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Hizem S, Maamouri R, Zaouak A, Rejeb I, Karoui S, Sebai M, Jilani H, Elaribi Y, Fenniche S, Cheour M, Bilan F, Ben Jemaa L. Absent meibomian glands and cone dystrophy in ADULT syndrome: identification by whole exome sequencing of pathogenic variants in two causal genes TP63 and CNGB3. Ophthalmic Genet 2024; 45:84-94. [PMID: 37158316 DOI: 10.1080/13816810.2023.2206891] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 04/20/2023] [Indexed: 05/10/2023]
Abstract
BACKGROUND Ectrodactyly is a rare congenital limb malformation characterized by a deep median cleft of the hand and/or foot due to the absence of central rays. It could be isolated or depicts a part of diverse syndromic forms. Heterozygous pathogenic variants in the TP63 gene are responsible for at least four rare syndromic human disorders associated with ectrodactyly. Among them, ADULT (Acro-Dermato-Ungual-Lacrimal-Tooth) syndrome is characterized by ectodermal dysplasia, excessive freckling, nail dysplasia, and lacrimal duct obstruction, in addition to ectrodactyly and/or syndactyly. Ophthalmic findings are very common in TP63-related disorders, consisting mainly of lacrimal duct hypoplasia. Absent meibomian glands have also been well documented in EEC3 (Ectrodactyly Ectodermal dysplasia Cleft lip/palate) syndrome but not in ADULT syndrome. METHODS We report a case of syndromic ectrodactyly consistent with ADULT syndrome, with an additional ophthalmic manifestation of agenesis of meibomian glands. The proband, as well as her elder sister, presented with congenital cone dystrophy.The molecular investigation was performed in the proband using Whole Exome Sequencing. Family segregation of the identified variants was confirmed by Sanger sequencing. RESULTS Two clinically relevant variants were found in the proband: the novel de novo heterozygous missense c.931A > G (p.Ser311Gly) in the TP63 gene classified as pathogenic, and the homozygous nonsense pathogenic c.1810C > T (p.Arg604Ter) in the CNGB3 gene. The same homozygous CNGB3 variation was also found in the sister, explaining the cone dystrophy in both cases. CONCLUSIONS Whole Exome Sequencing allowed dual molecular diagnoses: de novo TP63-related syndromic ectrodactyly and familial CNGB3-related congenital cone dystrophy.
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Affiliation(s)
- Syrine Hizem
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Human genetics laboratory, LR99ES10- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Rym Maamouri
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Ophthalmology, Habib Thameur hospital, Tunis, Tunisia
| | - Anissa Zaouak
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Dermatology, Genodermatosis and Cancers Laboratory LR12SP03, Habib Thameur Hospital, Tunis, Tunisia
| | - Imen Rejeb
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Maternal and Child health laboratory, LR22SP01- Mongi Slim Hospital, Tunis, Tunisia
| | - Sana Karoui
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Maternal and Child health laboratory, LR22SP01- Mongi Slim Hospital, Tunis, Tunisia
| | - Molka Sebai
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Human genetics laboratory, LR99ES10- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Houweyda Jilani
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Yasmina Elaribi
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
| | - Sami Fenniche
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Dermatology, Genodermatosis and Cancers Laboratory LR12SP03, Habib Thameur Hospital, Tunis, Tunisia
| | - Monia Cheour
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Department of Ophthalmology, Habib Thameur hospital, Tunis, Tunisia
| | - Frédéric Bilan
- Laboratoire de Génétique, Service de Génétique, CHU Poitiers, Poitiers, France
| | - Lamia Ben Jemaa
- Department of congenital and hereditary diseases, Mongi Slim hospital, La Marsa, Tunisia
- Faculty of Medicine of Tunis, University of Tunis El Manar, Tunis, Tunisia
- Maternal and Child health laboratory, LR22SP01- Mongi Slim Hospital, Tunis, Tunisia
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [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: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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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, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- 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.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; 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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Amaral RAS, Motta FL, Zin OA, da Palma MM, Rodrigues GD, Sallum JMF. Molecular and Clinical Characterization of CNGA3 and CNGB3 Genes in Brazilian Patients Affected with Achromatopsia. Genes (Basel) 2023; 14:1296. [PMID: 37372476 DOI: 10.3390/genes14061296] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023] Open
Abstract
Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by reduced visual acuity, nystagmus, photophobia, and very poor or absent color vision. Pathogenic variants in six genes encoding proteins composing the cone phototransduction cascade (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2) and of the unfolded protein response (ATF6) have been related to ACHM cases, while CNGA3 and CNGB3 alone are responsible for most cases. Herein, we provide a clinical and molecular overview of 42 Brazilian patients from 38 families affected with ACHM related to biallelic pathogenic variants in the CNGA3 and CNGB3 genes. Patients' genotype and phenotype were retrospectively evaluated. The majority of CNGA3 variants were missense, and the most prevalent CNGB3 variant was c.1148delC (p.Thr383Ilefs*13), resulting in a frameshift and premature stop codon, which is compatible with previous publications in the literature. A novel variant c.1893T>A (p.Tyr631*) in the CNGB3 gene is reported for the first time in this study. A great variability in morphologic findings was observed in our patients, although no consistent correlation with age and disease stage in OCT foveal morphology was found. The better understanding of the genetic variants landscape in the Brazilian population will help in the diagnosis of this disease.
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Affiliation(s)
- Rebeca A S Amaral
- Department of Ophthamology, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil
- Instituto de Genética Ocular, São Paulo 04552-050, Brazil
| | | | - Olivia A Zin
- Department of Ophthamology, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil
- Instituto Brasileiro de Oftalmologia (IBOL), Rio de Janeiro 22250-040, Brazil
| | - Mariana M da Palma
- Department of Ophthamology, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil
- Instituto de Genética Ocular, São Paulo 04552-050, Brazil
- Department of Surgery & Hospital Clinic of Barcelona, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
| | - Gabriela D Rodrigues
- Department of Ophthamology, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil
| | - Juliana M F Sallum
- Department of Ophthamology, Federal University of São Paulo (UNIFESP), São Paulo 04023-062, Brazil
- Instituto de Genética Ocular, São Paulo 04552-050, Brazil
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Park SA, Rhodes J, Iwabe S, Ying GS, Pan W, Huang J, Komáromy AM. Quantitative and qualitative characterization of retinal dystrophies in canine models of inherited retinal diseases using spectral domain optical coherence tomography (SD-OCT). Exp Eye Res 2022; 220:109106. [PMID: 35588783 PMCID: PMC9789526 DOI: 10.1016/j.exer.2022.109106] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 04/19/2022] [Accepted: 05/06/2022] [Indexed: 12/26/2022]
Abstract
The purpose of this study was to establish spectral domain optical coherence tomography (SD-OCT) assessment data in well-established canine models of inherited retinal dystrophies: PDE6B-rod-cone dysplasia 1 (RCD1: early onset retinitis pigmentosa), PRCD-progressive rod-cone degeneration (PRCD: late onset retinitis pigmentosa), CNGB3-achromatopsia, and RPE65-Leber congenital amaurosis (LCA). High resolution SD-OCT images of the retina were acquired from both eyes in 5 planes: temporal; superotemporal; superior; nasal; and inferior in adult dogs with: RCD1 (n = 4 dogs, median age: 1.5 yrs); PRCD (n = 2, 4.3 yrs); LCA (n = 3, 5.2 yrs); achromatopsia (n = 3, 4.2 yrs); and wild types (wt, n = 6, 5.5 yrs). Total, inner and outer retinal thicknesses and ellipsoid zone were analyzed. In selected animals, histomorphometric evaluations were performed. In dogs with RCD1, PRCD, and LCA, the thickness of the outer retina was, compared to wt, significantly decreased (p ≤ 0.02) in all OCT imaging planes, and in superotemporal and inferior imaging planes in dogs with achromatopsia. No significant thinning was observed in inner retina thickness in any disease model except in the inferior imaging plane in dogs with RCD1. Dogs with RCD1, PRCD, and LCA had significantly more areas with disrupted ellipsoid zone in the presumed area centralis than wt (p ≤ 0.001). OCT findings provide baseline information for research of retinal dystrophies using these canine models.
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Affiliation(s)
- Shin Ae Park
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; Department of Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA.
| | - Jamie Rhodes
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Simone Iwabe
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gui-Shuang Ying
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wei Pan
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiayan Huang
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Tekavčič Pompe M, Vrabič N, Volk M, Meglič A, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Disease Progression in CNGA3 and CNGB3 Retinopathy; Characteristics of Slovenian Cohort and Proposed OCT Staging Based on Pooled Data from 126 Patients from 7 Studies. Curr Issues Mol Biol 2021; 43:941-957. [PMID: 34449556 PMCID: PMC8929018 DOI: 10.3390/cimb43020067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/08/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 11/20/2022] Open
Abstract
Achromatopsia has been proposed to be a morphologically predominately stable retinopathy with rare reports of progression of structural changes in the macula. A five-grade system of optical coherence tomography (OCT) features has been used for the classification of structural macular changes. However, their association with age remains questionable. We characterized the Slovenian cohort of 12 patients with pathogenic variants in CNGA3 or CNGB3 who had been followed up with OCT for up to 9 years. Based on observed structural changes in association with age, the following four-stage classification of retinal morphological changes was proposed: (I) preserved inner segment ellipsoid band (Ise), (II) disrupted ISe, (III) ISe loss and (IV) ISe and RPE loss. Data from six previously published studies reporting OCT morphology in CNGA3 and CNGB3 patients were additionally collected, forming the largest CNGA3/CNGB3 cohort to date, comprising 126 patients aged 1–71 years. Multiple regression analysis showed a significant correlation of OCT stage with age (p < 0.001) and no correlation with gene (p > 0.05). The median ages of patients with stages I–IV were 12 years, 23 years, 27 years and 48 years, respectively, and no patient older than 50 years had continuous ISe. Our findings suggest that achromatopsia presents with slowly but steadily progressive structural changes of the macular outer retinal layers. However, whether morphological changes in time follow the proposed four-stage linear pattern needs to be confirmed in a long-term study.
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Affiliation(s)
- Manca Tekavčič Pompe
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Nika Vrabič
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.V.); (B.P.)
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.V.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
- Correspondence:
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Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F. Clinical and Molecular Characterization of Achromatopsia Patients: A Longitudinal Study. Int J Mol Sci 2021; 22:1681. [PMID: 33562422 PMCID: PMC7914547 DOI: 10.3390/ijms22041681] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/28/2021] [Accepted: 02/03/2021] [Indexed: 02/08/2023] Open
Abstract
Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in achromatopsia, we performed a detailed longitudinal phenotyping and genetic characterization of an Italian cohort comprising 21 ACHM patients (17 unrelated families). Molecular genetic testing identified biallelic pathogenic mutations in known ACHM genes, including four novel variants. At baseline, the patients presented a reduced best corrected visual acuity (BCVA), reduced macular sensitivity (MS), normal dark-adapted electroretinogram (ERG) responses and undetectable or severely reduced light-adapted ERG. The longitudinal analysis of 16 patients (mean follow-up: 5.4 ± 1.0 years) showed a significant decline of BCVA (0.012 logMAR/year) and MS (-0.16 dB/year). Light-adapted and flicker ERG responses decreased below noise level in three and two patients, respectively. Only two patients (12.5%) progressed to a worst OCT grading during the follow-up. Our findings corroborate the notion that ACHM is a progressive disease in terms of BCVA, MS and ERG responses, and affects slowly the structural integrity of the retina. These observations can serve towards the development of guidelines for patient selection and intervention timing in forthcoming gene replacement therapies.
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Affiliation(s)
- Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy;
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Antonella De Benedictis
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Gennarfrancesco Iaccarino
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy;
- Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, via Luigi De Crecchio 7, 80138 Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
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Jinda W, Tuekprakhon A, Thongnoppakhun W, Limwongse C, Trinavarat A, Atchaneeyasakul LO. Molecular and clinical characterization of Thai patients with achromatopsia: identification of three novel disease-associated variants in the CNGA3 and CNGB3 genes. Int Ophthalmol 2020; 41:121-134. [PMID: 32869108 DOI: 10.1007/s10792-020-01559-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 05/01/2020] [Accepted: 08/17/2020] [Indexed: 11/24/2022]
Abstract
PURPOSE Achromatopsia (ACHM) is an autosomal recessive cone disorder characterized by pendular nystagmus, photophobia, reduced visual acuity, and partial or total absence of color vision. Mutations in six genes (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6) have been reported in ACHM. There is no information on these disease-associated genes in Thai population. This study aimed to investigate the molecular and clinical characteristics in Thai patients with ACHM. METHODS Seven unrelated Thai patients with ACHM were recruited. Detailed ophthalmologic examination was performed. Polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism (SSCP) screening followed by Sanger sequencing was used to identify sequence variants in all exons and splice junctions of three genes (CNGA3, CNGB3, and GNAT2). The pathogenicity of the detected variants was interpreted. Segregation analysis was performed to determine variant sharing in available family members. RESULTS Four patients displayed different SSCP migration patterns. Sequence analysis revealed a reported pathogenic and a novel disease-associated variant in the CNGA3 gene. For the CNGB3 gene, we found two novel disease-associated variants and a reported variant of uncertain significance (VUS). Segregation analysis confirmed that the variants identified in each patient were present in the heterozygous state in their corresponding family members, which was consistent with an autosomal recessive mode of inheritance. CONCLUSIONS This study demonstrated the first molecular and clinical characterization of ACHM in Thai patients. The identification of disease-associated genes in a specific population leads to a personalized gene therapy benefiting those affected patients.
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Affiliation(s)
- Worapoj Jinda
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Aekkachai Tuekprakhon
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Wanna Thongnoppakhun
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chanin Limwongse
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Division of Medical Genetics, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Adisak Trinavarat
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - La-Ongsri Atchaneeyasakul
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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9
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Garafalo AV, Cideciyan AV, Héon E, Sheplock R, Pearson A, WeiYang Yu C, Sumaroka A, Aguirre GD, Jacobson SG. Progress in treating inherited retinal diseases: Early subretinal gene therapy clinical trials and candidates for future initiatives. Prog Retin Eye Res 2020; 77:100827. [PMID: 31899291 PMCID: PMC8714059 DOI: 10.1016/j.preteyeres.2019.100827] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/21/2019] [Accepted: 12/26/2019] [Indexed: 12/15/2022]
Abstract
Due to improved phenotyping and genetic characterization, the field of 'incurable' and 'blinding' inherited retinal diseases (IRDs) has moved substantially forward. Decades of ascertainment of IRD patient data from Philadelphia and Toronto centers illustrate the progress from Mendelian genetic types to molecular diagnoses. Molecular genetics have been used not only to clarify diagnoses and to direct counseling but also to enable the first clinical trials of gene-based treatment in these diseases. An overview of the recent reports of gene augmentation clinical trials by subretinal injections is used to reflect on the reasons why there has been limited success in this early venture into therapy. These first-in human experiences have taught that there is a need for advancing the techniques of delivery of the gene products - not only for refining further subretinal trials, but also for evaluating intravitreal delivery. Candidate IRDs for intravitreal gene delivery are then suggested to illustrate some of the disorders that may be amenable to improvement of remaining central vision with the least photoreceptor trauma. A more detailed understanding of the human IRDs to be considered for therapy and the calculated potential for efficacy should be among the routine prerequisites for initiating a clinical trial.
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Affiliation(s)
- Alexandra V Garafalo
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Artur V Cideciyan
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Rebecca Sheplock
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Alexander Pearson
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Caberry WeiYang Yu
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
| | - Alexander Sumaroka
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Gustavo D Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Samuel G Jacobson
- Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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10
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Zhang Y, Wang S, Xu M, Pang J, Yuan Z, Zhao C. AAV-mediated human CNGB3 restores cone function in an all-cone mouse model of CNGB3 achromatopsia. J Biomed Res 2020; 34:114-121. [PMID: 32305965 DOI: 10.7555/jbr.33.20190056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 12/30/2022] Open
Abstract
Complete congenital achromatopsia is a devastating hereditary visual disorder. Mutations in the CNGB3 gene account for more than 50% of all known cases of achromatopsia. This work investigated the efficiency of subretinal (SR) delivered AAV8 (Y447, 733F) vector containing a human PR2.1 promoter and a human CNGB3 cDNA in Cngb3 -/-/ Nrl -/- mice. The Cngb3 -/-/ Nrl -/- mouse was a cone-dominant model with Cngb3 channel deficiency, which partially mimicked the all-cone foveal structure of human achromatopsia with CNGB3 mutations. Following SR delivery of the vector, AAV-mediated CNGB3 expression restored cone function which was assessed by the restoration of the cone-mediated electroretinogram (ERG) and immunohistochemistry. This therapeutic rescue resulted in long-term improvement of retinal function with the restoration of cone ERG amplitude. This study demonstrated an AAV-mediated gene therapy in a cone-dominant mouse model using a human gene construct and provided the potential to be utilized in clinical trials.
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Affiliation(s)
- Yuxin Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shanshan Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Miao Xu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jijing Pang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China;Department of Ophthalmology, University of Florida, Gainesville, FL 32610, USA
| | - Zhilan Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Chen Zhao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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11
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Weisschuh N, Sturm M, Baumann B, Audo I, Ayuso C, Bocquet B, Branham K, Brooks BP, Catalá-Mora J, Giorda R, Heckenlively JR, Hufnagel RB, Jacobson SG, Kellner U, Kitsiou-Tzeli S, Matet A, Martorell Sampol L, Meunier I, Rudolph G, Sharon D, Stingl K, Streubel B, Varsányi B, Wissinger B, Kohl S. Deep-intronic variants in CNGB3 cause achromatopsia by pseudoexon activation. Hum Mutat 2019; 41:255-264. [PMID: 31544997 DOI: 10.1002/humu.23920] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [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: 05/20/2019] [Revised: 08/20/2019] [Accepted: 09/16/2019] [Indexed: 01/18/2023]
Abstract
Our comprehensive cohort of 1100 unrelated achromatopsia (ACHM) patients comprises a considerable number of cases (~5%) harboring only a single pathogenic variant in the major ACHM gene CNGB3. We sequenced the entire CNGB3 locus in 33 of these patients to find a second variant which eventually explained the patients' phenotype. Forty-seven intronic CNGB3 variants were identified in 28 subjects after a filtering step based on frequency and the exclusion of variants found in cis with pathogenic alleles. In a second step, in silico prediction tools were used to filter out those variants with little odds of being deleterious. This left three variants that were analyzed using heterologous splicing assays. Variant c.1663-1205G>A, found in 14 subjects, and variant c.1663-2137C>T, found in two subjects, were indeed shown to exert a splicing defect by causing pseudoexon insertion into the transcript. Subsequent screening of further unsolved CNGB3 subjects identified four additional cases harboring the c.1663-1205G>A variant which makes it the eighth most frequent CNGB3 variant in our cohort. Compound heterozygosity could be validated in ten cases. Our study demonstrates that whole gene sequencing can be a powerful approach to identify the second pathogenic allele in patients apparently harboring only one disease-causing variant.
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Affiliation(s)
- Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France.,CHNO des Quinze-Vingts, INSERM-DHOS CIC1423, Paris, France.,Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Carmen Ayuso
- Department of Genetics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital-Universidad Autónoma de Madrid (IIS-FJD UAM), Madrid, Spain.,Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Beatrice Bocquet
- Centre National de Référence «Maladies Sensorielles Génétiques», Service Ophtalmologie, Hôpital Gui de Chauliac, CHRU de Montpellier, Montpellier, France.,INSERM U1051, Institute for Neurosciences of Montpellier, Montpellier, France
| | - Kari Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Brian P Brooks
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | | | - Roberto Giorda
- Molecular Biology Lab, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan
| | - Robert B Hufnagel
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Samuel G Jacobson
- Department of Ophthalmology, Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ulrich Kellner
- Rare Retinal Disease Center, Augenzentrum Siegburg, MVZ ADTC Siegburg GmbH, Siegburg, Germany
| | - Sofia Kitsiou-Tzeli
- Department of Medical Genetics, National & Kapodistrian University of Athens, Athens, Greece
| | - Alexandre Matet
- Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | | | - Isabelle Meunier
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain.,Centre National de Référence «Maladies Sensorielles Génétiques», Service Ophtalmologie, Hôpital Gui de Chauliac, CHRU de Montpellier, Montpellier, France
| | - Günther Rudolph
- Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Berthold Streubel
- Department of Pathology, Medical University of Vienna, Vienna, Austria
| | - Balázs Varsányi
- Department of Ophthalmology, Semmelweis University, Budapest, Hungary.,Department of Ophthalmology, University of Pécs Medical School, Pécs, Hungary
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
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12
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Hlavatá L, Ďuďáková Ľ, Moravíková J, Zobanová A, Kousal B, Lišková P. Molecular genetic cause of achromatopsia in two patients of Czech origin. Cesk Slov Oftalmol 2019; 75:272-276. [PMID: 32397729 DOI: 10.31348/2019/5/5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
INTRODUCTION Achromatopsia is an autosomal recessive retinal disorder with an estimated prevalence ranging from 1 in 30.000 to 50.000. The disease is caused by mutations in six different genes. The aim of the study was to perform molecular genetic analysis in 11 unrelated probands with a clinical diagnosis of achromatopsia and to describe clinical findings in those that were found to carry biallelic pathogenic mutations. METHODS All probands and their parents underwent ophthalmic examination. Mutation detection was performed using Sanger sequencing of CNGB3 exons 6, 7, 9-13, which have been found to harbour most disease-causing mutations in patients with achromatopsia of European origin. RESULTS Three known pathogenic variants in CNGB3 were identified in 2 probands. Proband 1 was a compound heterozygote for the c.819_826del; p.(Arg274Valfs*13) and c.1006G>T; p.(Glu336*). Proband 2 carried the c.1148del; p.(Thr383Ilefs*13) in a homozygous state. The best corrected visual acuity in proband 1 (aged 19 years) was 0.1 in both eyes, in proband 2 (aged 8 years) 0.05 in the right eye and 0.1 in the left eye. Both individuals had nystagmus, photophobia, and absence of colour discrimination. Fundus examination appeared normal however spectral-domain optical coherence tomography revealed subtle bilaterally symmetrical structural changes in the fovea. CONCLUSION Molecular genetic analysis of Czech patients with achromatopsia was performed for the first time. Identification of disease-causing mutations in achromatopsia is important for establishing an early diagnosis, participation in clinical trials assessing gene therapies and may be also used for preimplantation genetic diagnosis.
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13
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Sheremet NL, Zhorzholadze NV, Ronzina IA, Grushke IG, Kurbatov SA, Chukhrova AL, Loginova AN, Shcherbakova PO, Tanas AS, Polyakov AV, Strel'nikov VV. [Molecular genetic diagnosis of Stargardt disease]. Vestn Oftalmol 2018; 133:4-11. [PMID: 28980559 DOI: 10.17116/oftalma201713344-11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 11/18/2022]
Abstract
AIM To comparatively evaluate the efficacy of genetic screening in patients with Stargardt disease (SD) by using an express panel of 5 most common ABCA4 mutations and performing massive parallel sequencing of all coding regions of the ABCA4, ELOVL4, PROM1, and CNGB3 genes. MATERIAL AND METHODS MLPA analysis for 5 ABCA4 mutations, namely p.G863A, p.L541P, p.A1038V, p.G1961E, and p.P1380L, was done in 54 patients with SD. In 25 patients, massive parallel sequencing of coding regions (exons) and neighboring introns of the ABCA4, ELOVL4, PROM1, and CNGB3 genes was also performed. RESULTS Gene testing for 5 ABCA4 mutations showed that 50% of patients (27 patients) harbored one mutation and 13% - two mutations. At massive parallel sequencing (25 patients), two pathogenic alleles were found in 21 patients (84%), one mutation - in 23 patients (91.7%). The majority of mutations was accounted for by the ABCA4 gene (83% of all mutation-positive patients). CONCLUSION Sequencing of exons and neighboring introns of the ABCA4, ELOVL4, PROM1, and CNGB3 genes with the new molecular genetic diagnostic system enabled confirmation of the diagnosis of SD in 84% of patients. High prevalence of p.L541P, p.A1038V, and p.G1961E mutations of the ABCA4 gene has been established.
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Affiliation(s)
- N L Sheremet
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - N V Zhorzholadze
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - I A Ronzina
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - I G Grushke
- Research Institute of Eye Diseases, 11 A, B, Rossolimo St., Moscow, Russia, 119021
| | - S A Kurbatov
- Voronezh Regional Clinical Consultative and Diagnostic Center, 5a Lenina Sq., Voronezh, Russia, 394018
| | - A L Chukhrova
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - A N Loginova
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - P O Shcherbakova
- Pirogov Russian National Research Medical University, 1 Ostrovityanova St., Moscow, Russia, 117997
| | - A S Tanas
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - A V Polyakov
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
| | - V V Strel'nikov
- Research Centre of Medical Genetics, 1 Moskvorech'e St., Moscow, Russia, 115478
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14
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Mayer AK, Van Cauwenbergh C, Rother C, Baumann B, Reuter P, De Baere E, Wissinger B, Kohl S. CNGB3 mutation spectrum including copy number variations in 552 achromatopsia patients. Hum Mutat 2017; 38:1579-1591. [PMID: 28795510 DOI: 10.1002/humu.23311] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [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: 05/09/2017] [Revised: 07/25/2017] [Accepted: 08/04/2017] [Indexed: 02/03/2023]
Abstract
Achromatopsia is a rare autosomal recessive cone disorder characterized by color vision defects, photophobia, nystagmus, and severely reduced visual acuity. The disease is caused by mutations in genes encoding crucial components of the cone phototransduction cascade (CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H) or in ATF6, involved in the unfolded protein response. CNGB3 encoding the beta subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors is the major achromatopsia gene. Here, we present a comprehensive spectrum of CNGB3 mutations and their prevalence in a cohort of 1074 independent families clinically diagnosed with achromatopsia. Of these, 485 (45.2%) carried mutations in CNGB3. We identified a total of 98 different potentially disease-causing CNGB3 variants, 58 of which are novel. About 10% of patients with CNGB3 mutations only harbored a single heterozygous variant. Therefore, we performed quantitative real-time PCR in 43 of such single heterozygotes in search of the missing allele, followed by microarray-based comparative genomic hybridization and breakpoint mapping. We discovered nine different heterozygous copy number variations encompassing one to 10 consecutive exons in 16 unrelated patients. Moreover, one additional patient with a homozygous CNGB3 deletion encompassing exons 4-18 was identified, highlighting the importance of CNV analysis for this gene.
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Affiliation(s)
- Anja K Mayer
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Christine Rother
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Britta Baumann
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Peggy Reuter
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Elfride De Baere
- Center for Medical Genetics Ghent, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Molecular Genetics Laboratory, Tuebingen, Germany
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15
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Abstract
As our understanding of the genetic basis for inherited retinal disease has expanded, gene therapy has advanced into clinical development. When the gene mutations associated with inherited retinal dystrophies were identified, it became possible to create animal models in which individual gene were altered to match the human mutations. The retina of these animals were then characterized to assess whether the mutated genes produced retinal phenotypes characteristic of disease-affected patients. Following the identification of a subpopulation of patients with the affected gene and the development of techniques for the viral gene transduction of retinal cells, it has become possible to deliver a copy of the normal gene into the retinal sites of the mutated genes. When this was performed in animal models of monogenic diseases, at an early stage of retinal degeneration when the affected cells remained viable, successful gene augmentation corrected the structural and functional lesions characteristic of the specific diseases in the areas of the retina that were successfully transduced. These studies provided the essential proof-of-concept needed to advance monogenic gene therapies into clinic development; these therapies include treatments for: Leber's congenital amaurosis type 2, caused by mutations to RPE65, retinoid isomerohydrolase; choroideremia, caused by mutations to REP1, Rab escort protein 1; autosomal recessive Stargardt disease, caused by mutations to ABCA4, the photoreceptor-specific ATP-binding transporter; Usher 1B disease caused by mutations to MYO7A, myosin heavy chain 7; X-linked juvenile retinoschisis caused by mutations to RS1, retinoschisin; autosomal recessive retinitis pigmentosa caused by mutations to MERTK, the proto-oncogene tyrosine-protein kinase MER; Leber's hereditary optic neuropathy caused by mutations to ND4, mitochondrial nicotinamide adenine dinucleotide ubiquinone oxidoreductase (complex I) subunit 4 and achromatopsia, caused by mutations to CNGA3, cyclic nucleotide-gated channel alpha 3 and CNGB3, cyclic nucleotide-gated channel beta 3. This review includes a tabulated summary of treatments for these monogenic retinal dystrophies that have entered into clinical development, as well as a brief summary of the preclinical data that supported their advancement into clinical development.
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16
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Meighan PC, Peng C, Varnum MD. Inherited macular degeneration-associated mutations in CNGB3 increase the ligand sensitivity and spontaneous open probability of cone cyclic nucleotide-gated channels. Front Physiol 2015; 6:177. [PMID: 26106334 PMCID: PMC4460308 DOI: 10.3389/fphys.2015.00177] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 05/25/2015] [Indexed: 11/13/2022] Open
Abstract
Cyclic nucleotide gated (CNG) channels are a critical component of the visual transduction cascade in the vertebrate retina. Mutations in the genes encoding these channels have been associated with a spectrum of inherited retinal disorders. To gain insight into their pathophysiological mechanisms, we have investigated the functional consequences of several CNGB3 mutations, previously associated with macular degeneration (Y469D and L595F) or complete achromatopsia (S156F, P309L, and G558C), by expressing these subunits in combination with wild-type CNGA3 in Xenopus oocytes and characterizing them using patch-clamp recordings in the inside-out configuration. These mutations did not prevent the formation of functional heteromeric channels, as indicated by sensitivity to block by L-cis-diltiazem. With the exception of S156F, each of the mutant channels displayed electrophysiological properties reflecting enhanced channel activity at physiological concentrations of cGMP (i.e., a gain-of-function phenotype). The increased channel activity produced by these mutations resulted from either increased functional expression levels, or increased sensitivity to cyclic nucleotides. Furthermore, L595F increased the spontaneous open probability in the absence of activating ligand, signifying a ligand independent gain-of-function change. In addition to the CNGB3 disease-associate mutations, we characterized the effects of several common CNGB3 and CNGA3 single-nucleotide polymorphisms (SNPs) on heteromeric CNGA3+CNGB3 channel function. Two of the SNPs examined (A3-T153M, and B3-W234C) produced decreased ligand sensitivity for heteromeric CNG channels. These changes may contribute to background disease susceptibility when combined with other genetic or non-genetic factors. Together, these studies help to define the underlying molecular phenotype for mutations relating to CNG channel disease pathogenesis.
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Affiliation(s)
- Peter C Meighan
- Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University Pullman, WA, USA
| | - Changhong Peng
- Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University Pullman, WA, USA
| | - Michael D Varnum
- Department of Integrative Physiology and Neuroscience, Program in Neuroscience, Washington State University Pullman, WA, USA ; Center for Integrated Biotechnology, Washington State University Pullman, WA, USA
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17
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Zein WM, Jeffrey BG, Wiley HE, Turriff AE, Tumminia SJ, Tao W, Bush RA, Marangoni D, Wen R, Wei LL, Sieving PA. CNGB3-achromatopsia clinical trial with CNTF: diminished rod pathway responses with no evidence of improvement in cone function. Invest Ophthalmol Vis Sci 2014; 55:6301-8. [PMID: 25205868 DOI: 10.1167/iovs.14-14860] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [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: 11/24/2022] Open
Abstract
PURPOSE Ciliary neurotrophic factor (CNTF) protects rod photoreceptors from retinal degenerative disease in multiple nonhuman models. Thus far, CNTF has failed to demonstrate rod protection in trials for human retinitis pigmentosa. Recently, CNTF was found to improve cone photoreceptor function in a canine CNGB3 achromatopsia model. This study explores whether this finding translates to humans with CNGB3 achromatopsia. METHODS A five-subject, open-label Phase I/II study was initiated by implanting intraocular microcapsules releasing CNTF (nominally 20 ng/d) into one eye each of CNGB3 achromat participants. Fellow eyes served as untreated controls. Subjects were followed for 1 year. RESULTS Pupil constriction in treated eyes gave evidence of intraocular CNTF release. Additionally, scotopic ERG responses were reduced, and dark-adapted psychophysical absolute thresholds were increased, attributable to diminished rod or rod pathway activity. Optical coherence tomography revealed that the cone-rich fovea underwent structural changes as the foveal hyporeflective zone (HRZ) became diminished in CNTF-treated eyes. No objectively measurable enhancement of cone function was found by assessments of visual acuity, mesopic increment sensitivity threshold, or the photopic ERG. Careful measurements of color hue discrimination showed no change. Nonetheless, subjects reported beneficial changes of visual function in the treated eyes, including reduced light sensitivity and aversion to bright light, which may trace to decreased effective ambient light from the pupillary constriction; further they noted slowed adaptation to darkness, consistent with CNTF action on rod photoreceptors. CONCLUSIONS Ciliary neurotrophic factor did not measurably enhance cone function, which reveals a species difference between human and canine CNGB3 cones in response to CNTF. (ClinicalTrials.gov number, NCT01648452.).
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Affiliation(s)
- Wadih M Zein
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Brett G Jeffrey
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Henry E Wiley
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Amy E Turriff
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Santa J Tumminia
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Weng Tao
- Neurotech Pharmaceuticals, Inc., Cumberland, Rhode Island, United States
| | - Ronald A Bush
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
| | - Dario Marangoni
- National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States Department of Biotechnology and Applied Clinical Science, University of L'Aquila, L'Aquila, Italy
| | - Rong Wen
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miller School of Medicine, Miami, Florida, United States
| | - Lisa L Wei
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland, United States
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