1
|
Zhang H, Zhang K, Wang J, Yu S, Li Z, Yin S, Zhu J, Wei W. Quickly diagnosing Bietti crystalline dystrophy with deep learning. iScience 2024; 27:110579. [PMID: 39220263 PMCID: PMC11365386 DOI: 10.1016/j.isci.2024.110579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 06/18/2024] [Accepted: 07/22/2024] [Indexed: 09/04/2024] Open
Abstract
Bietti crystalline dystrophy (BCD) is an autosomal recessive inherited retinal disease (IRD) and its early precise diagnosis is much challenging. This study aims to diagnose BCD and classify the clinical stage based on ultra-wide-field (UWF) color fundus photographs (CFPs) via deep learning (DL). All CFPs were labeled as BCD, retinitis pigmentosa (RP) or normal, and the BCD patients were further divided into three stages. DL models ResNeXt, Wide ResNet, and ResNeSt were developed, and model performance was evaluated using accuracy and confusion matrix. Then the diagnostic interpretability was verified by the heatmaps. The models achieved good classification results. Our study established the largest BCD database of Chinese population. We developed a quick diagnosing method for BCD and evaluated the potential efficacy of an automatic diagnosis and grading DL algorithm based on UWF fundus photography in a Chinese cohort of BCD patients.
Collapse
Affiliation(s)
- Haihan Zhang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Kai Zhang
- Chongqing Chang’an Industrial Group Co. Ltd, Chongqing, China
| | - Jinyuan Wang
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- School of Clinical Medicine, Tsinghua University, Beijing, China
| | - Shicheng Yu
- Department of Ophthalmology, Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Zhixi Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
- Guangdong Provincial Clinical Research Center for Ocular Diseases, Guangzhou, China
| | - Shiyi Yin
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Jingyuan Zhu
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Wenbin Wei
- Beijing Tongren Eye Center, Beijing Key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology & Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| |
Collapse
|
2
|
Dulken BW, Bahceci D, Leung LS, Mahajan VB, Choi WT, Tan SY. Crystalline Hepatopathy Associated With Bietti Crystalline Dystrophy: A Striking Manifestation of Disordered Fatty Acid Metabolism. Am J Surg Pathol 2024; 48:1138-1145. [PMID: 38802997 DOI: 10.1097/pas.0000000000002253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Bietti crystalline dystrophy (BCD) is a rare heritable retinal disease characterized by crystal deposition primarily in the retina. It is associated with atrophy of the retinal pigment epithelium (RPE) and is caused by variants in CYP4V2 , which encodes a cytochrome P450 hemethiolate protein superfamily member. CYP4V2 is involved in the selective hydrolysis of saturated medium chain fatty acids, and patients with BCD demonstrate abnormalities in fatty acid metabolism, including abnormal lipid profiles and the accumulation of the pathogenic crystals within the RPE, which leads to the visual pathologies characteristic of BCD. However, the precise identity of the crystals is currently unknown, and BCD has no established extraocular manifestations. Here, we report granulomatous hepatitis associated with abundant diffuse crystalline clefts in the hepatic parenchyma in 3 patients with retinal dystrophy and dyslipidemia: 2 with pathogenic CYP4V2 variants and 1 patient with clinical ophthalmologic findings suggestive of BCD but without available genetic testing. The unique and striking histologic features unifying the liver biopsies in all 3 patients strongly support a process related to abnormal fatty acid metabolism underlying the genetic disease of BCD, expanding the spectrum of BCD and shedding light on the importance of CYP4V2 in systemic fatty acid metabolism.
Collapse
Affiliation(s)
- Ben W Dulken
- Department of Pathology, Stanford University School of Medicine, Stanford
| | - Dorukhan Bahceci
- Department of Pathology, University of California San Francisco, San Francisco
| | - Loh-Shan Leung
- Department of Ophthalmology, Stanford University School of Medicine, Stanford
| | - Vinit B Mahajan
- Department of Ophthalmology, Stanford University School of Medicine, Stanford
- Molecular Surgery Laboratory, Stanford University
- Veterans Affairs Palo Alto Health Care System, Palo Alto, CA
| | - Won-Tak Choi
- Department of Pathology, University of California San Francisco, San Francisco
| | - Serena Y Tan
- Department of Pathology, Stanford University School of Medicine, Stanford
| |
Collapse
|
3
|
Li Q, Wang C, Zhang S, Fu Z, Jiao X, Jin ZB, Hejtmancik JF, Peng X. Bietti's crystalline dystrophy: genotyping and deep qualitative and quantitative phenotyping in preparation for clinical trials. Br J Ophthalmol 2024; 108:1145-1153. [PMID: 37963713 DOI: 10.1136/bjo-2022-322673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 10/02/2023] [Indexed: 11/16/2023]
Abstract
PURPOSE To qualitatively and quantitatively characterise the genotypes and phenotypes of Bietti's crystalline dystrophy (BCD) in a cohort of patients. DESIGN Cross-sectional and observational study. METHODS Clinically confirmed BCD patients were recruited for genotyping and phenotyping. Multiple retinal imaging modalities were employed. Atrophy in the fovea was adopted as major consideration for staging strategy, while percentage area of autofluorescence (AF) atrophy (PAFA) in the macula was determined for quantitation. RESULTS In 74 clinically diagnosed BCD patients, c.802-8_810del17insGC was shown the predominant variant of the CYP4V2 gene (allele frequency 55.4%). Sixty-two cases (123 eyes) with full imaging data were classified according to a modified criterion into stages 1 (n=8, 6.50%), 2A (n=9, 7.32%), 2B (n=17, 13.82%), 3A (n=30, 24.39%) and 3B (n=59, 47.97%). The eyes of the stage 2B were particularly deemed 'high risk' due to atrophy near fovea, while in stage 3A, though with remarkable foveal atrophy, preserved retinal pigment epithelium/photoreceptor islands near the fovea were found in 14 eyes. A tendency of increase in PAFA with age was found (rs=0.31, p=0.014). Significant PAFA increase was shown through stages 1 to 3B, and best-corrected visual acuity (BCVA, Logarithm of the Minimum Angle of Resolution) was shown to moderately correlate with PAFA (rs=0.56, p<0.001). CONCLUSION The PAFA might be an efficient biomarker for BCD severities correlating with BCVA. The highly heterogeneous chorioretinopathy and BCVA of BCD cases appear to be associated with disease stages, progression types and patients' ages. Foveal involvement should be of a major concern for consideration of potential therapeutic intervention.
Collapse
Affiliation(s)
- Qian Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | - Cong Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | | | - Zhongjie Fu
- Department of Ophthalmology, Harvard Medical School, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Zi-Bing Jin
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
- Beijing Institute of Ophthalmology, Beijing, China
| | - James Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Xiaoyan Peng
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| |
Collapse
|
4
|
Du X, Butler AG, Chen HY. Cell-cell interaction in the pathogenesis of inherited retinal diseases. Front Cell Dev Biol 2024; 12:1332944. [PMID: 38500685 PMCID: PMC10944940 DOI: 10.3389/fcell.2024.1332944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 02/06/2024] [Indexed: 03/20/2024] Open
Abstract
The retina is part of the central nervous system specialized for vision. Inherited retinal diseases (IRD) are a group of clinically and genetically heterogenous disorders that lead to progressive vision impairment or blindness. Although each disorder is rare, IRD accumulatively cause blindness in up to 5.5 million individuals worldwide. Currently, the pathophysiological mechanisms of IRD are not fully understood and there are limited treatment options available. Most IRD are caused by degeneration of light-sensitive photoreceptors. Genetic mutations that abrogate the structure and/or function of photoreceptors lead to visual impairment followed by blindness caused by loss of photoreceptors. In healthy retina, photoreceptors structurally and functionally interact with retinal pigment epithelium (RPE) and Müller glia (MG) to maintain retinal homeostasis. Multiple IRD with photoreceptor degeneration as a major phenotype are caused by mutations of RPE- and/or MG-associated genes. Recent studies also reveal compromised MG and RPE caused by mutations in ubiquitously expressed ciliary genes. Therefore, photoreceptor degeneration could be a direct consequence of gene mutations and/or could be secondary to the dysfunction of their interaction partners in the retina. This review summarizes the mechanisms of photoreceptor-RPE/MG interaction in supporting retinal functions and discusses how the disruption of these processes could lead to photoreceptor degeneration, with an aim to provide a unique perspective of IRD pathogenesis and treatment paradigm. We will first describe the biology of retina and IRD and then discuss the interaction between photoreceptors and MG/RPE as well as their implications in disease pathogenesis. Finally, we will summarize the recent advances in IRD therapeutics targeting MG and/or RPE.
Collapse
Affiliation(s)
| | | | - Holly Y. Chen
- Department of Cell, Developmental and Integrative Biology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
| |
Collapse
|
5
|
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
|
6
|
Genetic characteristics of suspected retinitis pigmentosa in a cohort of Chinese patients. Gene 2023; 853:147087. [PMID: 36464167 DOI: 10.1016/j.gene.2022.147087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 11/22/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022]
Abstract
The study aimed to screen for the causative variants in Chinese patients with suspected retinitis pigmentosa (RP). A cohort of 75 unrelated Chinese patients with a clinical diagnosis of RP and their available family members were enrolled in this study. Genomic DNA of all subjects was extracted and whole-exome sequencing (WES) was applied. Candidate variants were identified, and minigene assays were conducted to evaluate the pathogenicity of novel splicing variants. Totally, the diagnostic yield was 44 % (33/75) and 16 novel variants that had not been reported previously were found. Among the genetically solved 33 cases, 31 patients were identified as carrying causative variants of RP and 2 patients carried pathogenic variants implicated in other retinal diseases. USH2A, CYP4V2, and RPGR were the most common causative genes, accounting for about half of the genetically solved cases. Moreover, minigene assays validated that the novel splicing variants were detrimental. Additionally, 9 patients carried a single deleterious heterozygous variant in 6 genes with autosomal recessive hereditary patterns, and no corresponding copy number variants (CNVs) was detected. The findings of this study revealed the genetic landscape of RP in China and provided guidance for clinicians.
Collapse
|
7
|
Vessel density and choroidal vascularity index in patients with Bietti crystalline dystrophy and retinitis pigmentosa. Photodiagnosis Photodyn Ther 2022; 40:103181. [PMID: 36332895 DOI: 10.1016/j.pdpdt.2022.103181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/28/2022] [Accepted: 10/28/2022] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To evaluate and compare the vessel density (VD) using swept-source optical coherence tomography angiography (OCT-A) and the choroidal vascularity index (CVI) using spectral-domain optical coherence tomography (SD-OCT) in patients with Bietti crystalline dystrophy (BCD) and retinitis pigmentosa (RP). MATERIALS AND METHODS A cross-sectional retrospective study was conducted on 26 eyes of 13 BCD patients, 26 eyes of 13 RP patients, and 26 eyes of 13 age- and gender-matched healthy individuals. BCD patients were further staged as having early, intermediate, and advanced disease. VD was assessed in five quadrants of the macula (superior, temporal, inferior, nasal, and center) using a modified ETDRS technique with OCT-A. SD-OCT scans were binarized using Niblack's autolocal threshold, and CVI was determined as the ratio of the luminal area to the total choroidal area. RESULTS A significant difference was found in VD in all quadrants of the superficial capillary plexus (SCP) and the deep capillary plexus (DCP) slabs among the three groups (p < 0.001). A statistically significant difference was noted in the mean VD of temporal and inferior quadrants of the SCP and between the BCD and RP groups (p = 0.005, p = 0.015, respectively). A statistically significant difference was observed in the mean VD of the temporal, inferior, and nasal quadrants between the BCD and RP groups on DCP slabs (p = 0.002, p = 0.003, p = 0.003, respectively). The mean central choroidal thickness was 214.65±87.10 μm in the BCD group, 351.69±67.94 μm in the RP group, and 320.92±59.26 μm in the control group (p < 0.001). We found that CVI was significantly higher in the control group than BCD group (p < 0.001), and it was significantly lower in the BCD group when compared to the RP group (p < 0.001).There was no difference in CVI between RP and control groups (p = 0.948). Furthermore, the CVI was significantly lower in the intermediate and advanced disease stages than the early disease stage in the subgroup analysis of BCD patients (p < 0.001, p < 0.001, respectively). CONCLUSION CVI is a novel investigative tool to monitor disease progression. The CVI value was lower in BCD and RP patients than in the healthy subjects, and lower CVI values seem to be related to the disease severity in BCD patients. VD was also significantly lower in BCD patients when compared to RP patients, and VD analysis may help clinicians better understand the disease pathophysiology.
Collapse
|
8
|
Whole-exome sequencing identified genes known to be responsible for retinitis pigmentosa in 28 Chinese families. Mol Vis 2022; 28:96-113. [PMID: 35814500 PMCID: PMC9239900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/04/2022] [Indexed: 12/03/2022] Open
Abstract
PURPOSE Retinitis pigmentosa (RP) is a group of highly heterogenetic inherited retinal degeneration diseases. Molecular genetic diagnosis of RP is quite challenging because of the complicated disease-causing mutation spectrum. The aim of this study was to explore the mutation spectrum in Chinese RP patients using next-generation sequencing technology and to explore the genotype-phenotype relationship. METHOD In this study, a cost-effective strategy using whole-exome sequencing (WES) was employed to address the genetic diagnosis of 28 RP families in China. One to two patients and zero to two healthy relatives were sequenced in each family. All mutations in WES data that passed through the filtering procedure were searched in relation to 662 gene defects that can cause vision-associated phenotypes (including 89 RP genes in the RetNet Database). All patients visiting the outpatient department received comprehensive ophthalmic examinations. RESULT Twenty-five putative pathogenic mutations of 12 genes were detected by WES and were all confirmed by Sanger sequencing in 20 (20/28, 71.4%) families, including the 12 following genes: USH2A, CYP4V2, PRPF31, RHO, RP1, CNGA1, CNGB1, EYS, PRPF3, RP2, RPGR, and TOPORS. Three families were rediagnosed as having Bietti crystalline dystrophy (BCD). USH2A (4/20, 20%) and CYP4V2 (3/20, 15%) were found to be the most frequent mutated genes. Seven novel mutations were identified in this research, including mutations in USH2A1, USH2A2, PRPF31, RP2, TOPORS, CNGB1, and RPGR. Phenotype and genotype relationships in the 12 RP genes were analyzed, which revealed later disease onset and more severe visual function defects in CYP4V2. CONCLUSION Twenty-five putative pathogenic mutations of 12 genes were detected by WES, and these were all confirmed by Sanger sequencing in 20 (20/28, 71.4%) families, including seven novel mutations. USH2A and CYP4V2 were found to be the most frequent genes in this research. Phenotype and genotype relationships were revealed, and the mutation spectrum of RP in Chinese populations was expanded in this research, which may benefit future cutting-edge therapies.
Collapse
|
9
|
Gao P, Jia D, Li P, Huang Y, Hu H, Sun K, Lv Y, Chen X, Han Y, Zhang Z, Ren X, Wang Q, Liu F, Tang Z, Liu M. Accumulation of Lipid Droplets in a Novel Bietti Crystalline Dystrophy Zebrafish Model With Impaired PPARα Pathway. Invest Ophthalmol Vis Sci 2022; 63:32. [PMID: 35616930 PMCID: PMC9150832 DOI: 10.1167/iovs.63.5.32] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose Bietti crystalline dystrophy (BCD) is a progressive retinal degenerative disease primarily characterized by numerous crystal-like deposits and degeneration of retinal pigment epithelium (RPE) and photoreceptor cells. CYP4V2 (cytochrome P450 family 4 subfamily V member 2) is currently the only disease-causing gene for BCD. We aimed to generate a zebrafish model to explore the functional role of CYP4V2 in the development of BCD and identify potential therapeutic targets for future studies. Methods The cyp4v7 and cyp4v8 (homologous genes of CYP4V2) knockout zebrafish lines were generated by CRISPR/Cas9 technology. The morphology of photoreceptor and RPE cells and the accumulation of lipid droplets in RPE cells were investigated at a series of different developmental stages through histological analysis, immunofluorescence, and lipid staining. Transcriptome analysis was performed to investigate the changes in gene expression of RPE cells during the progression of BCD. Results Progressive retinal degeneration including RPE atrophy and photoreceptor loss was observed in the mutant zebrafish as early as seven months after fertilization. We also observed the excessive accumulation of lipid droplets in RPE cells from three months after fertilization, which preceded the retinal degeneration by several months. Transcriptome analysis suggested that multiple metabolism pathways, especially the lipid metabolism pathways, were significantly changed in RPE cells. The down-regulation of the peroxisome proliferator-activated receptor α (PPARα) pathway was further confirmed in the mutant zebrafish and CYP4V2-knockdown human RPE-1 cells. Conclusions Our work established an animal model that recapitulates the symptoms of BCD patients and revealed that abnormal lipid metabolism in RPE cells, probably caused by dysregulation of the PPARα pathway, might be the main and direct consequence of CYP4V2 deficiency. These findings will deepen our understanding of the pathogenesis of BCD and provide potential therapeutic approaches.
Collapse
Affiliation(s)
- Pan Gao
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Pei Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Hualei Hu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Kui Sun
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xiang Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yunqiao Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Zuxiao Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xiang Ren
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Qing Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Fei Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| |
Collapse
|
10
|
Chan LW, Sung YC, Wu DC, Chen CY, Yang CH, Yang CM, Chen PL, Chen TC. PREDICTED PROTEIN STRUCTURE VARIATIONS INDICATE THE CLINICAL PRESENTATION OF CYP4V2-RELATED BIETTI CRYSTALLINE DYSTROPHY. Retina 2022; 42:797-806. [PMID: 34923510 DOI: 10.1097/iae.0000000000003381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To investigate the relationship between different CYP4V2 disease-causing variants and disease severity in Bietti crystalline dystrophy (BCD). METHODS Twenty-one subjects from 19 unrelated families with a clinical diagnosis of BCD were enrolled. A novel severity prediction score for BCD based on the predicted molecular impact of CYP4V2 variants was applied for grouping and subsequent analyses. The more severe variants led to less CYP4V2 protein function preservation and a higher severity prediction score. RESULTS All subjects harbored two alleles of CYP4V2 disease-causing variants, of which c.802-8_810del17insGC was the most prevalent (14/21, 66.67%) and c.1507G>C was novel. According to the severity score, the subjects were categorized into severe, moderate, and mild groups with different preservation of central vision (mean logMAR visual acuity 0.95 ± 0.82, 0.89 ± 1.22, and 0.56 ± 0.64, respectively). The patients with a lower severity score had slower disease progression. CONCLUSION This is the first cohort study of BCD in Taiwan, and we established a novel BCD severity index based on the molecular impact of different CYP4V2 variants. More severe impairment of CYP4V2 protein led to a more severe disease course with earlier progression. Our results could be helpful in identifying a therapeutic window for patients with BCD.
Collapse
Affiliation(s)
- Li-Wei Chan
- Department of Ophthalmology, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan
| | - Yu-Chi Sung
- Department of Medical Education, National Taiwan University Hospital, Taipei, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
| | - Dung-Chi Wu
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
| | | | - Chang-Hao Yang
- Department of Ophthalmology, National Taiwan University, Taipei, Taiwan
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chung-May Yang
- Department of Ophthalmology, National Taiwan University, Taipei, Taiwan
- Department of Ophthalmology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Pei-Lung Chen
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Medical Genomics and Proteomics, College of Medicine, National Taiwan University, Taipei, Taiwan; and
- Department of Medical Genetics, National Taiwan University Hospital, Taipei, Taiwan
| | - Ta-Ching Chen
- Department of Ophthalmology, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
11
|
Zou T, Wang T, Zhen F, Dong S, Gong B, Zhang H. Identification of a novel compound heterozygous CYP4V2 variant in a patient with autosomal recessive retinitis pigmentosa. Biomed Rep 2022; 16:40. [PMID: 35386112 PMCID: PMC8972287 DOI: 10.3892/br.2022.1523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/23/2022] [Indexed: 11/24/2022] Open
Abstract
Retinitis pigmentosa (RP) belongs to a family of retinal disorders that is characterized by the progressive degeneration of rod and cone photoreceptors. The aim of the present study was to screen for possible disease-causing genetic variants in a non-consanguineous Chinese family with non-syndromic autosomal recessive RP. Whole-exome sequencing (WES) was performed in samples from the affected individual (the proband) and those from the two children of the proband. A novel compound heterozygous variant of c.C958T (p.R320X) and c.G1355A (p.R452H) in the Cytochrome P450 family 4 subfamily V member 2 (CYP4V2) gene was identified through WES. Subsequently, this variant was validated by direct Sanger sequencing. This compound heterozygous variant was found to be absent from other unaffected family members and 400 ethnically-matched healthy control individuals. In addition, this compound variant was co-segregated with the RP phenotype in an autosomal recessive manner. In silico analysis revealed that both c.C958T (p.R320X) and c.G1355A (p.R452H) could compromise the protein function of CYP4V2. These results strongly suggest this compound variant to be a disease-causing variant, which expands upon the spectrum of currently known CYP4V2 genetic variants associated with retinal diseases.
Collapse
Affiliation(s)
- Tongdan Zou
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, P.R. China
| | - Ting Wang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, P.R. China
| | - Fangyuan Zhen
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, Henan 450000, P.R. China
| | - Shuqian Dong
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Henan Provincial Ophthalmic Hospital, Zhengzhou, Henan 450000, P.R. China
| | - Bo Gong
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, P.R. China
| | - Houbin Zhang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province and Institute of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, P.R. China
| |
Collapse
|
12
|
Liu Z, Ayton LN, O'Hare F, Arslan J, Hu ML, Noar AP, Wang JH, Hickey DG, McGuinness MB, Vincent AL, Chen FK, Edwards TL. Intereye Symmetry in Bietti Crystalline Dystrophy. Am J Ophthalmol 2022; 235:313-325. [PMID: 34283985 DOI: 10.1016/j.ajo.2021.07.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 06/07/2021] [Accepted: 07/09/2021] [Indexed: 11/01/2022]
Abstract
PURPOSE To evaluate anatomic and functional intereye symmetry among individuals with Bietti crystalline dystrophy (BCD) using clinical and multimodal imaging methods, with a focus on the number, area, and distribution of the characteristic retinal crystalline deposits. DESIGN Observational case series with prospective and retrospective data. METHODS Setting: Multicenter. STUDY POPULATION Thirteen Australian and New Zealand participants (26 eyes) with confirmed biallelic CYP4V2 mutations and a characteristic BCD fundus appearance. Procedures and main outcome measures: Crystals visible on color fundus photography were manually counted. Crystals were superimposed on aligned multimodal fundus images. Spearman's correlation coefficients (ρ), intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to quantify symmetry between eyes. MAIN OUTCOME MEASURES Fundus crystal area and count, and absent-autofluorescence (absent-AF) area. RESULTS Median participant age was 48 years (interquartile range: 40-60 years). Intereye symmetry was high for fundus crystal area (ρ = 1.00, 95% confidence interval [CI]: 1.00-1.00; ICC = 0.97, 95% CI: 0.88-0.99), fundus crystal count (ρ = 0.98, 95% CI: 0.92-1.00; ICC = 0.97, 95% CI: 0.89-0.99), and absent-AF area (ρ = 0.88, 95% CI: 0.53-0.98; ICC = 0.98, 95% CI: 0.90-0.99). Average foveal volume, foveal crystal count and area, average and central foveal thickness, best corrected visual acuity, and average macular and central foveal sensitivity were not highly correlated between eyes. CONCLUSIONS This study demonstrated strong intereye symmetry measured by fundus crystal area, fundus crystal number, and absent-AF area. This may influence the choice of outcome measures for future therapeutic trials for BCD and provides valuable clinical information for ophthalmologists involved in the care and counseling of patients with BCD.
Collapse
|
13
|
Dai H, Zhang Y, Li R, Li Y, Li G. Genotype and Ocular Phenotype in Sixteen Chinese Patients with Bietti Corneoretinal Crystalline Dystrophy. Curr Eye Res 2021; 47:436-442. [PMID: 34724870 DOI: 10.1080/02713683.2021.1995004] [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: 10/19/2022]
Abstract
OBJECTIVE To investigate CYP4V2 gene variants and ocular clinical characteristics of Bietti corneoretinal crystalline dystrophy in China so as to provide more references for genotype and phenotype of BCD. METHODS Sixteen Chinese probands were recruited in Beijing Tongren Hospital in a retrospective study. All patients underwent CYP4V2 gene detection and ophthalmic clinical examinations. RESULTS CYP4V2 gene variants were detected in all patients. Eight variants were identified, and the most common one was c.802-8_810del17bpinsGC. Onset age of BCD was from 12 to 44 years, and the first symptoms mostly were decreased visual acuity or night blindness. Corneal crystalline depositions were observed in all patients and were found not only in epithelium and superficial stroma near the limbus but also in corneal endothelium. OCT showed atrophy of RPE in all patients, outer retinal tubulation in ten patients, macular edema in four patients, macular hole in three patients with one accompanied with retinal detachment, and choroidal neovascularization in one patient. CONCLUSION CYP4V2 gene variants were detected in all patients consistent with the genetic locus homogeneity of BCD, and c.802-8_810del17bpinsGC was the most common mutation. Corneal crystalline depositions were observed in all patients, which may be features of BCD and helpful for the diagnosis of BCD patients, especially those in the advanced stage without typical fundus crystalline depositions or without gene detection. However, considerable phenotypic variability was detected. Corneal crystalline deposits were observed not only in epithelium and superficial stroma but also in endothelium, which has not been reported before. This may provide further evidence for the variable phenotypic expression between affected individuals.
Collapse
Affiliation(s)
- Hehua Dai
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Yang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Ruyi Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Yuyu Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| |
Collapse
|
14
|
Choi KY, Wong HHY, Chan HHL. Utilizing Advanced Technology to Facilitate Diagnosis of Rare Retinal Disorders: A Case of Bietti Crystalline Dystrophy. Optom Vis Sci 2021; 98:1031-1038. [PMID: 34459467 DOI: 10.1097/opx.0000000000001763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE Optometrists, as primary eye care providers, encounter patients with rare ocular disease such as Bietti crystalline dystrophy from time to time. Using advanced technologies, which are also useful in managing common ocular conditions, to facilitate a prompt diagnosis is highly recommended. PURPOSE This report describes a patient with clinically diagnosed Bietti crystalline dystrophy with findings on funduscopy, multimodal imaging, and visual electrophysiology. CASE REPORT A 41-year-old Chinese woman who had subjectively progressing dimmed vision (especially in the left eye) for 9 months was referred to our clinic to test for retinitis pigmentosa. Best-corrected visual acuities were 6/6 and 6/7.6 in the right and left eyes, respectively. Funduscopy revealed multiple crystalline deposits on the posterior pole in both eyes. The 30-2 perimetry displayed bi-inferotemporal scotoma (left > right eye). Scotopic flash electroretinogram (ERG) yielded a normal result, whereas photopic ERG was slightly attenuated. Electro-oculogram showed an abnormal adaptation time course of the retinal pigmented epithelium (RPE). Multifocal ERG revealed a decreased central retinal response, but paracentral responses were relatively better preserved. Optical coherence tomography showed multiple patches of RPE atrophy, with disruption of the left ellipsoid zone. Outer retinal tubulations, hyperreflective dots on RPE-Bruch's membrane interface, and intraretinal bright spots were also identified. CONCLUSIONS Rare ocular diseases like Bietti crystalline dystrophy can be encountered by optometrists. This case report shows the ophthalmic findings of a rare chorioretinal dystrophy and provides insight on how to better use advanced equipment in an optometric practice to facilitate prompt diagnoses.
Collapse
Affiliation(s)
- Kai Yip Choi
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Horace Ho Yin Wong
- Laboratory of Experimental Optometry (Neuroscience), School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | | |
Collapse
|
15
|
Louati Y, Vaclavik V, Moulin A, Schorderet D, Munier FL, Viet Tran H. Crystals deposits in the anterior and posterior lens cortex in Bietti corneo-retinal dystrophy. Ophthalmic Genet 2021; 42:773-779. [PMID: 34310258 DOI: 10.1080/13816810.2021.1952620] [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: 10/20/2022]
Abstract
BACKGROUND Whereas crystals deposit in the retina, the cornea and limbus in Bietty corneo-retinal dystrophy (BCD) is now well established and documented, only two published cases report their findings in the lens and no cases deep in the lens cortex. MATERIAL AND METHODS Four consecutive adult patients from three different unrelated families presenting lens crystals associated with advanced genetically confirmed BCD were enrolled with advanced disease and long follow up (>12 years). Demographics, visual acuity, slit lamp biomicroscopy, lens and posterior pole photography, optical coherence tomography (OCT), autofluorescence, and screening for CYP4V2 type of mutation were performed. The setting was Jules Gonin Eye Hospital, Switzerland, between 1.1 2013 and 1.11. 2019. RESULTS All patients were European women. The ages ranged from 40 to 81 years. Best Snellen visual acuity ranged from light perception to 1.0. All patients presented with limbus and retinal crystals deposit that disappeared over time and the development of severe chorioretinal atrophy. With long-term follow up, multiple crystal-like deposits appeared in the anterior, posterior lens capsule and cortex. All patients, but one, had homozygous or compound heterozygous mutations in CYP4V2 gene. CONCLUSIONS To the best of our knowledge, there are no published cases of crystal deposits in the cortex of the lens of patients diagnosed with BCD associated with CYP4V2 gene mutation. This could be a feature of advanced BCD, and their presence in the lens cortex questions the hypothesis of floating deposits from posterior pole although their exact etiology remains to be determined.
Collapse
Affiliation(s)
- Youssr Louati
- Oculogenetic Unit, Jules-Gonin University Eye Hospital, Lausanne, Switzerland
| | - Veronika Vaclavik
- Oculogenetic Unit, Jules-Gonin University Eye Hospital, Lausanne, Switzerland
| | - Alexandre Moulin
- Oculogenetic Unit, Jules-Gonin University Eye Hospital, Lausanne, Switzerland
| | | | - Francis L Munier
- Oculogenetic Unit, Jules-Gonin University Eye Hospital, Lausanne, Switzerland
| | - Hoai Viet Tran
- Oculogenetic Unit, Jules-Gonin University Eye Hospital, Lausanne, Switzerland
| |
Collapse
|
16
|
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
|
17
|
Murakami Y, Koyanagi Y, Fukushima M, Yoshimura M, Fujiwara K, Akiyama M, Momozawa Y, Ueno S, Terasaki H, Oishi A, Miyata M, Ikeda H, Tsujikawa A, Mizobuchi K, Hayashi T, Fujinami K, Tsunoda K, Park JY, Han J, Kim M, Lee CS, Kim SJ, Park TK, Joo K, Woo SJ, Ikeda Y, Sonoda KH. Genotype and Long-term Clinical Course of Bietti Crystalline Dystrophy in Korean and Japanese Patients. Ophthalmol Retina 2021; 5:1269-1279. [PMID: 33636399 DOI: 10.1016/j.oret.2021.02.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/16/2021] [Accepted: 02/16/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate the genotype and long-term clinical phenotype of patients with Bietti crystalline dystrophy (BCD) in Korea and Japan. DESIGN Retrospective case series. PARTICIPANTS We analyzed 62 patients with clinical features of BCD who harbor pathogenic biallelic CYP4V2 variants in their homozygote or compound heterozygote. METHODS Data were collected from patient charts, including age, best-corrected visual acuity (BCVA), Goldmann perimetry results, fundus photography, OCT findings, fundus autofluorescence results, and electroretinography findings. We compared the clinical course of the patients with homozygous c.802-8_810de117insGC [exon7del], the most common mutation in the East Asian population, with those of the patients with other genotypes. MAIN OUTCOME MEASURES Best-corrected visual acuity, visual field (VF), and their changes during follow-up. RESULTS The mean age at the first visit was 55.2 years, with a mean follow-up of 7.1 years. The mean BCVAs at the first and last visits were 0.28 logarithm of the minimum angle of resolution (logMAR) and 0.89 logMAR, respectively. In genetic testing, c.802-8_810de117insGC was detected in 86 of 124 alleles of the patients, and 36 patients were homozygous for this mutation. The age, BCVA, VF area, central foveal thickness, and abnormal hypoautofluorescent area at either the first or last visit were not different between the exon7del homozygotes and the others. The mean BCVA changes per year were 0.089 logMAR in the exon7del homozygotes and 0.089 logMAR in the others. An age- and gender-adjusted linear regression analysis showed no association between the exon7del homozygote status and the rate of vision loss. Characteristic crystalline deposits in the posterior pole were generally observed in younger patients and disappeared over time along with progressive retinochoroidal atrophy. CONCLUSIONS Patients with BCD and a homozygote for c.802-8_810de117insGC accounted for more than 50% of this cohort of Korean and Japanese patients, and the clinical effect of this deleterious variant was not severe in the spectrum of CYP4V2 retinopathy.
Collapse
Affiliation(s)
- Yusuke Murakami
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
| | - Yoshito Koyanagi
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masatoshi Fukushima
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Marika Yoshimura
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kohta Fujiwara
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masato Akiyama
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Department of Ocular Pathology and Imaging Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yukihide Momozawa
- Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Akio Oishi
- Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Manabu Miyata
- Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Hanako Ikeda
- Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kaoru Fujinami
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Kazushige Tsunoda
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Jun Young Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University, Seoul, Korea
| | - Min Kim
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University, Seoul, Korea
| | - Christopher Seungkyu Lee
- Institute of Vision Research, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | - Sang Jin Kim
- Department of Ophthalmology, Samsung Medical Center, Seoul, Korea
| | - Tae Kwann Park
- Department of Ophthalmology, Soonchunhyang University Hospital, Bucheon, Korea
| | - Kwangsic Joo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea
| | - Yasuhiro Ikeda
- Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan
| | - Koh-Hei Sonoda
- Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| |
Collapse
|
18
|
Huang CY, Kang EYC, Yeh LK, Wu AL, Liu PK, Huang IW, Ryu J, Liu L, Wu WC, Lai CC, Chen KJ, Wang NK. Predicting visual acuity in Bietti crystalline dystrophy: evaluation of image parameters. BMC Ophthalmol 2021; 21:68. [PMID: 33541298 PMCID: PMC7860191 DOI: 10.1186/s12886-021-01811-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/11/2021] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND To analyze multiple imaging modalities in patients with Bietti crystalline dystrophy (BCD) and to investigate which factors from these modalities are associated with best corrected visual acuity (BCVA). METHODS In this retrospective study, 40 eyes from 22 patients with BCD were included and were separated into group 1 (BCVA ≤20/200) and group 2 (BCVA > 20/200). Data including BCVA and characteristic findings from near-infrared reflectance (NIR) imaging, fundus autofluorescence (FAF), and spectral domain-optic coherence tomography (SD-OCT) were analyzed and compared. The outcome measures of multimodal imaging were evaluated for correlation with BCVA. RESULTS NIR is a good diagnostic tool for detecting either crystalline or sclerotic vessels in BCD. Patients in group 1 tended to have a thinner choroid (P = 0.047) with ellipsoid zone (EZ) disruption (P = 0.011). Calculation of the area under the curve indicated that EZ disruption detected on SD-OCT could be a good predictor of legal blindness in BCD. CONCLUSION For the diagnosis of BCD, NIR could be a good diagnostic tool. Of the studied imaging modalities, we found that EZ disruption at the fovea were strongly associated with legal blindness, which could be easily assessed by SD-OCT.
Collapse
Affiliation(s)
- Chu-Yen Huang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Eugene Yu-Chuan Kang
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Lung-Kun Yeh
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - An-Lun Wu
- Department of Ophthalmology, Mackay Memorial Hospital, Hsinchu, Taiwan
| | - Pei-Kang Liu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, USA
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
- Department of Ophthalmology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Institute of Biochemical Science, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - I-Wen Huang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, USA
| | - Joseph Ryu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, USA
| | - Laura Liu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Wei-Chi Wu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chi-Chun Lai
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Ophthalmology, Chang Gung Memorial Hospital, Keelung, Taiwan
| | - Kuan-Jen Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Medical Center, Taoyuan, Taiwan.
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Nan-Kai Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, Columbia University, New York, USA.
| |
Collapse
|
19
|
Wang W, Chen W, Bai X, Chen L. Multimodal imaging features and genetic findings in Bietti crystalline dystrophy. BMC Ophthalmol 2020; 20:331. [PMID: 32799831 PMCID: PMC7429681 DOI: 10.1186/s12886-020-01545-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 07/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background Bietti crystalline dystrophy (BCD) is a distinct entity of retinitis pigmentosa with a wide range of genotypic and phenotypic variabilities. The goal of the present study was to investigate the morphological, functional and genetic features of BCD. Methods A full series of multimodal imaging was performed in four Chinese patients with BCD, including fundus photography, fundus autofluorescence, fundus fluorescein angiography (FFA), indocyanine green (ICG) angiography, optical coherence tomography (OCT) and microperimetry. Electrophysiological tests including full-field electroretinography (ERG) and multifocal ERG were employed. CYP4V2 gene sequencing was performed. Results Intraretinal crystalline deposits were observed in fundus photographs in all patients. The crystals were better appreciated in infrared images. Autofluorescence imaging demonstrated multifocal patchy hypofluorescence, suggesting massive RPE atrophy. FFA and ICG angiography further confirmed atrophy of the RPE and the underlying choroidal vessels. OCT revealed disruption of the photoreceptors, RPE and the choroid. Outer retinal tubulations (ORTs) confining to the outer nuclear layer were detected in three out of four patients. Full-field ERG showed markedly diminished responses. Multifocal ERG displayed reduced central and peripheral responses in a patient with normal vision. Gene sequencing identified two deletion mutations in CYP4V2, c.802_807del and c.810delT. BCD complicated by choroidal neovascularization (CNV) was diagnosed in one patient, and intravitreal anti-vascular endothelial growth factor (VEGF) injection was given with favorable response. Conclusions Multimodal imaging features and electrophysiological findings of BCD patients were comprehensively discussed. A novel deletion mutation, c.802_807del, in the CYP4V2 gene was reported. ORTs are important changes in the outer retina of BCD patients, further investigation of this structure may provide insights into pathology of BCD. Intravitreal anti-VEGF therapy was effective for treatment of BCD complicated by CNV.
Collapse
Affiliation(s)
- Wei Wang
- Department of Ophthalmology and Vision Science, the Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China.,Key Laboratory of Myopia of State Health Ministry (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China.,Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Wei Chen
- Department of Ophthalmology and Vision Science, the Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China.,Key Laboratory of Myopia of State Health Ministry (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
| | - Xinyue Bai
- Department of Ophthalmology and Vision Science, the Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China.,Key Laboratory of Myopia of State Health Ministry (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
| | - Ling Chen
- Department of Ophthalmology and Vision Science, the Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China. .,Key Laboratory of Myopia of State Health Ministry (Fudan University) and Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China.
| |
Collapse
|
20
|
Zhang Z, Yan B, Gao F, Li Q, Meng X, Chen P, Zhou L, Deng W, Li C, Xu W, Han S, Feng H, Li Y, Chen J, Yin Z, Liao C, Tse HF, Xu A, Lian Q. PSCs Reveal PUFA-Provoked Mitochondrial Stress as a Central Node Potentiating RPE Degeneration in Bietti's Crystalline Dystrophy. Mol Ther 2020; 28:2642-2661. [PMID: 32755565 PMCID: PMC7704739 DOI: 10.1016/j.ymthe.2020.07.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/25/2020] [Accepted: 07/21/2020] [Indexed: 12/21/2022] Open
Abstract
Bietti’s crystalline dystrophy (BCD) is an incurable retinal disorder caused by the polypeptide 2 of cytochrome P450 family 4 subfamily V (CYP4V2) mutations. Patients with BCD present degeneration of retinal pigmented epithelial (RPE) cells and consequent blindness. The lack of appropriate disease models and patients’ RPE cells limits our understanding of the pathological mechanism of RPE degeneration. In this study, using CYP4V2 mutant pluripotent stem cells as disease models, we demonstrated that RPE cells with CYP4V2 mutations presented a disrupted fatty acid homeostasis, which were characterized with excessive accumulation of poly-unsaturated fatty acid (PUFA), including arachidonic acid (AA) and eicosapentaenoic acid (EPA). The PUFA overload increased mitochondrial reactive oxygen species, impaired mitochondrial respiratory functions, and triggered mitochondrial stress-activated p53-independent apoptosis in CYP4V2 mutant RPE cells. Restoration of the mutant CYP4V2 using adeno-associated virus 2 (AAV2) can effectively reduce PUFA deposition, alleviate mitochondria oxidative stresses, and rescue RPE cell death in BCD RPE cells. Taken together, our results highlight a role of PUFA-induced mitochondrial damage as a central node to potentiate RPE degeneration in BCD patients. AAV2-mediated gene therapy may represent a feasible strategy for the treatment of BCD.
Collapse
Affiliation(s)
- Zhao Zhang
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Prenatal Diagnostic Centre and Cord Blood Bank, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Bin Yan
- Department of Computer Science, The University of Hong Kong, Hong Kong SAR, China; School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China; Intervention and Cell Therapy Center, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Fei Gao
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Qing Li
- Ophthalmology, Grantham Hospital, Hospital Authority, Hong Kong SAR, China
| | - Xiaohong Meng
- Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Peikai Chen
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Lei Zhou
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Wen Deng
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Cheng Li
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Weiyi Xu
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Shuo Han
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Hong Feng
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yaping Li
- Ophthalmology, The Second Hospital of Jilin University, Changchun 130022, China
| | - Junhui Chen
- Intervention and Cell Therapy Center, Peking University Shenzhen Hospital, Shenzhen 518036, China
| | - Zhengqin Yin
- Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | - Can Liao
- Prenatal Diagnostic Centre and Cord Blood Bank, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China
| | - Hung-Fat Tse
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Aimin Xu
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong SAR, China.
| | - Qizhou Lian
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China; Prenatal Diagnostic Centre and Cord Blood Bank, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, China; State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong SAR, China.
| |
Collapse
|
21
|
Jarrar YB, Shin JG, Lee SJ. Identification and functional characterization of CYP4V2 genetic variants exhibiting decreased activity of lauric acid metabolism. Ann Hum Genet 2020; 84:400-411. [PMID: 32396266 DOI: 10.1111/ahg.12388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 04/16/2020] [Accepted: 04/21/2020] [Indexed: 11/26/2022]
Abstract
The objectives of the present study were to identify CYP4V2 genetic variants and characterize their functional consequences. A total of 26CYP4V2 genetic variants were identified, including seven novel variants in 60 randomly selected healthy subjects. Six protein-coding variants were studied, including three novel variants (L22V, R287T, and G410C) and three previously reported variants (R36S, Q259K, and H331P). The cDNA sequences encoding each amino acid variant and the wild-type CYP4V2 protein were cloned into the pcDNA/PDEST40 expression vector and transfected into eukaryotic 293T cells for overexpression of the CYP4V2 coding variants. CYP4V2 H331P and CYP4V2 G410C exhibited significant decreases in activity for lauric acid oxidation (20-30% of wild-type activity), when compared to the wildtype, which was correlated with low expression of CYP4V2 H331P and G410C substituted proteins. The other four CYP4V2 amino variants were comparable to wild-type CYP4V2 for lauric acid metabolism. The CYP4V2 H331P and G410C substitutions were predicted to cause a structural change through in silico analysis. In conclusion, the present study provides functional information about CYP4V2 genetic variants. These findings will be valuable for interpreting individual variations in phenotypes associated with CYP4V2 function in the clinical setting.
Collapse
Affiliation(s)
- Yazun Bashir Jarrar
- Department of Pharmacology and Pharmacogenomics Research Center, Inje University College of Medicine, Inje University, Busan, South Korea.,Department of Pharmacy, College of Pharmacy, Alzaytoonah University of Jordan, Amman, Jordan
| | - Jae-Gook Shin
- Department of Pharmacology and Pharmacogenomics Research Center, Inje University College of Medicine, Inje University, Busan, South Korea.,Department of Clinical Pharmacology, Inje University College of Medicine, Inje University, Busan, South Korea
| | - Su-Jun Lee
- Department of Pharmacology and Pharmacogenomics Research Center, Inje University College of Medicine, Inje University, Busan, South Korea
| |
Collapse
|
22
|
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
|
23
|
Molecular Functionality of Cytochrome P450 4 (CYP4) Genetic Polymorphisms and Their Clinical Implications. Int J Mol Sci 2019; 20:ijms20174274. [PMID: 31480463 PMCID: PMC6747359 DOI: 10.3390/ijms20174274] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 01/03/2023] Open
Abstract
Enzymes in the cytochrome P450 4 (CYP4) family are involved in the metabolism of fatty acids, xenobiotics, therapeutic drugs, and signaling molecules, including eicosanoids, leukotrienes, and prostanoids. As CYP4 enzymes play a role in the maintenance of fatty acids and fatty-acid-derived bioactive molecules within a normal range, they have been implicated in various biological functions, including inflammation, skin barrier, eye function, cardiovascular health, and cancer. Numerous studies have indicated that genetic variants of CYP4 genes cause inter-individual variations in metabolism and disease susceptibility. Genetic variants of CYP4A11, 4F2 genes are associated with cardiovascular diseases. Mutations of CYP4B1, CYP4Z1, and other CYP4 genes that generate 20-HETE are a potential risk for cancer. CYP4V2 gene variants are associated with ocular disease, while those of CYP4F22 are linked to skin disease and CYP4F3B is associated with the inflammatory response. The present study comprehensively collected research to provide an updated view of the molecular functionality of CYP4 genes and their associations with human diseases. Functional analysis of CYP4 genes with clinical implications is necessary to understand inter-individual variations in disease susceptibility and for the development of alternative treatment strategies.
Collapse
|
24
|
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
|
25
|
Darki F, Fekri S, Farhangmehr S, Ahmadieh H, Dehghan MH, Elahi E. CYP4V2 mutation screening in an Iranian Bietti crystalline dystrophy pedigree and evidence for clustering of CYP4V2 mutations. J Curr Ophthalmol 2019; 31:172-179. [PMID: 31317096 PMCID: PMC6611930 DOI: 10.1016/j.joco.2019.01.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 12/26/2018] [Accepted: 01/16/2019] [Indexed: 10/31/2022] Open
Abstract
Purpose To report the genetic analysis of an Iranian Bietti crystalline dystrophy (BCD)-affected family, and to review previously reported mutations in the gene and assess the distribution of affected amino acids in the encoded protein. Methods The eleven exons of CYP4V2 were sequenced in the DNA of the proband of the Iranian BCD family. The putative disease-causing variation was screened in all affected and non-affected members. BCD causing CYP4V2 mutations previously reported in the literature were compiled, and positions of amino acids affected by nonsense and missense mutations were mapped onto the primary structure of the CYP4V2 protein. Results C.1219G > T in CYP4V2 that causes p.Glu407* was identified as cause of BCD in the Iranian family. The mutation segregated with disease status. Clinical presentations were similar among affected members, except that one patient presented with retinal macular hole. Twelve nonsense and 47 missense mutations in CYP4V2 were compiled. Inspection of distribution of amino acids affected by the mutations suggested non-random distribution and clustering of affected amino acids in nine regions of the protein, including regions that contain the heme binding site, the metal binding site, and a region between these binding sites. The most C-terminus proximal nonsense mutation affected position 482. Conclusions This study presents results of the genetic analysis of an Iranian BCD family. Protein regions affected by mutations within the nine mutation clusters include regions well conserved among orthologous proteins and human CYP4 proteins, some of which are associated with known functions. The findings may serve to identify reasonable candidate gene region targets for gene editing therapy approaches.
Collapse
Affiliation(s)
- Faezeh Darki
- School of Biology, University College of Science, University of Tehran, Tehran, Iran
| | - Sahba Fekri
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Ophthalmology, Labbafinejad Medical Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shaghayegh Farhangmehr
- School of Biology, University College of Science, University of Tehran, Tehran, Iran.,Department of Molecular Genetics, University of Toronto, Toronto, CA, USA
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Hossein Dehghan
- Department of Ophthalmology, Labbafinejad Medical Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elahe Elahi
- School of Biology, University College of Science, University of Tehran, Tehran, Iran
| |
Collapse
|
26
|
Zhang X, Xu K, Dong B, Peng X, Li Q, Jiang F, Xie Y, Tian L, Li Y. Comprehensive screening of CYP4V2 in a cohort of Chinese patients with Bietti crystalline dystrophy. Mol Vis 2018; 24:700-711. [PMID: 30429639 PMCID: PMC6204257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 10/24/2018] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Bietti crystalline dystrophy (BCD) is an autosomal recessive retinal degeneration disorder caused by mutations in CYP4V2. The aim of this study is to describe the genetic and clinical findings in 128 unrelated Chinese patients diagnosed with BCD. METHODS Ophthalmological evaluations were performed in all patients. All coding regions of CYP4V2 were amplified and sequenced directly. Real-time quantitative PCR was performed to detect copy number variations. Haplotype analysis was performed in 70 patients with c.802-8_810del17insGC and in 93 normal controls. RESULTS A total of 28 mutations in CYP4V2, including eight novel mutations, were identified in 125 patients. The most common mutation was c.802-8_810del17insGC, with an allele frequency of 62.6%, followed by p.H331P (8.7%) and c.1091-2A>G (7.5%). A novel large deletion encompassing exon 8 of CYP4V2 was detected. Haplotype analysis revealed four common haplotypes in patients with c.802-8_810del17insGC. A 17.6 kb haplotype CT(delCT)TA(Indel)A was the most common and was observed in 34.5% of the c.802-8_810del17insGC mutant alleles. The patients with mutations in CYP4V2 showed wide intra- and interfamilial variability in clinical severity. CONCLUSIONS The findings expand the mutational spectrum of CYP4V2 and further confirm the c.802-8_810del17insGC mutation was due to a founder effect in a large cohort of Chinese patients.
Collapse
Affiliation(s)
- Xiaohui Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Ke Xu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Bing Dong
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Xiaoyan Peng
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Qian Li
- Department of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Feng Jiang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Yue Xie
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Lu Tian
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China
| |
Collapse
|
27
|
Maeda A, Yoshida A, Kawai K, Arai Y, Akiba R, Inaba A, Takagi S, Fujiki R, Hirami Y, Kurimoto Y, Ohara O, Takahashi M. Development of a molecular diagnostic test for Retinitis Pigmentosa in the Japanese population. Jpn J Ophthalmol 2018; 62:451-457. [PMID: 29785639 DOI: 10.1007/s10384-018-0601-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 04/30/2018] [Indexed: 11/29/2022]
Abstract
PURPOSE Retinitis Pigmentosa (RP) is the most common form of inherited retinal dystrophy caused by different genetic variants. More than 60 causative genes have been identified to date. The establishment of cost-effective molecular diagnostic tests with high sensitivity and specificity can be beneficial for patients and clinicians. Here, we developed a clinical diagnostic test for RP in the Japanese population. STUDY DESIGN Evaluation of diagnostic technology, Prospective, Clinical and experimental study. METHODS A panel of 39 genes reported to cause RP in Japanese patients was established. Next generation sequence (NGS) technology was applied for the analyses of 94 probands with RP and RP-related diseases. After interpretation of detected genetic variants, molecular diagnosis based on a study of the genetic variants and a clinical phenotype was made by a multidisciplinary team including clinicians, researchers and genetic counselors. RESULTS NGS analyses found 14,343 variants from 94 probands. Among them, 189 variants in 83 probands (88.3% of all cases) were selected as pathogenic variants and 64 probands (68.1%) have variants which can cause diseases. After the deliberation of these 64 cases, molecular diagnosis was made in 43 probands (45.7%). The final molecular diagnostic rate with the current system combining supplemental Sanger sequencing was 47.9% (45 of 94 cases). CONCLUSIONS The RP panel provides the significant advantage of detecting genetic variants with a high molecular diagnostic rate. This type of race-specific high-throughput genotyping allows us to conduct a cost-effective and clinically useful genetic diagnostic test.
Collapse
Affiliation(s)
- Akiko Maeda
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan. .,Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan. .,Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, USA.
| | - Akiko Yoshida
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.,Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan
| | - Kanako Kawai
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan
| | - Yuki Arai
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan
| | - Ryutaro Akiba
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan
| | - Akira Inaba
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan
| | - Seiji Takagi
- Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan.,Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Ryoji Fujiki
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Yasuhiko Hirami
- Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan.,Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Yasuo Kurimoto
- Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan.,Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan
| | - Osamu Ohara
- Department of Technology Development, Kazusa DNA Research Institute, Kisarazu, Japan
| | - Masayo Takahashi
- Laboratory for Retinal Regeneration, RIKEN Center for Developmental Biology, 2-2-3 Minatojimaminamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan.,Division of Ophthalmology, Institute of Biomedical Research and Innovation Hospital, Kobe, Japan.,Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan
| |
Collapse
|
28
|
Oishi A, Oishi M, Miyata M, Hirashima T, Hasegawa T, Numa S, Tsujikawa A. Multimodal Imaging for Differential Diagnosis of Bietti Crystalline Dystrophy. Ophthalmol Retina 2018; 2:1071-1077. [PMID: 31047497 DOI: 10.1016/j.oret.2018.02.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/16/2018] [Accepted: 02/28/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE To evaluate the diagnostic usefulness of multimodal imaging in patients with Bietti crystalline dystrophy (BCD). DESIGN Retrospective cross-sectional study. PARTICIPANTS Patients with chorioretinal dystrophy accompanied by crystalline-like deposits. The right eyes of the patients were analyzed. METHODS Fundus photograph, near-infrared reflectance (NIR), fundus autofluorescence (FAF), and OCT images were evaluated. Presence of hyperreflectivity on NIR, well-demarcated areas of decreased FAF, hyperreflective material at or on the retinal pigment epithelium-Bruch's membrane complex, and outer retinal tubulation were graded for each patient. All exons and franking introns of CYP4V2 were screened using Sanger sequencing. MAIN OUTCOME MEASURES Sensitivity and specificity of the findings to discriminate patients with and without CYP4V2 mutation. RESULTS In total, 33 patients were included in the study. Sanger sequencing revealed homozygous or compound heterozygous CYP4V2 mutations in 20 patients and heterozygous mutations in 2 patients. Among the investigated factors, hyperreflective appearance on NIR imaging yielded 100% sensitivity and 100% specificity in this cohort. The presence of outer retinal tubulation also was sensitive (95%), but specificity was moderate (45%). The revised diagnoses of patients without CYP4V2 mutations included retinitis pigmentosa, late-onset macular dystrophy, and central areolar choroidal dystrophy. CONCLUSIONS Multimodal imaging, especially NIR imaging, is useful to differentiate BCD patients with CYP4V2 mutations from patients with other chorioretinal dystrophies accompanied by crystalline-like retinal deposits.
Collapse
Affiliation(s)
- Akio Oishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Maho Oishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Manabu Miyata
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takako Hirashima
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Tomoko Hasegawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shogo Numa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Akitaka Tsujikawa
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| |
Collapse
|
29
|
PRPF3-Associated Autosomal Dominant Retinitis Pigmentosa and CYP4V2-Associated Bietti's Crystalline Corneoretinal Dystrophy Coexist in a Multigenerational Chinese Family. J Ophthalmol 2017; 2017:4156386. [PMID: 28848678 PMCID: PMC5564071 DOI: 10.1155/2017/4156386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 07/02/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To characterize the clinical and molecular genetic characteristics of a large, multigenerational Chinese family showing different phenotypes. Methods A pedigree consisted of 56 individuals in 5 generations was recruited. Comprehensive ophthalmic examinations were performed in 16 family members affected. Mutation screening of CYP4V2 was performed by Sanger sequencing. Next-generation sequencing (NGS) was performed to capture and sequence all exons of 47 known retinal dystrophy-associated genes in two affected family members who had no mutations in CYP4V2. The detected variants in NGS were validated by Sanger sequencing in the family members. Results Two compound heterozygous CYP4V2 mutations (c.802-8_810del17insGC and c.992A>C) were detected in the proband who presented typical clinical features of BCD. One missense mutation (c.1482C>T, p.T494M) in the PRPF3 gene was detected in 9 out of 22 affected family members who manifested classical clinical features of RP. Conclusions Our results showed that two compound heterozygous CYP4V2 mutations caused BCD, and one missense mutation in PRPF3 was responsible for adRP in this large family. This study suggests that accurate phenotypic diagnosis, molecular diagnosis, and genetic counseling are necessary for patients with hereditary retinal degeneration in some large mutigenerational family.
Collapse
|
30
|
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
|
31
|
Akıncıoğlu D, Yolcu Ü, İlhan A, Gündoğan FÇ. Objective Determination of Retinal Function in Bietti Crystalline Retinopathy. Turk J Ophthalmol 2016; 46:144-147. [PMID: 27800277 PMCID: PMC5076297 DOI: 10.4274/tjo.02693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 09/26/2014] [Indexed: 12/01/2022] Open
Abstract
A 44-year-old female patient without any known systemic or ocular disease presented with progressive visual loss and night vision disturbance. Visual acuity was 0.6 in the right eye and 0.2 in the left eye. Tiny, yellow crystalline deposits were seen on fundus examination. In addition, areas of retinal pigment epithelium and choriocapillaris atrophy were detected. Rod and cone responses were depressed in full-field flash electroretinogram. Multifocal electroretinogram testing showed severe foveal function disturbance with less severe but still depressed responses toward the periphery. Multiple hyperreflective lesions were detected in the retina in optical coherence tomography. We aimed to present the role of ocular electrophysiology by comparing the patient’s signs and symptoms with her ocular electrophysiological test results.
Collapse
Affiliation(s)
- Dorukcan Akıncıoğlu
- Gülhane Military Medical Academy, Department of Ophthalmology, Ankara, Turkey
| | - Ümit Yolcu
- Siirt Military Hospital, Ophthalmology Clinic, Siirt, Turkey
| | - Abdullah İlhan
- Erzurum Military Hospital, Ophthalmology Clinic, Erzurum, Turkey
| | | |
Collapse
|
32
|
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
|
33
|
Fuerst NM, Serrano L, Han G, Morgan JIW, Maguire AM, Leroy BP, Kim BJ, Aleman TS. Detailed functional and structural phenotype of Bietti crystalline dystrophy associated with mutations in CYP4V2 complicated by choroidal neovascularization. Ophthalmic Genet 2016; 37:445-452. [PMID: 27028354 DOI: 10.3109/13816810.2015.1126616] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To describe in detail the phenotype of a patient with Bietti crystalline dystrophy (BCD) complicated by choroidal neovascularization (CNV) and the response to intravitreal Bevacizumab (Avastin®; Genentech/Roche). METHODS A 34-year-old woman with BCD and mutations in CYP4V2 (c.802-8_806del13/p.H331P:c992A>C) underwent a complete ophthalmic examination, full-field flash electroretinography (ERG), kinetic and two-color dark-adapted perimetry, and dark-adaptometry. Imaging was performed with spectral domain optical coherence tomography (SD-OCT), near infrared (NIR) and short wavelength (SW) fundus autofluorescence (FAF), and fluorescein angiography (FA). RESULTS Best-corrected visual acuity (BCVA) was 20/20 and 20/60 for the right and left eye, respectively. There were corneal paralimbal crystal-like deposits. Kinetic fields were normal in the peripheral extent. Retinal crystals were most obvious on NIR-reflectance and corresponded with hyperreflectivities within the RPE on SD-OCT. There was parafoveal/perifoveal hypofluorescence on SW-FAF and NIR-FAF. Rod > cone sensitivity loss surrounded fixation and extended to ~10° of eccentricity corresponding to regions of photoreceptor outer segment-retinal pigmented epithelium (RPE) interdigitation abnormalities. The outer nuclear layer was normal in thickness. Recovery of sensitivity following a ~76% rhodopsin bleach was normal. ERGs were normal. A subretinal hemorrhage in the left eye co-localized with elevation of the RPE on SD-OCT and leakage on FA, suggestive of CNV. Three monthly intravitreal injections of Bevacizumab led to restoration of BCVA to baseline (20/25). CONCLUSION crystals in BCD were predominantly located within the RPE. Photoreceptor outer segment and apical RPE abnormalities underlie the relatively extensive retinal dysfunction observed in relatively early-stage BCD. Intravitreal Bevacizumab was effective in treating CNV in this setting.
Collapse
Affiliation(s)
- Nicole M Fuerst
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Leona Serrano
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Grace Han
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Jessica I W Morgan
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Albert M Maguire
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA.,b Division of Ophthalmology, Children's Hospital of Philadelphia, and Department of Ophthalmology , University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Bart P Leroy
- b Division of Ophthalmology, Children's Hospital of Philadelphia, and Department of Ophthalmology , University of Pennsylvania , Philadelphia , Pennsylvania , USA.,c Center for Cellular & Molecular Therapeutics, Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,d Department of Ophthalmology and the Center for Medical Genetics, Ghent University and Ghent University Hospital , Ghent , Belgium
| | - Benjamin J Kim
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Tomas S Aleman
- a Scheie Eye Institute and Perelman Center for Advanced Medicine, University of Pennsylvania , Philadelphia , Pennsylvania , USA.,b Division of Ophthalmology, Children's Hospital of Philadelphia, and Department of Ophthalmology , University of Pennsylvania , Philadelphia , Pennsylvania , USA
| |
Collapse
|
34
|
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
|
35
|
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
|
36
|
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
|
37
|
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
|
38
|
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
|
39
|
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
|
40
|
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
|
41
|
Genotype-phenotype analysis of Bietti crystalline dystrophy in a family with the CYP4V2 Ile111Thr mutation. Cornea 2014; 32:1002-8. [PMID: 23538635 DOI: 10.1097/ico.0b013e31828a27bc] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The purposes of this study were to evaluate the genotypic and phenotypic correlations of Bietti crystalline dystrophy and to investigate the utility of in vivo corneal confocal microscopy in diagnosing this disorder. METHODS A Spanish woman (proband) with a clinical diagnosis of Bietti crystalline dystrophy and 7 members of her family were recruited prospectively for complete clinical ophthalmic examination and genetic study. The medical records of an additional family member were reviewed retrospectively. Genomic DNA was obtained from blood samples, and 11 exons of the CYP4V2 gene were screened for mutations by polymerase chain reaction DNA sequencing. RESULTS Clinical examination revealed an atypical pattern of corneal dystrophy with central and paracentral distribution not only in the proband but also in 2 elderly heterozygous carriers. Corneal deposits were observed by slit-lamp examination and in vivo corneal confocal microscopy. Genetic analysis revealed the homozygous CYP4V2 Ile111Thr mutation in the proband and identified 5 heterozygous carriers. CONCLUSIONS The authors identified a case of Bietti crystalline dystrophy with central and paracentral keratopathy and the molecular analysis of the causative gene in a Spanish family. Data suggest a dose-dependent phenotype ranging from subclinical corneal changes in subjects carrying 1 mutant Ile111Thr CYP4V2 allele to the complete manifestation of the disease in homozygous subjects. In vivo corneal confocal microscopy is a useful technique in the diagnosis of this disorder.
Collapse
|
42
|
Insights into food preference in hybrid F1 of Siniperca chuatsi (♀) × Siniperca scherzeri (♂) mandarin fish through transcriptome analysis. BMC Genomics 2013; 14:601. [PMID: 24007400 PMCID: PMC3846499 DOI: 10.1186/1471-2164-14-601] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 09/02/2013] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND As economically relevant traits, feeding behavior and food preference domestication determine production cost and profitability. Although there are intensive research efforts on feeding behavior and food intake, little is known about food preference. Mandarin fish accept only live prey fish and refuse dead prey fish or artificial diets. Very little is currently known about the genes regulating this unique food preference. RESULTS Using transcriptome sequencing and digital gene expression profiling, we identified 1,986 and 4,526 differentially expressed genes in feeders and nonfeeders of dead prey fish, respectively. Up-regulation of Crbp, Rgr and Rdh8, and down-regulation of Gc expression, consistent with greater visual ability in feeders, could promote positive phototaxis. Altered expressions of period, casein kinase and Rev-erbα might reset circadian phase. Down-regulation of orexigenic and up-regulation of anorexigenic genes in feeders were associated with lower appetite. The mRNA levels of Creb, c-fos, C/EBP, zif268, Bdnf and Syt were dramatically decreased in feeders, which might result in significant deficiency in memory retention of its natural food preference (live prey fish). There were roughly 100 times more potential SNPs in feeders than in nonfeeders. CONCLUSIONS In summary, differential expression in the genes identified shed new light on why mandarin fish only feed on live prey fish, with pathways regulating retinal photosensitivity, circadian rhythm, appetite control, learning and memory involved. We also found dramatic difference in SNP abundance in feeders vs nonfeeders. These differences together might account for the different food preferences. Elucidating the genes regulating the unique food preference (live prey fish) in mandarin fish could lead to a better understanding of mechanisms controlling food preference in animals, including mammals.
Collapse
|
43
|
Song Y, Mo G, Yin G. A novel mutation in the CYP4V2 gene in a Chinese patient with Bietti's crystalline dystrophy. Int Ophthalmol 2012; 33:269-76. [PMID: 23242590 DOI: 10.1007/s10792-012-9686-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 11/24/2012] [Indexed: 11/25/2022]
Abstract
Bietti crystalline corneoretinal dystrophy (BCD, MIM 210370) is a type of hereditary retinal disorder which commonly occurs in China. It is known that mutations in the CYP4V2 gene result in BCD. The purpose of this study was to investigate the case of a Chinese family and characterize the polymorphisms of the CYP4V2 gene. A 29-year-old male (the son of a Chinese family) with typical clinical symptoms of BCD and his family were recruited into this study. Ophthalmologic examination, including best-corrected visual acuity, slit-lamp, and fundus examination with dilated pupils, was conducted to determine the clinical characteristics of the whole family. The entire coding region and adjacent intronic sequences of 11 coding regions of the CYP4V2 gene of the whole family were then amplified by polymerase chain reaction and sequenced. Our results show that the son had typical clinical features of BCD. His bilateral decimal visual acuity was 0.06 (left eye) and 0.01 (right eye). Bilateral crystal-like deposits were found in the posterior pole of his fundus, and differing extent of atrophy of the retinal pigment epithelium, and carpet-like retinal degeneration along with numerous tiny glittering crystals were also clearly observed. However, such characteristics were not found on the fundus of his parents' eyes. Five mutations within the CYP4V2 gene (c.64C>G, c.775C>A, c.810T>G, c.1091-2A>G, and c.1399T>C) were identified in the son. Among the five mutations, four had previously been reported and the c.1399T>C was discovered for the first time. This novel mutation causes an amino acid substitution (C467R) in the CYP4V2 protein, but it was not detected in the parents. As there is no apparent relationship in genotype-phenotype correlation between the CYP4V2 gene and the occurrence of BCD, this novel mutation may be a possible cause that could induce the clinical phenotype of BCD.
Collapse
Affiliation(s)
- Yanping Song
- Department of Ophthalmology, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 430070, China
| | | | | |
Collapse
|
44
|
Rossi S, Testa F, Li A, Yaylacioğlu F, Gesualdo C, Hejtmancik JF, Simonelli F. Clinical and genetic features in Italian Bietti crystalline dystrophy patients. Br J Ophthalmol 2012; 97:174-9. [PMID: 23221965 PMCID: PMC3582089 DOI: 10.1136/bjophthalmol-2012-302469] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Aim The aim of the study was to describe the clinical and genetic features of 15 Italian patients with Bietti crystalline dystrophy (BCD). Methods All study participants underwent a complete ophthalmological examination, including standard electroretinogram (ERG), optical coherence tomography, microperimetry, autofluorescence and multifocal electroretinogram. The 11 exons of the CYP4V2 gene were sequenced. The effect of mutations on protein function was estimated by a combination of web based programs. Results 15 patients (eight women, 7 men, aged 29–60 years) with BCD were recruited into this study. Sequencing of CYP4V2 revealed nine sequence variants in four unrelated families and six isolated individuals with BCD. Seven of these variants were novel. Among the patients, even with the same genotype, considerable variability in phenotypic expression with different degrees of accumulation of the typical intraretinal crystalline deposits was detected. Moreover, we found that more than 50% of patients had recordable standard ERG responses and in two patients the responses were within normal limits after 20 years of symptom onset. Conclusions In conclusion, we have reported seven new mutations and illustrated the large range of genotypic and phenotypic variability in BCD, highlighting the lack of a clear genotype–phenotype correlation and underlining the existence of less severe clinical manifestations, probably linked to relatively mild mutations.
Collapse
Affiliation(s)
- Settimio Rossi
- Department of Ophthalmology, Seconda Università degli Studi di Napoli, Via S Panini, 5, Naples 80131, Italy
| | | | | | | | | | | | | |
Collapse
|
45
|
Nakano M, Kelly EJ, Wiek C, Hanenberg H, Rettie AE. CYP4V2 in Bietti's crystalline dystrophy: ocular localization, metabolism of ω-3-polyunsaturated fatty acids, and functional deficit of the p.H331P variant. Mol Pharmacol 2012; 82:679-86. [PMID: 22772592 DOI: 10.1124/mol.112.080085] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Bietti's crystalline corneoretinal dystrophy (BCD) is a recessive degenerative eye disease caused by germline mutations in the CYP4V2 gene. More than 80% of mutant alleles consist of three mutations, that is, two splice-site alterations and one missense mutation, c.992C>A, which translates to p.H331P. In the present study, we analyzed the expression of CYP4 family members in human tissues and conducted functional studies with the wild-type and p.H331P enzymes, to elucidate the link between CYP4V2 activity and BCD. Expression analysis of 17 CYP1 to CYP4 genes showed CYP4V2 to be a major cytochrome P450 in ARPE-19 cells (a human cell line spontaneously generated from normal human retinal pigmented epithelium) and the only detectable CYP4 transcript. Immunohistochemical analyses demonstrated that CYP4V2 protein was present in epithelial cells of the retina and cornea and the enzyme was localized to endoplasmic reticulum. Recombinant reconstituted CYP4V2 protein metabolized eicosapentaenoic acid and docosahexaenoic acid (an important constituent of the retina) to their respective ω-hydroxylated products at rates similar to those observed with purified CYP4F2, which is an established hepatic polyunsaturated fatty acid (PUFA) hydroxylase. The disease-associated p.H331P variant was undetectable in Western blot analyses of HepG2 cells stably transduced with lentiviral expression vectors. Finally, overexpression of functional CYP4V2 in HepG2 cells altered lipid homeostasis. We demonstrated that CYP4V2 protein is expressed at high levels in ocular target tissues of BCD, that the enzyme is metabolically active toward PUFAs, and that the functional deficit among patients with BCD who carry the H331P variant is most likely a consequence of the instability of the mutant protein.
Collapse
Affiliation(s)
- Mariko Nakano
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Washington, USA
| | | | | | | | | |
Collapse
|
46
|
Wang Y, Guo L, Cai SP, Dai M, Yang Q, Yu W, Yan N, Zhou X, Fu J, Guo X, Han P, Wang J, Liu X. Exome sequencing identifies compound heterozygous mutations in CYP4V2 in a pedigree with retinitis pigmentosa. PLoS One 2012; 7:e33673. [PMID: 22693542 PMCID: PMC3365069 DOI: 10.1371/journal.pone.0033673] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Accepted: 02/14/2012] [Indexed: 02/05/2023] Open
Abstract
Retinitis pigmentosa (RP) is a heterogeneous group of progressive retinal degenerations characterized by pigmentation and atrophy in the mid-periphery of the retina. Twenty two subjects from a four-generation Chinese family with RP and thin cornea, congenital cataract and high myopia is reported in this study. All family members underwent complete ophthalmologic examinations. Patients of the family presented with bone spicule-shaped pigment deposits in retina, retinal vascular attenuation, retinal and choroidal dystrophy, as well as punctate opacity of the lens, reduced cornea thickness and high myopia. Peripheral venous blood was obtained from all patients and their family members for genetic analysis. After mutation analysis in a few known RP candidate genes, exome sequencing was used to analyze the exomes of 3 patients III2, III4, III6 and the unaffected mother II2. A total of 34,693 variations shared by 3 patients were subjected to several filtering steps against existing variation databases. Identified variations were verified in the rest family members by PCR and Sanger sequencing. Compound heterozygous c.802-8_810del17insGC and c.1091-2A>G mutations of the CYP4V2 gene, known as genetic defects for Bietti crystalline corneoretinal dystrophy, were identified as causative mutations for RP of this family.
Collapse
Affiliation(s)
- Yun Wang
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Liheng Guo
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Su-Ping Cai
- Shenzhen Eye Hospital, Jinan University, Shenzhen, People’s Republic of China
| | - Meizhi Dai
- BGI-Shenzhen, Shenzhen, Guangdong Province, People’s Republic of China
| | - Qiaona Yang
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Wenhan Yu
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Naihong Yan
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Xiaomin Zhou
- Ophthalmic Laboratories & Department of Ophthalmology, State Key Laboratory of Biotherapy, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan Province, People’s Republic of China
| | - Jin Fu
- BGI-Shenzhen, Shenzhen, Guangdong Province, People’s Republic of China
| | - Xinwu Guo
- BGI-Shenzhen, Shenzhen, Guangdong Province, People’s Republic of China
| | - Pengfei Han
- BGI-Shenzhen, Shenzhen, Guangdong Province, People’s Republic of China
| | - Jun Wang
- BGI-Shenzhen, Shenzhen, Guangdong Province, People’s Republic of China
- * E-mail: (XL); (JW)
| | - Xuyang Liu
- Shenzhen Eye Hospital, Jinan University, Shenzhen, People’s Republic of China
- * E-mail: (XL); (JW)
| |
Collapse
|
47
|
Haddad NMN, Waked N, Bejjani R, Khoueir Z, Chouery E, Corbani S, Mégarbané A. Clinical and molecular findings in three Lebanese families with Bietti crystalline dystrophy: report on a novel mutation. Mol Vis 2012; 18:1182-8. [PMID: 22605929 PMCID: PMC3351416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Accepted: 05/02/2012] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Bietti crystalline dystrophy (BCD) is a rare autosomal recessive disorder caused by mutation of the cytochrome P450, family 4, subfamily V, polypeptide 2 (CYP4V2) gene and characterized by retinal pigmentary abnormalities and scattered deposits of crystals in the retina and the marginal cornea. The aim of this study was to investigate the spectrum of mutations in CYP4V2 in Lebanese families, and to characterize the phenotype of patients affected with BCD. METHODS Nine patients from three unrelated Lebanese families were clinically and molecularly investigated. Detailed characterization of the patients' phenotype was performed with comprehensive ophthalmic examination, color vision study, fundus photography, visual field testing, retinal fluorescein angiography, electroretinography, and electrooculography. One family was followed for 12 years. The 11 exons of the CYP4V2 gene were sequenced. RESULTS Symptoms consisting of night blindness, loss of paracentral visual field, and disturbed color vision were apparent during the third decade of life. Ophthalmoscopy revealed posterior pole crystalline deposits and areas of retinal pigment epithelium atrophy. Fluorescein angiography disclosed geographic areas of the pigment epithelium layer and choriocapillaris atrophy in the posterior pole and fundus periphery. The most striking findings were those of normal electroretinographic responses in some patients and clinical heterogeneity. Two mutations in CYP4V2 were found: p.I111T (c.332T>C) in exon 3 in two families and the novel p.V458M (c.1372G>A) mutation in exon 9 in one family. CONCLUSIONS These patients are affected with Bietti crystalline dystrophy without corneal involvement. Variation in disease severity and electroretinographic responses suggests that environmental or additional genetic factors influence the course of the retinal disease. The CYP4V2 p.I111T (c.332T>C) mutant allele may be especially prevalent among patients with BCD in Lebanon, resulting from a single founder.
Collapse
Affiliation(s)
- Nour Maya N. Haddad
- Service d’Ophtalmologie, Hôtel-Dieu de France Hospital, Beirut, Lebanon,Fondation ophtalmologique Adolphe de Rothschild, Paris, France
| | - Naji Waked
- Service d’Ophtalmologie, Hôtel-Dieu de France Hospital, Beirut, Lebanon
| | - Riad Bejjani
- Service d’Ophtalmologie, Hôtel-Dieu de France Hospital, Beirut, Lebanon
| | - Ziad Khoueir
- Service d’Ophtalmologie, Hôtel-Dieu de France Hospital, Beirut, Lebanon
| | - Eliane Chouery
- Unité de Génétique Médicale. Faculté de Médecine, Université Saint-Joseph, Beirut, Lebanon
| | - Sandra Corbani
- Unité de Génétique Médicale. Faculté de Médecine, Université Saint-Joseph, Beirut, Lebanon
| | - André Mégarbané
- Unité de Génétique Médicale. Faculté de Médecine, Université Saint-Joseph, Beirut, Lebanon
| |
Collapse
|
48
|
Yokoi Y, Sato K, Aoyagi H, Takahashi Y, Yamagami M, Nakazawa M. A Novel Compound Heterozygous Mutation in the CYP4V2 Gene in a Japanese Patient with Bietti's Crystalline Corneoretinal Dystrophy. Case Rep Ophthalmol 2011; 2:296-301. [PMID: 22087103 PMCID: PMC3214674 DOI: 10.1159/000331885] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Purpose: To describe the clinical and genetic characteristics of a Japanese family in which one member exhibited Bietti's crystalline corneoretinal dystrophy (BCD). Methods: Using direct sequencing, mutation screening was performed in the CYP4V2 gene of both the patient with BCD and her daughter. Ophthalmic examinations were performed to determine the clinical features of both subjects. Results: The 64-year-old female patient had a bilateral visual acuity of 0.4. Slit lamp examination revealed bilateral crystalline-like deposits at the superior limbus of the cornea. Fundus examination revealed there was chorioretinal atrophy along with numerous glistening yellowish-white crystalline deposits that were scattered throughout the posterior pole and the mid-peripheral retina. Standard flash electroretinography showed an extinguished electroretinogram and Goldmann kinetic perimetry detected a relative scotoma. Genetic analysis revealed that the patient had a heterozygous mutation in the CYP4V2 gene (IVS6-8delTCATACAGGTCATCGCG/GC), which is the most commonly found mutation in Japanese patients with BCD. Furthermore, the patient was also shown to have a novel heterozygous point mutation in exon 9 of the CYP4V2 gene (c.1168C>T). In contrast, her daughter exhibited no clinical findings for BCD even though she carried the same heterozygous mutation in the CYP4V2 gene (c.1168C>T). Conclusion: A novel compound heterozygous mutation was found in the CYP4V2 gene of a patient with BCD. This previously unreported c.1168C>T mutation causes a missense mutation (p.R390C) in the CYP4V2 protein.
Collapse
Affiliation(s)
- Yumiko Yokoi
- Department of Ophthalmology, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, Japan
| | | | | | | | | | | |
Collapse
|
49
|
Liu DN, Liu Y, Meng XH, Yin ZQ. The characterization of functional disturbances in Chinese patients with Bietti's crystalline dystrophy at different fundus stages. Graefes Arch Clin Exp Ophthalmol 2011; 250:191-200. [PMID: 21892605 DOI: 10.1007/s00417-011-1809-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 08/07/2011] [Accepted: 08/15/2011] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The aim of this study was to characterize the functional and clinical disturbances and screen the optimal functional tests in assessing Bietti's crystalline dystrophy (BCD) patients by a cross-sectional method. METHODS The clinical characteristics of BCD were studied in 15 Chinese patients using fundoscopy, fundus fluorescein angiography (FFA), and autofluorescence (AF). The functional features were evaluated by full-field electroretinography (fERG), 85º and 30º perimetry, multifocal ERG (mERG), and chromatic pupillometry. RESULTS The 15 patients were separated into three clinical stages according to their fundus features. fERG- and mERG- showed reduced reponses in the early stages. Substages could be further defined according to the fERG results in the intermediate stages. Reduced pupillary light reflex (PLR) activities with blue-and white-light stumili existed in all patients. The most reduced PLR activities were elicited in the advanced stage of patients who had other nonresponsive functional tests. CONCLUSIONS This study identified the most sensitive functional methods for assessing BCD patients, and the significance of PLR in the advanced stages. In addition, the defined-substages can help us understand the disease more clearly.
Collapse
Affiliation(s)
- Dan Ning Liu
- Southwest Hospital, Southwest Eye Hospital, Third Military Medical University, Chongqing 400038, China
| | | | | | | |
Collapse
|
50
|
Kelly EJ, Nakano M, Rohatgi P, Yarov-Yarovoy V, Rettie AE. Finding homes for orphan cytochrome P450s: CYP4V2 and CYP4F22 in disease states. Mol Interv 2011; 11:124-32. [PMID: 21540472 DOI: 10.1124/mi.11.2.10] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The cytochrome P450 (CYP) 4 family of enzymes contains several recently identified membersthat are referred to as “orphan P450s” because their endogenous substrates are unknown.Human CYP4V2 and CYP4F22 are two such orphan P450s that are strongly linked to ocular andskin disease, respectively. Genetic analyses have identified a wide spectrum of mutations in the CYP4V2gene from patients suffering from Bietti’s crystalline corneoretinal dystrophy, and mutations in theCYP4F22 gene have been linked to lamellar ichthyosis. The strong gene–disease associations provideunique opportunities for elucidating the substrate specificity of these orphan P450s and unraveling thebiochemical pathways that may be impacted in patients with CYP4V2 and CYP4F22 functional deficits.
Collapse
Affiliation(s)
- Edward J Kelly
- Department of Pharmaceutics, University of Washington, Seattle, WA 98195, USA.
| | | | | | | | | |
Collapse
|