1
|
Li H, Wei X, Wu S, Zhu T, Sun Z, Li H, Han X, Zou X, Yao F, Sui R. Clinical and genetic characterization of a large cohort of Chinese patients with Bietti crystalline retinopathy. Graefes Arch Clin Exp Ophthalmol 2024; 262:337-351. [PMID: 37584790 DOI: 10.1007/s00417-023-06178-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 07/10/2023] [Accepted: 07/16/2023] [Indexed: 08/17/2023] Open
Abstract
PURPOSE To investigate the clinical and genetic characteristics for a large cohort of Chinese patients with Bietti crystalline retinopathy (BCR). METHODS A total of 208 Chinese BCR patients from 175 families were recruited. Comprehensive clinical evaluations and genetic analysis were performed. Genotype-phenotype correlations were evaluated through statistical analysis. RESULTS The patients' median age was 37 years (range, 20-76 years). The median best corrected visual acuity (BCVA) was 0.8 LogMAR unit (range, 2.8 to -0.12). A significant decline of BCVA was revealed in patients over 40 years old (P<0.001). Two clinical types were observed: peripheral type (type P) and central type (type C). Significantly more type C patients had a worse central visual acuity, but a more preserved retinal function (P<0.05). Molecular screening detected biallelic CYP4V2 pathogenic variants in 98.3% (172/175) of the families, including 19 novel ones. The most frequent pathogenic variant was c.802-8_810del17insGC, with the allele frequency of 55.7% (195/350), followed by c.992A>C (28/350, 8%) and c.1091-2A>G (23/350, 6.6%). BCR patients with one c.802-8_810del17insGC and one truncating variant (IVS6-8/Tru) had BCVA>1.3 LogMAR unit (Snellen equivalent<20/400) at a younger age than those with homozygous c.802-8_810del17insGC variants (homo IVS6-8) (P=0.031). CONCLUSIONS BCR patients preserved relatively good vision before 40 years old. Two distinct clinical types of BCR were observed. BCR patients with IVS6-8/Tru had an earlier decline in visual acuity than those with homo IVS6-8. Our findings enhance the knowledge of BCR and will be helpful in patient selection for gene therapy.
Collapse
Affiliation(s)
- Huajin Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- Department of Ophthalmology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xiaoxu Han
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Fengxia Yao
- Medical Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
- State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
| |
Collapse
|
2
|
Wang JH, Lidgerwood GE, Daniszewski M, Hu ML, Roberts GE, Wong RCB, Hung SSC, McClements ME, Hewitt AW, Pébay A, Hickey DG, Edwards TL. AAV2-mediated gene therapy for Bietti crystalline dystrophy provides functional CYP4V2 in multiple relevant cell models. Sci Rep 2022; 12:9525. [PMID: 35680963 PMCID: PMC9184470 DOI: 10.1038/s41598-022-12210-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 04/06/2022] [Indexed: 12/23/2022] Open
Abstract
Bietti crystalline dystrophy (BCD) is an inherited retinal disease (IRD) caused by mutations in the CYP4V2 gene. It is a relatively common cause of IRD in east Asia. A number of features of this disease make it highly amenable to gene supplementation therapy. This study aims to validate a series of essential precursor in vitro experiments prior to developing a clinical gene therapy for BCD. We demonstrated that HEK293, ARPE19, and patient induced pluripotent stem cell (iPSC)-derived RPE cells transduced with AAV2 vectors encoding codon optimization of CYP4V2 (AAV2.coCYP4V2) resulted in elevated protein expression levels of CYP4V2 compared to those transduced with AAV2 vectors encoding wild type CYP4V2 (AAV2.wtCYP4V2), as assessed by immunocytochemistry and western blot. Similarly, we observed significantly increased CYP4V2 enzyme activity in cells transduced with AAV2.coCYP4V2 compared to those transduced with AAV2.wtCYP4V2. We also showed CYP4V2 expression in human RPE/choroid explants transduced with AAV2.coCYP4V2 compared to those transduced with AAV2.wtCYP4V2. These preclinical data support the further development of a gene supplementation therapy for a currently untreatable blinding condition—BCD. Codon-optimized CYP4V2 transgene was superior to wild type in terms of protein expression and enzyme activity. Ex vivo culture of human RPE cells provided an effective approach to test AAV-mediated transgene delivery.
Collapse
Affiliation(s)
- Jiang-Hui Wang
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia
| | - Grace E Lidgerwood
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia.,Department of Anatomy and Physiology, The University of Melbourne, Parkville, Australia
| | - Maciej Daniszewski
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Australia
| | - Monica L Hu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia
| | - Georgina E Roberts
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia
| | - Raymond C B Wong
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, VIC, Australia.,Shenzhen Eye Hospital, Shenzhen University School of Medicine, Shenzhen, China
| | - Sandy S C Hung
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, VIC, Australia
| | - Michelle E McClements
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, Oxford, UK
| | - Alex W Hewitt
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia.,Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, VIC, Australia.,Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS, Australia
| | - Alice Pébay
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, Australia.,Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, Australia
| | - Doron G Hickey
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia
| | - Thomas L Edwards
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Level 7, 32 Gisborne Street, East Melbourne, VIC, 3002, Australia. .,Ophthalmology, Department of Surgery, The University of Melbourne, East Melbourne, VIC, Australia.
| |
Collapse
|
3
|
Zhang S, Wang L, Liu Z, Sun H, Li Q, Xing C, Xiao Z, Peng X. Observation of the characteristics of the natural course of Bietti crystalline dystrophy by fundus fluorescein angiography. BMC Ophthalmol 2021; 21:239. [PMID: 34049507 PMCID: PMC8161580 DOI: 10.1186/s12886-021-01999-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 05/18/2021] [Indexed: 11/25/2022] Open
Abstract
Background Bietti crystalline dystrophy (BCD) is an autosomal recessive genetic disorder that causes progressive vision loss. Here, 12 patients were followed up for 1–5 years with fundus fluorescein angiography (FFA) to observe BCD disease progression. Methods FFA images were collected for 12 patients with BCD who visited our clinic twice or more over a 5-year period. Peripheral venous blood was collected to identify the pathogenic gene related to the clinical phenotype. Results We observed two types in FFA images of patients with BCD. Type 1 showed retinal pigment epithelium (RPE) atrophy in the macular area, followed by choriocapillaris atrophy and the subsequent appearance of RPE atrophy appeared at the peripheral retina. Type 2 showed RPE atrophy at the posterior pole and peripheral retina, followed by choriocapillaris atrophy around the macula and along the superior and inferior vascular arcades and the nasal side of the optic disc. The posterior and peripheral lesions of both type 1 and type 2 BCD subsequently extended to the mid-periphery; finally, all the RPEs and choriocapillaris atrophied, exposing the choroid great vessels, but type 2 macular RPE atrophy could last longer. Conclusions The characterization of two different types of BCD development provides a better understanding of the phenotype and the progression of the disease for a precise prognosis and prediction of pathogenesis.
Collapse
Affiliation(s)
- Shengjuan Zhang
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China.,Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Lifei Wang
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Zhiqiang Liu
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Huijing Sun
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Qian Li
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China
| | - Chen Xing
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Zhe Xiao
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Xiaoyan Peng
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China.
| |
Collapse
|
4
|
da Palma MM, Motta FL, Salles MV, Texeira CHM, Gomes AV, Casaroli-Marano R, Sallum JMF. Expanding the Phenotypic and Genotypic Spectrum of Bietti Crystalline Dystrophy. Genes (Basel) 2021; 12:genes12050713. [PMID: 34068831 PMCID: PMC8151499 DOI: 10.3390/genes12050713] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 11/16/2022] Open
Abstract
The rare form of retinal dystrophy, Bietti crystalline dystrophy, is associated with variations in CYP4V2, a member of the cytochrome P450 family. This study reports patients affected by typical and atypical Bietti crystalline dystrophy, expanding the spectrum of this disease. This is an observational case series of patients with a clinical and molecular diagnosis of Bietti crystalline dystrophy that underwent multimodal imaging. Four unrelated patients are described with two known variants, c.802-8_810del17insGC and c.518T > G (p.Leu173Trp), and one novel missense variant, c.1169G > T (p.Arg390Leu). The patient with the novel homozygous variant had the most severe phenotype resulting in macular hole formation and retinal detachment in both eyes. To the best of our knowledge, there is no association of these features with Bietti crystalline dystrophy. Patient 1 was the youngest patient and had the mildest phenotype with crystals in the retina without chorioretinal atrophy and visual complaints. Patients 2 and 3 presented with fewer crystals and chorioretinal atrophy. These three patients presented a classic phenotype. The fourth patient presented with an atypical and severe phenotype. This study reveals a new genotype and new phenotype associated with this disorder.
Collapse
Affiliation(s)
- Mariana Matioli da Palma
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Instituto de Genética Ocular, São Paulo, SP 04552-050, Brazil
- Instituto Suel Abujamra, São Paulo, SP 01525-001, Brazil;
- Department of Surgery & Hospital Cínic de Barcelona, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
| | - Fabiana Louise Motta
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Instituto de Genética Ocular, São Paulo, SP 04552-050, Brazil
| | - Mariana Vallim Salles
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Instituto de Genética Ocular, São Paulo, SP 04552-050, Brazil
| | - Caio Henrique Marques Texeira
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Instituto de Genética Ocular, São Paulo, SP 04552-050, Brazil
| | - André V. Gomes
- Instituto Suel Abujamra, São Paulo, SP 01525-001, Brazil;
| | - Ricardo Casaroli-Marano
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Department of Surgery & Hospital Cínic de Barcelona, School of Medicine, Universitat de Barcelona, 08007 Barcelona, Spain
| | - Juliana Maria Ferraz Sallum
- Department of Ophthalmology, Federal University of São Paulo—UNIFESP, São Paulo, SP 04023-062, Brazil; (M.M.d.P.); (F.L.M.); (M.V.S.); (C.H.M.T.); (R.C.-M.)
- Instituto de Genética Ocular, São Paulo, SP 04552-050, Brazil
- Correspondence: ; Tel.: +55-11-9-9974-6530
| |
Collapse
|
5
|
Chen ZJ, Lin KH, Lee SH, Shen RJ, Feng ZK, Wang XF, Huang XF, Huang ZQ, Jin ZB. Mutation spectrum and genotype-phenotype correlation of inherited retinal dystrophy in Taiwan. Clin Exp Ophthalmol 2020; 48:486-499. [PMID: 31872526 DOI: 10.1111/ceo.13708] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 12/15/2019] [Accepted: 12/15/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND Inherited retinal dystrophy (IRD) is a group of irreversible retinal degenerative disorders with significant genotypic and phenotypic heterogeneity, which cause difficulty in making a precise clinical diagnosis. Furthermore, the mutation spectrum of IRD in Taiwan remains unknown. Therefore, our study focused on investigating the spectrum of mutations among Taiwanese families with IRD using targeted exome sequencing (TES) technology. METHODS We recruited a total of 60 unrelated Taiwanese families with IRD; most of them were retinitis pigmentosa. We employed TES to investigate 284 candidate genes. Bioinformatics analysis, Sanger sequencing-based co-segregation testing, and computational assessment were performed to validate each mutation and its pathogenicity. The genotype-phenotype correlation was analysed in all patients with mutations defined in the guidelines provided by the American College of Medical Genetics. RESULTS We successfully identified genetic causes in 32 families (detection rate of 53.3%). Among them, 16 had a sporadic inheritance (16/36, 44.4%); eight had an autosomal recessive inheritance (8/14, 57.1%); four had an autosomal dominant inheritance (4/5, 80%); four had an X-linked inheritance (4/5, 80%). Among 38 pathological mutations in 19 known genes, 20 mutations are reported here for the first time. Novel mutation spectrum and genotype-phenotype correlations were revealed as well. CONCLUSION Here we achieved a detection rate of 53.3% and elucidated the mutation spectrum in Taiwanese families with IRD for the first time. The results indicated that CYP4V2 and USH2A might be the most common pathogenic genes in IRD patients in Taiwan.
Collapse
Affiliation(s)
- Zhen-Ji Chen
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Keng-Hung Lin
- Department of Ophthalmology, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Shi-Huang Lee
- Department of Ophthalmology, Taichung Tzu Chi Hospital, Taichung, Taiwan
| | - Ren-Juan Shen
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Zhuo-Kun Feng
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Xiao-Fang Wang
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Xiu-Feng Huang
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Zhi-Qin Huang
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| | - Zi-Bing Jin
- Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.,Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Wenzhou Medical University, Wenzhou, China.,National Center for International Research in Regenerative Medicine and Neurogenetics, Wenzhou Medical University, Wenzhou, China.,State Key Laboratory of Ophthalmology, Optometry and Visual Science, National Clinical Research Center for Ocular Diseases, Wenzhou Medical University, Wenzhou, China
| |
Collapse
|
6
|
Meng XH, He Y, Zhao TT, Li SY, Liu Y, Yin ZQ. Novel mutations in CYP4V2 in Bietti corneoretinal crystalline dystrophy: Next-generation sequencing technology and genotype-phenotype correlations. Mol Vis 2019; 25:654-662. [PMID: 31741654 PMCID: PMC6828992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/29/2019] [Indexed: 11/11/2022] Open
Abstract
Purpose To identify any novel mutations in CYP4V2 in 85 Chinese families with Bietti corneoretinal crystalline dystrophy (BCD) by using next-generation sequencing, and to summarize the mutation spectrum in this population, along with any genotype-phenotype correlations. Methods A total of 90 patients with BCD from 85 unrelated Chinese families were recruited. All probands were analyzed by using gene chip-based next-generation sequencing, to capture and sequence all the exons of 57 known hereditary retinal degeneration-associated genes. The candidate variants were validated with PCR and Sanger sequencing. Results Twenty-eight mutations were detected in all patients, including thirteen novel mutations (five missense, six deletions, one splicing and one frame-shift mutations) and 15 previously reported mutations. Mutations in 64 patients were inherited from their parents, while three patients had de novo mutations. c.802-8_810del17insGC was the most common mutation, accounting for 78% of the mutations. Although 16 patients were homozygous at this site, the clinical features of all 16 patients were highly heterogeneous. Conclusions These results expand the spectrum of mutations in CYP4V2, and suggest that mutations in CYP4V2 may be common in the Chinese population. The phenotype of patients with the homozygous mutation (hom.c.802-8_810del17insGC) is highly heterogeneous.
Collapse
Affiliation(s)
- Xiao Hong Meng
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| | - Yan He
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| | - Tong Tao Zhao
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| | - Shi Ying Li
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| | - Yong Liu
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| | - Zheng Qin Yin
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China
| |
Collapse
|
7
|
García-García GP, Martínez-Rubio M, Moya-Moya MA, Pérez-Santonja JJ, Escribano J. Current perspectives in Bietti crystalline dystrophy. Clin Ophthalmol 2019; 13:1379-1399. [PMID: 31440027 PMCID: PMC6679682 DOI: 10.2147/opth.s185744] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 07/08/2019] [Indexed: 01/17/2023] Open
Abstract
Bietti crystalline dystrophy (BCD) is a rare-inherited disease caused by mutations in the CYP4V2 gene and characterized by the presence of multiple shimmering yellow-white deposits in the posterior pole of the retina in association with atrophy of the retinal pigment epithelium (RPE) and chorioretinal atrophy. The additional presence of glittering dots located at the corneal limbus is also a frequent finding. The CYP4V2 protein belongs to the cytochrome P450 subfamily 4 and is mainly expressed in the retina and the RPE and less expressed in the cornea. The disease has its metabolic origin in the diminished transformation of fatty acid substrates into n-3 polyunsaturated fatty acids due to a dysregulation of the lipid metabolism. In this review, we provide updated insights on clinical and molecular characteristics of BCD including underlying mechanisms of BCD, genetic diagnosis, progress in the identification of causative genetic and epigenetic factors, available techniques of exploration and development of novel therapies. This information will help clinicians to improve accuracy of BCD diagnosis, providing the patient reliable information regarding prognosis and clinical prediction of the disease course.
Collapse
Affiliation(s)
- G P García-García
- Department of Ophthalmology, General University Hospital of Alicante, Alicante 03010, Spain
| | - M Martínez-Rubio
- Department of Ophthalmology, General University Hospital of Alicante, Alicante 03010, Spain
| | - M A Moya-Moya
- Department of Ophthalmology, General University Hospital of Alicante, Alicante 03010, Spain
| | - J J Pérez-Santonja
- Department of Ophthalmology, General University Hospital of Alicante, Alicante 03010, Spain
| | - J Escribano
- Cooperative Research Network on Ophthalmology (OftaRed), Visual and Life Quality, Instituto de Salud Carlos III, Madrid, Spain.,Laboratory of Human Molecular Genetics, Medicine Faculty/Research Institute on Neurological Disabilities (IDINE), University of Castilla La-Mancha, Albacete 02006, Spain
| |
Collapse
|
8
|
Identification and population history of CYP4V2 mutations in patients with Bietti crystalline corneoretinal dystrophy. Eur J Hum Genet 2017; 25:461-471. [PMID: 28051075 DOI: 10.1038/ejhg.2016.184] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 11/15/2016] [Accepted: 11/24/2016] [Indexed: 11/08/2022] Open
Abstract
To identify known and novel CYP4V2 mutations in patients with Bietti crystalline cornea (BCD), expand the spectrum of CYP4V2 mutations, and characterize the population history of the c.802-8_810del17insGC mutation common in Asian populations, genomic DNA was isolated from peripheral blood samples from 58 unrelated patients with clinical diagnoses of BCD. Exons and flanking intronic regions of the CYP4V2 gene were dideoxy DNA sequenced. Nonpathogenic polymorphisms were excluded and known mutations were identified by sequencing 192 unaffected individuals from similar ethnic backgrounds and examination of online databases. The age of the c.802-8_810del17insGC mutation was estimated using three independent approaches. A total of 28 CYP4V2 mutations, 9 of which were novel, were detected in the 58 patients with BCD. These included 19 missense, 4 nonsense, 2 deletion, 2 splice site, and 1 insertion-deletion mutations. Two missense variants of uncertain significance were also detected. The age of the c.802-8_810del17insGC mutation was estimated to be 1040-8200 generations in the Chinese and 300-1100 generations in the Japanese populations. These results expand the mutation spectrum of CYP4V2, and provide insight into the origin of the c.802-8_810del17insGC mutation in the Chinese population and its transmission to the Japanese population.
Collapse
|
9
|
Abstract
Bietti crystalline dystrophy (BCD) is an inherited retinal degenerative disease characterized by crystalline deposits in the retina, followed by progressive atrophy of the retinal pigment epithelium (RPE), choriocapillaris, and photoreceptors. CYP4V2 has been identified as the causative gene for BCD. The CYP4V2 gene belongs to the cytochrome P450 superfamily and encodes for fatty acid ω-hydroxylase of both saturated and unsaturated fatty acids. The CYP4V2 protein is localized most abundantly within the endoplasmic reticulum in the RPE and is postulated to play a role in the physiological lipid recycling system between the RPE and photoreceptors to maintain visual function. Electroretinographic assessments have revealed progressive dysfunction of rod and cone photoreceptors in patients with BCD. Several genotypes have been associated with more severe phenotypes based on clinical and electrophysiological findings. With the advent of multimodal imaging with spectral domain optical coherence tomography, fundus autofluorescence, and adaptive optics scanning laser ophthalmoscopy, more precise delineation of BCD severity and progression is now possible, allowing for the potential future development of targets for gene therapy.
Collapse
Affiliation(s)
- Danny S C Ng
- From the *Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong; and †2010 Retina and Macula Centre, Kowloon, Hong Kong
| | | | | | | |
Collapse
|
10
|
Yin X, Yang L, Chen N, Cui H, Zhao L, Feng L, Li A, Zhang H, Ma Z, Li G. Identification of CYP4V2 mutation in 36 Chinese families with Bietti crystalline corneoretinal dystrophy. Exp Eye Res 2016; 146:154-162. [PMID: 26971461 DOI: 10.1016/j.exer.2016.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 01/20/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
Bietti crystalline corneoretinal dystrophy (BCD) is an inherited eye disease that is most common in the Chinese. It is caused by a mutation in the CYP4V2 gene. In this study, 43 Chinese BCD families were recruited; most patients manifested the characteristic phenotype of BCD, with 2 families initially misdiagnosed with retinitis pigmentosa. Five patients in our cohort presented with BCD and choroidal neovascularization (CNV), and 1 patient presented with typical BCD and abnormality in the terminals of both fingers and toes. A total of 17 pathogenic mutations involving 68 alleles were identified from 36 families using targeted exon sequencing and Sanger sequencing; we achieved a diagnostic rate of approximately 84%. Fifteen families were found to carry homozygous mutations, 17 families carried compound heterozygous mutations, and 4 families carried a single heterozygous mutation. Of the mutations identified, four variants c.802-8_810del17bpinsGC, c.802-8_810del17bpinsGT, c.992A > C (p.H331P), and c.1091-2A > G accounted for 71% of the mutations identified in CYP4V2. These mutations were hotspots in Chinese populations for BCD. Five among them were novel and predicted to be disease-causing, including c.65T > A (p.L22H), c.681_4delTGAG (p.S227Rfs*1), c.802-8_810del17bpinsGT, c.965_7delAAG (p.321delE), and c.994G > A (p.D332N). No apparent correlation between genotype and phenotype was identified. Our findings broaden the spectrum of CYP4V2 mutations that cause BCD and the phenotypic spectrum of the disease in Chinese families. These results will be useful for the genetic diagnosis of BCD, genetic consultation, and gene therapy in the future.
Collapse
Affiliation(s)
- Xiaobei Yin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, PR China
| | - Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Ningning Chen
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Hui Cui
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, PR China
| | - Lin Zhao
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Lina Feng
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Aijun Li
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Huirong Zhang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Zhizhong Ma
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, PR China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing 100005, PR China.
| |
Collapse
|
11
|
Tian R, Wang SR, Wang J, Chen YX. Novel CYP4V2 mutations associated with Bietti crystalline corneoretinal dystrophy in Chinese patients. Int J Ophthalmol 2015; 8:465-9. [PMID: 26085992 DOI: 10.3980/j.issn.2222-3959.2015.03.06] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/02/2014] [Indexed: 11/02/2022] Open
Abstract
AIM To analyze the CYP4V2 mutations in five unrelated Chinese patients with Bietti crystalline corneoretinal dystrophy (BCD) and to provide clinical features of these patients. BCD is a rare monogenic autosomal recessively inherited disorder characterized by the presence of crystals in the retina and retinal pigment epithelium atrophy. Mutations in the CYP4V2 gene have been found to be causative for BCD. METHODS Ophthalmic examinations were carried out in the affected individuals. Peripheral blood samples were collected and genomic DNA was extracted. All exons and flanking intronic regions of the CYP4V2 gene were amplified with polymerase chain reaction and screened for mutations by direct DNA sequencing. One hundred control chromosomes were also screened to exclude nonpathogenic polymorphisms. RESULTS Fundus examination revealed the presence of tiny yellowish-sparkling crystals at the posterior pole of the fundus and atrophy of the retinal pigment epithelium in all patients. Choroid neovascularization was noted in one patient. Five different CYP4V2 mutations were identified, including two missense mutations (p.F73L, p.R400H), two splice site mutations (c.802-8_810del17insGC, c.1091-2A>G), and one single base-pair deletion (p.T479TfsX7 or c.1437delC). The two splice site mutations were identified in three of the patients with BCD. Mutation p.T479TfsX7 was a novel mutation not observed in any of 100 ethnically matched control chromosomes. CONCLUSION Mutation c.802-8_810del17insGC and c.1091-2A>G are common mutations in Chinese patients with BCD. Our results expand the allelic heterogeneity of BCD.
Collapse
Affiliation(s)
- Rong Tian
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Shu-Ran Wang
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - Jing Wang
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| | - You-Xin Chen
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China
| |
Collapse
|
12
|
Meng XH, Guo H, Xu HW, Li QY, Jin X, Bai Y, Li SY, Yin ZQ. Identification of novel CYP4V2 gene mutations in 92 Chinese families with Bietti's crystalline corneoretinal dystrophy. Mol Vis 2014; 20:1806-14. [PMID: 25593508 PMCID: PMC4287718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 12/30/2014] [Indexed: 10/26/2022] Open
Abstract
PURPOSE To characterize the spectrum of CYP4V2 gene mutations in 92 unrelated Chinese probands with Bietti's crystalline dystrophy (BCD) and to describe the molecular and clinical characteristics of four novel CYP4V2 mutations associated with BCD. METHODS All study participants underwent a complete ophthalmological examination. Mutational screening of CYP4V2 coding regions and flanking intron sequences was examined via directional Sanger sequencing, with allele separation confirmed by screening other family members. Subsequent in silico analysis of the mutational consequence on protein function was undertaken, with the impact of the novel mutation on pre-mRNA splicing examined via RT-PCR. RESULTS Fifteen disease-causing variants were identified in 92 probands with BCD, including four novel mutations and eleven previously reported mutations. The most prevalent mutation was c.802_810del17insGC, which was detected in 69 unrelated families, with an allele frequency of 52.7% (97/184). Homozygosity was revealed in 35 unrelated families, and compound heterozygosity was observed in 43 subjects. Four patients harbored four novel variants, with these mutations cosegregated within all affected individuals and were not found in unaffected family members and 100 unrelated controls. Transcriptional analysis of a novel splice mutation revealed altered RNA splicing. In silico analysis predicted that the missense variant, p.Tyr343Asp, disrupted the CYP4V2 surface electrostatic potential distribution and spatial conformation. Among the patients with four novel mutations, genotype did not always correlate with age at onset, disease course, or electroretinogram (ERG) changes, with phenotypic variations even noted within the same genotype. CONCLUSIONS The c.802_810del17insCG mutation was the most common mutation in the 92 Chinese probands with BCD examined. Four novel mutations were identified, contributing to the spectrum of CYP4V2 mutations associated with BCD, with no clear link established between disease phenotype and genotype.
Collapse
Affiliation(s)
- Xiao Hong Meng
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, PR China
| | - Hong Guo
- Department of Medical Genetics, Third Military Medical University, Chongqing, PR China
| | - Hai Wei Xu
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, PR China
| | - Qi You Li
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, PR China
| | - Xin Jin
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Department of Ophthalmology, Chinese PLA General Hospital, Beijing, PR China
| | - Yun Bai
- Department of Medical Genetics, Third Military Medical University, Chongqing, PR China
| | - Shi Ying Li
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, PR China
| | - Zheng Qin Yin
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing, China,Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, PR China
| |
Collapse
|
13
|
Astuti GDN, Sun V, Bauwens M, Zobor D, Leroy BP, Omar A, Jurklies B, Lopez I, Ren H, Yazar V, Hamel C, Kellner U, Wissinger B, Kohl S, De Baere E, Collin RWJ, Koenekoop RK. Novel insights into the molecular pathogenesis of CYP4V2-associated Bietti's retinal dystrophy. Mol Genet Genomic Med 2014; 3:14-29. [PMID: 25629076 PMCID: PMC4299712 DOI: 10.1002/mgg3.109] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 07/24/2014] [Accepted: 07/31/2014] [Indexed: 11/09/2022] Open
Abstract
Bietti's crystalline dystrophy (BCD) is a rare, autosomal recessive retinal degenerative disease associated with mutations in CYP4V2. In this study, we describe the genetic and clinical findings in 19 unrelated BCD patients recruited from five international retinal dystrophy clinics. Patients underwent ophthalmic examinations and were screened for CYP4V2 mutations by Sanger sequencing and quantitative polymerase chain reaction (qPCR) copy number variation screening. Eight CYP4V2 mutations were found in 10/19 patients, including three patients in whom only monoallelic mutations were detected. Four novel mutations were identified: c.604G>A; p.(Glu202Lys), c.242C>G; p.(Thr81Arg), c.604+4A>G; p.(?), and c.1249dup; p.(Thr417Asnfs*2). In addition, we identified a heterozygous paternally inherited genomic deletion of at least 3.8 Mb, encompassing the complete CYP4V2 gene and several other genes, which is novel. Clinically, patients demonstrated phenotypic variability, predominantly showing choroidal sclerosis, attenuated vessels, and crystalline deposits of varying degrees of severity. To our knowledge, our study reports the first heterozygous CYP4V2 deletion and hence a novel mutational mechanism underlying BCD. Our results emphasize the importance of copy number screening in BCD. Finally, the identification of CYP4V2-negative patients with indistinguishable phenotypes from CYP4V2-positive patients might suggest the presence of mutations outside the coding regions of CYP4V2, or locus heterogeneity, which is unreported so far.
Collapse
Affiliation(s)
- Galuh D N Astuti
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, The Netherlands ; Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre Nijmegen, The Netherlands ; Division of Human Genetics, Center for Biomedical Research, Faculty of Medicine, Diponegoro University Semarang, Indonesia
| | - Vincent Sun
- McGill Ocular Genetics Laboratory, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University Health Centre Montreal, Quebec, Canada
| | - Miriam Bauwens
- Center for Medical Genetics, Ghent University Hospital Ghent, Belgium
| | - Ditta Zobor
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen Tübingen, Germany
| | - Bart P Leroy
- Center for Medical Genetics, Ghent University Hospital Ghent, Belgium ; Department of Ophthalmology, Ghent University Hospital Ghent, Belgium
| | - Amer Omar
- McGill Ocular Genetics Laboratory, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University Health Centre Montreal, Quebec, Canada ; Moorfields Eye Hospital London, United Kingdom
| | | | - Irma Lopez
- McGill Ocular Genetics Laboratory, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University Health Centre Montreal, Quebec, Canada
| | - Huanan Ren
- McGill Ocular Genetics Laboratory, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University Health Centre Montreal, Quebec, Canada
| | - Volkan Yazar
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, The Netherlands
| | - Christian Hamel
- Institute of Neurosciences of Montpellier, Hôpital Saint Eloi Montpellier, France
| | - Ulrich Kellner
- Rare Retinal Disease Center, AugenZentrum Siegburg, MVZ ADTC Siegburg GmbH Siegburg, Germany
| | - 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
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University Hospital Ghent, Belgium
| | - Rob W J Collin
- Department of Human Genetics, Radboud University Medical Centre Nijmegen, The Netherlands ; Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre Nijmegen, The Netherlands
| | - Robert K Koenekoop
- McGill Ocular Genetics Laboratory, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, Montreal Children's Hospital, McGill University Health Centre Montreal, Quebec, Canada
| |
Collapse
|
14
|
Lockhart CM, Nakano M, Rettie AE, Kelly EJ. Generation and characterization of a murine model of Bietti crystalline dystrophy. Invest Ophthalmol Vis Sci 2014; 55:5572-81. [PMID: 25118264 DOI: 10.1167/iovs.13-13717] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Bietti crystalline dystrophy (BCD) is a rare, autosomal recessive, progressive, degenerative eye disease caused by mutations in the CYP4V2 gene, for which no treatments are currently available. Cyp4v3 is the murine ortholog to CYP4V2, and to better understand the molecular pathogenesis of this disease we have established a Cyp4v3-null mouse line. METHODS Cyp4v3(-/-) mice were generated by homologous recombination in embryonic stem cells. Ocular morphologic characteristics were evaluated via fundus imaging, plasma lipid profiling, and histologic analysis via Oil Red O reactivity, hematoxylin and eosin staining, and transmission electron microscopy. RESULTS The Cyp4v3(-/-) mouse recapitulates the characteristic features of corneoretinal crystal accumulation and systemic dyslipidemia seen in BCD. The Cyp4v3(-/-) mice behave normally and are viable and fertile when maintained under specific pathogen-free (SPF) housing conditions. CONCLUSIONS Cyp4v3(-/-) mice represent a promising preclinical model that may be used to better understand the disease etiology and to evaluate pharmacotherapies for this devastating condition.
Collapse
Affiliation(s)
- Catherine M Lockhart
- Department of Pharmaceutics, University of Washington, Seattle, Washington, United States
| | - Mariko Nakano
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Allan E Rettie
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, United States
| | - Edward J Kelly
- Department of Pharmaceutics, University of Washington, Seattle, Washington, United States
| |
Collapse
|
15
|
Nakano M, Lockhart CM, Kelly EJ, Rettie AE. Ocular cytochrome P450s and transporters: roles in disease and endobiotic and xenobiotic disposition. Drug Metab Rev 2014; 46:247-60. [PMID: 24856391 PMCID: PMC4676416 DOI: 10.3109/03602532.2014.921190] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Drug metabolism and transport processes in the liver, intestine and kidney that affect the pharmacokinetics and pharmacodynamics of therapeutic agents have been studied extensively. In contrast, comparatively little research has been conducted on these topics as they pertain to the eye. Recently, however, catalytic functions of ocular cytochrome P450 enzymes have gained increasing attention, in large part due to the roles of CYP1B1 and CYP4V2 variants in primary congenital glaucoma and Bietti's corneoretinal crystalline dystrophy, respectively. In this review, we discuss challenges to ophthalmic drug delivery, including Phase I drug metabolism and transport in the eye, and the role of three specific P450s, CYP4B1, CYP1B1 and CYP4V2 in ocular inflammation and genetically determined ocular disease.
Collapse
Affiliation(s)
- Mariko Nakano
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Catherine M. Lockhart
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Edward J. Kelly
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Allan E. Rettie
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA, USA
| |
Collapse
|
16
|
Halford S, Liew G, Mackay DS, Sergouniotis PI, Holt R, Broadgate S, Volpi EV, Ocaka L, Robson AG, Holder GE, Moore AT, Michaelides M, Webster AR. Detailed Phenotypic and Genotypic Characterization of Bietti Crystalline Dystrophy. Ophthalmology 2014; 121:1174-84. [DOI: 10.1016/j.ophtha.2013.11.042] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 11/27/2013] [Accepted: 11/27/2013] [Indexed: 10/25/2022] Open
|
17
|
Molecular analysis and phenotypic study in 14 Chinese families with Bietti crystalline dystrophy. PLoS One 2014; 9:e94960. [PMID: 24739949 PMCID: PMC3989252 DOI: 10.1371/journal.pone.0094960] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 03/21/2014] [Indexed: 11/19/2022] Open
Abstract
Purpose To investigate the clinical features and cytochrome P450 family 4 subfamily V polypeptide 2 (CYP4V2) gene mutations in 14 Chinese families with Bietti crystalline dystrophy (BCD). Methods Seventeen patients from 14 unrelated Chinese families with BCD were recruited for complete clinical ophthalmic examination and genetic study. The 11 exons of CYP4V2 were amplified from genomic DNA of all patients and their family members by polymerase chain reaction (PCR) and then sequenced. Exons of TIMP3 were also sequenced in BCD patient associated with choroidal neovascularization (CNV). One hundred and seventy unrelated healthy Chinese subjects were screened for mutations in CYP4V2. Results All 17 patients with BCD had mutations in CYP4V2; one of these mutations was novel (c.219T>A, p.F73L) and four other mutations had been reported. The p.F73L mutation was a commonly detected mutation in our study (seven out of 34 alleles), either in the homozygous state or in the heterozygous state. Among the patients, considerable phenotypic variability was detected, both within and between families. Screening of TIMP3 did not find any mutation in the BCD patient associated with CNV. Conclusion The novel CYP4V2 c.219T>A (p.F73L) mutation may be another recurrent mutation in Chinese patients with BCD. Our study expands the mutation spectrum of CYP4V2 and characterizes novel genotype–phenotype associations in Chinese patients with BCD.
Collapse
|