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Thompson MD, Chidiac P, Jose PA, Hauser AS, Gorvin CM. Genetic variants of accessory proteins and G proteins in human genetic disease. Crit Rev Clin Lab Sci 2025; 62:113-134. [PMID: 39743506 PMCID: PMC11854058 DOI: 10.1080/10408363.2024.2431853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/14/2024] [Accepted: 11/16/2024] [Indexed: 01/04/2025]
Abstract
We present a series of three articles on the genetics and pharmacogenetics of G protein- coupled receptors (GPCR). In the first article, we discuss genetic variants of the G protein subunits and accessory proteins that are associated with human phenotypes; in the second article, we build upon this to discuss "G protein-coupled receptor (GPCR) gene variants and human genetic disease" and in the third article, we survey "G protein-coupled receptor pharmacogenomics". In the present article, we review the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane in the context of human genetic disease resulting from pathogenic variants of accessory proteins and G proteins. Pathogenic variants of the genes encoding G protein α and β subunits are examined in diverse phenotypes. Variants in the genes encoding accessory proteins that modify or organize G protein coupling have been associated with disease; these include the contribution of variants of the regulator of G protein signaling (RGS) to hypertension; the role of variants of activator of G protein signaling type III in phenotypes such as hypoxia; the contribution of variation at the RGS10 gene to short stature and immunological compromise; and the involvement of variants of G protein-coupled receptor kinases (GRKs), such as GRK4, in hypertension. Variation in genes that encode proteins involved in GPCR signaling are outlined in the context of the changes in structure and function that may be associated with human phenotypes.
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Affiliation(s)
- Miles D. Thompson
- Krembil Brain Institute, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Peter Chidiac
- Department of Physiology and Pharmacology, University of Western Ontario, London, Ontario, Canada
| | - Pedro A. Jose
- Division of Renal Diseases & Hypertension, Departments of Medicine and Pharmacology/Physiology, The George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Alexander S. Hauser
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Caroline M. Gorvin
- Institute of Metabolism and Systems Research (IMSR), University of Birmingham, Birmingham, West Midlands, UK
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Choi YJ, Joo K, Lim HT, Kim SS, Han J, Woo SJ. Clinical and Genetic Features of Korean Patients with Achromatopsia. Genes (Basel) 2023; 14:519. [PMID: 36833446 PMCID: PMC9957537 DOI: 10.3390/genes14020519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
This multicenter study aimed to characterize Korean patients with achromatopsia. The patients' genotypes and phenotypes were retrospectively evaluated. Twenty-one patients (with a mean age at the baseline of 10.9 years) were enrolled and followed up for a mean of 7.3 years. A targeted gene panel or exome sequencing was performed. The pathogenic variants of the four genes and their frequencies were identified. CNGA3 and PDE6C were equally the most prevalent genes: CNGA3 (N = 8, 38.1%), PDE6C (N = 8, 38.1%), CNGB3 (N = 3, 14.3%), and GNAT2 (N = 2, 9.5%). The degree of functional and structural defects varied among the patients. The patients' age exhibited no significant correlation with structural defects. During the follow-up, the visual acuity and retinal thickness did not change significantly. In CNGA3-achromatopsia patients, a proportion of patients with a normal foveal ellipsoid zone on the OCT was significantly higher than that of patients with other causative genes (62.5% vs. 16.7%; p = 0.023). In PDE6C-achromatopsia patients, the same proportion was significantly lower than that of patients with other causative genes (0% vs. 58.3%; p = 0.003). Korean patients with achromatopsia showed similar clinical features but a higher prevalence of PDE6C variants than those of other ethnic groups. The retinal phenotypes of the PDE6C variants were more likely to be worse than those of other genes.
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Affiliation(s)
- Yong Je Choi
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
| | - Hyun Taek Lim
- Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Orthopia Eye Clinic, Seoul 06162, Republic of Korea
| | - Sung Soo Kim
- Institute of Vision Research, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Republic of Korea
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Georgiou M, Singh N, Kane T, Robson AG, Kalitzeos A, Hirji N, Webster AR, Dubra A, Carroll J, Michaelides M. Photoreceptor Structure in GNAT2-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2020; 61:40. [PMID: 32203983 PMCID: PMC7401776 DOI: 10.1167/iovs.61.3.40] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to report GNAT2-associated achromatopsia (GNAT2-ACHM) natural history, characterize photoreceptor mosaic, and determine a therapeutic window for potential intervention. Methods Patients with GNAT2-ACHM were recruited from a single tertiary referral eye center (Moorfields Eye Hospital, London, UK). We performed longitudinal clinical evaluation and ophthalmic examination, and multimodal retinal imaging, including adaptive optics scanning light ophthalmoscopy, quantitative analysis of the cone mosaic, and outer nuclear layer (ONL) thickness, including cone densities evaluation in selected regions of interest and comparison with reported healthy controls. Results All nine subjects (3 women) presented with nystagmus, decreased visual acuity (VA), light sensitivity, and highly variable color vision loss. One patient had normal color vision and better VA. Mean VA was 1.01 (±0.10) logarithms of the minimal angle of resolution (LogMAR) at baseline, and 1.04 (±0.10) LogMAR after a mean follow-up (range) of 7.6 years (1.7−12.8 years). Optical coherence tomography showed preservation of the foveal ellipsoid zone (EZ; n = 8; 88.9%), and EZ disruption (n = 1; 11.1%). Mean ONL thickness (range, ± SD) was 84.72 µm (28.57−113.33, ± 25.46 µm) and 86.47 µm (28.57−113.33, ± 24.65 µm) for right and left eyes, respectively. Mean cone densities (±SD) at 190 µm, 350 µm, and 500 µm from the foveal center, were 48.4 (±24.6), 37.8 (±14.7), and 30.7 (±9.9), ×103 cones/mm2, respectively. Mean cone densities were lower than these of unaffected individuals, but with an overlap. Conclusions The cone mosaic in GNAT2-ACHM is relatively well preserved, potentially allowing for a wide therapeutic window for cone-directed interventions.
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Tobias P, Philipp SI, Stylianos M, Martin B, Barbara W, Felix R, Alexander OG, Eberhart Z, Marius U, Birgit K, Sven K, Ulrich BSK, Dominik FM, Bartz-Schmidt KU, Bolz S, Fischer D, Kohl S, Kühlewein L, Mühlfriedel R, Neubauer J, Ochakovski A, Paquet-Durand F, Seeliger M, Sothilingam V, Ueffing M, Weisschuh N, Wissinger B, Zhour A, Zobor D, Zrenner E, Biel M, Michalakis S, Schön C, Kahle N, Peters T, Wilhelm B, Tsang S, Glöckner CJ. Safety and Toxicology of Ocular Gene Therapy with Recombinant AAV Vector rAAV.hCNGA3 in Nonhuman Primates. HUM GENE THER CL DEV 2019; 30:50-56. [DOI: 10.1089/humc.2018.188] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Peters Tobias
- University Eye Hospital Tübingen, University of Tübingen, Tübingen, Germany
- STZ Eyetrial, University of Tübingen, Tübingen, Germany
| | | | - Michalakis Stylianos
- Center for Integrated Protein Science Munich, Department of Pharmacy – Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | - Biel Martin
- Center for Integrated Protein Science Munich, Department of Pharmacy – Center for Drug Research, Ludwig Maximilian University of Munich, Munich, Germany
| | | | - Reichel Felix
- University Eye Hospital Tübingen, University of Tübingen, Tübingen, Germany
| | | | - Zrenner Eberhart
- Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Ueffing Marius
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | | | - Korte Sven
- Covance Preclinical Services GmbH, Münster, Germany
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Felden J, Baumann B, Ali M, Audo I, Ayuso C, Bocquet B, Casteels I, Garcia-Sandoval B, Jacobson SG, Jurklies B, Kellner U, Kessel L, Lorenz B, McKibbin M, Meunier I, de Ravel T, Rosenberg T, Rüther K, Vadala M, Wissinger B, Stingl K, Kohl S. Mutation spectrum and clinical investigation of achromatopsia patients with mutations in the GNAT2 gene. Hum Mutat 2019; 40:1145-1155. [PMID: 31058429 DOI: 10.1002/humu.23768] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 02/04/2023]
Abstract
Achromatopsia (ACHM) is a hereditary cone photoreceptor disorder characterized by the inability to discriminate colors, nystagmus, photophobia, and low-visual acuity. Six genes have been associated with this rare autosomal recessively inherited disease, including the GNAT2 gene encoding the catalytic α-subunit of the G-protein transducin which is expressed in the cone photoreceptor outer segment. Out of a cohort of 1,116 independent families diagnosed with a primary clinical diagnosis of ACHM, we identified 23 patients with ACHM from 19 independent families with likely causative mutations in GNAT2, representing 1.7% of our large ACHM cohort. In total 22 different potentially disease-causing variants, of which 12 are novel, were identified. The mutation spectrum also includes a novel copy number variation, a heterozygous duplication of exon 4, of which the breakpoint matches exactly that of the previously reported exon 4 deletion. Two patients carry just a single heterozygous variant. In addition to our previous study on GNAT2-ACHM, we also present detailed clinical data of these patients.
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Affiliation(s)
- Julia Felden
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Manir Ali
- Section of Ophthalmology and Neuroscience, Leeds Institute of Medical Research at St. James's University Hospital, University of Leeds, Leeds, England
| | - Isabelle Audo
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institute de la Vision/ CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS, Paris, France
| | - Carmen Ayuso
- University Hospital Fundación Jiménez Díaz/Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Beatrice Bocquet
- Centre de Référence Maladies Sensorielles Génétiques, Hôpital Gui de Chauliac; Montpellier University and INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Ingele Casteels
- Department of Ophthalmology, University Hospitals Leuven, Leuven, Belgium
| | | | - Samuel G Jacobson
- Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Ulrich Kellner
- Rare Retinal Disease Center, AugenZentrum Siegburg, MVZ ADTC Siegburg GmbH, Europaplatz 3, Siegburg, Germany
| | - Line Kessel
- The National Eye Clinic, Rigshospitalet, Kennedy Center, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Martin McKibbin
- Section of Ophthalmology and Neuroscience, Leeds Institute of Medical Research at St. James's University Hospital, University of Leeds, Leeds, England
| | - Isabelle Meunier
- Centre de Référence Maladies Sensorielles Génétiques, Hôpital Gui de Chauliac; Montpellier University and INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Thomy de Ravel
- Center for Human Genetics, University Hospitals Leuven, University of Leuven, Leuven, Belgium
| | - Thomas Rosenberg
- The National Eye Clinic, Rigshospitalet, Kennedy Center, Glostrup, Denmark.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Klaus Rüther
- Augenarztpraxis, Dorotheenstrasse 56, Berlin, Germany
| | - Maria Vadala
- Ophthalmology Institute, Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata (BiND), Università degli Studi di Palermo
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University Tuebingen, Tuebingen, Germany
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Dai X, He Y, Zhang H, Zhang Y, Liu Y, Wang M, Chen H, Pang JJ. Long-term retinal cone rescue using a capsid mutant AAV8 vector in a mouse model of CNGA3-achromatopsia. PLoS One 2017; 12:e0188032. [PMID: 29131863 PMCID: PMC5683625 DOI: 10.1371/journal.pone.0188032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 10/29/2017] [Indexed: 01/26/2023] Open
Abstract
Adeno-associated virus (AAV) vectors are important gene delivery tools for the treatment of many recessively inherited retinal diseases. For example, a wild-type (WT) AAV5 vector can deliver a full-length Cnga3 (cyclic nucleotide-gated channel alpha-3) cDNA to target cells of the cone photoreceptor function loss 5 (cpfl5) mouse, a spontaneous animal model of achromatopsia with a Cnga3 mutation. Gene therapy restores cone-mediated function and blocks cone degeneration in the mice. However, since transgene expression delivered by an AAV vector shows relatively short-term effectiveness, this cannot be regarded as a very successful therapy. AAV2 and AAV8 vectors with capsid mutations have significantly enhanced transduction efficiency in retinas compared to WT AAV controls. In this study, AAV8 (Y447, 733F+T494V)-treated cpfl5 retinas showed greater preservation of short-term cone electroretinogram (ERG) responses than AAV8 (Y447, 733F)- or AAV2 (Y272, 444, 500, 730F+T491V)-mediated treatments. To explore the long-term rescue effect, AAV8 (Y447, 733F+T494V)-treated cpfl5 retinas were evaluated at 9 months following postnatal day 14 (P14) treatment. Rescued ERG responses in the cones of treated cpfl5 eyes decreased with increasing age, but still maintained more than 60% of the WT mouse responses at the oldest time point examined. Expression of CNGA3 and M/S-opsins was maintained in cone outer segments of the treated cpfl5 eyes and was equal to expression in age-matched WT retinas. Near-normal cone-mediated water maze behavior was observed in the treated cpfl5 mice. As these are the longest follow-up data reported thus far, AAV8 with capsid Y-F and T-V mutations may be one of the most effective AAV vectors for long-term treatment in a naturally occurring mouse model of CNGA3 achromatopsia.
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Affiliation(s)
- Xufeng Dai
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Ying He
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Hua Zhang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Yangyang Zhang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Yan Liu
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Muran Wang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
| | - Hao Chen
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
- * E-mail: (HC); (JP)
| | - Ji-jing Pang
- School of Ophthalmology and Optometry, The Eye Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, P.R. China
- * E-mail: (HC); (JP)
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Abeshi A, Zulian A, Beccari T, Dundar M, Falsini B, Bertelli M. Genetic testing for achromatopsia. EUROBIOTECH JOURNAL 2017. [DOI: 10.24190/issn2564-615x/2017/s1.03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for achromatopsia. The disease has autosomal recessive inheritance, a prevalence of 1/30000-1/50000, and is caused by mutations in the CNGB3, CNGA3, GNAT2, PDE6C, ATF6 and PDE6H genes. Clinical diagnosis is by ophthalmological examination, color vision testing and electrophysiological testing. Genetic testing is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.
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Affiliation(s)
- Andi Abeshi
- MAGI Balkans, Tirana , Albania
- MAGI’S Lab, Rovereto , Italy
| | | | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, Perugia , Italy
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University Medical School, Kayseri , Turkey
| | - Benedetto Falsini
- Department of Ophthalmology, Catholic University of Rome, Rome , Italy
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Maguire J, McKibbin M, Khan K, Kohl S, Ali M, McKeefry D. CNGB3 mutations cause severe rod dysfunction. Ophthalmic Genet 2017; 39:108-114. [PMID: 28929832 DOI: 10.1080/13816810.2017.1368087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE Congenital achromatopsia or rod monochromatism is a rare autosomal recessive condition defined by a severe loss of cone photoreceptor function in which rods purportedly retain normal or near-to-normal function. This report describes the results of electroretinography in two siblings with CNGB3-associated achromatopsia. METHODS Full field light- and dark-adapted electroretinograms (ERGs) were recorded using standard protocols detailed by the International Society for Clinical Electrophysiology of Vision (ISCEV). We also examined rod-mediated ERGs using series of stimuli that varied over a 6 log unit range of retinal illuminances (-1.9-3.5 log scotopic trolands). RESULTS Dark-adapted ERGs in achromatopsia patients exhibited severely reduced b-wave amplitudes with abnormal b:a ratios (1.3 and 0.6). In comparison, the reduction in a-wave amplitude was less marked. The rod-mediated ERG took on an electronegative appearance at high-stimulus illuminances. CONCLUSION Although the defect that causes achromatopsia is primarily in the cone photoreceptors, our results reveal an accompanying disruption of rod function that is more severe than has previously been reported. The differential effects on the b-wave relative to the a-wave points to an inner-retinal locus for the disruption of rod function in these patients.
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Affiliation(s)
- J Maguire
- a School of Optometry and Vision Sciences , University of Bradford , Bradford , West Yorkshire , UK
| | - M McKibbin
- b Department of Ophthalmology , St. James's University Teaching Hospital , Leeds , UK
| | - K Khan
- b Department of Ophthalmology , St. James's University Teaching Hospital , Leeds , UK
| | - S Kohl
- c Molecular Genetics Laboratory, Institute of Ophthalmic Research, Centre of Ophthalmology , University Clinics Tubingen , Tubingen , Germany
| | - M Ali
- d Section of Ophthalmology and Neuroscience, Leeds Institute of Biomedical and Clinical Sciences , University of Leeds , Leeds , UK
| | - D McKeefry
- a School of Optometry and Vision Sciences , University of Bradford , Bradford , West Yorkshire , UK
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Ueno S, Nakanishi A, Kominami T, Ito Y, Hayashi T, Yoshitake K, Kawamura Y, Tsunoda K, Iwata T, Terasaki H. In vivo imaging of a cone mosaic in a patient with achromatopsia associated with a GNAT2 variant. Jpn J Ophthalmol 2017; 61:92-98. [PMID: 27718025 DOI: 10.1007/s10384-016-0484-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 08/30/2016] [Indexed: 11/26/2022]
Abstract
PURPOSE The 2 most common causative genes for achromatopsia (ACHM) are CNGA3 and CNGB3; other genes including GNAT2 account for only a small portion of ACHM cases. The cone mosaics in eyes with CNGA3 and CNGB3 variants are severely disrupted; the cone mosaics in patients with GNAT2-associated ACHM; however, have been reported to show a contiguous pattern in adaptive optics (AO) retinal images. The purpose of this study was to analyze the cone mosaic of another case of GNAT2-associated ACHM. PATIENT AND METHODS The patient was a 17-year-old Japanese boy. Comprehensive ocular examinations including fundus photography, electroretinography (ERGs), optical coherence tomography (OCT), and whole-exome analysis were performed. The cone mosaic was recorded with a flood-illuminated AO fundus camera, and the cone density was compared with those of 10 normal control eyes. RESULTS The patient had the typical phenotype of ACHM, and a novel homozygous variant, c.730_743del, in GNAT2 was identified. The fundus did not show any specific abnormalities, and the OCT images showed the presence of the ellipsoid zone. The AO fundus image showed a clearly defined cone mosaic around the fovea. The cone density at 500 μm from the fovea was reduced by 15-30 % as compared with those of the normal eyes. CONCLUSIONS This is the first description of a Japanese patient with ACHM with a novel GNAT2 variant. The eyes of this patient had a preserved cone structure with loss of function.
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Affiliation(s)
- Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan.
| | - Ayami Nakanishi
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Taro Kominami
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Yasuki Ito
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazutoshi Yoshitake
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Yuichi Kawamura
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Kazushige Tsunoda
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Takeshi Iwata
- National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya, 466-8550, Japan
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Chen XT, Huang H, Chen YH, Dong LJ, Li XR, Zhang XM. Achromatopsia caused by novel missense mutations in the CNGA3 gene. Int J Ophthalmol 2015; 8:910-5. [PMID: 26558200 DOI: 10.3980/j.issn.2222-3959.2015.05.10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 03/14/2015] [Indexed: 11/02/2022] Open
Abstract
AIM To identify the genetic defects in a Chinese family with achromatopsia. METHODS A 2.5-year-old boy, who displayed nystagmus, photophobia, and hyperopia since early infancy, was clinically evaluated. To further confirm and localize the causative mutations in this family, targeted region capture and next-generation sequencing of candidate genes, such as CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H were performed using a custom-made capture array. RESULTS Slit-lamp examination showed no specific findings in the anterior segments. The optic discs and maculae were normal on fundoscopy. The unaffected family members reported no ocular complaints. Clinical signs and symptoms were consistent with a clinical impression of autosomal recessive achromatopsia. The results of sequence analysis revealed two novel missense mutations in CNGA3, c.633T>A (p.D211E) and c.1006G>T (p.V336F), with an autosomal recessive mode of inheritance. CONCLUSION Genetic analysis of a Chinese family confirmed the clinical diagnosis of achromatopsia. Two novel mutations were identified in CNGA3, which extended the mutation spectrum of this disorder.
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Affiliation(s)
- Xi-Teng Chen
- Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
| | - Hui Huang
- BGI Health Service Co., Ltd. Airport Industrial Zone, Tianjin 300308, China
| | - Yan-Hua Chen
- BGI Health Service Co., Ltd. Airport Industrial Zone, Tianjin 300308, China
| | - Li-Jie Dong
- Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
| | - Xiao-Rong Li
- Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
| | - Xiao-Min Zhang
- Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
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Contribution du SD-OCT de la macula dans le diagnostic de l’achromatopsie congénitale : à propos de 6 patients. J Fr Ophtalmol 2014; 37:296-302. [DOI: 10.1016/j.jfo.2013.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 12/11/2013] [Accepted: 12/12/2013] [Indexed: 11/20/2022]
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12
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G protein-coupled receptor accessory proteins and signaling: pharmacogenomic insights. Methods Mol Biol 2014; 1175:121-52. [PMID: 25150869 DOI: 10.1007/978-1-4939-0956-8_7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The identification and characterization of the genes encoding G protein-coupled receptors (GPCRs) and the proteins necessary for the processes of ligand binding, GPCR activation, inactivation, and receptor trafficking to the membrane are discussed in the context of human genetic disease. In addition to functional GPCR variants, the identification of genetic disruptions affecting proteins necessary to GPCR functions have provided insights into the function of these pathways. Gsα and Gβ subunit polymorphisms have been found to result in complex phenotypes. Disruptions in accessory proteins that normally modify or organize heterotrimeric G-protein coupling may also result in disease states. These include the contribution of variants of the regulator of G protein signaling (RGS) protein to hypertension; the role variants of the activator of G protein signaling (AGS) proteins to phenotypes (such as the type III AGS8 variant to hypoxia); the contribution of G protein-coupled receptor kinase (GRK) proteins, such as GRK4, in disorders such as hypertension. The role of accessory proteins in GPCR structure and function is discussed in the context of genetic disorders associated with disruption of the genes that encode them. An understanding of the pharmacogenomics of GPCR and accessory protein signaling provides the basis for examining both GPCR pharmacogenetics and the genetics of monogenic disorders that result from disruption of given receptor systems.
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