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Sakai D, Maeda T, Maeda A, Yamamoto M, Yokota S, Hirami Y, Nakamura M, Takahashi M, Mandai M, Kurimoto Y. DISCREPANCY BETWEEN FUNDUS AUTOFLUORESCENCE ABNORMALITY AND VISUAL FIELD LOSS IN BIETTI CRYSTALLINE DYSTROPHY. Retina 2024; 44:1394-1402. [PMID: 39047130 PMCID: PMC11280442 DOI: 10.1097/iae.0000000000004114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2024]
Abstract
PURPOSE The aim of this study was to explore the potential benefits of retinal pigment epithelium replacement therapy in patients with Bietti crystalline dystrophy (BCD) by assessing the disease pathology with the distinctive relationship between fundus autofluorescence (FAF) abnormality and visual field defect. METHODS Sixteen eyes from 16 patients with BCD and 16 eyes from 16 patients with RHO-associated retinitis pigmentosa were included. Fundus autofluorescence, optical coherence tomography, and Goldmann perimetry results were retrospectively reviewed and assessed using image analyses. RESULTS In patients with BCD, the FAF abnormality area was not correlated with the overall visual field defect area and median overall visual field defect area (57.5%) was smaller than FAF abnormality area (98.5%). By contrast, the ellipsoid zone width was significantly correlated with the central visual field area (r = 0.806, P < 0.001). In patients with RHO-associated retinitis pigmentosa, the FAF abnormality area and ellipsoid zone width were significantly correlated with the overall visual field defect area (r = 0.833, P < 0.001) and central visual field area (r = 0.887, P < 0.001), respectively. CONCLUSION The FAF abnormality shown in patients with BCD involves retinal pigment epithelium degeneration without complete loss of photoreceptors or visual function. These results suggest that patients with BCD are good candidates for retinal pigment epithelium replacement therapy for preservation of residual visual function.
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Affiliation(s)
- Daiki Sakai
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
| | - Tadao Maeda
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
| | - Akiko Maeda
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
| | - Midori Yamamoto
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
| | - Satoshi Yokota
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
| | - Yasuhiko Hirami
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
| | - Makoto Nakamura
- Division of Ophthalmology, Department of Surgery, Kobe University Graduate School of Medicine, Kobe, Japan.
| | - Masayo Takahashi
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
| | - Michiko Mandai
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
| | - Yasuo Kurimoto
- Department of Ophthalmology, Kobe City Eye Hospital, Kobe, Japan;
- Department of Ophthalmology, Kobe City Medical Center General Hospital, Kobe, Japan; and
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Cheloni R, Clough N, Jackson D, Moosajee M. Longitudinal structure-function analysis of molecularly-confirmed CYP4V2 Bietti Crystalline Dystrophy. Eye (Lond) 2024; 38:853-862. [PMID: 37898718 DOI: 10.1038/s41433-023-02791-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 09/26/2023] [Accepted: 10/10/2023] [Indexed: 10/30/2023] Open
Abstract
OBJECTIVES Bietti Crystalline Dystrophy (BCD) is an autosomal recessive progressive retinal disease caused by mutations in CYP4V2. We have characterised the natural history including structural and functional measures to identify potential outcome metrics for future clinical trials. METHODS Molecularly-confirmed BCD patients with biallelic variants in CYP4V2 were retrospectively identified from Moorfields Eye Hospital (UK). Clinical details including results of molecular genetic testing, best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (OCT) scans were extracted. From OCT scans, ellipsoid zone (EZ) measures, foveal thickness of the whole retina, outer retina and choroid were measured. Age-related changes of clinical parameters were assessed with linear mixed models. RESULTS Twenty-eight BCD patients were identified, with median age at baseline of 37 years (interquartile range [IQR]: 30-49.5). Median follow-up was 7.7 years (IQR: 3.4-14.5). Most patients (41.7%) showed chorioretinal atrophy at baseline. All OCT parameters showed significant age-related loss (p < 0.05), with EZ measures and choroidal thickness displaying the most rapid degeneration (2.3-3.3% per year vs 0.6-1.5% per year). Median BCVA was 0.2 LogMAR (IQR: 0-0.5) at baseline and showed small age-related loss ( + 0.016 LogMAR per year, p = 0.0019). Patients exhibited substantial phenotypic variability. CONCLUSIONS BCD presents between age 25 and 40, and slowly progresses to an advanced chorioretinal atrophy and vision loss by age 60. BCVA may be preserved until late, and is seemingly poorly representative of disease progression. OCT parameters capturing EZ and choroid changes may afford more suitable trial outcome measures.
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Affiliation(s)
- Riccardo Cheloni
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Neil Clough
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Daniel Jackson
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, EC1V 9EL, UK.
- Moorfields Eye Hospital NHS Foundation Trust, London, EC1V 2PD, UK.
- The Francis Crick Institute, London, NW1 1AT, UK.
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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.
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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.
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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.
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Bazvand F, Asadi Khameneh E. Presumed Bietti crystalline dystrophy with optic nerve head drusen: a case report. J Med Case Rep 2022; 16:413. [PMID: 36320086 PMCID: PMC9628052 DOI: 10.1186/s13256-022-03581-7] [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: 05/17/2022] [Accepted: 08/21/2022] [Indexed: 11/06/2022] Open
Abstract
Background Bietti crystalline dystrophy is primarily a retinal dystrophy caused by a CYP4V2 mutation and typically presents with crystalline retinal deposits in the posterior fundus. Case presentation We present the case of an otherwise healthy 39-year-old Iranian woman with no family history of ocular disease who suffered with progressive vision loss that had started 2 years prior to presentation. Ocular examination revealed blurry optic nerve head margin and diffuse retinal crystalline deposit in both eyes. Spectral domain optical coherence tomography images showed retinal crystals, located mostly in outer retinal layers, with some areas of outer retinal tubulation and attenuation of outer retinal layers. Crystalline deposits were better visualized on near-infrared images as hyperreflective spots. Fundus autofluorescence images showed hyperautofluorescence areas on optic nerve head consistent with optic nerve head drusen and large hypoautofluorescence areas in posterior retina consistent with retinal pigment epithelium atrophy. Cystinosis was ruled out by blood testing. Conclusion Bietti crystalline dystrophy may be associated with optic nerve head drusen.
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Affiliation(s)
- Fatemeh Bazvand
- Vitreoretina Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Esmaeil Asadi Khameneh
- Vitreoretina Department of Ophthalmology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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A Bietti Crystalline Dystrophy Mouse Model Shows Increased Sensitivity to Light-Induced Injury. Int J Mol Sci 2022; 23:ijms232113108. [DOI: 10.3390/ijms232113108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/24/2022] [Accepted: 10/25/2022] [Indexed: 11/16/2022] Open
Abstract
Bietti crystalline corneo-retinal dystrophy (BCD) is an autosomal recessive inherited retinal dystrophy characterized by multiple shimmering yellow-white deposits in the posterior pole of the retina in association with atrophy of the retinal pigment epithelium (RPE), pigment clumps, and choroidal atrophy and sclerosis. Blindness and severe visual damage are common in late-stage BCD patients. We generated a Cyp4v3 knockout mouse model to investigate the pathogenesis of BCD. This model exhibits decreased RPE numbers and signs of inflammation response in the retina. Rod photoreceptors were vulnerable to light-induced injury, showing increased deposits through fundoscopy, a decrease in thickness and a loss of cells in the ONL, and the degeneration of rod photoreceptors. These results suggest that an inflammatory response might be an integral part of the pathophysiology of BCD, suggesting that it might be reasonable for BCD patients to avoid strong light, and the results provide a useful model for evaluating the effects of therapeutic approaches.
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Jenny LA, Liu PK, Kolesnikova M, Duong J, Kim AH, Levi SR, Greenstein VC, Tsang SH. Foveolar thickness as potential standardized structural outcome measurement in studies of Bietti crystalline dystrophy. Sci Rep 2022; 12:14706. [PMID: 36038562 PMCID: PMC9424222 DOI: 10.1038/s41598-022-16563-y] [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: 02/01/2022] [Accepted: 07/12/2022] [Indexed: 11/16/2022] Open
Abstract
Bietti crystalline dystrophy (BCD) is an ultra-rare orphan disorder that can lead to blindness. Because of the variable rates of progression of the disease, it is necessary to identify suitable outcome measurements for tracking progression in BCD. A retrospective analysis of patients with a clinical and genetic diagnosis of BCD was conducted. Four measurements of spectral domain-optical coherence tomography were compared to patients’ best corrected visual acuity. We observed that patients with higher measurements of foveolar thickness, choroidal thickness in the foveolar region, ellipsoid zone band length and the outer nuclear layer + area, had on average better visual acuity. Future studies are needed to validate the structural–functional correlations we observed in BCD and to propose a sensitive and clinically meaningful outcome measurement for tracking this rare, variable disease.
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Affiliation(s)
- Laura A Jenny
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Pei-Kang Liu
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA.,Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan.,School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Masha Kolesnikova
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Jimmy Duong
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Angela H Kim
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | - Sarah R Levi
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA
| | | | - Stephen H Tsang
- Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA. .,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University, New York, NY, USA. .,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY, USA. .,Institute of Human Nutrition, Columbia University, New York, NY, USA. .,Columbia University Stem Cell Initiative, New York, NY, USA.
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Ratra D, Chattree S, Raviselvan M, Pradhan A, Giridhar S. Structural and functional phenotypic features and molecular analysis of Indian patients with Bietti crystalline dystrophy. Indian J Ophthalmol 2022; 70:2526-2532. [PMID: 35791149 PMCID: PMC9426155 DOI: 10.4103/ijo.ijo_2146_21] [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] [Indexed: 12/02/2022] Open
Abstract
Purpose: Bietti crystalline dystrophy (BCD) is a rare retinal dystrophy, uncommon in Indians. This study describes the various phenotypic features seen in the Indian population. Methods: In this retrospective, descriptive case series, records of patients with either clinical or molecular diagnosis of BCD from 2009 to 2020 were perused. Phenotypic and genotype information was collected and analyzed. Results: This study included 58 patients of BCD (31 males) aged 21–79 years (mean: 47 ± 14 years). The age at onset ranged from 7 to 41 years (mean: 28.8 ± 5.1 years). Vision ranged from 20/20 to counting fingers. There were 18 (31%) patients with stage 1 with crystals and mild retinochoroidal atrophy, 22 (38%) with stage 2 with atrophy extending beyond arcades, and 18 (31%) with absent crystals and extensive atrophy of stage 3. Choroidal neovascular membrane was seen in four patients. The optical coherence tomography showed retinochoroidal thinning (84.6%), outer retinal tubulations (71.8%), and paradoxical foveal thickening with interlaminar bridges (7.7%). Electrophysiology and visual fields showed reduced responses in advanced retinochoroidal changes. Molecular confirmation was available in five patients; five mutations were seen in the CYP4V2. Conclusion: A wide variation is seen in the phenotypic picture of BCD. A molecular diagnosis is helpful in differentiating from other retinal dystrophies. The OCT shows the peculiar feature of the interlaminar bridge in early cases with photoreceptor loss. Further investigations into this OCT feature may provide insights into the pathogenesis of BCD. A genotype–phenotype correlation could not be done.
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Affiliation(s)
- Dhanashree Ratra
- Department of Vitreoretinal Diseases, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Surabhi Chattree
- Department of Vitreoretinal Diseases, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Munispriyan Raviselvan
- Department of Vitreoretinal Diseases, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Arkaprava Pradhan
- Department of Vitreoretinal Diseases, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
| | - Sneha Giridhar
- Department of Vitreoretinal Diseases, Medical Research Foundation, Sankara Nethralaya, Chennai, Tamil Nadu, India
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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.
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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
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贾 睿, 姜 尚, 赵 琳, 杨 丽. [Generation and characterization of Cyp4v3 gene knockout mice]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2021; 53:1099-1106. [PMID: 34916689 PMCID: PMC8695138 DOI: 10.19723/j.issn.1671-167x.2021.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Indexed: 06/14/2023]
Abstract
OBJECTIVE Bietti crystalline dystrophy (BCD) is a rare degenerative eye disease caused by mutations in the CYP4V2 gene, and Cyp4v3 is the murine ortholog to CYP4V2. To better understand the molecular pathogenesis of this disease and to explore the potential treatment we have established a Cyp4v3 knock-out mouse model. METHODS Cyp4v3-/- mice were generated by clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in embryonic stem cells of C57BL/6J mice. Ocular morphologic characteristics were evaluated via fundus imaging, histologic analysis of rods and cones via immunofluorescence, and phalloidin stain to observe retinal pigment epithelium (RPE) in whole-mounts, electroretinogram (ERG) was also conducted to examine the retinal function. RESULTS The characteristic features of BCD recurred in the Cyp4v3-/- mice, including retinal crystalline deposits, atrophy and degeneration of RPE cells, and ERG amplitude decline of dark and light adapted a- and b- wave; however, the immunofluorescence stain of rod and cone cells did not show obvious differences when compared with the wild type (WT) mice. In the early stage of the disease, no crystal-like deposits were found in the fundus, ERG detection of the retinal function did not find a significant decline, and the morphological structure and quantity of the neural retina and RPE did not change significantly. Crystalline deposits occurred and converged when the Cyp4v3-/- mice at the end of 6 months, and the deposits disappeared when the Cyp4v3-/- mice at the end of 12 months. The ERG amplitude started to decline when the Cyp4v3-/- mice at the end of 6 months and deteriorated at the end of 12 months. The RPE cells of the 12-month old Cyp4v3-/- mice showed irregular shape by phalloidin staining of F-actin. The Cyp4v3-/- mice behaved normally and were viable and fertile when maintained under specific pathogen-free (SPF) housing conditions. CONCLUSION Just like BCD patients, the disease progress of Cyp4v3-/- mouse is correlated with the age, which provides a good model for pathogenesis and gene therapy study in the future. The atrophy and degeneration of RPE take the lead in progressing of the disease, but the mechanism is not clear yet.
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Affiliation(s)
- 睿璇 贾
- />北京大学第三医院眼科,眼部神经损伤的重建保护与康复北京市重点实验室,北京 100191Department of Ophthalmology, Peking University Third Hospital; Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Beijing 100191, China
| | - 尚伟 姜
- />北京大学第三医院眼科,眼部神经损伤的重建保护与康复北京市重点实验室,北京 100191Department of Ophthalmology, Peking University Third Hospital; Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Beijing 100191, China
| | - 琳 赵
- />北京大学第三医院眼科,眼部神经损伤的重建保护与康复北京市重点实验室,北京 100191Department of Ophthalmology, Peking University Third Hospital; Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Beijing 100191, China
| | - 丽萍 杨
- />北京大学第三医院眼科,眼部神经损伤的重建保护与康复北京市重点实验室,北京 100191Department of Ophthalmology, Peking University Third Hospital; Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Beijing 100191, China
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11
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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.
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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
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12
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Xu Y, Qin Z, Wu N, Zhao T, Gu P, Ren B, Li L, Meng X, Liu Y. RETINAL AND CHOROIDAL BLOOD PERFUSION IN PATIENTS WITH BIETTI CRYSTALLINE DYSTROPHY. Retina 2021; 41:2351-2360. [PMID: 33840785 DOI: 10.1097/iae.0000000000003182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare changes of chorioretinal blood perfusion between Bietti crystalline dystrophy (BCD) and typical retinitis pigmentosa and perform a staging and a longitudinal analysis of chorioretinal perfusion in BCD. METHODS Twenty-eight patients with BCD (56 eyes), 28 patients with typical retinitis pigmentosa (56 eyes), and 28 healthy subjects (56 eyes) were enrolled. Macular structural parameters and subfoveal choroidal thickness were measured using optical coherence tomography. Retinal vessel and perfusion densities were calculated using optical coherence tomography angiography. Choroidal blood perfusion was assessed through indocyanine green angiography. The results of the BCD group were compared with those of the retinitis pigmentosa and control groups and followed by a staging and a longitudinal analysis of BCD. RESULTS Macular structural and perfusion parameters were decreased less in the BCD group than those in the retinitis pigmentosa group. Subfoveal choroidal thickness was significantly thinner in the BCD group, with a remarkable choroidal perfusion deficit using indocyanine green angiography. The staging analysis revealed damage of both retinal and choroidal perfusion in BCD; however, the longitudinal analysis showed the impairment of choroidal perfusion outweighed retinal. CONCLUSION Both retinal and choroidal blood perfusion are impaired in BCD, but choroidal perfusion deficit caused by CYP4V2 mutations may play a more vital pathologic role.
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Affiliation(s)
- Yufei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Zuoxin Qin
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Nan Wu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Tongtao Zhao
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Peng Gu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Bangqi Ren
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Lin Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Xiaohong Meng
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Yong Liu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China; and
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
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13
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Zhang S, Wang L, Liu Z, Sun H, Li Q, Xing C, Xiao Z, Peng X. Observation of the characteristics of the natural course of Bietti crystalline dystrophy by fundus fluorescein angiography. BMC Ophthalmol 2021; 21:239. [PMID: 34049507 PMCID: PMC8161580 DOI: 10.1186/s12886-021-01999-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 05/18/2021] [Indexed: 11/25/2022] Open
Abstract
Background Bietti crystalline dystrophy (BCD) is an autosomal recessive genetic disorder that causes progressive vision loss. Here, 12 patients were followed up for 1–5 years with fundus fluorescein angiography (FFA) to observe BCD disease progression. Methods FFA images were collected for 12 patients with BCD who visited our clinic twice or more over a 5-year period. Peripheral venous blood was collected to identify the pathogenic gene related to the clinical phenotype. Results We observed two types in FFA images of patients with BCD. Type 1 showed retinal pigment epithelium (RPE) atrophy in the macular area, followed by choriocapillaris atrophy and the subsequent appearance of RPE atrophy appeared at the peripheral retina. Type 2 showed RPE atrophy at the posterior pole and peripheral retina, followed by choriocapillaris atrophy around the macula and along the superior and inferior vascular arcades and the nasal side of the optic disc. The posterior and peripheral lesions of both type 1 and type 2 BCD subsequently extended to the mid-periphery; finally, all the RPEs and choriocapillaris atrophied, exposing the choroid great vessels, but type 2 macular RPE atrophy could last longer. Conclusions The characterization of two different types of BCD development provides a better understanding of the phenotype and the progression of the disease for a precise prognosis and prediction of pathogenesis.
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Affiliation(s)
- Shengjuan Zhang
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China.,Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Lifei Wang
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Zhiqiang Liu
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Huijing Sun
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Qian Li
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China
| | - Chen Xing
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Zhe Xiao
- Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China
| | - Xiaoyan Peng
- Beijing Institute of Ophthalmology, Beijing Ophthalmology and Visual Science Key Laboratory, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, 17 Hougou Lane, Chongnei Street, 100005, Beijing, People's Republic of China.
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14
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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.
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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
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15
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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.
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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.
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16
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Qu B, Wu S, Jiao G, Zou X, Li Z, Guo L, Sun X, Huang C, Sun Z, Zhang Y, Li H, Zhou Q, Sui R, Li W. Treating Bietti crystalline dystrophy in a high-fat diet-exacerbated murine model using gene therapy. Gene Ther 2020; 27:370-382. [PMID: 32483213 DOI: 10.1038/s41434-020-0159-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/12/2020] [Accepted: 05/19/2020] [Indexed: 11/09/2022]
Abstract
Lipid metabolic deficiencies are associated with many genetic disorders. Bietti crystalline dystrophy (BCD), a blindness-causing inherited disorder with changed lipid profiles, is more common in Chinese and Japanese than other populations. Our results reveal that mouse models lacking Cyp4v3 have less physiological and functional changes than those of BCD patients with this gene defect. After the administration of a high-fat diet (HFD), the occurrence of retinal lesions were both accelerated and aggregated in the Cyp4v3-/- mouse models, implying that changed lipid levels were not only associated factors but also risk factors to BCD patients. Facilitated by the results, we found that the reduced electroretinography waveforms and retinal thickness observed in the HFD-induced mouse models were effectively recovered after subretinal delivery of a human CYP4V2 gene carried by an adeno-associated virus vector, which demonstrates the potential curability of BCD by gene therapy.
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Affiliation(s)
- Bin Qu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Guanyi Jiao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Zhikun Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lu Guo
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Xuehan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cheng Huang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China.,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China. .,Key Laboratory of Ocular Fundus Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China.
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China. .,Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, 100101, China.
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17
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Surve A, Balaji A, Azad SV, Kumar V, Vohra R, Venkatesh P. Role of red free imaging, retinal reflectance and fundus autofluorescence in Bietti crystalline dystrophy: case report. THERAPEUTIC ADVANCES IN RARE DISEASE 2020; 1:2633004020958013. [PMID: 37180496 PMCID: PMC10032466 DOI: 10.1177/2633004020958013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/27/2020] [Indexed: 05/16/2023]
Abstract
Bietti crystalline dystrophy (BCD), a rare autosomal recessive hereditary disorder, is identified by its clinical features. It is characterised by crystalline deposits and hence called crystalline retinopathy. The retinopathy progresses with age, showing a decrease in the number of crystalline deposits and increase in the area of chorioretinal degeneration, which spreads in a centrifugal pattern. Thus, BCD can be confused with other disorders with crystalline-like deposits and chorioretinal degenerations. The red-free and near-infrared reflectance allows prominent visualisation of crystalline deposits that may be missed. The non-inferiority of red-free imaging and its wider availability could allow its use as a screening tool. The enhanced depth imaging optical coherence tomography shows crystalline deposits throughout the retina and outer retinal tubulation. Thus, multimodality imaging can act as an adjunct in diagnosis, monitoring and follow up in these cases, acting not only as a teaching tool but also giving an insight into the underlying pathophysiology of the disorder. Plain language summary Use of imaging in diagnosis of Bietti crystalline dystrophy Bietti crystalline dystrophy is a rare familial disorder but is not shown in all family members and may skip generations, as it has an autosomal recessive pattern of inheritance. It shows refractile yellow-white crystalline deposits and degenerative changes in the retina. These crystalline deposits disappear with age while degenerative changes increase and spread from centre to the periphery. This may cause difficulty in early detection, and confusion with similar degenerative diseases of the retina. The use of various imaging modalities can help in diagnosis and follow up of these cases. These modalities also provide understanding of the basic disease process.
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Affiliation(s)
- Abhidnya Surve
- Vitreoretinal, trauma and uvea services, Dr.
Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of
Medical Sciences, Ansari Nagar, New Delhi, India
| | - Akshaya Balaji
- Dr. Rajendra Prasad Centre for Ophthalmic
Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi,
India
| | - Shorya Vardhan Azad
- Assistant Professor, Vitreo-retina, Trauma &
Uvea Services, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India
Institute of Medical Sciences, Ansari nagar, New Delhi 110029, India
| | - Vinod Kumar
- Vitreoretinal, trauma and uvea services, Dr.
Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of
Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rajpal Vohra
- Vitreoretinal, trauma and uvea services, Dr.
Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of
Medical Sciences, Ansari Nagar, New Delhi, India
| | - Pradeep Venkatesh
- Vitreoretinal, trauma and uvea services, Dr.
Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of
Medical Sciences, Ansari Nagar, New Delhi, India
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18
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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.
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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
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Song WK, Clouston P, MacLaren RE. Presence of corneal crystals confirms an unusual presentation of Bietti's retinal dystrophy. Ophthalmic Genet 2019; 40:461-465. [PMID: 31638456 DOI: 10.1080/13816810.2019.1678176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Background: Bietti crystalline corneoretinal dystrophy (BCD) (OMIM 210370) is a rare autosomal recessive retinal dystrophy typically characterized by multiple intraretinal crystals over the posterior pole of the retina. Degeneration of the retina and sclerosis of the choroidal vessels results in progressive night blindness and central visual field loss.Methods: Detailed ophthalmic and genetic testing of the patient and his father were performed.Results: We report on a 41-year-old male patient with advanced chorioretinal dystrophy at the posterior pole extending into the peripheral retina. His sister and his father were similarly affected with nyctalopia and decreased visual acuity, although his father had a milder phenotype of a typical macular dystrophy. On close slit-lamp examination, however, both patient and his father had multiple yellow-white crystals in the peripheral cornea. Corneal findings and consanguinity of the patient's parents lead to suspicion of BCD. Molecular genetic results of the patient and his father showed homozygous for CYP4V2, c. 197T>G p.(Met66Arg) confirming the diagnosis of BCD.Conclusions: The patient's pedigree shows pseudodominant inheritance due to consanguineous parents. However, careful examination of the corneal findings strengthened the clinical suspicion of BCD, facilitating the molecular genetic confirmation of this autosomal recessive disease.
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Affiliation(s)
- Won Kyung Song
- Nuffield Laboratory of Ophthalmology, University of Oxford & Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK.,CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Penny Clouston
- Oxford Medical Genetics Laboratories, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, University of Oxford & Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
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20
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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.
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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
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21
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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.
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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
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22
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García-García GP, Martínez-Rubio M, Moya-Moya MA, Pérez-Santonja JJ, Escribano J. Identification of novel CYP4V2 genotypes associated with Bietti crystalline dystrophy and atypical anterior segment phenotypes in Spanish patients. Acta Ophthalmol 2018; 96:e865-e873. [PMID: 29691984 DOI: 10.1111/aos.13768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/01/2018] [Indexed: 11/29/2022]
Abstract
PURPOSE To identify the spectrum of disease-causing CYP4V2 variants in Spanish patients with clinically diagnosed Bietti crystalline dystrophy (BCD) over an 8-year period and to analyse the phenotype-genotype correlation of the identified variants. METHODS Four unrelated Spanish probands with a clinical diagnosis of BCD were recruited. Ophthalmological examination included visual acuity (VA), slit lamp examination, in vivo corneal confocal microscopy, funduscopy and fluoresceinic angiography. Genomic DNA was obtained from blood samples, and the exons and flanking intron sequences of the CYP4V2 gene were screened by Sanger sequencing. Family members of the patients with mutations in CYP4V2 gene were subsequently studied. RESULTS Clinical examination revealed retinal and corneal patterns compatible with BCD in all the participants. We identified a total of six CYP4V2 variants among the four carriers. As far as we know, the variant p.(Trp244Cysfs*33) has not previously been reported. This variant along with p.(Ala204Thr) and p.(Arg443Trp) were combined in three novel pathogenic phenotypes that share the presence of bilateral limbic glistening deposits, severe retinal damage and visual impairment and a fast rate of progression of the disease. CONCLUSION To the best of our knowledge, this study represents the largest effort to determine the genetic alterations underlying BCD in Spain to date. Our results show that analysis of CYP4V2 variants is required for a reliable diagnosis of BCD. We report a high prevalence of anterior segment changes in this Spanish BCD cohort, which we consider representative of the Spanish patients.
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Affiliation(s)
| | | | | | | | - Julio Escribano
- Laboratory of Human Molecular Genetics; School of Medicine/Research Institute of Neurological Disabilities (IDINE); University of Castilla La-Mancha; Albacete Spain
- Cooperative Research Network on Visual and Life Quality; Instituto de Salud Carlos III; Madrid Spain
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23
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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.
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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
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24
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Lockhart CM, Smith TB, Yang P, Naidu M, Rettie AE, Nath A, Weleber R, Kelly EJ. Longitudinal characterisation of function and structure of Bietti crystalline dystrophy: report on a novel homozygous mutation in CYP4V2. Br J Ophthalmol 2017; 102:187-194. [PMID: 28698241 DOI: 10.1136/bjophthalmol-2016-309696] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 05/03/2017] [Accepted: 05/06/2017] [Indexed: 01/11/2023]
Abstract
BACKGROUND Bietti crystalline dystrophy (BCD) is a rare inherited disorder characterised by fine crystalline deposits in the corneal limbus and retinal posterior pole. In 2004, mutations in the CYP4V2 gene were identified as the cause of BCD. Here, we describe the report of a homozygous point mutation in a patient with BCD and provide detailed characterisation of functional and structural changes over 20 years. METHODS At regular intervals, the patient underwent repeat ophthalmic evaluations. DNA was extracted from buccal swabs, amplified by standard PCR and analysed for homology to the CYP4V2 sequence. Homology modelling was conducted using Iterative Threading ASSEmbly Refinement and molecular dynamics simulations using GROningen MAchine for Chemical Simulations. RESULTS The proband, a 47-year-old woman of German ancestry was diagnosed with crystalline retinopathy at age 25. Over the next 20 years, visual acuity and function gradually declined with progression of retinal pigment epithelium and choroidal atrophy. When first tested at 39 years of age, the multifocal electroretinogram (ERG) was markedly abnormal, more so for the right eye, whereas the full-field ERG was more symmetrical and lagged other measures of visual function. Gene sequencing showed a single C>T point mutation in exon 9 encoding a R400C amino acid change. Computational modelling suggests the mutation impairs function due to loss of a hydrogen bonding interaction with the propionate side chains of the haeme prosthetic group. CONCLUSION This is the first report of a homozygous R400C mutation in CYP4V2 with protein modelling showing high likelihood of enzyme dysfunction. The comprehensive long-term clinical follow-up provides insight into disease progression and highlights possible anti-inflammatory modulation of disease severity.
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Affiliation(s)
| | - Travis B Smith
- Casey Eye Institute, Oregon Health Sciences University, Portland, Oregon, USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health Sciences University, Portland, Oregon, USA
| | - Malini Naidu
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
| | - Allan E Rettie
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - Abhinav Nath
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington, USA
| | - Richard Weleber
- Casey Eye Institute, Oregon Health Sciences University, Portland, Oregon, USA
| | - Edward J Kelly
- Department of Pharmaceutics, University of Washington, Seattle, Washington, USA
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25
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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.
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26
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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.
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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
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27
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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.
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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
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28
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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.
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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.
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29
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Evaluation of Photoreceptors in Bietti Crystalline Dystrophy with CYP4V2 Mutations Using Adaptive Optics Scanning Laser Ophthalmoscopy. Am J Ophthalmol 2016; 161:196-205.e1. [PMID: 26521715 DOI: 10.1016/j.ajo.2015.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 10/16/2015] [Accepted: 10/18/2015] [Indexed: 01/28/2023]
Abstract
PURPOSE To evaluate photoreceptors in Bietti crystalline dystrophy patients with CYP4V2 mutations using high-resolution images of the macula obtained with adaptive optics scanning laser ophthalmoscopy (AO-SLO). DESIGN Prospective observational case series with comparison to healthy controls. METHODS Seven eyes of 7 Bietti crystalline dystrophy patients with CYP4V2 mutations and 12 normal eyes of 12 age- and axial length-matched healthy volunteers were studied. All participants underwent ophthalmologic examinations and AO-SLO assessments. All patients underwent spectral-domain optical coherence tomography, fundus autofluorescence, Humphrey field analysis, and electroretinography. AO-SLO images were analyzed 0.5 mm and 1.0 mm from the center of the fovea in the superior, inferior, nasal, and temporal quadrants. RESULTS Mean ± standard deviation cone density (cells/mm(2)) 0.5 mm from the center of the fovea was 17,209 ± 2276 in patients and 20 493 ± 2758 in controls, which was statistically different (P = .001); however, mean cone density 1.0 mm from the center of the fovea was 15 685 ± 2302 in patients and 15 705 ± 1848 in controls, which was not statistically different (P = .20). There was no correlation between cone density and mean deviation measured using a Humphrey field analysis or visual acuity in patients. CONCLUSIONS In Bietti crystalline dystrophy patients with CYP4V2 mutations, cone density remained for visual dysfunction by evaluation using high-resolution AO-SLO. These findings support the theory that disorder of the retinal pigment epithelium and the photoreceptors in the patients are the primary and secondary pathologic changes, respectively. This is consistent with results from previous basic studies.
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Vahedi M, Davis G, Coleman MJ, Garrett BS, Eghrari AO. Smartphone-based Video of Demodex folliculorum In Biopsied Human Eyelash Follicles. MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2015; 4:36-8. [PMID: 26060828 PMCID: PMC4458324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The ability of smartphone technology to document static microscopy images has been well documented and is gaining widespread use in ophthalmology, where slit-lamp biomicroscopy is frequently utilized. However, little has been described regarding the use of smartphone technology to relay video of tissue microscopy results to patients, particularly when a tissue sample integrates motility of organisms as a characteristic feature of the disease. Here, we describe the method to use smartphone video to document motility of Demodex folliculorum in human eyelashes, individual results of which can be shown to patients for education and counseling purposes. The use of smartphone video in documenting the motility of organisms may prove to be beneficial in a variety of medical fields; producers of electronic medical records, therefore, may find it helpful to integrate video drop box tools.
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Affiliation(s)
- Mithaq Vahedi
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA,Correspondence to: Allen Eghrari, MD, Wilmer Eye Institute, 600 N. Wolfe St, Maumenee 327, Baltimore, Maryland USA; Tel: +1-410-955-5490; E-Mail:
| | - Gavin Davis
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA,Correspondence to: Allen Eghrari, MD, Wilmer Eye Institute, 600 N. Wolfe St, Maumenee 327, Baltimore, Maryland USA; Tel: +1-410-955-5490; E-Mail:
| | - Michael James Coleman
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Brian Steven Garrett
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Allen Omid Eghrari
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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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.
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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
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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.
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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
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High-Resolution Imaging of Patients with Bietti Crystalline Dystrophy with CYP4V2 Mutation. J Ophthalmol 2014; 2014:283603. [PMID: 25276414 PMCID: PMC4167809 DOI: 10.1155/2014/283603] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 08/02/2014] [Accepted: 08/03/2014] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to determine the retinal morphology of eyes with Bietti crystalline dystrophy (BCD) associated with a CYP4V2 mutation using high-resolution imaging techniques. Three subjects with BCD underwent detailed ophthalmic examinations. High-resolution fundus images were obtained with an adaptive optics (AO) fundus camera. A common homozygous mutation was detected in the three patients. Funduscopic examination of the three patients revealed the presence of crystalline deposits in the retina, and all of the crystalline deposits were also detected in the infrared (IR) images. The crystals observed in the IR images were seen as bright reflective plaques located on the RPE layer in the SD-OCT images. The clusters of hyperreflective signals in the AO images corresponded to the crystals in the IR images. High-magnification AO images revealed that the clusters of hyperreflective signals consisted of circular spots that are similar to the signals of cone photoreceptors. Most of these circular spots were detected in healthy areas in the FAF images. There is a possibility that circular spots observed by AO are residual cone photoreceptors located over the crystals.
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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.
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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
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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.
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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
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36
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Cystoid Macular Edema in Bietti's Crystalline Retinopathy. Case Rep Ophthalmol Med 2014; 2014:964892. [PMID: 24949209 PMCID: PMC4037624 DOI: 10.1155/2014/964892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 04/19/2014] [Accepted: 05/02/2014] [Indexed: 11/17/2022] Open
Abstract
A 27-year-old man with progressive bilateral visual decline was diagnosed to have Bietti's crystalline dystrophy (BCD). Fluorescein angiography revealed bilateral petaloid type late hyperfluorescence implicating concurrent cystoid macular edema (CME). Optical coherence tomography exhibited cystoid foveal lacunas OU. During the follow-up of six years, intraretinal crystals reduced in amount but CME persisted angiographically and tomographically. CME is among the rare macular features of BCD including subfoveal sensorial detachment, subretinal neovascular membrane, and macular hole.
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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
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Molecular analysis and phenotypic study in 14 Chinese families with Bietti crystalline dystrophy. PLoS One 2014; 9:e94960. [PMID: 24739949 PMCID: PMC3989252 DOI: 10.1371/journal.pone.0094960] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 03/21/2014] [Indexed: 11/19/2022] Open
Abstract
Purpose To investigate the clinical features and cytochrome P450 family 4 subfamily V polypeptide 2 (CYP4V2) gene mutations in 14 Chinese families with Bietti crystalline dystrophy (BCD). Methods Seventeen patients from 14 unrelated Chinese families with BCD were recruited for complete clinical ophthalmic examination and genetic study. The 11 exons of CYP4V2 were amplified from genomic DNA of all patients and their family members by polymerase chain reaction (PCR) and then sequenced. Exons of TIMP3 were also sequenced in BCD patient associated with choroidal neovascularization (CNV). One hundred and seventy unrelated healthy Chinese subjects were screened for mutations in CYP4V2. Results All 17 patients with BCD had mutations in CYP4V2; one of these mutations was novel (c.219T>A, p.F73L) and four other mutations had been reported. The p.F73L mutation was a commonly detected mutation in our study (seven out of 34 alleles), either in the homozygous state or in the heterozygous state. Among the patients, considerable phenotypic variability was detected, both within and between families. Screening of TIMP3 did not find any mutation in the BCD patient associated with CNV. Conclusion The novel CYP4V2 c.219T>A (p.F73L) mutation may be another recurrent mutation in Chinese patients with BCD. Our study expands the mutation spectrum of CYP4V2 and characterizes novel genotype–phenotype associations in Chinese patients with BCD.
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Broadhead GK, Chang AA. Acetazolamide for cystoid macular oedema in Bietti crystalline retinal dystrophy. KOREAN JOURNAL OF OPHTHALMOLOGY 2014; 28:189-91. [PMID: 24688265 PMCID: PMC3958638 DOI: 10.3341/kjo.2014.28.2.189] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/05/2014] [Indexed: 11/23/2022] Open
Abstract
Bietti crystalline retinal dystrophy is a rare, inherited disorder whose hallmark is the presence of retinal crystal deposits associated with later chorioretinal degeneration. This condition may rarely be complicated by the development of cystoid macular oedema leading to rapid visual decline. Currently, treatment options for this complication of Bietti dystrophy are limited and the visual prognosis is poor. Here, we present a case of cystoid macular oedema associated with Bietti dystrophy that was successfully diagnosed using multimodal imaging techniques including optical coherence tomography and fluorescein angiography. These modalities confirmed the diagnosis of macular oedema and excluded other possible causes of oedema such as choroidal neovascularisation. In this patient, cystoid macular oedema was resolved with oral acetazolamide therapy, a treatment that has not been previously reported in this context. Acetazolamide treatment resulted in oedema resolution and improvement in visual function, and can be considered a therapeutic option for other patients with Bietti dystrophy who develop cystoid macular oedema.
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Affiliation(s)
- Geoffrey K Broadhead
- Sydney Institute of Vision Science, Sydney, Australia. ; Sydney Retina Clinic & Day Surgery, Sydney, Australia. ; Save Sight Institute, The University of Sydney, Sydney, Australia
| | - Andrew A Chang
- Sydney Institute of Vision Science, Sydney, Australia. ; Sydney Retina Clinic & Day Surgery, Sydney, Australia. ; Save Sight Institute, The University of Sydney, Sydney, Australia
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Osman Saatci A, Can Doruk H. An Overview of Rare and Unusual Clinical Features of Bietti's Crystalline Dystrophy. MEDICAL HYPOTHESIS, DISCOVERY & INNOVATION OPHTHALMOLOGY JOURNAL 2014; 3:51-6. [PMID: 25738160 PMCID: PMC4346678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Bietti's crystalline dystrophy (BCD) is a rare disease presenting with the appearance of intraretinal crystalline deposits and varying degrees of chorioretinal atrophy commencing at the posterior pole. Within time, intraretinal crystals gradually disappear and chorioretinal atrophy extends beyond the macula even resulting in complete chorioretinal atrophy. Concomitant corneal crystals can be noted in 1/2 - 1/3 of the patients, and the presence of corneal crystals is not a must for establishing the diagnosis. For the past decade, genetic evaluations and newer imaging modalities expand our knowledge about the disease. CYP4V2 gene is found to be the gene responsible for the disease process and new mutations are still being described. Modern imaging modalities, such as a spectral domain optical coherence tomography (SD-OCT) shed light on the anatomic features of the disease. By this, we reiterate the rare and unusual clinical features of BCD.
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