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Mizobuchi K, Hayashi T, Oishi N, Kubota D, Kameya S, Higasa K, Futami T, Kondo H, Hosono K, Kurata K, Hotta Y, Yoshitake K, Iwata T, Matsuura T, Nakano T. Genotype-Phenotype Correlations in RP1-Associated Retinal Dystrophies: A Multi-Center Cohort Study in JAPAN. J Clin Med 2021; 10:jcm10112265. [PMID: 34073704 PMCID: PMC8197273 DOI: 10.3390/jcm10112265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 05/14/2021] [Accepted: 05/21/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Little is known about genotype–phenotype correlations of RP1-associated retinal dystrophies in the Japanese population. We aimed to investigate the genetic spectrum of RP1 variants and provide a detailed description of the clinical findings in Japanese patients. Methods: In total, 607 patients with inherited retinal diseases were examined using whole-exome/whole-genome sequencing (WES/WGS). PCR-based screening for an Alu element insertion (c.4052_4053ins328/p.Tyr1352AlafsTer9) was performed in 18 patients with autosomal-recessive (AR)-retinitis pigmentosa (RP) or AR-cone dystrophy (COD)/cone-rod dystrophy (CORD), including seven patients with heterozygous RP1 variants identified by WES/WGS analysis, and 11 early onset AR-RP patients, in whom no pathogenic variant was identified. We clinically examined 25 patients (23 families) with pathogenic RP1 variants, including five patients (five families) with autosomal-dominant (AD)-RP, 13 patients (11 families) with AR-RP, and seven patients (seven families) with AR-COD/CORD. Results: We identified 18 pathogenic RP1 variants, including seven novel variants. Interestingly, the Alu element insertion was the most frequent variant (32.0%, 16/50 alleles). The clinical findings revealed that the age at onset and disease progression occurred significantly earlier and faster in AR-RP patients compared to AD-RP or AR-COD/CORD patients. Conclusions: Our results suggest a genotype–phenotype correlation between variant types/locations and phenotypes (AD-RP, AR-RP, and AR-COD/CORD), and the Alu element insertion was the most major variant in Japanese patients with RP1-associated retinal dystrophies.
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Affiliation(s)
- Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo 105-8471, Japan; (T.H.); (T.N.)
- Correspondence: ; Tel.: +81-3-3433-1111
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo 105-8471, Japan; (T.H.); (T.N.)
- Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, 6-41-2 Aoto, Katsushika-ku, Tokyo 125-8506, Japan
| | - Noriko Oishi
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan; (N.O.); (D.K.); (S.K.)
| | - Daiki Kubota
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan; (N.O.); (D.K.); (S.K.)
| | - Shuhei Kameya
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, 1715 Kamagari, Inzai, Chiba 270-1694, Japan; (N.O.); (D.K.); (S.K.)
| | - Koichiro Higasa
- Department of Genome Analysis, Institute of Biomedical Science, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka 573-1010, Japan;
| | - Takuma Futami
- Department of Ophthalmology, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku Kitakyushu-shi, Fu-kuoka 807-8555, Japan; (T.F.); (H.K.)
| | - Hiroyuki Kondo
- Department of Ophthalmology, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku Kitakyushu-shi, Fu-kuoka 807-8555, Japan; (T.F.); (H.K.)
| | - Katsuhiro Hosono
- Department of Ophthalmology, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Shizuoka, Hamamatsu 431-3192, Japan; (K.H.); (K.K.); (Y.H.)
| | - Kentaro Kurata
- Department of Ophthalmology, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Shizuoka, Hamamatsu 431-3192, Japan; (K.H.); (K.K.); (Y.H.)
| | - Yoshihiro Hotta
- Department of Ophthalmology, Hamamatsu University School of Medicine, 1-20-1, Handayama, Higashi-ku, Shizuoka, Hamamatsu 431-3192, Japan; (K.H.); (K.K.); (Y.H.)
| | - Kazutoshi Yoshitake
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan; (K.Y.); (T.I.)
| | - Takeshi Iwata
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, 2-5-1 Higashigaoka, Meguro-ku, Tokyo 152-8902, Japan; (K.Y.); (T.I.)
| | - Tomokazu Matsuura
- Department of Laboratory Medicine, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo 105-8471, Japan;
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, 3-19-18, Nishi-shimbashi, Minato-ku, Tokyo 105-8471, Japan; (T.H.); (T.N.)
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Clinical Phenotype of PDE6B-Associated Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22052374. [PMID: 33673512 PMCID: PMC7956818 DOI: 10.3390/ijms22052374] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 11/25/2022] Open
Abstract
In this retrospective, longitudinal, observational cohort study, we investigated the phenotypic and genotypic features of retinitis pigmentosa associated with variants in the PDE6B gene. Patients underwent clinical examination and genetic testing at a single tertiary referral center, including best-corrected visual acuity (BCVA), kinetic visual field (VF), full-field electroretinography, full-field stimulus threshold, spectral domain optical coherence tomography, and fundus autofluorescence imaging. The genetic testing comprised candidate gene sequencing, inherited retinal disease gene panel sequencing, whole-genome sequencing, and testing for familial variants by Sanger sequencing. Twenty-four patients with mutations in PDE6B from 21 families were included in the study (mean age at the first visit: 32.1 ± 13.5 years). The majority of variants were putative splicing defects (8/23) and missense (7/23) mutations. Seventy-nine percent (38/48) of eyes had no visual acuity impairment at the first visit. Visual acuity impairment was mild in 4% (2/48), moderate in 13% (6/48), and severe in 4% (2/48). BCVA was symmetrical in the right and left eyes. The kinetic VF measurements were highly symmetrical in the right and left eyes, as was the horizontal ellipsoid zone (EZ) width. Regarding the genetic findings, 43% of the PDE6B variants found in our patients were novel. Thus, this study contributed substantially to the PDE6B mutation spectrum. The visual acuity impairment was mild in 83% of eyes, providing a window of opportunity for investigational new drugs. The EZ width was reduced in all patients and was highly symmetric between the eyes, making it a promising outcome measure. We expect these findings to have implications on the design of future PDE6B-related retinitis pigmentosa (RP) clinical trials.
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3
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Perea-Romero I, Gordo G, Iancu IF, Del Pozo-Valero M, Almoguera B, Blanco-Kelly F, Carreño E, Jimenez-Rolando B, Lopez-Rodriguez R, Lorda-Sanchez I, Martin-Merida I, Pérez de Ayala L, Riveiro-Alvarez R, Rodriguez-Pinilla E, Tahsin-Swafiri S, Trujillo-Tiebas MJ, Garcia-Sandoval B, Minguez P, Avila-Fernandez A, Corton M, Ayuso C. Genetic landscape of 6089 inherited retinal dystrophies affected cases in Spain and their therapeutic and extended epidemiological implications. Sci Rep 2021; 11:1526. [PMID: 33452396 PMCID: PMC7810997 DOI: 10.1038/s41598-021-81093-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/31/2020] [Indexed: 02/08/2023] Open
Abstract
Inherited retinal diseases (IRDs), defined by dysfunction or progressive loss of photoreceptors, are disorders characterized by elevated heterogeneity, both at the clinical and genetic levels. Our main goal was to address the genetic landscape of IRD in the largest cohort of Spanish patients reported to date. A retrospective hospital-based cross-sectional study was carried out on 6089 IRD affected individuals (from 4403 unrelated families), referred for genetic testing from all the Spanish autonomous communities. Clinical, demographic and familiar data were collected from each patient, including family pedigree, age of appearance of visual symptoms, presence of any systemic findings and geographical origin. Genetic studies were performed to the 3951 families with available DNA using different molecular techniques. Overall, 53.2% (2100/3951) of the studied families were genetically characterized, and 1549 different likely causative variants in 142 genes were identified. The most common phenotype encountered is retinitis pigmentosa (RP) (55.6% of families, 2447/4403). The most recurrently mutated genes were PRPH2, ABCA4 and RS1 in autosomal dominant (AD), autosomal recessive (AR) and X-linked (XL) NON-RP cases, respectively; RHO, USH2A and RPGR in AD, AR and XL for non-syndromic RP; and USH2A and MYO7A in syndromic IRD. Pathogenic variants c.3386G > T (p.Arg1129Leu) in ABCA4 and c.2276G > T (p.Cys759Phe) in USH2A were the most frequent variants identified. Our study provides the general landscape for IRD in Spain, reporting the largest cohort ever presented. Our results have important implications for genetic diagnosis, counselling and new therapeutic strategies to both the Spanish population and other related populations.
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Affiliation(s)
- Irene Perea-Romero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Gema Gordo
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Ionut F Iancu
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Del Pozo-Valero
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Berta Almoguera
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Fiona Blanco-Kelly
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Ester Carreño
- Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Belen Jimenez-Rolando
- Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Rosario Lopez-Rodriguez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Isabel Lorda-Sanchez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Inmaculada Martin-Merida
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Lucia Pérez de Ayala
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Rosa Riveiro-Alvarez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Elvira Rodriguez-Pinilla
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Saoud Tahsin-Swafiri
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Maria J Trujillo-Tiebas
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | | | | | | | - Blanca Garcia-Sandoval
- Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.,Department of Ophthalmology, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
| | - Pablo Minguez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Almudena Avila-Fernandez
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Marta Corton
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
| | - Carmen Ayuso
- Department of Genetics, Health Research Institute-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain. .,Center for Biomedical Network Research on Rare Diseases (CIBERER), Instituto de Salud Carlos III, Madrid, Spain.
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4
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Whole exome sequencing and homozygosity mapping reveals genetic defects in consanguineous Iranian families with inherited retinal dystrophies. Sci Rep 2020; 10:19413. [PMID: 33173045 PMCID: PMC7655865 DOI: 10.1038/s41598-020-75841-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/08/2020] [Indexed: 12/17/2022] Open
Abstract
Inherited retinal dystrophies (IRDs), displaying pronounced genetic and clinical heterogeneity, comprise of a broad range of diseases characterized by progressive retinal cell death and gradual loss of vision. By the combined use of whole exome sequencing (WES), SNP-array and WES-based homozygosity mapping, as well as directed DNA sequencing (Sanger), we have identified nine pathogenic variants in six genes (ABCA4, RPE65, MERTK, USH2A, SPATA7, TULP1) in 10 consanguineous Iranian families. Six of the nine identified variants were novel, including a putative founder mutation in ABCA4 (c.3260A>G, p.Glu1087Gly), detected in two families from Northeastern Iran. Our findings provide additional information to the molecular pathology of IRDs in Iran, hopefully contributing to better genetic counselling and patient management in the respective families from this country.
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5
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Spencer WJ, Ding JD, Lewis TR, Yu C, Phan S, Pearring JN, Kim KY, Thor A, Mathew R, Kalnitsky J, Hao Y, Travis AM, Biswas SK, Lo WK, Besharse JC, Ellisman MH, Saban DR, Burns ME, Arshavsky VY. PRCD is essential for high-fidelity photoreceptor disc formation. Proc Natl Acad Sci U S A 2019; 116:13087-13096. [PMID: 31189593 PMCID: PMC6601265 DOI: 10.1073/pnas.1906421116] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Progressive rod-cone degeneration (PRCD) is a small protein residing in the light-sensitive disc membranes of the photoreceptor outer segment. Until now, the function of PRCD has remained enigmatic despite multiple demonstrations that its mutations cause blindness in humans and dogs. Here, we generated a PRCD knockout mouse and observed a striking defect in disc morphogenesis, whereby newly forming discs do not properly flatten. This leads to the budding of disc-derived vesicles, specifically at the site of disc morphogenesis, which accumulate in the interphotoreceptor matrix. The defect in nascent disc flattening only minimally alters the photoreceptor outer segment architecture beyond the site of new disc formation and does not affect the abundance of outer segment proteins and the photoreceptor's ability to generate responses to light. Interestingly, the retinal pigment epithelium, responsible for normal phagocytosis of shed outer segment material, lacks the capacity to clear the disc-derived vesicles. This deficiency is partially compensated by a unique pattern of microglial migration to the site of disc formation where they actively phagocytize vesicles. However, the microglial response is insufficient to prevent vesicular accumulation and photoreceptors of PRCD knockout mice undergo slow, progressive degeneration. Taken together, these data show that the function of PRCD is to keep evaginating membranes of new discs tightly apposed to each other, which is essential for the high fidelity of photoreceptor disc morphogenesis and photoreceptor survival.
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Affiliation(s)
- William J Spencer
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Jin-Dong Ding
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Tylor R Lewis
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Chen Yu
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Sebastien Phan
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Jillian N Pearring
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Keun-Young Kim
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Andrea Thor
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Rose Mathew
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Joan Kalnitsky
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Ying Hao
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Amanda M Travis
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Sondip K Biswas
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA 30310
| | - Woo-Kuen Lo
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA 30310
| | - Joseph C Besharse
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Mark H Ellisman
- National Center for Microscopy and Imaging Research, School of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Daniel R Saban
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710
| | - Marie E Burns
- Department of Cell Biology and Human Anatomy, University of California, Davis, CA 95616
- Department of Ophthalmology, University of California, Davis, CA 95616
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710;
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
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6
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Fahim AT, Bouzia Z, Branham KH, Kumaran N, Vargas ME, Feathers KL, Perera ND, Young K, Khan NW, Heckenlively JR, Webster AR, Pennesi ME, Ali RR, Thompson DA, Michaelides M. Detailed clinical characterisation, unique features and natural history of autosomal recessive RDH12-associated retinal degeneration. Br J Ophthalmol 2019; 103:1789-1796. [PMID: 30979730 DOI: 10.1136/bjophthalmol-2018-313580] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/28/2019] [Accepted: 02/05/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND Defects in retinol dehydrogenase 12 (RDH12) account for 3.4%-10.5 % of Leber congenital amaurosis and early-onset severe retinal dystrophy (EOSRD) and are a potential target for gene therapy. Clinical trials in inherited retinal diseases have unique challenges, and natural history studies are critical to successful trial design. The purpose of this study was to characterise the natural history of RDH12-associated retinal degeneration. METHODS A retrospective chart review was performed in individuals with retinal degeneration and two likely disease-causing variants in RDH12. RESULTS 57 subjects were enrolled from nine countries. 33 subjects had clinical records available from childhood. The data revealed an EOSRD, with average age of onset of 4.1 years. Macular atrophy was a universal clinical finding in all subjects, as young as 2 years of age. Scotopic and photopic electroretinography (ERG) responses were markedly reduced in all subjects, and a non-recordable ERG was documented as young as 1 year of age. Assessment of visual acuity, visual field and optical coherence tomography revealed severe loss of function and structure in the majority of subjects after the age of 10 years. Widefield imaging in 23 subjects revealed a unique, variegated watercolour-like pattern of atrophy in 13 subjects and sparing of the peripapillary area in 18 subjects. CONCLUSIONS This study includes the largest collection of phenotypic data from children with RDH12-associated EOSRD and provides a comprehensive description of the timeline of vision loss in this severe, early-onset condition. These findings will help identify patients with RDH12-associated retinal degeneration and will inform future design of therapeutic trials.
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Affiliation(s)
- Abigail T Fahim
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Zaina Bouzia
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Kari H Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Neruban Kumaran
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Mauricio E Vargas
- Department of Ophthalmology, Oregon Health & Science University - Casey Eye Institute, Portland, Oregon, USA
| | - Kecia L Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - N Dayanthi Perera
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Kelly Young
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Naheed W Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Andrew R Webster
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Mark E Pennesi
- Department of Ophthalmology, Oregon Health & Science University - Casey Eye Institute, Portland, Oregon, USA
| | - Robin R Ali
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA.,Institute of Ophthalmology, University College London, London, UK
| | - Debra A Thompson
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Institute of Ophthalmology, University College London, London, UK
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7
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Imani S, Cheng J, Mobasher‐Jannat A, Wei C, Fu S, Yang L, Jadidi K, Khosravi MH, Mohazzab‐Torabi S, Shasaltaneh MD, Li Y, Chen R, Fu J. Identification of a novel RPGRIP1 mutation in an Iranian family with leber congenital amaurosis by exome sequencing. J Cell Mol Med 2018; 22:1733-1742. [PMID: 29193763 PMCID: PMC5824405 DOI: 10.1111/jcmm.13454] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 10/13/2017] [Indexed: 12/18/2022] Open
Abstract
Leber congenital amaurosis (LCA) is a heterogeneous, early-onset inherited retinal dystrophy, which is associated with severe visual impairment. We aimed to determine the disease-causing variants in Iranian LCA and evaluate the clinical implications. Clinically, a possible LCA disease was found through diagnostic imaging, such as fundus photography, autofluorescence and optical coherence tomography. All affected patients showed typical eye symptoms associated with LCA including narrow arterioles, blindness, pigmentary changes and nystagmus. Target exome sequencing was performed to analyse the proband DNA. A homozygous novel c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene was identified, which was likely the deleterious and pathogenic mutation in the proband. Structurally, this mutation lost a retinitis pigmentosa GTPase regulator (RPGR)-interacting domain at the C-terminus which most likely impaired stability in the RPGRIP1 with the distribution of polarised proteins in the cilium connecting process. Sanger sequencing showed complete co-segregation in this pedigree. This study provides compelling evidence that the c. 2889delT (p.P963 fs) mutation in the RPGRIP1 gene works as a pathogenic mutation that contributes to the progression of LCA.
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Affiliation(s)
- Saber Imani
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
- Hunan Normal University Medical CollegeChangshaHunanChina
- Chemical Injuries Research CenterBaqiyatallah University of Medical SciencesTehranIran
| | - Jingliang Cheng
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Abdolkarim Mobasher‐Jannat
- Chemical Injuries Research CenterBaqiyatallah University of Medical SciencesTehranIran
- Student Research CommitteeBaqiyatallah University of Medical SciencesTehran Iran
| | - Chunli Wei
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Shangyi Fu
- The Honors CollegeUniversity of HoustonHoustonTXUSA
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Lisha Yang
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
| | - Khosrow Jadidi
- Department of OphthalmologyBaqiyatallah University of Medical SciencesTehranIran
| | | | - Saman Mohazzab‐Torabi
- Eye Research CenterFarabi Eye HospitalTehran University of Medical SciencesTehranIran
| | - Marzieh Dehghan Shasaltaneh
- Laboratory of Neuro‐organic ChemistryInstitute of Biochemistry and Biophysics (IBB)University of TehranTehranIran
- Laboratory of Systems Biology and Bioinformatics (LBB)Institute of Biochemistry and BiophysicsUniversity of TehranTehranIran
| | - Yumei Li
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Rui Chen
- Department of Molecular and Human GeneticsBaylor College of MedicineHoustonTXUSA
| | - Junjiang Fu
- Key Laboratory of Epigenetics and OncologyResearch Center for Preclinical MedicineSouthwest Medical UniversityLuzhouSichuanChina
- Hunan Normal University Medical CollegeChangshaHunanChina
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8
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Ghofrani M, Yahyaei M, Brunner HG, Cremers FP, Movasat M, Imran Khan M, Keramatipour M. Homozygosity Mapping and Targeted Sanger Sequencing Identifies Three Novel CRB1 (Crumbs homologue 1) Mutations in Iranian Retinal Degeneration Families. IRANIAN BIOMEDICAL JOURNAL 2017; 21:294-302. [PMID: 28460491 PMCID: PMC5548961 DOI: 10.18869/acadpub.ibj.21.5.294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background: Inherited retinal diseases (IRDs) are a group of genetic disorders with high degrees of clinical, genetic and allelic heterogeneity. IRDs generally show progressive retinal cell death resulting in gradual vision loss. IRDs constitute a broad spectrum of disorders including retinitis pigmentosa and Leber congenital amaurosis. In this study, we performed genotyping studies to identify the underlying mutations in three Iranian families. Methods: Having employed homozygosity mapping and Sanger sequencing, we identified the underlying mutations in the crumbs homologue 1 gene. The CRB1 protein is a part of a macromolecular complex with a vital role in retinal cell polarity, morphogenesis, and maintenance. Results: We identified a novel homozygous variant (c.1053_1061del; p.Gly352_Cys354del) in one family, a combination of a novel (c.2086T>C; p.Cys696Arg) and a known variant (c.2234C>T, p.Thr745Met) in another family and a homozygous novel variant (c.3090T>A; p.Asn1030Lys) in a third family. Conclusion: This study shows that mutations in CRB1 are relatively common in Iranian non-syndromic IRD patients.
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Affiliation(s)
- Mohammad Ghofrani
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mahin Yahyaei
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Han G. Brunner
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans P.M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Morteza Movasat
- Eye Research Center, Tehran University of Medical Sciences, Farabi Eye Hospital, Tehran, Iran
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
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9
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Spencer WJ, Pearring JN, Salinas RY, Loiselle DR, Skiba NP, Arshavsky VY. Progressive Rod-Cone Degeneration (PRCD) Protein Requires N-Terminal S-Acylation and Rhodopsin Binding for Photoreceptor Outer Segment Localization and Maintaining Intracellular Stability. Biochemistry 2016; 55:5028-37. [PMID: 27509380 PMCID: PMC5513659 DOI: 10.1021/acs.biochem.6b00489] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The light-sensing outer segments of photoreceptor cells harbor hundreds of flattened membranous discs containing the visual pigment, rhodopsin, and all the proteins necessary for visual signal transduction. PRCD (progressive rod-cone degeneration) protein is one of a few proteins residing specifically in photoreceptor discs, and the only one with completely unknown function. The importance of PRCD is highlighted by its mutations that cause photoreceptor degeneration and blindness in canine and human patients. Here we report that PRCD is S-acylated at its N-terminal cysteine and anchored to the cytosolic surface of disc membranes. We also showed that mutating the S-acylated cysteine to tyrosine, a common cause of blindness in dogs and a mutation found in affected human families, causes PRCD to be completely mislocalized from the photoreceptor outer segment. We next undertook a proteomic search for PRCD-interacting partners in disc membranes and found that it binds rhodopsin. This interaction was confirmed by reciprocal precipitation and co-chromatography experiments. We further demonstrated this interaction to be critically important for supporting the intracellular stability of PRCD, as the knockout of rhodopsin caused a drastic reduction in the photoreceptor content of PRCD. These data reveal the cause of photoreceptor disease in PRCD mutant dogs and implicate rhodopsin to be involved in PRCD's unknown yet essential function in photoreceptors.
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Affiliation(s)
- William J. Spencer
- Department of Pharmacology, Duke University, Durham, NC 27710
- Department of Ophthalmology, Duke University, Durham, NC 27710
| | | | - Raquel Y. Salinas
- Department of Pharmacology, Duke University, Durham, NC 27710
- Department of Ophthalmology, Duke University, Durham, NC 27710
| | | | | | - Vadim Y. Arshavsky
- Department of Pharmacology, Duke University, Durham, NC 27710
- Department of Ophthalmology, Duke University, Durham, NC 27710
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