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Duan W, Zhou T, Jiang H, Zhang M, Hu M, Zhang L. A novel nonsense variant (c.1499C>G) in CRB1 caused Leber congenital amaurosis-8 in a Chinese family and a literature review. BMC Med Genomics 2022; 15:197. [PMID: 36115989 PMCID: PMC9482190 DOI: 10.1186/s12920-022-01356-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 09/09/2022] [Indexed: 12/04/2022] Open
Abstract
Background Leber’s congenital amaurosis (LCA) is a severe hereditary retinopathy disease that is characterized by early and severe reduction of vision, nystagmus, and sluggish or absent pupillary responses. To date, the pathogenesis of LCA remains unclear, and the majority of cases are caused by autosomal recessive inheritance. In this study, we explored the variant in the Crumbs homologue 1 (CRB1) gene in a Chinese family with LCA.
Methods We conducted comprehensive ocular examinations and collected 5 ml of blood samples from members of a Chinese family with LCA. A pathogenic variant was identified by capturing (the panel in NGS) and Sanger sequencing validation. Results A nonsense variant (c.1499C>G) in the 6th exon of CRB1 gene in a Chinese family with LCA was identified, which predicted a change in the protein p. S500*, may lead to loss of gene function. We summarized the 76 variants reported thus far in CRB1 that caused LCA8. Conclusions This study reported a novel variant c.1499C>G (p. S500*) of the CRB1 gene occurred in a Chinese family with LCA, thus expanding the spectrum of CRB1 variants causing LCA.
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Grudzinska Pechhacker MK, Di Scipio M, Vig A, Tumber A, Roslin N, Tavares E, Vincent A, Hèon E. CRB1-related retinopathy overlapping the ocular phenotype of S-adenosylhomocysteine hydrolase deficiency. Ophthalmic Genet 2020; 41:457-464. [PMID: 32689861 DOI: 10.1080/13816810.2020.1790013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND S-adenosylhomocysteine hydrolase deficiency due to pathologic variants in AHCY gene is a rare neurometabolic disease for which no eye phenotype has been documented. Pathologic variants in CRB1 gene are known to cause a wide spectrum of autosomal recessive retinal diseases with Leber's congenital amaurosis as a most common. The aim of this study is to report co-inheritance of neurometabolic disease and eye disease in a pedigree. MATERIALS AND METHODS Comprehensive eye examination was performed in available family members together with color vision test, visual fields, fundus images, OCT, electroretinogram and visual evoked potentials. Genetic testing included whole-exome sequencing (WES), retinal dystrophy gene panel and segregation analysis. RESULTS Two children from a family not known to be consanguineous were affected with neurometabolic disease and one of them presented with reduced vision due to maculopathy. The mother had symptoms of retinal degeneration of unspecified cause. Clinical WES revealed homozygous missense pathologic variants in AHCY gene c.148G>A, p.(Ala50Thr) as a cause of S-adenosylhomocysteine hydrolase deficiency. Retinal dystrophy gene panel sequencing revealed two heterozygous missense pathologic variants in CRB1 gene c.1831T>C, p.(Ser611Pro) and c.3955T>C, p.(Phe1319Leu) in the proband and her mother. These variants segregated with disease phenotype in family members. CONCLUSIONS Establishing an ocular genetic diagnosis may be challenging with the co-existence of a rare systemic genetic disease with previously unknown eye involvement. Extensive phenotyping and genotyping of available family members showed that the proband and her mother shared a CRB1-related retinopathy at different stages while the brother did not.
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Affiliation(s)
- Monika K Grudzinska Pechhacker
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada
| | - Matteo Di Scipio
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Anjali Vig
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Anupreet Tumber
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada
| | - Nicole Roslin
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Erika Tavares
- Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
| | - Elise Hèon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children , Toronto, Canada.,Department of Ophthalmology and Vision Sciences, University of Toronto , Toronto, Canada.,Genetics and Genome Biology, The Hospital for Sick Children , Toronto, Canada
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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Talib M, van Schooneveld MJ, van Genderen MM, Wijnholds J, Florijn RJ, Ten Brink JB, Schalij-Delfos NE, Dagnelie G, Cremers FPM, Wolterbeek R, Fiocco M, Thiadens AA, Hoyng CB, Klaver CC, Bergen AA, Boon CJF. Genotypic and Phenotypic Characteristics of CRB1-Associated Retinal Dystrophies: A Long-Term Follow-up Study. Ophthalmology 2017; 124:884-895. [PMID: 28341475 DOI: 10.1016/j.ophtha.2017.01.047] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/27/2017] [Accepted: 01/27/2017] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To describe the phenotype, long-term clinical course, clinical variability, and genotype of patients with CRB1-associated retinal dystrophies. DESIGN Retrospective cohort study. PARTICIPANTS Fifty-five patients with CRB1-associated retinal dystrophies from 16 families. METHODS A medical record review of 55 patients for age at onset, medical history, initial symptoms, best-corrected visual acuity, ophthalmoscopy, fundus photography, full-field electroretinography (ffERG), Goldmann visual fields (VFs), and spectral-domain optical coherence tomography. MAIN OUTCOME MEASURES Age at onset, visual acuity survival time, visual acuity decline rate, and electroretinography and imaging findings. RESULTS A retinitis pigmentosa (RP) phenotype was present in 50 patients, 34 of whom were from a Dutch genetic isolate (GI), and 5 patients had a Leber congenital amaurosis phenotype. The mean follow-up time was 15.4 years (range, 0-55.5 years). For the RP patients, the median age at symptom onset was 4.0 years. In the RP group, median ages for reaching low vision, severe visual impairment, and blindness were 18, 32, and 44 years, respectively, with a visual acuity decline rate of 0.03 logarithm of the minimum angle of resolution per year. The presence of a truncating mutation did not alter the annual decline rate significantly (P = 0.75). Asymmetry in visual acuity was found in 31% of patients. The annual VF decline rate was 5% in patients from the genetic isolate, which was significantly faster than in non-GI patients (P < 0.05). Full-field electroretinography responses were extinguished in 50% of patients, were pathologically attenuated without a documented rod or cone predominance in 30% of patients, and showed a rod-cone dysfunction pattern in 20% of RP patients. Cystoid fluid collections in the macula were found in 50% of RP patients. CONCLUSIONS Mutations in the CRB1 gene are associated with a spectrum of progressive retinal degeneration. Visual acuity survival analyses indicate that the optimal intervention window for subretinal gene therapy is within the first 2 to 3 decades of life.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Maria M van Genderen
- Bartiméus, Diagnostic Centre for Complex Visual Disorders, Zeist, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ralph J Florijn
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Jacoline B Ten Brink
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | | | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
| | - Frans P M Cremers
- Department of Human Genetics and Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ron Wolterbeek
- Department of Medical Statistics, Leiden University Medical Center, Leiden, The Netherlands
| | - Marta Fiocco
- Department of Medical Statistics, Leiden University Medical Center, Leiden, The Netherlands; Mathematical Institute, Leiden University, Leiden, The Netherlands
| | - Alberta A Thiadens
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Carel B Hoyng
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Caroline C Klaver
- Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Arthur A Bergen
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands; The Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands; Department of Ophthalmology, Academic Medical Center, Amsterdam, The Netherlands.
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