caused by this frameshifting mutation in RP2, broadens the phenotypic spectrum of X linked retinitis pigmentosa. The absence of RP2 protein suggests that loss of protein function and not novel gain of function could account for the atypical phenotype. A definitive diagnosis of X linked retinitis pigmentosa permits appropriate genetic counselling with important implications for other family members. Clinicians should have a low threshold for screening RP2 in families with retinal dystrophy, including posterior retinal disease, not immediately suggestive of X linked inheritance.
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Hoffman DR, Locke KG, Wheaton DH, Fish GE, Spencer R, Birch DG. A randomized, placebo-controlled clinical trial of docosahexaenoic acid supplementation for X-linked retinitis pigmentosa. Am J Ophthalmol 2004; 137:704-18. [PMID: 15059710 DOI: 10.1016/j.ajo.2003.10.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/30/2003] [Indexed: 10/26/2022]
Abstract
PURPOSE Low docosahexaenoic acid (DHA) in X-linked retinitis pigmentosa (XLRP) may influence retinal function. The goals of this study were to elevate blood DHA levels and determine the effect on the rate of disease progression. DESIGN In a 4-year prospective randomized clinical trial, male patients with XLRP (mean age = 16 years; range = 4-38 years) received DHA (400 mg/d; n = 23; +DHA group) or placebo (n = 21) capsules. METHODS Red blood cell (RBC)-DHA concentrations were assessed every 6 months. Full-field cone electroretinograms (ERGs; the primary outcome measure), visual acuity, dark-adaptation, visual fields, rod ERGs, and fundus photos were recorded annually. RESULTS In the +DHA group, RBC-DHA increased 2.5-fold over placebo levels (70 vs 28 mg DHA/l). Repeated measures analysis of variance for cone ERG showed a significant main effect of year (P <.0001) but not of group (P =.16). Preservation of cone ERG function correlated with RBC-DHA (P =.018), and there was less change in fundus appearance in the +DHA group (P =.04). Neither visual acuity nor visual fields were changed. In subset analysis, DHA supplementation was beneficial in reducing rod ERG functional loss in patients aged <12 years (P =.040) and preserving cone ERG function in patients > or =12 years (P =.038). CONCLUSIONS Although DHA-supplemented patients had significantly elevated mean RBC-DHA levels, the rate of cone ERG functional loss was not significantly different between groups. Supplemental analyses provided evidence for a DHA benefit and a direction for subsequent investigations.
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Andréasson S, Breuer DK, Eksandh L, Ponjavic V, Frennesson C, Hiriyanna S, Filippova E, Yashar BM, Swaroop A. Clinical studies of X-linked retinitis pigmentosa in three Swedish families with newly identified mutations in the RP2 and RPGR-ORF15 genes. Ophthalmic Genet 2004; 24:215-23. [PMID: 14566651 DOI: 10.1076/opge.24.4.215.17228] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To describe new disease-causing RP2 and RPGR-ORF15 mutations and their corresponding clinical phenotypes in Swedish families with X-linked retinitis pigmentosa (XLRP) and to establish genotype-phenotype correlations by studying the clinical spectrum of disease in families with a known molecular defect. METHODS Seventeen unrelated families with RP and an apparent X-linked pattern of disease inheritance were identified from the Swedish RP registry and screened for mutations in the RP2 and RPGR (for the RP3 disease) genes. These families had been previously screened for the RPGR exons 1-19, and disease-causing mutations were identified in four of them. In the remaining 13 families, we sequenced the RP2 gene and the newly discovered RPGR-ORF exon. Detailed clinical evaluations were then obtained from individuals in the three families with identified mutations. RESULTS Mutations in RP2 and RPGR-ORF15 were identified in three of the 13 families. Clinical evaluations of affected males and carrier females demonstrated varying degrees of retinal dysfunction and visual handicap, with early onset and severe disease in the families with mutations in the ORF15 exon of the RPGR gene. CONCLUSIONS A total of seven mutations in the RP2 and RPGR genes have been discovered so far in Swedish XLRP families. All affected individuals express a severe form of retinal degeneration with visual handicap early in life, although the degree of retinal dysfunction varies both in hemizygous male patients and in heterozygous carrier females. Retinal disease phenotypes in patients with mutations in the RPGR-ORF15 were more severe than in patients with mutations in RP2 or other regions of the RPGR.
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Affiliation(s)
- Sten Andréasson
- Department of Ophthalmology, University Hospital of Lund, Lund, Sweden.
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Sharon D, Sandberg MA, Rabe VW, Stillberger M, Dryja TP, Berson EL. RP2 and RPGR mutations and clinical correlations in patients with X-linked retinitis pigmentosa. Am J Hum Genet 2003; 73:1131-46. [PMID: 14564670 PMCID: PMC1180492 DOI: 10.1086/379379] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2003] [Accepted: 08/29/2003] [Indexed: 11/03/2022] Open
Abstract
We determined the mutation spectrum of the RP2 and RPGR genes in patients with X-linked retinitis pigmentosa (XLRP) and searched for correlations between categories of mutation and severity of disease. We screened 187 unrelated male patients for mutations, including 135 with a prior clinical diagnosis of XLRP, 11 with probable XLRP, 30 isolate cases suspected of having XLRP, and 11 with cone-rod degeneration. Mutation screening was performed by single-strand conformation analysis and by sequencing of all RP2 exons and RPGR exons 1-14, ORF15, and 15a. The refractive error, visual acuity, final dark-adapted threshold, visual field area, and 30-Hz cone electroretinogram (ERG) amplitude were measured in each patient. Among the 187 patients, we found 10 mutations in RP2, 2 of which are novel, and 80 mutations in RPGR, 41 of which are novel; 66% of the RPGR mutations were within ORF15. Among the 135 with a prior clinical diagnosis of XLRP, mutations in the RP2 and RPGR genes were found in 9 of 135 (6.7%) and 98 of 135 (72.6%), respectively, for a total of 79% of patients. Patients with RP2 mutations had, on average, lower visual acuity but similar visual field area, final dark-adapted threshold, and 30-Hz ERG amplitude compared with those with RPGR mutations. Among patients with RPGR mutations, those with ORF15 mutations had, on average, a significantly larger visual field area and a borderline larger ERG amplitude than did patients with RPGR mutations in exons 1-14. Among patients with ORF15 mutations, regression analyses showed that the final dark-adapted threshold became lower (i.e., closer to normal) and that the 30-Hz ERG amplitude increased as the length of the wild-type ORF15 amino acid sequence increased. Furthermore, as the length of the abnormal amino acid sequence following ORF15 frameshift mutations increased, the severity of disease increased.
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Affiliation(s)
- Dror Sharon
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
| | - Michael A. Sandberg
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
| | - Vivian W. Rabe
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
| | - Melissa Stillberger
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
| | - Thaddeus P. Dryja
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
| | - Eliot L. Berson
- Ocular Molecular Genetics Institute and the Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston
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Rebello G, Vorster A, Greenberg J, Coutts N, Roberts L, Ehrenreich L, Gama D, Ramesar R. Analysis of RPGR in a South African family with X-linked retinitis pigmentosa: research and diagnostic implications. Clin Genet 2003; 64:137-41. [PMID: 12859409 DOI: 10.1034/j.1399-0004.2003.00090.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Analysis of exon ORF15 of the RPGR gene has revealed a novel mutation in a South African family with X-linked retinitis pigmentosa (XLRP), which has implications for the rest of the family in terms of pre-symptomatic testing. The ability to test for this mutation will be beneficial for the accurate determination of carrier status in female relatives who may have been unaware of their risk before this study was performed. This work also highlights the need to be aware of the ramifications of mutation testing in what may appear to be small families. This is the first report of an RPGR ORF15 mutation in a South African family of mixed ancestry.
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Affiliation(s)
- G Rebello
- Division of Human Genetics, Department of Clinical Laboratory Sciences, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, South Africa.
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Ayyagari R, Demirci FY, Liu J, Bingham EL, Stringham H, Kakuk LE, Boehnke M, Gorin MB, Richards JE, Sieving PA. X-linked recessive atrophic macular degeneration from RPGR mutation. Genomics 2002; 80:166-71. [PMID: 12160730 DOI: 10.1006/geno.2002.6815] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We mapped a new X-linked recessive atrophic macular degeneration locus to Xp21.1-p11.4 and show allelic involvement of the gene RPGR, which normally causes severe peripheral retinal degeneration leading to global blindness. Ten affected males whom we examined had primarily macular atrophy causing progressive loss of visual acuity with minimal peripheral visual impairment. One additional male showed extensive macular degeneration plus peripheral loss of retinal pigment epithelium and choriocapillaries. Full-field electroretinograms (ERGs) showed normal cone and rod responses in some affected males despite advanced macular degeneration, emphasizing the dissociation of atrophic macular degeneration from generalized cone degenerations, including X-linked cone dystrophy (COD1). The RPGR gene nonsense mutation G-->T at open reading frame (ORF)15+1164 cosegregated with the disease and may create a donor splice site. Identification of an RPGR mutation in atrophic maculardegeneration expands the phenotypic range associated with this gene and provides a new tool for the dissection of the relationship between clinically different retinal pathologies.
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Affiliation(s)
- Radha Ayyagari
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, 48105, USA
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43
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Breuer DK, Yashar BM, Filippova E, Hiriyanna S, Lyons RH, Mears AJ, Asaye B, Acar C, Vervoort R, Wright AF, Musarella MA, Wheeler P, MacDonald I, Iannaccone A, Birch D, Hoffman DR, Fishman GA, Heckenlively JR, Jacobson SG, Sieving PA, Swaroop A. A comprehensive mutation analysis of RP2 and RPGR in a North American cohort of families with X-linked retinitis pigmentosa. Am J Hum Genet 2002; 70:1545-54. [PMID: 11992260 PMCID: PMC379141 DOI: 10.1086/340848] [Citation(s) in RCA: 181] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2002] [Accepted: 03/21/2002] [Indexed: 11/03/2022] Open
Abstract
X-linked retinitis pigmentosa (XLRP) is a clinically and genetically heterogeneous degenerative disease of the retina. At least five loci have been mapped for XLRP; of these, RP2 and RP3 account for 10%-20% and 70%-90% of genetically identifiable disease, respectively. However, mutations in the respective genes, RP2 and RPGR, were detected in only 10% and 20% of families with XLRP. Mutations in an alternatively spliced RPGR exon, ORF15, have recently been shown to account for 60% of XLRP in a European cohort of 47 families. We have performed, in a North American cohort of 234 families with RP, a comprehensive screen of the RP2 and RPGR (including ORF15) genes and their 5' upstream regions. Of these families, 91 (39%) show definitive X-linked inheritance, an additional 88 (38%) reveal a pattern consistent with X-linked disease, and the remaining 55 (23%) are simplex male patients with RP who had an early onset and/or severe disease. In agreement with the previous studies, we show that mutations in the RP2 gene and in the original 19 RPGR exons are detected in <10% and approximately 20% of XLRP probands, respectively. Our studies have revealed RPGR-ORF15 mutations in an additional 30% of 91 well-documented families with X-linked recessive inheritance and in 22% of the total 234 probands analyzed. We suggest that mutations in an as-yet-uncharacterized RPGR exon(s), intronic changes, or another gene in the region might be responsible for the disease in the remainder of this North American cohort. We also discuss the implications of our studies for genetic diagnosis, genotype-phenotype correlations, and gene-based therapy.
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Affiliation(s)
- Debra K. Breuer
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Beverly M. Yashar
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Elena Filippova
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Suja Hiriyanna
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Robert H. Lyons
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Alan J. Mears
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Bersabell Asaye
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Ceren Acar
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Raf Vervoort
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Alan F. Wright
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Maria A. Musarella
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Patricia Wheeler
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Ian MacDonald
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Alessandro Iannaccone
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - David Birch
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Dennis R. Hoffman
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Gerald A. Fishman
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - John R. Heckenlively
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Samuel G. Jacobson
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Paul A. Sieving
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
| | - Anand Swaroop
- Departments of Human Genetics, Ophthalmology and Visual Sciences, and Biological Chemistry and Sequencing Core Facility, University of Michigan, Ann Arbor; Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology, SUNY Downstate Medical Center, Brooklyn; New England Medical Center, Boston; Department of Ophthalmology, University of Alberta, Edmonton, Alberta; Department of Ophthalmology, University of Tennessee Health Science Center, Memphis; Retina Foundation of the Southwest, Dallas; University of Illinois at Chicago, Chicago; Jules Stein Eye Institute, University of California at Los Angeles, Los Angeles; Scheie Eye Institute, University of Pennsylvania, Philadelphia; and National Eye Institute, Bethesda, MD
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44
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Abstract
Mutations in RPGR, retinitis pigmentosa GTPase regulator, are associated with RP3 type of X-linked retinitis pigmentosa, a severe, non-syndromic form of retinal degeneration. In the majority of subjects RPGR mutations are associated with a typical rod-cone degeneration, but in a small number, cone-rod dystrophy, deafness, and abnormalities in respiratory cilia have been noted. Alternative splicing of RPGR is complex in all species examined. In RP3 patients, mutations have been found in exons 1-14 and ORF15, thus delineating a transcript necessary for normal retinal function in humans. The great majority of mutations are predicted to result in premature termination of translation. These mutations are scattered over exons 1-14 and ORF15, while most missense mutations occur in a domain with homology to the protein RCC1, encoded by exons 1-10. Exon ORF15 is a "hot spot" for mutation, at least in the British population, in which it harbors 80% of the mutations found within a sample of 47 X-linked retinitis pigmentosa patients. Most RPGR mutations are unique to single families, which makes it difficult to demonstrate phenotype-genotype correlations.
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Affiliation(s)
- Raf Vervoort
- MRC Human Genetics Unit, Western General Hospital, Edinburgh, UK
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45
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Demirci FYK, Rigatti BW, Wen G, Radak AL, Mah TS, Baic CL, Traboulsi EI, Alitalo T, Ramser J, Gorin MB. X-linked cone-rod dystrophy (locus COD1): identification of mutations in RPGR exon ORF15. Am J Hum Genet 2002; 70:1049-53. [PMID: 11857109 PMCID: PMC379101 DOI: 10.1086/339620] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2001] [Accepted: 01/10/2002] [Indexed: 11/03/2022] Open
Abstract
X-linked cone-rod dystrophy (COD1) is a retinal disease that primarily affects the cone photoreceptors; the disease was originally mapped to a limited region of Xp11.4. We evaluated the three families from our original study with new markers and clinically reassessed all key recombinants; we determined that the critical intervals in families 2 and 3 overlapped the RP3 locus and that a status change (from affected to probably unaffected) of a key recombinant individual in family 1 also reassigned the disease locus to include RP3 as well. Mutation analysis of the entire RPGR coding region identified two different 2-nucleotide (nt) deletions in ORF15, in family 2 (delAG) and in families 1 and 3 (delGG), both of which result in a frameshift leading to altered amino acid structure and early termination. In addition, an independent individual with X-linked cone-rod dystrophy demonstrated a 1-nt insertion (insA) in ORF15. The presence of three distinct mutations associated with the same disease phenotype provides strong evidence that mutations in RPGR exon ORF15 are responsible for COD1. Genetic heterogeneity was observed in three other families, including the identification of an in-frame 12-nt deletion polymorphism in ORF15 that did not segregate with the disease in one of these families.
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Affiliation(s)
- F. Yesim K. Demirci
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Brian W. Rigatti
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Gaiping Wen
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Amy L. Radak
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Tammy S. Mah
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Corrine L. Baic
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Elias I. Traboulsi
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Tiina Alitalo
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Juliane Ramser
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
| | - Michael B. Gorin
- Departments of Ophthalmology and Human Genetics, University of Pittsburgh, Pittsburgh; Department of Genome Analysis, Institute of Molecular Biotechnology, Jena, Germany; Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland; Department of Obstetrics/Gynecology, Helsinki University Hospital, Helsinki; and Department of Medical Genetics, Ludwig-Maximilians-University, Munich
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46
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Abstract
The cliché 'a picture is worth a thousand words' is a testament to the power of the visual system in helping us deal with our physical environment. Rarely do perturbations to the visual system, even minor ones, go unnoticed. Major defects in eye development may occur in the absence of systemic problems which threaten health. Ocular anomalies offer a window into many developmental events which would otherwise be difficult to study.
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Affiliation(s)
- R A Saleem
- Department of Medical Genetics, University of Alberta, Edmonton, Canada
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47
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Arden GB. The absence of diabetic retinopathy in patients with retinitis pigmentosa: implications for pathophysiology and possible treatment. Br J Ophthalmol 2001; 85:366-70. [PMID: 11222350 PMCID: PMC1723904 DOI: 10.1136/bjo.85.3.366] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- G B Arden
- Applied Vision Research Centre, City University, Northampton Square London EC1V 0HB, UK.
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48
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Yokoyama A, Maruiwa F, Hayakawa M, Kanai A, Vervoort R, Wright AF, Yamada K, Niikawa N, Na?i N. Three novel mutations of theRPGR gene exon ORF15 in three Japanese families with X-linked retinitis pigmentosa. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/ajmg.10035] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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De Luca A, Torrente I, Mangino M, Danesi R, Dallapiccola B, Novelli G. Three novel mutations causing a truncated protein within the RP2 gene in Italian families with X-linked retinitis pigmentosa. Mutat Res 2001; 432:79-82. [PMID: 11465545 DOI: 10.1016/s1383-5726(00)00007-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
X-linked retinitis pigmentosa (XLRP) results from mutations in a number of loci, including RP2 at Xp11.3, and RP3 at Xp21.1. RP2 and RP3 genes have been identified by positional cloning. RP2 mutations are found in about 10% of XLRP patients. We performed a mutational screening of RP2 gene inpatients belonging to seven unrelated families in linkage with the RP2 locus. SSCP analysis detected three conformation variants, within exon 2 and 3. Direct sequencing of exon 2, disclosed a G-->A transition at nucleotide 449 (W150X), and a G-->T transversion in position 547 (E183X). Sequence analysis of exon 3 variant revealed an insertion (853/854insG), leading to a frameshift. In this patient, we detected an additional sequence alteration (A-->G at nucleotide 848, E283G). Each mutation was co-segregating with the disease in the affected family members available for the study. These mutations are expected to introduce a stop codon within the RP2 coding sequence probably resulting in a truncated or unstable protein.
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Affiliation(s)
- A De Luca
- Dipartimento di Biopatologia e Diagnostica per Immagini, Università di Roma Tor Vergata, Rome, Italy
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Mears AJ, Hiriyanna S, Vervoort R, Yashar B, Gieser L, Fahrner S, Daiger SP, Heckenlively JR, Sieving PA, Wright AF, Swaroop A. Remapping of the RP15 locus for X-linked cone-rod degeneration to Xp11.4-p21.1, and identification of a de novo insertion in the RPGR exon ORF15. Am J Hum Genet 2000; 67:1000-3. [PMID: 10970770 PMCID: PMC1287869 DOI: 10.1086/303091] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2000] [Accepted: 08/14/2000] [Indexed: 01/11/2023] Open
Abstract
X-linked forms of retinitis pigmentosa (XLRP) are among the most severe, because of their early onset, often leading to significant vision loss before the 4th decade. Previously, the RP15 locus was assigned to Xp22, by linkage analysis of a single pedigree with "X-linked dominant cone-rod degeneration." After clinical reevaluation of a female in this pedigree identified her as affected, we remapped the disease to a 19.5-cM interval (DXS1219-DXS993) at Xp11.4-p21.1. This new interval overlapped both RP3 (RPGR) and COD1. Sequencing of the previously published exons of RPGR revealed no mutations, but a de novo insertion was detected in the new RPGR exon, ORF15. The identification of an RPGR mutation in a family with a severe form of cone and rod degeneration suggests that RPGR mutations may encompass a broader phenotypic spectrum than has previously been recognized in "typical" retinitis pigmentosa.
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Affiliation(s)
- Alan J. Mears
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Suja Hiriyanna
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Raf Vervoort
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Beverly Yashar
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Linn Gieser
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Stacey Fahrner
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Stephen P. Daiger
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - John R. Heckenlively
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Paul A. Sieving
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Alan F. Wright
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
| | - Anand Swaroop
- Departments of Ophthalmology and Visual Sciences and Human Genetics, University of Michigan, Ann Arbor; MRC Human Genetics Unit, Western General Hospital, Edinburgh; Department of Ophthalmology and Visual Science, University of Texas–Houston Health Science Center, Houston; and Jules Stein Eye Institute, University of California, Los Angeles
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