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Vinikoor-Imler LC, Simpson C, Narayanan D, Abbasi S, Lally C. Prevalence of RPGR-mutated X-linked retinitis pigmentosa among males. Ophthalmic Genet 2022; 43:581-588. [PMID: 36004681 DOI: 10.1080/13816810.2022.2109686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
BACKGROUND X-linked retinitis pigmentosa (XLRP) is a rare inherited retinal disease predominantly affecting males. MATERIALS AND METHODS A comprehensive literature review was conducted to determine the prevalence of retinitis pigmentosa GTPase regulator (RPGR)-mutated XLRP. Identified studies were used to estimate four components among males: the prevalence of retinitis pigmentosa (RP), the proportion of RP that was X-linked, the proportion of misclassified inheritance type among RP cases, and the proportion of XLRP that was RPGR-mutated. Studies providing a direct estimate of XLRP prevalence were also included. The components' sample size-weighted averages were combined to determine an overall prevalence estimate. RESULTS The prevalence of XLRP was estimated to be between 2.7-3.5 per 100,000 males in the US, Europe, and Australia. After correction for misclassification, the prevalence increased to 4.0-5.2 per 100,000 males. Finally, the proportion of XLRP cases due to RPGR mutations was applied, resulting in an RPGR-mutated XLRP estimate of 3.4-4.4 per 100,000 males. Studies from other countries were consistent with the results for the overall XLRP prevalence but were not included in the final calculation because of regional variations and lack of detailed information. CONCLUSIONS These findings address an important gap in the understanding of RPGR-mutated XLRP by summarizing the global burden of this condition.
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Affiliation(s)
| | | | - Divya Narayanan
- Global Medical Affairs, Biogen, Cambridge, Massachusetts, USA
| | - Saad Abbasi
- Global Medical Affairs, Biogen, Cambridge, Massachusetts, USA
| | - Cathy Lally
- Epidemiologic Research & Methods, LLC, Atlanta, Georgia, USA
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Beigi F, Del Pozo-Valero M, Martin-Merida I, Manaviat MR, Ayuso C, Ghasemi N. Homozygous females for a X-linked RPGR- ORF15 mutation in an Iranian family with retinitis pigmentosa. Exp Eye Res 2021; 211:108714. [PMID: 34390733 DOI: 10.1016/j.exer.2021.108714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/10/2021] [Accepted: 07/30/2021] [Indexed: 11/17/2022]
Abstract
Mutations in Retinitis pigmentosa GTPase regulator gene (RPGR) are the most common cause of X-linked retinitis pigmentosa (RP). Almost 60% of disease-causing RPGR mutations are located in ORF-15 region which cannot be detected by Next Generation Sequencing (NGS) due to the existence of highly repetitive regions. An Iranian family with a priori diagnosis of autosomal dominant RP was studied by Sanger sequencing of ORF15 of RPGR gene after an inconclusive NGS result. A frameshift two-base-pair deletion (c.2323_2324del, p.Arg775Glufs*59) in this region was segregating in both affected hemizygous males and affected homozygous females. To our knowledge, this is the first example of homozygous females for RPGR-ORF15 mutations.
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Affiliation(s)
- Fahimeh Beigi
- Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Marta Del Pozo-Valero
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Inmaculada Martin-Merida
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Masoud Reza Manaviat
- Department of Ophthalmology, Shahid Sadoughi University of Medical Science, Yazd Diabetes Research Center, Yazd, Iran
| | - Carmen Ayuso
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain.
| | - Nasrin Ghasemi
- Abortion Research Centre, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
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Hadalin V, Šuštar M, Volk M, Maver A, Sajovic J, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Cone Dystrophy Associated with a Novel Variant in the Terminal Codon of the RPGR- ORF15. Genes (Basel) 2021; 12:genes12040499. [PMID: 33805381 PMCID: PMC8066792 DOI: 10.3390/genes12040499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/30/2022] Open
Abstract
Mutations in RPGRORF15 are associated with rod-cone or cone/cone-rod dystrophy, the latter associated with mutations at the distal end. We describe the phenotype associated with a novel variant in the terminal codon of the RPGRORF15 c.3457T>A (Ter1153Lysext*38), which results in a C-terminal extension. Three male patients from two families were recruited, aged 31, 35, and 38 years. Genetic testing was performed by whole exome sequencing. Filtered variants were analysed according to the population frequency, ClinVar database, the variant’s putative impact, and predicted pathogenicity; and were classified according to the ACMG guidelines. Examination included visual acuity (Snellen), colour vision (Ishihara), visual field, fundus autofluorescence (FAF), optical coherence tomography (OCT), and electrophysiology. All patients were myopic, and had central scotoma and reduced colour vision. Visual acuities on better eyes were counting fingers, 0.3 and 0.05. Electrophysiology showed severely reduced cone-specific responses and macular dysfunction, while the rod-specific response was normal. FAF showed hyperautofluorescent ring centred at the fovea encompassing an area of photoreceptor loss approximately two optic discs in diameter (3462–6342 μm). Follow up after 2–11 years showed enlargement of the diameter (avg. 100 μm/year). The novel c.3457T>A (Ter1153Lysext*38) mutation in the terminal RPGRORF15 codon is associated with cone dystrophy, which corresponds to the previously described phenotypes associated with mutations in the distal end of the RPGRORF15. Minimal progression during follow-up years suggests a relatively stable disease after the initial loss of the central cones.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Maja Šuštar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Aleš Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
- Correspondence:
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Maggi J, Roberts L, Koller S, Rebello G, Berger W, Ramesar R. De Novo Assembly-Based Analysis of RPGR Exon ORF15 in an Indigenous African Cohort Overcomes Limitations of a Standard Next-Generation Sequencing (NGS) Data Analysis Pipeline. Genes (Basel) 2020; 11:genes11070800. [PMID: 32679846 PMCID: PMC7396994 DOI: 10.3390/genes11070800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/24/2020] [Accepted: 07/13/2020] [Indexed: 01/10/2023] Open
Abstract
RPGR exon ORF15 variants are one of the most frequent causes for inherited retinal disorders (IRDs), in particular retinitis pigmentosa. The low sequence complexity of this mutation hotspot makes it prone to indels and challenging for sequence data analysis. Whole-exome sequencing generally fails to provide adequate coverage in this region. Therefore, complementary methods are needed to avoid false positives as well as negative results. In this study, next-generation sequencing (NGS) was used to sequence long-range PCR amplicons for an IRD cohort of African ancestry. By developing a novel secondary analysis pipeline based on de novo assembly, we were able to avoid the miscalling of variants generated by standard NGS analysis tools. We identified pathogenic variants in 11 patients (13% of the cohort), two of which have not been reported previously. We provide a novel and alternative end-to-end secondary analysis pipeline for targeted NGS of ORF15 that is less prone to false positive and negative variant calls.
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Affiliation(s)
- Jordi Maggi
- Institute of Medical Molecular Genetic, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.)
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8006 Zurich, Switzerland
| | - Lisa Roberts
- University of Cape Town/MRC Genomic and Precision Medicine Research Unit, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (L.R.); (G.R.); (R.R.)
| | - Samuel Koller
- Institute of Medical Molecular Genetic, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.)
| | - George Rebello
- University of Cape Town/MRC Genomic and Precision Medicine Research Unit, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (L.R.); (G.R.); (R.R.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetic, University of Zurich, 8952 Schlieren, Switzerland; (J.M.); (S.K.)
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8006 Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, 8006 Zurich, Switzerland
- Correspondence:
| | - Rajkumar Ramesar
- University of Cape Town/MRC Genomic and Precision Medicine Research Unit, Division of Human Genetics, Department of Pathology, Institute of Infectious Disease and Molecular Medicine (IDM), Faculty of Health Sciences, University of Cape Town, Cape Town 7925, South Africa; (L.R.); (G.R.); (R.R.)
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Zhang Z, Dai H, Wang L, Tao T, Xu J, Sun X, Yang L, Li G. Novel mutations of RPGR in Chinese families with X-linked retinitis pigmentosa. BMC Ophthalmol 2019; 19:240. [PMID: 31775781 PMCID: PMC6882249 DOI: 10.1186/s12886-019-1250-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/18/2019] [Indexed: 12/15/2022] Open
Abstract
Background RP (retinitis pigmentosa) is a group of hereditary retinal degenerative diseases. XLRP is a relatively severe subtype of RP. Thus, it is necessary to identify genes and mutations in patients who present with X-linked retinitis pigmentosa. Methods Genomic DNA was extracted from peripheral blood. The coding regions and intron-exon boundaries of the retinitis pigmentosa GTPase regulator (RPGR) and RP2 genes were amplified by PCR and then sequenced directly. Ophthalmic examinations were performed to identify affected individuals from two families and to characterize the phenotype of the disease. Results Mutation screening demonstrated two novel nonsense mutations (c.1541C > G; p.S514X and c.2833G > T; p.E945X) in the RPGR gene. The clinical manifestation of family 1 with mutations in exon 13 was mild. Genotype-phenotype correlation analysis suggested that patients with mutations close to the downstream region of ORF15 in family 2 manifested an early loss of cone function. Family 2 carried a nonsense mutation in ORF15 that appeared to have a semi-dominant pattern of inheritance. All male patients and two female carriers in family 2 manifested pathological myopia (PM), indicating that there may be a distinctive X-linked genotype-phenotype correlation between RP and PM. Conclusions We identified two novel mutations of the RPGR gene, which broadens the spectrum of RPGR mutations and the phenotypic spectrum of the disease in Chinese families.
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Affiliation(s)
- Zhimeng Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Hehua Dai
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Lei Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Tianchang Tao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Jing Xu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Xiaowei Sun
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Liping Yang
- Department of Ophthalmology, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Peking University Third Hospital, Beijing, People's Republic of China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China.
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