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Gwack J, Kim N, Park J. Improving the Yield of Genetic Diagnosis through Additional Genetic Panel Testing in Hereditary Ophthalmic Diseases. Curr Issues Mol Biol 2024; 46:5010-5022. [PMID: 38785568 PMCID: PMC11119902 DOI: 10.3390/cimb46050300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 05/17/2024] [Accepted: 05/18/2024] [Indexed: 05/25/2024] Open
Abstract
Numerous hereditary ophthalmic diseases display significant genetic diversity. Consequently, the utilization of gene panel sequencing allows a greater number of patients to receive a genetic diagnosis for their clinical manifestations. We investigated how to improve the yield of genetic diagnosis through additional gene panel sequencing in hereditary ophthalmic diseases. A gene panel sequencing consisting of a customized hereditary retinopathy panel or hereditary retinitis pigmentosa (RP) panel was prescribed and referred to a CAP-accredited clinical laboratory. If no significant mutations associated with hereditary retinopathy and RP were detected in either panel, additional gene panel sequencing was requested for research use, utilizing the remaining panel. After additional gene panel sequencing, a total of 16 heterozygous or homozygous variants were identified in 15 different genes associated with hereditary ophthalmic diseases. Of 15 patients carrying any candidate variants, the clinical symptoms could be tentatively accounted for by genetic mutations in seven patients. However, in the remaining eight patients, given the in silico mutation predictive analysis, variant allele frequency in gnomAD, inheritance pattern, and genotype-phenotype correlation, fully elucidating the clinical manifestations with the identified rare variant was challenging. Our study highlights the utility of gene panel sequencing in achieving accurate diagnoses for hereditary ophthalmic diseases and enhancing the diagnostic yield through additional gene panel sequencing. Thus, gene panel sequencing can serve as a primary tool for the genetic diagnosis of hereditary ophthalmic diseases, even in cases where a single genetic cause is suspected. With a deeper comprehension of the genetic mechanisms underlying these diseases, it becomes feasible.
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Affiliation(s)
- Jin Gwack
- Department of Preventive Medicine, Jeonbuk National University Medical School, Jeonju 54907, Republic of Korea;
| | - Namsu Kim
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
| | - Joonhong Park
- Department of Laboratory Medicine, Jeonbuk National University Medical School and Hospital, Jeonju 54907, Republic of Korea;
- Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Republic of Korea
- Department of Laboratory Medicine, Daejeon St. Mary’s Hospital, Daejeon 34943, Republic of Korea
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Chang MS, Jun I, Kim EK. Mini-Review: Clinical Features and Management of Granular Corneal Dystrophy Type 2. KOREAN JOURNAL OF OPHTHALMOLOGY 2023; 37:340-347. [PMID: 37336511 PMCID: PMC10427907 DOI: 10.3341/kjo.2023.0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/28/2023] [Accepted: 05/23/2023] [Indexed: 06/21/2023] Open
Abstract
Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant corneal stromal dystrophy that is caused by p.Arg124His mutation of transforming growth factor β induced (TGFBI) gene. It is characterized by well demarcated granular shaped opacities in central anterior stroma and as the disease progresses, extrusion of the deposits results in ocular pain due to corneal epithelial erosion. Also, diffuse corneal haze which appears late, causes decrease in visual acuity. The prevalence of GCD2 is high in East Asia including Korea. Homozygous patients show a severe phenotype from an early age, and the heterozygote phenotype varies among patients, depending on several types of compound heterozygous TGFBI mutations. In the initial stage, conservative treatments such as artificial tears, antibiotic eye drops, and bandage contact lenses are used to treat corneal erosion. Different surgical methods are used depending on the depth and extent of the stromal deposits. Phototherapeutic keratectomy removes anterior opacities and is advantageous in terms of its applicability and repeatability. For deeper lesions, deep anterior lamellar keratoplasty can be used as the endothelial layer is not always affected. Recurrence following these treatments are reported within a wide range of rates in different studies due to varying definition of recurrence and follow-up period. In patients who have undergone corneal laser vision-correction surgeries such as photorefractive keratectomy, LASEK, or LASIK including SMILE surgery, corneal opacity exacerbates rapidly with severe deterioration of visual acuity. Further investigations on new treatments of GCD2 are necessary.
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Affiliation(s)
- Myung Soo Chang
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
| | - Ikhyun Jun
- Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul,
Korea
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
| | - Eung Kweon Kim
- Corneal Dystrophy Research Institute, Yonsei University College of Medicine, Seoul,
Korea
- Saevit Eye Hospital, Goyang,
Korea
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Suh JH, Ryu IH, Hong JP, Moon JY, Choi JS, Jun I, Kim TI, Kim EK. Phenotypes of Granular Corneal Dystrophy Type 2 among Koreans in Their Twenties. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2022. [DOI: 10.3341/jkos.2022.63.12.965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Purpose: Granular corneal dystrophy type 2 (GCD2) is a hereditary disease that features granular and lattice stromal deposits in the cornea. There are homozygotes and heterozygotes and the opacities are exacerbated by corneal trauma or surgery, such as laser in situ keratomileusis (LASIK). As there is individual variability in GCD2 phenotypes, we investigated various corneal features of GCD2 patients in their twenties, the main age group for refractive surgery.Methods: From genetically confirmed GCD2 patients who had an R124H mutation of the transforming growth factor β induced (<i>TGFBI</i>) gene at age 20 to 29 years, we chose representative patients: one homozygote; one compound heterozygote; one simple heterozygote with a severe phenotype with many granular deposits; one common heterozygote; and four heterozygotes with normal corneas. The corneas of all patients were subject to slit-lamp examination and photographed.Results: The homozygote had confluent granular deposits covering the cornea. The compound heterozygote had granular and lattice deposits covering the center of the cornea. The patient with a severe phenotype had more than 30 granular deposits in one eye, but was a simple GCD2 heterozygote, verified by full-sequencing of the <i>TGFBI</i> gene. In the four patients with normal corneas, a single small lesion was subsequently detected during follow-up in two, at 3 weeks and 6 months, respectively. Both corneas were judged clear at chance examinations.Conclusions: Among Koreans in their twenties, GCD2 patients have various phenotypes, from clear corneas to severe confluent opacities. There are GCD2 heterozygotes with nearly clear corneas, so caution must be taken when choosing patients for refractive surgery.
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Li T, Wu S, Wen Y, Zhang X, Dai Q. Mutation analysis of the TGFBI gene in pedigrees of lattice corneal dystrophy in Eastern China. Ophthalmic Genet 2022; 43:594-601. [PMID: 35484844 DOI: 10.1080/13816810.2022.2068616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND To delineate the mutations of the TGFBI gene in Eastern China by whole-exome sequencing (WES) in eight Chinese families with lattice corneal dystrophy (LCD). MATERIALS AND METHODS This retrospective study included eight families with LCD from Eastern China. Clinical features were examined using slit-lamp examination, anterior segment optical coherence tomography, and in vivo confocal microscopy. Peripheral blood samples of probands were collected for WES, and saliva samples from family members were collected for TGFBI screening using Sanger sequencing. The physicochemical effects of mutations were investigated using bioinformatics tools. RESULTS Family 1 presented a classic LCD I with a p.R124C mutation of the TGFBI gene, while the other seven families were diagnosed with LCD IIIA. Six of the seven LCD IIIA families had heterozygous single-gene mutations (p.A546D, p.L565 H, p.T621P), and one had a compound heterozygous (cis) mutation (p.P501T and p.N622 H). The mutation of p.L565 H was the first time of integrated family report in contrast to the cases reported in 2019, and the p.T621P mutation was first reported in a Chinese population. Notably, the family with the compound mutation was associated with an obvious early-onset (in the 2nd decade of life) compared to the LCD IIIA patients with each single mutation (p.P501T or p.N622 H) showing late-onset (in the 7th decade of life). CONCLUSIONS WES is efficient for the genomic testing of LCD and genetic relationship identification in different families with the same mutated gene. We identified a compound heterozygous mutation (p.P501T and p.N622 H) and two mutations (p.T621P and p.L565 H) uncommon in China.
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Affiliation(s)
- Tiankun Li
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Nankai University Affiliated Eye Hospital, Tianjin, China
| | - Shuangqing Wu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yajing Wen
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Xin Zhang
- Zhejiang Maternal Child and Reproductive Health Center, Hangzhou, China
| | - Qi Dai
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
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Prevalence of granular corneal dystrophy type 2-related TGFBI p.R124H variant in a South Korean population. Mol Vis 2021; 27:283-287. [PMID: 34012230 PMCID: PMC8116257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Accepted: 05/06/2021] [Indexed: 11/03/2022] Open
Abstract
Purpose Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant disorder and is associated with the arginine to histidine substitution at codon 124 (p.R124H) of the TGFBI gene. Although TGFBI p.R124H is known to be the most common corneal dystrophy-related pathogenic variant, there are few data on the frequency of this variant in the South Korean population. Methods In total, 2,060 anonymous DNA samples from a public umbilical cord blood bank were tested for the TFGBI p.R124H variant using real-time PCR. Results Six of the 2,060 samples [0.29%; 95% confidence interval (CI), 0.12-0.67%] were heterozygous for the TGFBI p.R124H variant. The prevalence of the GCD2-related TGFBI p.R124H variant in this population was estimated to be 291.3 per 100,000 [95% confidence interval (CI), 118.5-667.0]. Conclusions To our knowledge, this is the largest study that has estimated the prevalence of the GCD2-related TGFBI p.R124H variant in South Korea.
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Compound heterozygous mutations in TGFBI cause a severe phenotype of granular corneal dystrophy type 2. Sci Rep 2021; 11:6986. [PMID: 33772078 PMCID: PMC7997986 DOI: 10.1038/s41598-021-86414-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/10/2021] [Indexed: 12/28/2022] Open
Abstract
We investigated the clinical and genetic features of patients with severe phenotype of granular corneal dystrophy type 2 (GCD2) associated with compound heterozygosity in the transforming growth factor-β-induced (TGFBI) gene. Patients with severe GCD2 underwent ophthalmic examination (best-corrected visual acuity test, intraocular pressure measurement, slit-lamp examination, and slit-lamp photograph analysis) and direct Sanger sequencing of whole-TGFBI. The patient’s family was tested to determine the pedigrees. Five novel mutations (p.(His174Asp), p.(Ile247Asn), p.(Tyr88Cys), p.(Arg257Pro), and p.(Tyr468*)) and two known mutations (p.(Asn544Ser) and p.(Arg179*)) in TGFBI were identified, along with p.(Arg124His), in the patients. Trans-phase of TGFBI second mutations was confirmed by pedigree analysis. Multiple, extensive discoid granular, and increased linear deposits were observed in the probands carrying p.(Arg124His) and other nonsense mutations. Some patients who had undergone phototherapeutic keratectomy experienced rapid recurrence (p.(Ile247Asn) and p.(Asn544Ser)); however, the cornea was well-maintained in a patient who underwent deep anterior lamellar keratoplasty (p.(Ile247Asn)). Thus, compound heterozygosity of TGFBI is associated with the phenotypic variability of TGFBI corneal dystrophies, suggesting that identifying TGFBI second mutations may be vital in patients with extraordinarily severe phenotypes. Our findings indicate the necessity for a more precise observation of genotype–phenotype correlation and additional care when treating TGFBI corneal dystrophies.
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Han SB, Anandalakshmi V, Wong CW, Ng SR, Mehta JS. Genotypic Homogeneity in Distinctive Transforming Growth Factor-Beta Induced (TGFBI) Protein Phenotypes. Int J Mol Sci 2021; 22:ijms22031230. [PMID: 33513810 PMCID: PMC7866065 DOI: 10.3390/ijms22031230] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 11/16/2022] Open
Abstract
Background: To evaluate the distribution of the transforming growth factor-beta induced (TGFBI) corneal dystrophies in a multi-ethnic population in Singapore, and to present the different phenotypes with the same genotype. Methods: This study included 32 patients. Slit lamp biomicroscopy was performed for each patient to determine the disease phenotype. Genomic DNA was extracted from the blood samples and the 17 exons of the TGFBI gene were amplified by PCR and sequenced bi-directionally for genotype analysis. Results: Regarding phenotypes, the study patients comprised 11 (34.4%; 8 with R555W and 3 with R124H mutation) patients with granular corneal dystrophy type 1 (GCD1), 6 (18.8%; 5 with R124H and 1 with R124C mutation) patients with GCD2, 13 (40.6%; 7 with R124C, 2 with H626R, 2 with L550P, 1 with A620D and 1 with H572R) patients with lattice corneal dystrophy (LCD) and 2 (6.3%; 1 with R124L and 1 with R124C) patients with Reis–Bückler corneal dystrophy. Regarding genotype, R124H mutation was associated with GCD2 (5 cases; 62.5%) and GCD1 (3 cases; 37.5%). R124C mutation was associated with LCD (7 cases; 87.5%) and GCD2 (1 case; 12.5%). All the 8 cases (100%) of R555W mutation were associated with GCD1. Conclusions: Although the association between genotype and phenotype was good in most cases (65.7%; 21 of 32 patients), genotype/phenotype discrepancy was observed in a significant number.
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Affiliation(s)
- Sang Beom Han
- Department of Ophthalmology, Kangwon National University School of Medicine, Chuncheon 24289, Korea;
- Department of Ophthalmology, Kangwon National University Hospital, Chuncheon 24289, Korea
| | | | - Chee Wai Wong
- Singapore Eye Research Institute, Singapore 169856, Singapore; (V.A.); (C.W.W.); (S.R.N.)
- Singapore National Eye Centre, Singapore 168751, Singapore
| | - Si Rui Ng
- Singapore Eye Research Institute, Singapore 169856, Singapore; (V.A.); (C.W.W.); (S.R.N.)
- Singapore National Eye Centre, Singapore 168751, Singapore
| | - Jodhbir S. Mehta
- Singapore National Eye Centre, Singapore 168751, Singapore
- Ophthalmology and Visual Sciences Academic Clinical Program, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
- Correspondence: ; Tel.: +65-91825146; Fax: +65-08701316622
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Benbouchta Y, Cherkaoui Jaouad I, Tazi H, Elorch H, Ouhenach M, Zrhidri A, Sadki K, Sefiani A, Lyahyai J, Berraho A. Novel mutation in the TGFBI gene in a Moroccan family with atypical corneal dystrophy: a case report. BMC Med Genomics 2021; 14:9. [PMID: 33407479 PMCID: PMC7789668 DOI: 10.1186/s12920-020-00861-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 12/25/2022] Open
Abstract
Background Corneal dystrophies (CDs) are a heterogeneous group of bilateral, genetically determined, noninflammatory bilateral corneal diseases that are usually limited to the cornea. CD is characterized by a large variability in the age of onset, evolution and visual impact and the accumulation of insoluble deposits at different depths in the cornea. Clinical symptoms revealed bilateral multiple superficial, epithelial, and stromal anterior granular opacities in different stages of severity among three patients of this family. A total of 99 genes are involved in CDs. The aim of this study was to identify pathogenic variants causing atypical corneal dystrophy in a large Moroccan family and to describe the clinical phenotype with severely different stages of evolution. Case presentation In this study, we report a large Moroccan family with CD. Whole-exome sequencing (WES) was performed in the three affected members who shared a phenotype of corneal dystrophy in different stages of severity. Variant validation and familial segregation were performed by Sanger sequencing in affected sisters and mothers and in two unaffected brothers. Whole-exome sequencing showed a novel heterozygous mutation (c.1772C > A; p.Ser591Tyr) in the TGFBI gene. Clinical examinations demonstrated bilaterally multiple superficial, epithelial and stromal anterior granular opacities in different stages of severity among three patients in this family. Conclusions This report describes a novel mutation in the TGFBI gene found in three family members affected by different phenotypic aspects. This mutation is associated with Thiel-Behnke corneal dystrophy; therefore, it could be considered a novel phenotype genotype correlation, which will help in genetic counselling for this family.
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Affiliation(s)
- Yahya Benbouchta
- Department of Medical Genetics, National Institute of Health, 27, Avenue Ibn, BP 769 Agdal, 10 090, Rabat, Morocco. .,Laboratory of Human Pathology, Faculty of Sciences, Mohammed V University, Rabat, Morocco.
| | - Imane Cherkaoui Jaouad
- Department of Medical Genetics, National Institute of Health, 27, Avenue Ibn, BP 769 Agdal, 10 090, Rabat, Morocco
| | - Habiba Tazi
- Ophtalmology Department, Hôpital Des Spécialités, Rabat, Morocco
| | - Hamza Elorch
- Ophtalmology Department, Hôpital Des Spécialités, Rabat, Morocco
| | - Mouna Ouhenach
- Research Team in Genomics and Molecular Epidemiology of Genetic Diseases, Genomic Center of Human Pathologies, Medical School and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Abdelali Zrhidri
- Research Team in Genomics and Molecular Epidemiology of Genetic Diseases, Genomic Center of Human Pathologies, Medical School and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Khalid Sadki
- Laboratory of Human Pathology, Faculty of Sciences, Mohammed V University, Rabat, Morocco
| | - Abdelaziz Sefiani
- Department of Medical Genetics, National Institute of Health, 27, Avenue Ibn, BP 769 Agdal, 10 090, Rabat, Morocco.,Research Team in Genomics and Molecular Epidemiology of Genetic Diseases, Genomic Center of Human Pathologies, Medical School and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Jaber Lyahyai
- Research Team in Genomics and Molecular Epidemiology of Genetic Diseases, Genomic Center of Human Pathologies, Medical School and Pharmacy, University Mohammed V, Rabat, Morocco
| | - Amina Berraho
- Ophtalmology Department, Hôpital Des Spécialités, Rabat, Morocco
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Christie KA, Robertson LJ, Conway C, Blighe K, DeDionisio LA, Chao-Shern C, Kowalczyk AM, Marshall J, Turnbull D, Nesbit MA, Moore CBT. Mutation-Independent Allele-Specific Editing by CRISPR-Cas9, a Novel Approach to Treat Autosomal Dominant Disease. Mol Ther 2020; 28:1846-1857. [PMID: 32416058 PMCID: PMC7403340 DOI: 10.1016/j.ymthe.2020.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 02/14/2020] [Accepted: 05/01/2020] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas9 provides a tool to treat autosomal dominant disease by non-homologous end joining (NHEJ) gene disruption of the mutant allele. In order to discriminate between wild-type and mutant alleles, Streptococcus pyogenes Cas9 (SpCas9) must be able to detect a single nucleotide change. Allele-specific editing can be achieved by using either a guide-specific approach, in which the missense mutation is found within the guide sequence, or a protospacer-adjacent motif (PAM)-specific approach, in which the missense mutation generates a novel PAM. While both approaches have been shown to offer allele specificity in certain contexts, in cases where numerous missense mutations are associated with a particular disease, such as TGFBI (transforming growth factor β-induced) corneal dystrophies, it is neither possible nor realistic to target each mutation individually. In this study, we demonstrate allele-specific CRISPR gene editing independent of the disease-causing mutation that is capable of achieving complete allele discrimination, and we propose it as a targeting approach for autosomal dominant disease. Our approach utilizes natural variants in the target region that contain a PAM on one allele that lies in cis with the causative mutation, removing the constraints of a mutation-dependent approach. Our innovative patient-specific guide design approach takes into account the patient's individual genetic make-up, allowing on- and off-target activity to be assessed in a personalized manner.
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Affiliation(s)
- Kathleen A Christie
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | - Louise J Robertson
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | - Caroline Conway
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | - Kevin Blighe
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | | | - Connie Chao-Shern
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK; Avellino Laboratories, Menlo Park, CA 94025, USA
| | - Amanda M Kowalczyk
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | - John Marshall
- Department of Genetics, UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Doug Turnbull
- Genomics and Cell Characterization Core Facility, University of Oregon, OR 97403, USA
| | - M Andrew Nesbit
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK
| | - C B Tara Moore
- Biomedical Sciences Research Institute, Ulster University, Coleraine BT52 1SA, Northern Ireland, UK; Avellino Laboratories, Menlo Park, CA 94025, USA.
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Nielsen NS, Poulsen ET, Lukassen MV, Chao Shern C, Mogensen EH, Weberskov CE, DeDionisio L, Schauser L, Moore TC, Otzen DE, Hjortdal J, Enghild JJ. Biochemical mechanisms of aggregation in TGFBI-linked corneal dystrophies. Prog Retin Eye Res 2020; 77:100843. [DOI: 10.1016/j.preteyeres.2020.100843] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 01/17/2020] [Accepted: 01/23/2020] [Indexed: 12/22/2022]
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Kheir V, Cortés-González V, Zenteno JC, Schorderet DF. Mutation update: TGFBI pathogenic and likely pathogenic variants in corneal dystrophies. Hum Mutat 2019; 40:675-693. [PMID: 30830990 DOI: 10.1002/humu.23737] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 02/26/2019] [Accepted: 02/28/2019] [Indexed: 01/07/2023]
Abstract
Human transforming growth factor β-induced (TGFBI), is a gene responsible for various corneal dystrophies. TGFBI produces a protein called TGFBI, which is involved in cell adhesion and serves as a recognition sequence for integrins. An alteration in cell surface interactions could be the underlying cause for the progressive accumulation of extracellular deposits in different layers of the cornea with the resulting changes of refractive index and transparency. To this date, 69 different pathogenic or likely pathogenic variants in TGFBI have been identified in a heterozygous or homozygous state in various corneal dystrophies, including a novel variant reported here. All disease-associated variants were inherited as autosomal-dominant traits but one; this latter was inherited as an autosomal recessive trait. Most corneal dystrophy-associated variants are located at amino acids Arg124 and Arg555. To keep the list of corneal dystrophy-associated variant current, we generated a locus-specific database for TGFBI (http://databases.lovd.nl/shared/variants/TGFBI) containing all pathogenic and likely pathogenic variants reported so far. Non-disease-associated variants are described in specific databases, like gnomAD and ExAC but are not listed here. This article presents the most recent up-to-date list of disease-associated variants.
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Affiliation(s)
- Valeria Kheir
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Vianney Cortés-González
- Department of Genetics, Hospital "Dr. Luis Sanchez Bulnes", Asociación Para Evitar la Ceguera en México, Mexico City, Mexico
| | - Juan C Zenteno
- Department of Genetics, Institute of Ophthalmology "Conde de Valenciana", Mexico City, Mexico.,Department of Biochemistry, Faculty of Medicine, UNAM, Mexico City, Mexico
| | - Daniel F Schorderet
- Institute for Research in Ophthalmology, Sion, Switzerland.,Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.,Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Identification of a Heterozygous Mutation in the TGFBI Gene in a Hui-Chinese Family with Corneal Dystrophy. J Ophthalmol 2019; 2019:2824179. [PMID: 30915236 PMCID: PMC6399521 DOI: 10.1155/2019/2824179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/16/2019] [Accepted: 01/30/2019] [Indexed: 11/18/2022] Open
Abstract
Background/Aims Corneal dystrophies (CDs) belong to a group of hereditary heterogeneous corneal diseases which result in visual impairment due to the progressive accumulation of deposits in different corneal layers. So far, mutations in several genes have been responsible for various CDs. The purpose of this study is to identify gene mutations in a three-generation Hui-Chinese family associated with granular corneal dystrophy type I (GCD1). Methods A three-generation Hui-Chinese pedigree with GCD1 was recruited for this study. Slit-lamp biomicroscopy, optical coherence tomography, and confocal microscopy were performed to determine the clinical features of available members. Whole exome sequencing was performed on two patients to screen for potential disease-causing variants in the family. Sanger sequencing was used to test the variant in the family members. Results Clinical examinations demonstrated bilaterally abundant multiple grayish-white opacities in the basal epithelial and superficial stroma layers of corneas of the two patients. Whole exome sequencing revealed that a heterozygous missense mutation (c.1663C > T, p.Arg555Trp) in the transforming growth factor beta-induced gene (TGFBI) was shared by the two patients, and it cosegregated with this disease in the family confirmed by Sanger sequencing. Conclusions The results suggested that the heterozygous TGFBI c.1663C > T (p.Arg555Trp) mutation was responsible for GCD1 in the Hui-Chinese family, which should be of great help in genetic counseling for this family.
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Cao WP, Yuan HG, Liu P, Li X, Hu Q. Two mutations in the transforming growth factor beta-induced gene associated with familial Lattice corneal dystrophy. Int J Ophthalmol 2017; 10:343-347. [PMID: 28393022 DOI: 10.18240/ijo.2017.03.03] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 11/05/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To report a phenotypic variant pedigree of lattice corneal dystrophy (LCD) associated with two mutations, R124C and A546D, in the transforming growth factor beta-induced gene (TGFBI). METHODS A detailed ocular examination was taken for all participants of a LCD family. Peripheral blood leukocytes from each participant were extracted to obtain the DNA. Polymerase chain reaction (PCR) of all seventeen exons of TGFBI gene was performed. The products were sequenced and analyzed. Histological examination was carried out after a penetrating keratoplasty from the right eye of proband. RESULTS Genetic analysis showed that the proband and all 6 affected individuals harbored both a heterozygous CGC to TGC mutation at codon 124 and a heterozygous GCC to GAC mutation at codon 546 of TGFBI. None of the 100 control subjects and unaffected family members was positive for these two mutations. Ocular examination displayed multiple refractile lattice-like opacities in anterior stroma of the central cornea and small granular deposits in the peripheral cornea. The deposits were stained positively with Congo red indicating be amyloid in nature and situated mainly in the anterior and middle stroma. CONCLUSION We observed a novel LCD family which carried two pathogenic mutations (R124C and A546D) in the TGFBI gene. The phenotypic features were apparently different from those associated with corresponding single mutations. The result reveals that although the definite mutation is the most important genetic cause of the disease, some different modifier alleles may influence the phenotype.
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Affiliation(s)
- Wen-Ping Cao
- Eye Hospital, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province, China
| | - Hai-Gang Yuan
- First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150001, Heilongjiang Province, China
| | - Ping Liu
- Eye Hospital, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province, China
| | - Xue Li
- Eye Hospital, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province, China
| | - Qi Hu
- Eye Hospital, the First Affiliated Hospital, Harbin Medical University, Harbin 150001, Heilongjiang Province, China
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Chae H, Kim M, Kim Y, Kim J, Kwon A, Choi H, Park J, Jang W, Lee YS, Park SH, Kim MS. Mutational spectrum of Korean patients with corneal dystrophy. Clin Genet 2016; 89:678-89. [PMID: 26748743 DOI: 10.1111/cge.12726] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 12/29/2015] [Accepted: 01/04/2016] [Indexed: 11/29/2022]
Abstract
Corneal dystrophy typically refers to a group of rare hereditary disorders with a heterogeneous genetic background. A comprehensive molecular genetic analysis was performed to characterize the genetic spectrum of corneal dystrophies in Korean patients. Patients with various corneal dystrophies underwent thorough ophthalmic examination, histopathologic examination, and Sanger sequencing. A total of 120 probands were included, with a mean age of 50 years (SD = 18 years) and 70% were female. A total of 26 mutations in five genes (14 clearly pathogenic and 12 likely pathogenic) were identified in 49 probands (41%). Epithelial-stromal TGFBI dystrophies, macular corneal dystrophy and Schnyder corneal dystrophy (SCD) showed 100% mutation detection rates, while endothelial corneal dystrophies showed lower detection rates of 3%. Twenty six non-duplicate mutations including eight novel mutations were identified and mutations associated with SCD were identified genetically for the first time in this population. This study provides a comprehensive characterization of the genetic aberrations in Korean patients and also highlights the diagnostic value of molecular genetic analysis in corneal dystrophies.
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Affiliation(s)
- H Chae
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - M Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Y Kim
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - J Kim
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - A Kwon
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - H Choi
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - J Park
- Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - W Jang
- Catholic Genetic Laboratory Center, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Y S Lee
- Department of Hospital Pathology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - S H Park
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - M S Kim
- Department of Ophthalmology, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
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