1
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Zhao R, Liu M, Dai E, Chen C, Lv L, Peng L, He Y, Li S, Yang M. Deciphering a crucial dimeric interface governing Norrin dimerization and the pathogenesis of familial exudative vitreoretinopathy. FASEB J 2024; 38:e23493. [PMID: 38363575 DOI: 10.1096/fj.202302387r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/18/2024] [Accepted: 02/02/2024] [Indexed: 02/17/2024]
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary eye disease that could cause blindness. It has been established that Norrin forms dimers to activate β-catenin signaling, yet the core interface for Norrin dimerization and the precise mechanism by which Norrin dimerization contributes to the pathogenesis of FEVR remain elusive. Here, we report an NDP variant, c.265T>C (p.Phe89Leu), that interrupted β-catenin signaling by disrupting Norrin dimerization. Structural and functional analysis revealed that the Phe-89 of one Norrin monomer interacts with Pro-98, Ser-101, Arg-121, and Ile-123 of another, forming two core symmetrical dimerization interfaces that are pivotal for the formation of a "hand-by-arm" dimer. Intriguingly, we proved that one of the two core symmetrical interfaces is sufficient for dimerization and activation of β-catenin signaling, with a substantial contribution from the Phe-89/Pro-98 interaction. Further functional analysis revealed that the disruption of both dimeric interfaces eliminates potential binding sites for LRP5, which could be partially restored by over-expression of TSPAN12. In conclusion, our findings unveil a core dimerization interface that regulates Norrin/LRP5 interaction, highlighting the essential role of Norrin dimerization on β-catenin signaling and providing potential therapeutic avenues for the treatment of FEVR.
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Affiliation(s)
- Rulian Zhao
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Min Liu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Erkuan Dai
- Department of Ophthalmology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chen Chen
- Center for Natural Products Research, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Liting Lv
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Li Peng
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Yunqi He
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Shujin Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Mu Yang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, The Department of Medical Genetics, The Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
- Research Unit for Blindness Prevention, Chinese Academy of Medical Sciences (No.2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
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2
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Li H, Li Z, Wang D, Chen C, Chen Z, Wang J, Xu C, Dong X. Next-generation sequencing reveals a case of Norrie disease in a child with bilateral ocular malformation. Front Genet 2022; 13:870232. [PMID: 36035112 PMCID: PMC9412000 DOI: 10.3389/fgene.2022.870232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 06/27/2022] [Indexed: 12/04/2022] Open
Abstract
A Norrie disease protein gene (NDP) variant, c.174 + 1G > A, was found in a Chinese family through next-generation sequencing and verified with Sanger sequencing. A case of Norrie disease was reported in the first child, and the symptoms were consistent with the results of gene sequencing. The child’s mother, who was pregnant at the time, was found to be a carrier of the identified pathogenic variant. To determine if the fetus carried the same disease-causing variant, prenatal examination and prenatal diagnosis were conducted. The fetus had biocular vitreous abnormalities and complete retinal abnormalities. Genetic testing showed that the fetus had maternally inherited the NDP gene variant found in the proband. It was concurrently confirmed that the NDP gene variant led to the deletion of 246 bp at the 3′ end of exon 2, resulting in the deletion of the initiation codon and the occurrence of disease. Our study suggests that the diagnosis of rare diseases through next-generation sequencing, combined with prenatal ultrasound and prenatal diagnosis, can help families with known familial genetic diseases. Furthermore, the findings of this study broaden the known genetic spectrum of Norrie disease.
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Affiliation(s)
- Haijun Li
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Zhiming Li
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Degang Wang
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Chuanming Chen
- Radiological Department, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Zhiqiang Chen
- Pathology Department, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Jinhua Wang
- Gynaecology Department, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Chenxia Xu
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, GD, China
| | - Xingsheng Dong
- Prenatal Diagnosis Center, Boai Hospital of Zhongshan, Zhongshan, GD, China
- *Correspondence: Xingsheng Dong,
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3
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Hassan A, Mir YR, Kuchay RAH. Ocular findings and genomics of X-linked recessive disorders: A review. Indian J Ophthalmol 2022; 70:2386-2396. [PMID: 35791118 PMCID: PMC9426149 DOI: 10.4103/ijo.ijo_252_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Advent of new sequencing technologies and modern diagnostic procedures has opened the door for a deeper understanding of disorders about which little was known previously. Discovery of novel genes, new genetic variants in previously known genes and better techniques of functional validation has immensely contributed to unraveling the molecular basis of genetic disorders. Availability of knockout animal models like the zebrafish and gene editing tools like CRISPR-Cas9 has elucidated the function of many new genes and helped us to better understand the functional consequences of various gene defects. This has also led to better diagnosis and therapeutic interventions. In this context, a good body of research work has been done on X-linked recessive disorders with ocular findings. This review will focus on ocular and genetic findings of these rare disorders. To our knowledge, this is the first comprehensive review encompassing ocular and genomic spectrum of X-linked recessive disorders.
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Affiliation(s)
- Asima Hassan
- Department of Health and Medical Education, Srinagar, Jammu and Kashmir, India
| | - Yaser R Mir
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
| | - Raja A H Kuchay
- Department of Biotechnology, Baba Ghulam Shah Badshah University, Rajouri, Jammu and Kashmir, India
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4
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Gong Y, Liu Z, Zhang X, Shen S, Xu Q, Zhao H, Shang J, Li W, Wang Y, Chen J, Liu X, Zheng QY. Endolymphatic Hydrop Phenotype in Familial Norrie Disease Caused by Large Fragment Deletion of NDP. Front Aging Neurosci 2022; 14:771328. [PMID: 35517050 PMCID: PMC9062296 DOI: 10.3389/fnagi.2022.771328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 03/14/2022] [Indexed: 11/13/2022] Open
Abstract
Norrie disease (ND; OMIM 310600), a rare X-linked recessive genetic disorder, is characterized by congenital blindness and occasionally, sensorineural hearing loss, and developmental delay. The congenital blindness of ND patients is almost untreatable; thus, hearing is particularly important for them. However, the mechanism of hearing loss of ND patients is unclear, and no good treatment is available except wearing hearing-aid. Therefore, revealing the mechanism of hearing loss in ND patients and exploring effective treatment methods are greatly important. In addition, as a serious monogenic genetic disease, convenient gene identification method is important for ND patients and their family members, as well as prenatal diagnosis and preimplantation genetic diagnosis to block intergenerational transmission of pathogenic genes. In this study, a Norrie family with two male patients was reported. This pedigree was ND caused by large fragment deletion of NDP (norrin cystine knot growth factor NDP) gene. In addition to typical severe ophthalmologic and audiologic defects, the patients showed new pathological features of endolymphatic hydrops (EH), and they also showed acoustic nerves abnormal as described in a very recent report. PCR methods were developed to analyze and diagnose the variation of the family members. This study expands the understanding of the clinical manifestation and pathogenesis of ND and provides a new idea for the treatment of patients in this family and a convenient method for the genetic screen for this ND family.
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Affiliation(s)
- Yuerong Gong
- Department of Ophthalmology, Binzhou Medical University Hospital, Binzhou, China
| | - Zhang Liu
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Xiaolin Zhang
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Shuang Shen
- Institute of Hearing and Speech Rehabilitation, College of Special Education, Binzhou Medical University, Yantai, China
| | - Qijun Xu
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Hongchun Zhao
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Jing Shang
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Weiguo Li
- Department of Ophthalmology, Binzhou Medical University Hospital, Binzhou, China
| | - Yanfei Wang
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
| | - Jun Chen
- Department of Otolaryngology Head and Neck Surgery, Institute of Otolaryngology, Binzhou Medical University Hospital, Binzhou, China
- *Correspondence: Jun Chen,
| | - Xiuzhen Liu
- Medical Research Center, Binzhou Medical University Hospital, Binzhou, China
- Xiuzhen Liu,
| | - Qing Yin Zheng
- Department of Otolaryngology Head and Neck Surgery, Case Western Reserve University, Cleveland, OH, United States
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5
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Yang J, Xiao X, Li S, Mai G, Jia X, Wang P, Sun W, Zhang Q. Severe Exudative Vitreoretinopathy as a Common Feature for CTNNB1, KIF11 and NDP Variants Plus Sector Degeneration for KIF11. Am J Ophthalmol 2022; 235:178-187. [PMID: 34582765 DOI: 10.1016/j.ajo.2021.09.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 11/17/2022]
Abstract
PURPOSE To characterize ocular phenotypes in patients with CTNNB1, KIF11, or NDP variants. DESIGN Retrospective case series. METHODS Seventy-four patients from 59 unrelated families with CTNNB1, KIF11, and NDP variants were enrolled based on exome sequencing. The clinical data of ophthalmoscope, fundus photography, fluorescein angiography, and ocular ultrasound scan were evaluated. RESULTS A total of 55 potential pathogenic variants were identified, including 26 in KIF11 (28 families), 23 in NDP (25 families), and 6 in CTNNB1 (6 families). In total, 74 patients from the 59 families carried the variants, in whom clinical data were available from 70 patients for the current analysis. Severe familial exudative vitreoretinopathy (FEVR), stages 4 and 5, was present in 72.9% (51/70) of patients. In addition, panretinal or sector chorioretinal degeneration along with FEVR is a specific feature associated with KIF11 variants, present in 93.8% (30/32) of patients. FEVR-like change was observed in almost all patients with rare hemizygous variants in NDP, patients with heterozygous truncation variants in CTNNB1, as well as patients with heterozygous truncation or damaging missense variants in KIF11. CONCLUSIONS Severe FEVR-like change with or without significant chorioretinopathy is a common feature in addition to neurodevelopmental disorders for variants in CTNNB1, KIF11, and NDP. In our cohort, the frequency of families with variants in KIF11 was comparable to that in TSPAN12, so as for NDP. Recognizing the characteristics of variants in the 3 genes and associated ocular phenotypes may enrich our understanding and potential management of this disease.
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Affiliation(s)
- Junxing Yang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xueshan Xiao
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Shiqiang Li
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Guiying Mai
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Xiaoyun Jia
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Panfeng Wang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Wenmin Sun
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China
| | - Qingjiong Zhang
- From the State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China.
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6
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Tao T, Xu N, Li J, Li H, Qu J, Yin H, Liang J, Zhao M, Li X, Huang L. Ocular Features and Mutation Spectrum of Patients With Familial Exudative Vitreoretinopathy. Invest Ophthalmol Vis Sci 2021; 62:4. [PMID: 34860240 PMCID: PMC8648064 DOI: 10.1167/iovs.62.15.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Purpose To investigate the clinical findings in Chinese patients diagnosed with familial exudative vitreoretinopathy (FEVR) and carrying pathogenic mutations. Methods One hundred twenty unrelated patients with FEVR were enrolled in this study. Genomic DNA and ophthalmic examinations were collected from all the patients and their available relatives. Targeted next-generation sequencing was performed to detect mutations. In silico programs were used to evaluate the pathogenicity of all the mutations. Results Eighty identified mutations were found in 81 unrelated patients (31/81 in LRP5, 25/81 in FZD4, 12/81 in TSPAN12, 8/81 in NDP, 4/81 in KIF11, and 1/81 in ZNF408). Among those mutations, 53 were novel (23/35 in LRP5, 15/21 in FZD4, 8/11 in TSPAN12, 3/8 in NDP, 3/4 in KIF11, 1/1 in ZNF408). Patients with LRP5, FZD4, TSPAN12, or NDP mutations were mainly classified into stage 4 and stage 5 and one-half of patients with KIF11 mutations were in stage 4. In addition, all the patients in NDP group were found to have bilateral symmetry in FEVR stage. Conclusions Our results present profound phenotypic variability and a wide mutation spectrum of FEVR in the Chinese population, which could be useful for a precise and comprehensive genetic diagnosis for patients with FEVR in the future.
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Affiliation(s)
- Tianchang Tao
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Ningda Xu
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Jiarui Li
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Hongyan Li
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Jinfeng Qu
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Hong Yin
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Jianhong Liang
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Mingwei Zhao
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
| | - Xiaoxin Li
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China.,Department of Ophthalmology, Xiamen Eye Center of Xiamen University, Xiamen, China
| | - Lvzhen Huang
- Department of Ophthalmology, Peking University People's Hospital Eye diseases and optometry institute, Beijing, China.,Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China.,College of Optometry, Peking University Health Science Center, Beijing, China
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7
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Jokela M, Karhu J, Nurminen J, Martikainen MH. Multiple Cranial Nerve Gadolinium Enhancement in Norrie Disease. Ann Neurol 2021; 91:158-159. [PMID: 34786741 PMCID: PMC9299797 DOI: 10.1002/ana.26274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 11/08/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022]
Affiliation(s)
- Manu Jokela
- Neurology, Clinical Medicine, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland
| | - Jari Karhu
- Department of Radiology, Turku University Hospital, Turku, Finland
| | - Janne Nurminen
- Department of Radiology, Turku University Hospital, Turku, Finland
| | - Mika H Martikainen
- Neurology, Clinical Medicine, University of Turku, Turku, Finland.,Neurocenter, Turku University Hospital, Turku, Finland.,Department of Neurology, Satasairaala Hospital, Pori, Finland
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8
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Yemanyi F, Bora K, Blomfield AK, Wang Z, Chen J. Wnt Signaling in Inner Blood-Retinal Barrier Maintenance. Int J Mol Sci 2021; 22:11877. [PMID: 34769308 PMCID: PMC8584977 DOI: 10.3390/ijms222111877] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 10/28/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022] Open
Abstract
The retina is a light-sensing ocular tissue that sends information to the brain to enable vision. The blood-retinal barrier (BRB) contributes to maintaining homeostasis in the retinal microenvironment by selectively regulating flux of molecules between systemic circulation and the retina. Maintaining such physiological balance is fundamental to visual function by facilitating the delivery of nutrients and oxygen and for protection from blood-borne toxins. The inner BRB (iBRB), composed mostly of inner retinal vasculature, controls substance exchange mainly via transportation processes between (paracellular) and through (transcellular) the retinal microvascular endothelium. Disruption of iBRB, characterized by retinal edema, is observed in many eye diseases and disturbs the physiological quiescence in the retina's extracellular space, resulting in vision loss. Consequently, understanding the mechanisms of iBRB formation, maintenance, and breakdown is pivotal to discovering potential targets to restore function to compromised physiological barriers. These unraveled targets can also inform potential drug delivery strategies across the BRB and the blood-brain barrier into retinas and brain tissues, respectively. This review summarizes mechanistic insights into the development and maintenance of iBRB in health and disease, with a specific focus on the Wnt signaling pathway and its regulatory role in both paracellular and transcellular transport across the retinal vascular endothelium.
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Affiliation(s)
| | | | | | | | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA; (F.Y.); (K.B.); (A.K.B.); (Z.W.)
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9
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Zhou Y, Shapiro MJ, Burton BK, Mets MB, Kurup SP. Case report: A case of Norrie disease due to deletion of the entire coding region of NDP gene. Am J Ophthalmol Case Rep 2021; 23:101151. [PMID: 34189345 PMCID: PMC8220341 DOI: 10.1016/j.ajoc.2021.101151] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 04/07/2021] [Accepted: 06/14/2021] [Indexed: 10/24/2022] Open
Abstract
Purpose Norrie disease is a rare X-linked recessive vitreoretinopathy. Variants of the NDP gene are associated with this condition. This case reports aims to demonstrate the variations of clinical presentations and exam findings of this disease. Observations A retrospective chart review of the patient's ocular and systemic findings and imaging results was performed. The patient had received genetic testing, including mutational analysis of targeted genes associated with retrolental masses. The patient had a comprehensive eye exam for bilateral leukocoria, demonstrating large retrolental masses, anterior polar cataracts, stretched ciliary processes, and roving eye movements. B-scan ultrasonography and magnetic resonance imaging indicated total, funnel-shaped retinal detachments, which is a unique retinal configuration in Norrie disease. Genetic testing confirmed deletion of the coding region of all three exons in the NDP gene, which confirmed Norrie disease. He has not shown any extraocular involvement to date. Conclusions and Importance This is a case demonstrating the association between deletion of the coding region NDP gene and Norrie disease. The phenotypical variation of this disease warrants further studies of genotype-phenotype correlations and mutations of the NDP gene.
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Affiliation(s)
- Yujia Zhou
- Division of Ophthalmology, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave, Chicago, IL, 60611, USA
| | - Michael J Shapiro
- Retina Consultants, Ltd., 2454 E Dempster St Ste 400, Des Plaines, IL, 60016, USA
| | - Barbara K Burton
- Division of Genetics, Birth Defects & Metabolism, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave, Chicago, IL, 60611, USA.,Department of Pediatrics, Northwestern University Feinberg School of Medicine, 420 E Superior St, Chicago, IL, 60611, USA
| | - Marilyn B Mets
- Division of Ophthalmology, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave, Chicago, IL, 60611, USA.,Department of Ophthalmology, Northwestern University Feinberg School of Medicine, 645 N Michigan Ave, Suite 440, Chicago, IL, 60611, USA
| | - Sudhi P Kurup
- Division of Ophthalmology, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E Chicago Ave, Chicago, IL, 60611, USA.,Department of Ophthalmology, Northwestern University Feinberg School of Medicine, 645 N Michigan Ave, Suite 440, Chicago, IL, 60611, USA
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10
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Whole-Gene Deletions of FZD4 Cause Familial Exudative Vitreoretinopathy. Genes (Basel) 2021; 12:genes12070980. [PMID: 34199009 PMCID: PMC8306649 DOI: 10.3390/genes12070980] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/07/2021] [Accepted: 06/22/2021] [Indexed: 12/28/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is an inherited disorder characterized by abnormalities in the retinal vasculature. The FZD4 gene is associated with FEVR, but the prevalence and impact of FZD4 copy number variation (CNV) on FEVR patients are unknown. The aim of this study was to better understand the genetic features and clinical manifestations of patients with FZD4 CNVs. A total of 651 FEVR families were recruited. Families negative for mutations in FEVR-associated genes were selected for CNV analysis using SeqCNV. Semiquantitative multiplex polymerase chain reaction and multiplex ligation-dependent probe amplification were conducted to verify the CNVs. Four probands were found to carry whole-gene deletions of FZD4, accounting for 5% (4/80) of probands with FZD4 mutations and 0.6% (4/651) of all FEVR probands. The four probands exhibited similar phenotypes of unilateral retinal folds. FEVR in probands with CNVs was not more severe than in probands with FZD4 missense mutations (p = 1.000). Although this is the first report of FZD4 CNVs and the associated phenotypes, the interpretation of FZD4 CNVs should be emphasized when analyzing the next-generation sequencing data of FEVR patients because of their high prevalence.
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11
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Jia LY, Ma K. Novel Norrie disease gene mutations in Chinese patients with familial exudative vitreoretinopathy. BMC Ophthalmol 2021; 21:84. [PMID: 33588793 PMCID: PMC7885586 DOI: 10.1186/s12886-021-01852-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/04/2021] [Indexed: 01/22/2023] Open
Abstract
Purpose This study aims to analyze the Norrie disease gene (NDP) variants in patients with familial exudative vitreoretinopathy (FEVR) and their clinical features. Methods Thirty-three Chinese patients (22 familial and 11 simplex) who were diagnosed as FEVR underwent detailed ocular examinations in Beijing Tongren Hospital. Peripheral venous blood was drawn from the patients and their family members for the extraction of genomic DNA. All exons of NDP gene were analyzed by direct sequencing of PCR-amplified DNA fragments. Results Four novel mutations in NDP gene were identified in four X-linked FEVR families: a C → T transversion, c. 625C → T, in exon 3, resulting in a serine-to-proline change in codon 73 (S73P); a C → G transition, c. 751C → G, in exon 3, resulting in an arginine-to-glycine change in codon 115 (R115G); a T → C transversion of nucleotide 331 at 5’UTR in exon 2 (c.331 T → C); and a C → T transversion of the nucleotide 5 in intron 1 (IVS1 + 5C → T). The mutations were not present in the control group (n = 100). Conclusions Our results extend the spectrum of NDP gene mutations. The mutations in the non-coding region of NDP may play a crucial role in the pathogenesis of FEVR.
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Affiliation(s)
- Li-Yun Jia
- Beijing Tongren Hospital, Capital Medical University, Beijing, China.
| | - Kai Ma
- Beijing Tongren Hospital, Capital Medical University, Beijing, China
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Marakhonov AV, Mishina IA, Kadyshev VV, Repina SA, Shurygina MF, Shchagina OA, Vasserman NN, Vasilyeva TA, Kutsev SI, Zinchenko RA. Prenatal diagnosis of Norrie disease after whole exome sequencing of an affected proband during an ongoing pregnancy: a case report. BMC MEDICAL GENETICS 2020; 21:156. [PMID: 33092543 PMCID: PMC7579785 DOI: 10.1186/s12881-020-01093-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 11/29/2022]
Abstract
Background Hereditary ophthalmic pathology is a genetically heterogeneous group of diseases that occur either as an isolated eye disorder or as a symptom of hereditary syndromes (chromosomal or monogenic). Thus, a diagnostic search in some cases of ophthalmic pathology can be time- and cost-consuming. The most challenging situation can arise when prenatal diagnosis is needed during an ongoing pregnancy. Case presentation A family was referred to the Research Centre for Medical Genetics (RCMG) for childbirth risk prognosis at 7–8 week of gestation because a previous child, a six-year-old boy, has congenital aniridia, glaucoma, retinal detachment, severe psychomotor delay, and lack of speech and has had several ophthalmic surgeries. The affected child had been previously tested for PAX6 mutations and 11p13 copy number variations, which revealed no changes. Considering the lack of pathogenic changes and precise diagnosis for the affected boy, NGS sequencing of clinically relevant genes was performed for the ongoing pregnancy; it revealed a novel hemizygous substitution NM_000266.3(NDP):c.385G > T, p.(Glu129*), in the NDP gene, which is associated with Norrie disease (OMIM #310600). Subsequent Sanger validation of the affected boy and his mother confirmed the identified substitution inherited in X-linked recessive mode. Amniotic fluid testing revealed the fetus was hemizygous for the variant and lead to the decision of the family to interrupt the pregnancy. Complications which developed during the termination of pregnancy required hysterectomy due to medical necessity. Conclusions Clinical polymorphism of hereditary ophthalmic pathology can severely complicate establishment of an exact diagnosis and make it time- and cost-consuming. NGS appears to be the method-of-choice in complicated cases, and this could substantially hasten the establishment of a diagnosis and genetic risk estimation.
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Affiliation(s)
- Andrey V Marakhonov
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation.
| | - Irina A Mishina
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Vitaly V Kadyshev
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Svetlana A Repina
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Maria F Shurygina
- S. Fyodorov Eye Microsurgery Federal State Institution, Moscow, Russian Federation
| | - Olga A Shchagina
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Natalya N Vasserman
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Tatyana A Vasilyeva
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Sergey I Kutsev
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation
| | - Rena A Zinchenko
- Laboratory of Genetic Epidemiology, Research Centre for Medical Genetics, Moscow, Russian Federation.,N.A. Semashko National Research Institute of Public Health, Moscow, Russian Federation
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Siswanto JE, Ronoatmodjo S, Sitorus RS, Soemantri A, Setijaningsih I, Sauer PJJ. Norrie disease gene polymorphism in Indonesian infants with retinopathy of prematurity. BMJ Open Ophthalmol 2019; 4:e000211. [PMID: 30997400 PMCID: PMC6440590 DOI: 10.1136/bmjophth-2018-000211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVE Retinopathy of prematurity (ROP) is a major cause of blindness in newborn infants, which also occurs in low-income and middle-income countries. Why ROP progresses in some infants while it regresses in others is still presently unknown. Studies suggest that genetic factors might be involved. Mutations in the Norrie disease (ND) gene are suspected to be related to advanced ROP development. Indonesia is a country with relatively high incidence of ROP, yet the role of these genetic factors in the pathogenesis of ROP cases is still unknown. The study aimed to investigate the presence of mutations in ND on the X chromosome in infants with both non-advanced and advanced ROP in Indonesia. METHODS AND ANALYSIS This is a case-control study of polymorphisms in six variants within the ND gene in exon 3, C597A, L108P, R121W, A105T, V60E and C110G, in preterm newborn infants in four major hospitals in Greater Jakarta, Indonesia. RESULTS We included 162 preterm newborn infants. ROP was diagnosed in 83 infants, and 79 infants served as controls. Among those with ROP, 57 infants had type 2, while others had type 1. We did not find any gene polymorphisms in any of the infants with ROP nor in the control group. CONCLUSION We conclude that it is very unlikely that the six polymorphisms in exon 3 of the ND gene studied in this paper are involved in the development or progression of ROP in preterm infants in our population sample in Indonesia.
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Affiliation(s)
- J Edy Siswanto
- Neonatology, Harapan Kita Women and Children Hospital, Jakarta, Indonesia
| | - Sudarto Ronoatmodjo
- Epidemiology, University of Indonesia, School of Public Health, Depok, Indonesia
| | - Rita S Sitorus
- Ophthalmology, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
| | - Ag Soemantri
- Pediatric, Dr Kariadi General Hospital Medical Center, Semarang, Indonesia
| | | | - Pieter J J Sauer
- Pediatric, Universitair Medisch Centrum Groningen, Groningen, The Netherlands
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Liu J, Zhu J, Yang J, Zhang X, Zhang Q, Zhao P. Prenatal diagnosis of familial exudative vitreoretinopathy and Norrie disease. Mol Genet Genomic Med 2018; 7:e00503. [PMID: 30474316 PMCID: PMC6382493 DOI: 10.1002/mgg3.503] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 06/10/2018] [Accepted: 10/10/2018] [Indexed: 11/27/2022] Open
Abstract
Background Both familial exudative vitreoretinopathy (FEVR) and Norrie disease (ND) are hereditary retinal disorders which can cause severe visual impairment and blindness at a young age. The present study aimed to report the use of antenatal genetic testing and ultrasound in the diagnosis and counseling of FEVR and ND. Methods Amniocentesis and ultrasonography were performed in high‐risk mothers, with children having FEVR or ND, to predict severe ocular abnormalities. Results Case 1: A homozygous NDP mutation (c.376T>C, NM_000266) was detected in the proband and his mother. Molecular prenatal analysis of the fetal DNA revealed no mutations. No ocular abnormalities were detected on ultrasonography. The pregnancy progressed uneventfully to a normal outcome. Case 2: A novel heterozygous FZD4 mutation (c.1010dupA, NM_012193) was detected in the proband and his mother. The same mutation was detected in the fetus, but ultrasonography showed no ocular abnormalities. A healthy baby boy with stage 1 FEVR was born after an uneventful pregnancy. Case 3: Deletions of exons 2 and 3 in the NDP were found in the proband and his mother. The same deletion mutation was detected in the female fetus, but the ultrasound scan was normal. The pregnancy progressed uneventfully to a normal outcome. Conclusions To our knowledge, antenatal genetic analyses were used in conjunction with ultrasound for the first time, to diagnose FEVR and ND, and predict the postnatal prognoses in at‐risk babies.
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Affiliation(s)
- Jingjing Liu
- Shanghai Jiao Tong University School of Medicine Affiliated Xinhua Hospital, Shanghai, China
| | - Jing Zhu
- Shanghai Jiao Tong University School of Medicine Affiliated Xinhua Hospital, Shanghai, China
| | - Jiyun Yang
- Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiang Zhang
- Shanghai Jiao Tong University School of Medicine Affiliated Xinhua Hospital, Shanghai, China
| | - Qi Zhang
- Shanghai Jiao Tong University School of Medicine Affiliated Xinhua Hospital, Shanghai, China
| | - Peiquan Zhao
- Shanghai Jiao Tong University School of Medicine Affiliated Xinhua Hospital, Shanghai, China
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Jia B, Huang L, Chen Y, Liu S, Chen C, Xiong K, Song L, Zhou Y, Yang X, Zhong M. A novel contiguous deletion involving NDP, MAOB and EFHC2 gene in a patient with familial Norrie disease: bilateral blindness and leucocoria without other deficits. J Genet 2018; 96:1015-1020. [PMID: 29321361 DOI: 10.1007/s12041-017-0869-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Contiguous microdeletions of the Norrie disease pseudoglioma (NDP) region on chromosome Xp11.3 have been widely confirmed as contributing to the typical clinical features of Norrie disease (ND). However, the precise relation between genotype and phenotype could vary. The contiguous deletion of NDP and its neighbouring genes, MAOA/B and EFHC2, reportedly leads to syndromic clinical features such as microcephaly, intellectual disability, and epilepsy. Herewe report a novel contiguous microdeletion of the NDP region containing the MAOB and EFHC2 genes,which causes eye defects but no cognitive disability.We detected a deletion of 494.6 kb atXp11.3 in both the proband and carrier mother. This deletionwas then used as the molecular marker in prenatal diagnosis for two subsequent pregnancies. The deletion was absent in one of the foetuses, who remain without any abnormalities at 2 years of age. The proband shows the typical ocular clinical features of ND including bilateral retinal detachment, microphthalmia, atrophic irides, corneal opacification, and cataracts, but no symptoms of microcephaly, intellectual disability, and epilepsy. This familial study demonstrates that a deficiency in one of two MAO genes may not lead to psychomotor delay, and deletion of EFHC2 may not cause epilepsy. Our observations provide new information on the genotype-phenotype relations of MAOA/B and EFHC2 genes involved in the contiguous deletions of ND.
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Affiliation(s)
- Bei Jia
- The Center for Prenatal and Hereditary DiseaseDiagnosis,Department of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, People's Republic of China.
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16
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Andarva M, Jamshidi J, Ghaedi H, Daftarian N, Emamalizadeh B, Alehabib E, Taghavi S, Pouriran R, Darvish H. A novel c.240_241insGG mutation in NDP gene in a family with Norrie disease. Clin Exp Optom 2017; 101:255-259. [PMID: 28922694 DOI: 10.1111/cxo.12599] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 03/25/2017] [Accepted: 05/17/2017] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Norrie disease (ND) is a rare, X-linked recessive disorder with the main characteristic of early childhood blindness. The aim of the present study was to identify the genetic cause of the disease and the phenotypic characteristics of the patients in an Iranian family with four affected males with ND. METHODS Norrie disease pseudoglioma (NDP) gene was sequenced and clinical examination was performed on patients. RESULTS A GG dinucleotide insertion in exon 3 (c.240_241insGG) of NDP was detected in all patients. The mutation caused a frameshift and an early stop codon (p.Phe81Glyfs*23). CONCLUSIONS A novel mutation was found in the NDP gene in the affected males of the family. As the mutation was absent in the normal male members of the family, it should be the genetic cause of the disease.
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Affiliation(s)
- Monavvar Andarva
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Javad Jamshidi
- Noncommunicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran
| | - Hamid Ghaedi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narsis Daftarian
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Babak Emamalizadeh
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elham Alehabib
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shaghyegh Taghavi
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ramin Pouriran
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Darvish
- Department of Medical Genetics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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17
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Clinical and genetic analysis of Indian patients with NDP-related retinopathies. Int Ophthalmol 2017; 38:1251-1260. [DOI: 10.1007/s10792-017-0589-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 06/05/2017] [Indexed: 11/25/2022]
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18
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Fangting L, Lvzhen H, Xiaoxin L. A novel c.2T>A NDP missense mutation in a Chinese family with Norrie disease. Acta Ophthalmol 2016; 94:e516-7. [PMID: 26547627 DOI: 10.1111/aos.12904] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Li Fangting
- Department of Ophthalmology; Peking University People's Hospital; Beijing China
- Key Laboratory of Vision Loss and Restoration; Ministry of Education; Beijing China
| | - Huang Lvzhen
- Department of Ophthalmology; Peking University People's Hospital; Beijing China
- Key Laboratory of Vision Loss and Restoration; Ministry of Education; Beijing China
| | - Li Xiaoxin
- Department of Ophthalmology; Peking University People's Hospital; Beijing China
- Key Laboratory of Vision Loss and Restoration; Ministry of Education; Beijing China
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Paulus YM, Alcorn DM, Gaynon M, Moshfeghi DM. Peripheral Avascular Retina in a Term Male Neonate With Microvillus Inclusion Disease and Pancreatic Insufficiency. Ophthalmic Surg Lasers Imaging Retina 2015; 46:589-91. [PMID: 26057766 DOI: 10.3928/23258160-20150521-14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 03/17/2015] [Indexed: 11/20/2022]
Abstract
The authors present the first case of peripheral avascular retina in a term male neonate with pancreatic exocrine insufficiency, atypical microvillus inclusion disease, flat tympanograms, and recurrent urinary tract infections. Clinical examination showed avascular peripheral retina to posterior zone II temporally, with a flat stage 1-like demarcation line, and no plus disease. Genetic testing results were normal. The patient developed peripheral neovascularization and underwent panretinal photocoagulation. This case likely represents mild Norrie disease, familial exudative vitreoretinopathy, or incontinentia pigmenti due to a Wnt signaling abnormality. While these conditions are usually more severe, a variable spectrum of Wnt abnormalities exists throughout the body.
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20
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Gal M, Levanon EY, Hujeirat Y, Khayat M, Pe'er J, Shalev S. Novel mutation in TSPAN12 leads to autosomal recessive inheritance of congenital vitreoretinal disease with intra-familial phenotypic variability. Am J Med Genet A 2014; 164A:2996-3002. [DOI: 10.1002/ajmg.a.36739] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 06/23/2014] [Indexed: 11/05/2022]
Affiliation(s)
- Moran Gal
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Erez Y. Levanon
- The Mina and Everard Goodman Faculty of Life Sciences; Bar-Ilan University; Ramat-Gan Israel
| | - Yasir Hujeirat
- The Genetic Institute; Emek Medical Center; Afula Israel
| | - Morad Khayat
- The Genetic Institute; Emek Medical Center; Afula Israel
| | - Jacob Pe'er
- Department of Ophthalmology; Hadassah-Hebrew University Medical Center; Jerusalem Israel
| | - Stavit Shalev
- The Genetic Institute; Emek Medical Center; Afula Israel
- Rappaport Faculty of Medicine; Technion; Haifa Israel
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21
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Familial cases of Norrie disease detected by copy number analysis. Jpn J Ophthalmol 2014; 58:448-54. [DOI: 10.1007/s10384-014-0334-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 06/02/2014] [Indexed: 11/25/2022]
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Zhang XY, Jiang WY, Chen LM, Chen SQ. A novel Norrie disease pseudoglioma gene mutation, c.-1_2delAAT, responsible for Norrie disease in a Chinese family. Int J Ophthalmol 2013; 6:739-43. [PMID: 24392318 DOI: 10.3980/j.issn.2222-3959.2013.06.01] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 09/26/2013] [Indexed: 11/02/2022] Open
Abstract
AIM To investigate the genetic findings and phenotypic characteristics of a Chinese family with Norrie disease (ND). METHODS Molecular genetic analysis and clinical examinations were performed on a Chinese family with ND. Mutations in the Norrie disease pseudoglioma (NDP) gene were detected by direct sequencing. Haplotypes were constructed and compared with the phenotypes in the family. Evolutionary comparisons and mutant open reading frame (ORF) prediction were also undertaken. RESULTS Two family members with ocular manifestations were diagnosed with ND. No signs of sensorineural hearing loss were observed in either patient, while one of them showed signs of mild mental retardation. A novel heterozygous mutation in the NDP gene, c.-1_2delAAT, was detected in both patients. The mutation and the mutation bearing haplotype co-segregated with the ND phenotype in males and was transmitted from their mothers and/or grandmothers (II:2). The male without ND did not harbor the mutation. The mutation occurred at the highly conserved nucleotides. ORF finder predicted that the mutation would lead to the production of a truncated protein that lacks the first 11 N-terminal amino acids. CONCLUSION A novel mutation, c.-1_2delAAT in the NDP gene, was identified in a Chinese family with ND. This mutation caused ND without obvious sensorineural hearing loss. Mental disorder was found in one but not the other patients. The clinical heterogeneity in the family indicated that other genetic variants and epigenetic factors may also play a role in the disease presentation.
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Affiliation(s)
- Xin-Yu Zhang
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China
| | - Wei-Ying Jiang
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
| | - Lu-Ming Chen
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
| | - Su-Qin Chen
- Department of Medical Genetics, Zhongshan Medical College, Sun Yat-sen University, Guangzhou 510080, Guangdong Province, China
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Romaniello R, Arrigoni F, Citterio A, Tonelli A, Sforzini C, Rizzari C, Pessina M, Triulzi F, Bassi MT, Borgatti R. Cerebroretinal microangiopathy with calcifications and cysts associated with CTC1 and NDP mutations. J Child Neurol 2013; 28:1702-8. [PMID: 23220793 DOI: 10.1177/0883073812467849] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations in the conserved telomere maintenance component 1 (CTC1) gene were recently described in Coats plus syndrome and in cerebroretinal microangiopathy with calcifications and cysts. Norrie disease protein (NDP) gene was found mutated in Norrie disease, in Familial Exudative Vitreoretinopathy, and in Coats syndrome. Here we describe a boy affected by Norrie disease who developed typical features of cerebroretinal microangiopathy with calcifications and cysts. Direct sequencing of the CTC1 and NDP genes in this patient shows the presence of compound heterozygosity for 2 mutations in CTC1 (c.775G>A, pV259M and a novel microdeletion c.1213delG) and a missense mutation in the NDP gene (c.182T>C, p.L61P). Based on these genetic findings and on the expression of both genes in endothelial cells, we postulate that microangiopathy might be a primary underlying pathologic abnormality in cerebroretinal microangiopathy with calcifications and cysts. This hypothesis is further supported by magnetic resonance imaging (MRI) data showing multiple minute calcifications in the deep gray nuclei and in terminal arteriolar zones.
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Affiliation(s)
- Romina Romaniello
- 1Department of Child Neuropsychiatry and Neurorehabilitation, "Eugenio Medea" Scientific Institute, Bosisio Parini, Lecco, Italy
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Gregory-Evans CY, Wallace VA, Gregory-Evans K. Gene networks: dissecting pathways in retinal development and disease. Prog Retin Eye Res 2012; 33:40-66. [PMID: 23128416 DOI: 10.1016/j.preteyeres.2012.10.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 01/21/2023]
Abstract
During retinal neurogenesis, diverse cellular subtypes originate from multipotent neural progenitors in a spatiotemporal order leading to a highly specialized laminar structure combined with a distinct mosaic architecture. This is driven by the combinatorial action of transcription factors and signaling molecules which specify cell fate and differentiation. The emerging approach of gene network analysis has allowed a better understanding of the functional relationships between genes expressed in the developing retina. For instance, these gene networks have identified transcriptional hubs that have revealed potential targets and pathways for the development of therapeutic options for retinal diseases. Much of the current knowledge has been informed by targeted gene deletion experiments and gain-of-functional analysis. In this review we will provide an update on retinal development gene networks and address the wider implications for future disease therapeutics.
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Affiliation(s)
- Cheryl Y Gregory-Evans
- Department of Ophthalmology, University of British Columbia, Vancouver, BC V5Z 3N9, Canada.
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Ghosh M, Sharma S, Shastri S, Arora S, Shukla R, Gupta N, Deka D, Kabra M. Norrie disease: first mutation report and prenatal diagnosis in an Indian family. Indian J Pediatr 2012; 79:1529-31. [PMID: 22674248 DOI: 10.1007/s12098-012-0788-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 05/21/2012] [Indexed: 11/29/2022]
Abstract
Norrie Disease (ND) is a rare X-linked recessive disorder characterised by congenital blindness due to severe retinal dysgenesis. Hearing loss and intellectual disability is present in 30-50 % cases. ND is caused by mutations in the NDP gene, located at Xp11.3. The authors describe mutation analysis of a proband with ND and subsequently prenatal diagnosis. Sequence analysis of the NDP gene revealed a hemizygous missense mutation arginine to serine in codon 41 (p.Arg41Ser) in the affected child. Mother was carrier for the mutation. In a subsequent di-chorionic di-amniotic pregnancy, the authors performed prenatal diagnosis by mutation analysis on chorionic villi sample at 11 wk of gestation. The fetuses were unaffected. This is a first mutation report and prenatal diagnosis of a familial case of Norrie disease from India. The importance of genetic testing of Norrie disease for confirmation, carrier testing, prenatal diagnosis and genetic counseling is emphasized.
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Affiliation(s)
- Manju Ghosh
- Genetics Unit, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
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Yang H, Li S, Xiao X, Guo X, Zhang Q. Screening for NDP mutations in 44 unrelated patients with familial exudative vitreoretinopathy or Norrie disease. Curr Eye Res 2012; 37:726-9. [PMID: 22563645 DOI: 10.3109/02713683.2012.675615] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To screen mutations in the norrin (NDP) gene in 44 unrelated Chinese patients with familial exudative vitreoretinopathy (FEVR, 38 cases) or Norrie disease (6 cases) and to describe the associated phenotypes. METHODS Of the 44 patients, mutation in FZD4, LRP5, and TSPAN12 was excluded in 38 patients with FEVR in previous study. Sanger sequencing was used to analyze the 2 coding exons and their adjacent regions of NDP in the 44 patients. Clinical data were presented for patients with mutation. RESULTS NDP variants in 5 of the 6 patients with Norrie disease were identified, including a novel missense mutation (c.164G>A, p.Cys55Phe) in one patient, two known missense mutations (c.122G>A, p.Arg41Lys; c.220C>T, p.Arg74Cys) in two patients, and a gross deletion encompassing the two coding exons in two patients. Of the 5 patients, 3 had a family history and 2 were singleton cases. No mutation in NDP was detected in the 38 patients with FEVR. CONCLUSIONS NDP mutations are common cause of Norrie disease but might be rare cause for FEVR in Chinese.
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Affiliation(s)
- Huiqin Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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27
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Xu S, Cheng F, Liang J, Wu W, Zhang J. Maternal xNorrin, a canonical Wnt signaling agonist and TGF-β antagonist, controls early neuroectoderm specification in Xenopus. PLoS Biol 2012; 10:e1001286. [PMID: 22448144 PMCID: PMC3308935 DOI: 10.1371/journal.pbio.1001286] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 02/06/2012] [Indexed: 12/28/2022] Open
Abstract
Xenopus maternal Norrin, which activates Wnt signaling but inhibits TGF-β family molecules, is essential for neuroectoderm formation. Loss of TGF-β inhibition in Norrin may contribute to the development of Norrie disease. Dorsal–ventral specification in the amphibian embryo is controlled by β-catenin, whose activation in all dorsal cells is dependent on maternal Wnt11. However, it remains unknown whether other maternally secreted factors contribute to β-catenin activation in the dorsal ectoderm. Here, we show that maternal Xenopus Norrin (xNorrin) promotes anterior neural tissue formation in ventralized embryos. Conversely, when xNorrin function is inhibited, early canonical Wnt signaling in the dorsal ectoderm and the early expression of the zygotic neural inducers Chordin, Noggin, and Xnr3 are severely suppressed, causing the loss of anterior structures. In addition, xNorrin potently inhibits BMP- and Nodal/Activin-related functions through direct binding to the ligands. Moreover, a subset of Norrin mutants identified in humans with Norrie disease retain Wnt activation but show defective inhibition of Nodal/Activin-related signaling in mesoderm induction, suggesting that this disinhibition causes Norrie disease. Thus, xNorrin is an unusual molecule that acts on two major signaling pathways, Wnt and TGF-β, in opposite ways and is essential for early neuroectoderm specification. A key step during early embryogenesis is the generation of neural precursors, which later form the central nervous system. In vertebrates, this process requires proper dorsal–ventral axis specification, and we know that the canonical Wnt and BMP signaling pathways help pattern the dorsal ectoderm. In this study, we examine other factors that are involved in neuroectoderm development in the frog species Xenopus laevis. We find that maternal Xenopus Norrin (xNorrin) is required for canonical Wnt signaling in the dorsal ectoderm, functions upstream of neural inducers, and is required for neural formation. We also find that xNorrin not only activates Wnt signaling, but also inhibits BMP/Nodal-related signaling. In humans, mutations in Norrin cause Norrie disease. Using Norrin mutants identified in patients with Norrie disease, we find that some Norrin mutants fail to inhibit BMP/Nodal-related signaling (specifically, TGF-β) but retain the ability to activate the Wnt pathway, suggesting that loss of TGF-β inhibition may contribute to Norrie disease development.
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Affiliation(s)
- Suhong Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Feng Cheng
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School of Chinese Academy of Sciences, Beijing, China
| | - Juan Liang
- Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wei Wu
- Protein Science Laboratory of the Ministry of Education, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jian Zhang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Jakobiec FA, Zakka FR, D'Amato R, Deangelis MM, Walton DS, Rao RC. Unilateral sporadic retinal dysplasia: results of histopathologic, immunohistochemical, chromosomal, genetic, and VEGF-A analyses. J AAPOS 2011; 15:579-86. [PMID: 22153404 PMCID: PMC4242509 DOI: 10.1016/j.jaapos.2011.08.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Revised: 07/28/2011] [Accepted: 08/19/2011] [Indexed: 11/16/2022]
Abstract
PURPOSE To describe new findings in a case of unilateral retinal dysplasia. METHODS Histopathologic evaluation of an enucleated globe and analysis with immunohistochemical probes, karyotyping, and genetic analysis for the Norrie gene, and aqueous assay for vascular endothelial growth factor A (VEGF-A). RESULTS Histopathological examination of the globe revealed retinal dysplasia with pseudorosette formation, abnormal or absent retinal nuclear lamination, a paucity of disorganized retinal microvasculature, retinal infoldings, advanced gliosis, persistent hyperplastic vitreous, exuberant neovascularization of the vitreous, and iris neovascularization (identical to the findings observed in bilateral Norrie disease). Immunohistochemistry disclosed GFAP-positive and GLUT-1-positive gliosis and retinal and persistent hyperplastic vitreous microvessels that were CD34-positive and GLUT-1-negative. Ki-67-positive retinal cells were polarized toward the subretinal space and absent in the retinal invaginations and pseudorosettes. A normal karyotype was found, and DNA sequencing revealed no known mutation in the region of the Norrie gene (NDP) in sputum or retinal DNA. Aqueous obtained immediately after enucleation contained an exceptionally high concentration of VEGF-A (4.5 ng/mL). CONCLUSIONS Despite the failure to find an abnormal NDP allele, other unexplored NDP regions, an undetected defect restricted to retinal tissues, or an autosomal mutation coupled with disrupted signaling pathways may be responsible for the condition. High aqueous VEGF-A suggests that this cytokine may play a role in pathogenesis in conjunction with other pathways.
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Affiliation(s)
- Frederick A Jakobiec
- David G. Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts 02114, USA.
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Waryah AM, Ahmed ZM, Bhinder MA, Binder MA, Choo DI, Sisk RA, Shahzad M, Khan SN, Friedman TB, Riazuddin S, Riazuddin S. Molecular and clinical studies of X-linked deafness among Pakistani families. J Hum Genet 2011; 56:534-40. [PMID: 21633365 PMCID: PMC3143270 DOI: 10.1038/jhg.2011.55] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
There are 68 sex-linked syndromes that include hearing loss as one feature and five sex-linked nonsyndromic deafness loci listed in the OMIM database. The possibility of additional such sex-linked loci was explored by ascertaining three unrelated Pakistani families (PKDF536, PKDF1132, PKDF740) segregating X-linked recessive deafness. Sequence analysis of POU3F4 (DFN3) in affected members of families PKDF536 and PKDF1132 revealed two novel nonsense mutations, p.Q136X and p.W114X, respectively. Family PKDF740 is segregating congenital blindness, mild to profound progressive hearing loss that is characteristic of Norrie disease (MIM#310600). Sequence analysis of NDP among affected members of this family revealed a novel single nucleotide deletion c.49delG causing a frameshift and premature truncation (p.V17fsX1) of the encoded protein. These mutations were not found in 150 normal DNA samples. Identification of pathogenic alleles causing X-linked recessive deafness will improve molecular diagnosis, genetic counseling, and molecular epidemiology of hearing loss among Pakistanis.
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Affiliation(s)
- Ali M Waryah
- National Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
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30
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Betancur C. Etiological heterogeneity in autism spectrum disorders: more than 100 genetic and genomic disorders and still counting. Brain Res 2010; 1380:42-77. [PMID: 21129364 DOI: 10.1016/j.brainres.2010.11.078] [Citation(s) in RCA: 578] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/22/2010] [Accepted: 11/23/2010] [Indexed: 12/31/2022]
Abstract
There is increasing evidence that autism spectrum disorders (ASDs) can arise from rare highly penetrant mutations and genomic imbalances. The rare nature of these variants, and the often differing orbits of clinical and research geneticists, can make it difficult to fully appreciate the extent to which we have made progress in understanding the genetic etiology of autism. In fact, there is a persistent view in the autism research community that there are only a modest number of autism loci known. We carried out an exhaustive review of the clinical genetics and research genetics literature in an attempt to collate all genes and recurrent genomic imbalances that have been implicated in the etiology of ASD. We provide data on 103 disease genes and 44 genomic loci reported in subjects with ASD or autistic behavior. These genes and loci have all been causally implicated in intellectual disability, indicating that these two neurodevelopmental disorders share common genetic bases. A genetic overlap between ASD and epilepsy is also apparent in many cases. Taken together, these findings clearly show that autism is not a single clinical entity but a behavioral manifestation of tens or perhaps hundreds of genetic and genomic disorders. Increased recognition of the etiological heterogeneity of ASD will greatly expand the number of target genes for neurobiological investigations and thereby provide additional avenues for the development of pathway-based pharmacotherapy. Finally, the data provide strong support for high-resolution DNA microarrays as well as whole-exome and whole-genome sequencing as critical approaches for identifying the genetic causes of ASDs.
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31
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Chow CC, Kiernan DF, Chau FY, Blair MP, Ticho BH, Galasso JM, Shapiro MJ. Laser Photocoagulation at Birth Prevents Blindness in Norrie's Disease Diagnosed Using Amniocentesis. Ophthalmology 2010; 117:2402-6. [DOI: 10.1016/j.ophtha.2010.03.057] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/18/2010] [Accepted: 03/25/2010] [Indexed: 12/01/2022] Open
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Whibley A, Urquhart J, Dore J, Willatt L, Parkin G, Gaunt L, Black G, Donnai D, Raymond FL. Deletion of MAOA and MAOB in a male patient causes severe developmental delay, intermittent hypotonia and stereotypical hand movements. Eur J Hum Genet 2010; 18:1095-9. [PMID: 20485326 DOI: 10.1038/ejhg.2010.41] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Monoamine oxidases (MAO-A and MAO-B) have a key role in the degradation of amine neurotransmitters, such as dopamine, norepinephrine and serotonin. We identified an inherited 240 kb deletion on Xp11.3-p11.4, which encompasses both monoamine oxidase genes but, unlike other published reports, does not affect the adjacent Norrie disease gene (NDP). The brothers who inherited the deletion, and thus have no monoamine oxidase function, presented with severe developmental delay, intermittent hypotonia and stereotypical hand movements. The clinical features accord with published reports of larger microdeletions and selective MAO-A and MAO-B deficiencies in humans and mouse models and suggest considerable functional compensation between MAO-A and MAO-B under normal conditions.
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Affiliation(s)
- Annabel Whibley
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, UK
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33
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Nikopoulos K, Venselaar H, Collin RW, Riveiro-Alvarez R, Boonstra FN, Hooymans JM, Mukhopadhyay A, Shears D, van Bers M, de Wijs IJ, van Essen AJ, Sijmons RH, Tilanus MA, van Nouhuys CE, Ayuso C, Hoefsloot LH, Cremers FP. Overview of the mutation spectrum in familial exudative vitreoretinopathy and Norrie disease with identification of 21 novel variants in FZD4, LRP5, and NDP. Hum Mutat 2010; 31:656-66. [DOI: 10.1002/humu.21250] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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34
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Gal A, Veske A, Jojart G, Grammatico B, Huber B, Gu S, del Porto G, Senyi K. Norrie-Warburg syndrome: two novel mutations in patients with classical clinical phenotype. ACTA OPHTHALMOLOGICA SCANDINAVICA. SUPPLEMENT 2009:13-6. [PMID: 8741107 DOI: 10.1111/j.1600-0420.1996.tb00374.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Norrie-Warburg syndrome (NWS) is a rare X-linked disorder characterized by blindness, which is invariable, deafness and mental disturbances, which are present occasionally. We describe here two novel mutations, a missense mutation (C126S) and a 1-base pair insertion (insT466/T467), together with a recurrent mutation (M1V), found in patients presenting with the classical clinical phenotype of NWS. All three mutations are likely to result in prominent structural changes of the norrin protein.
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Affiliation(s)
- A Gal
- Institut für Humangenetik, Universitäts-Krankenhaus Eppendorf, Hamburg, Germany
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35
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Abstract
Single nucleotide polymorphism (SNP) is the simplest form of DNA variation among individuals. These simple changes can be of transition or transversion type and they occur throughout the genome at a frequency of about one in 1,000 bp. They may be responsible for the diversity among individuals, genome evolution, the most common familial traits such as curly hair, interindividual differences in drug response, and complex and common diseases such as diabetes, obesity, hypertension, and psychiatric disorders. SNPs may change the encoded amino acids (nonsynonymous) or can be silent (synonymous) or simply occur in the noncoding regions. They may influence promoter activity (gene expression), messenger RNA (mRNA) conformation (stability), and subcellular localization of mRNAs and/or proteins and hence may produce disease. Therefore, identification of numerous variations in genes and analysis of their effects may lead to a better understanding of their impact on gene function and health of an individual. This improved knowledge may provide a starting point for the development of new, useful SNP markers for medical testing and a safer individualized medication to treat the most common devastating disorders. This will revolutionize the medical field in the future. To illustrate the effect of SNPs on gene function and phenotype, this minireview focuses on evidences revealing the impact of SNPs on the development and progression of three human eye disorders (Norrie disease, familial exudative vitreoretinopathy, and retinopathy of prematurity) that have overlapping clinical manifestations.
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Affiliation(s)
- Barkur S Shastry
- Department of Biological Sciences, Oakland University, Rochester, MI, USA
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36
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Luhmann UFO, Neidhardt J, Kloeckener-Gruissem B, Schäfer NF, Glaus E, Feil S, Berger W. Vascular changes in the cerebellum of Norrin /Ndph knockout mice correlate with high expression of Norrin and Frizzled-4. Eur J Neurosci 2008; 27:2619-28. [PMID: 18547247 DOI: 10.1111/j.1460-9568.2008.06237.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
X-linked Norrie disease, familial exudative vitreoretinopathy (FEVR), Coat's disease and retinopathy of prematurity are severe human eye diseases and can all be caused by mutations in the Norrie disease pseudoglioma gene. They all show vascular defects and characteristic features of retinal hypoxia. Only Norrie disease displays additional neurological symptoms, which are sensorineural hearing loss and mental retardation. In the present study, we analysed transcript levels of the ligand Norrin (Ndph) and its two receptors Frizzled-4 (Fzd4) and LDL-related protein receptor 5 (Lrp5) in six different brain regions (cerebellum, cortex, hippocampus, olfactory bulb, pituitary and brain stem) of 6- to 8-month-old wild-type and Ndph knockout mice by quantitative real-time PCR. No effect of the Ndph knockout allele on Fzd4 or Lrp5 receptor expression was found. Furthermore, no alterations of the transcript levels of three hypoxia-regulated angiogenic factors (Vegfa, Itgrb3 and Tie1) were observed in the absence of Norrin. Interestingly, we identified significant differences in Ndph, Fzd4 and Lrp5 transcript levels in brain regions of wild-type mice and observed highest expression of Norrin and frizzled-4 in cerebellum. Transcript analyses were correlated with morphological data obtained from cerebellum and immunohistochemical studies of blood vessels in different brain regions. Vessel density was reduced in the cerebellum of Ndph knockout mice but the number of Purkinje and granular cells was not altered. This provides the first description of a brain phenotype in Ndph knockout mice, which will help to elucidate the role of Norrin in the brain.
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Affiliation(s)
- Ulrich F O Luhmann
- Division of Medical Molecular Genetics & Gene Diagnostics, Institute of Medical Genetics, University of Zurich, Schorenstrasse 16, CH-8603 Schwerzenbach, Switzerland
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Lev D, Weigl Y, Hasan M, Gak E, Davidovich M, Vinkler C, Leshinsky-Silver E, Lerman-Sagie T, Watemberg N. A novel missense mutation in theNDP gene in a child with Norrie disease and severe neurological involvement including infantile spasms. Am J Med Genet A 2007; 143A:921-4. [PMID: 17334993 DOI: 10.1002/ajmg.a.31531] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Norrie disease (ND) is a rare X-linked recessive disorder characterized by congenital blindness and in some cases, mental retardation and deafness. Other neurological complications, particularly epilepsy, are rare. We report on a novel mutation identified in a patient with ND and profound mental retardation. The patient was diagnosed at the age of 6 months due to congenital blindness. At the age of 8 months he developed infantile spasms, which were diagnosed at 11 months as his EEG demonstrated hypsarrhythmia. Mutation analysis of the ND gene (NDP) of the affected child and his mother revealed a novel missense mutation at position c.134T > A resulting in amino acid change at codon V45E. To the best of our knowledge, such severe neurological involvement has not been previously reported in ND patients. The severity of the phenotype may suggest the functional importance of this site of the NDP gene.
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Affiliation(s)
- Dorit Lev
- Institute of Medical Genetics, Wolfson Medical Center, Holon, Israel.
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38
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Rodriguez-Revenga L, Madrigal I, Alkhalidi LS, Armengol L, González E, Badenas C, Estivill X, Milà M. Contiguous deletion of theNDP,MAOA,MAOB, andEFHC2 genes in a patient with Norrie disease, severe psychomotor retardation and myoclonic epilepsy. Am J Med Genet A 2007; 143A:916-20. [PMID: 17431911 DOI: 10.1002/ajmg.a.31521] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Norrie disease (ND) is an X-linked disorder, inherited as a recessive trait that, therefore, mostly affects males. The gene responsible for ND, called NDP, maps to the short arm of chromosome X (Xp11.4-p11.3). We report here an atypical case of ND, consisting of a patient harboring a large submicroscopic deletion affecting not only the NDP gene but also the MAOA, MAOB, and EFHC2 genes. Microarray comparative genomic hybridization (CGH) analysis showed that 11 consecutive bacterial artificial chromosome (BAC) clones, mapping around the NDP gene, were deleted. These clones span a region of about 1 Mb on Xp11.3. The deletion was ascertained by fluorescent in situ hybridization (FISH) analysis with different BAC clones located within the region. Clinical features of the proband include bilateral retinal detachment, microcephaly, severe psychomotor retardation without verbal language skills acquired, and epilepsy. The identification and molecular characterization of this case reinforces the idea of a new contiguous gene syndrome that would explain the complex phenotype shared by atypical ND patients.
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Affiliation(s)
- L Rodriguez-Revenga
- Biochemistry and Molecular Genetics Department, Hospital Clínic, Barcelona, Spain
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39
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Dickinson JL, Sale MM, Passmore A, FitzGerald LM, Wheatley CM, Burdon KP, Craig JE, Tengtrisorn S, Carden SM, Maclean H, Mackey DA. Mutations in the NDP gene: contribution to Norrie disease, familial exudative vitreoretinopathy and retinopathy of prematurity. Clin Exp Ophthalmol 2006; 34:682-8. [PMID: 16970763 DOI: 10.1111/j.1442-9071.2006.01314.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND To examine the contribution of mutations within the Norrie disease (NDP) gene to the clinically similar retinal diseases Norrie disease, X-linked familial exudative vitreoretinopathy (FEVR), Coat's disease and retinopathy of prematurity (ROP). METHODS A dataset comprising 13 Norrie-FEVR, one Coat's disease, 31 ROP patients and 90 ex-premature babies of <32 weeks' gestation underwent an ophthalmologic examination and were screened for mutations within the NDP gene by direct DNA sequencing, denaturing high-performance liquid chromatography or gel electrophoresis. Controls were only screened using denaturing high-performance liquid chromatography and gel electrophoresis. Confirmation of mutations identified was obtained by DNA sequencing. RESULTS Evidence for two novel mutations in the NDP gene was presented: Leu103Val in one FEVR patient and His43Arg in monozygotic twin Norrie disease patients. Furthermore, a previously described 14-bp deletion located in the 5' unstranslated region of the NDP gene was detected in three cases of regressed ROP. A second heterozygotic 14-bp deletion was detected in an unaffected ex-premature girl. Only two of the 13 Norrie-FEVR index cases had the full features of Norrie disease with deafness and mental retardation. CONCLUSION Two novel mutations within the coding region of the NDP gene were found, one associated with a severe disease phenotypes of Norrie disease and the other with FEVR. A deletion within the non-coding region was associated with only mild-regressed ROP, despite the presence of low birthweight, prematurity and exposure to oxygen. In full-term children with retinal detachment only 15% appear to have the full features of Norrie disease and this is important for counselling parents on the possible long-term outcome.
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40
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Martin AC, Thornton JD, Liu J, Wang X, Zuo J, Jablonski MM, Chaum E, Zindy F, Skapek SX. Pathogenesis of persistent hyperplastic primary vitreous in mice lacking the arf tumor suppressor gene. Invest Ophthalmol Vis Sci 2004; 45:3387-96. [PMID: 15452040 PMCID: PMC1557705 DOI: 10.1167/iovs.04-0349] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Persistent hyperplastic primary vitreous (PHPV) is an idiopathic developmental eye disease associated with failed involution of the hyaloid vasculature. The present work addressed the pathogenesis of PHPV in a mouse model that replicates many aspects of the human disease. METHODS Ophthalmoscopic and histologic analyses documented pathologic processes in eyes of mice lacking the Arf gene compared with Ink4a-deficient and wild-type control animals. Immunohistochemical staining, in situ hybridization, and RT-PCR demonstrated the expression of relevant gene products. Arf gene expression was determined by in situ hybridization using wholemounts of wild-type mouse eyes and by immunofluorescence staining for green fluorescent protein (GFP) in Arf(+/GFP) heterozygous knock-in mouse eyes. RESULTS Abnormalities in Arf(-/-) mice mimicked those found in patients with severe PHPV. The mice had microphthalmia; fibrovascular, retrolental tissue containing retinal pigment epithelial cells and remnants of the hyaloid vascular system; posterior lens capsule destruction with lens degeneration and opacity; and severe retinal dysplasia and detachment. Eyes of mice lacking the overlapping Ink4a gene were normal. Arf was selectively expressed in perivascular cells within the vitreous of the postnatal eye. Cells composing the retrolental mass in Arf(-/-) mice expressed the Arf promoter. The remnant hyaloid vessels expressed Flk-1. Its ligand, vascular endothelial growth factor (Vegf), was expressed in the retrolental tissue and the adjacent dysplastic neuroretina. CONCLUSIONS Arf(-/-) mice have features that accurately mimic severe PHPV. In the HVS, Arf expression in perivascular cells may block their accumulation or repress Vegf expression to promote HVS involution and prevent PHPV.
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Affiliation(s)
- Amy C. Martin
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - J. Derek Thornton
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Jiewiu Liu
- From the Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - XiaoFei Wang
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Departments of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Tennessee Mouse Genome Consortium, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jian Zuo
- From the Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Monica M. Jablonski
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Departments of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, Tennessee
- The Tennessee Mouse Genome Consortium, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Edward Chaum
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Frederique Zindy
- From the Departments of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Stephen X. Skapek
- From the Departments of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
- From the Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, Tennessee
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41
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Wheatley CM, Dickinson JL, Mackey DA, Craig JE, Sale MM. Retinopathy of prematurity: recent advances in our understanding. Arch Dis Child Fetal Neonatal Ed 2002; 87:F78-82. [PMID: 12193510 PMCID: PMC1721447 DOI: 10.1136/fn.87.2.f78] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Retinopathy of prematurity (ROP) has been recognised as an important cause of childhood visual impairment and blindness since the 1940s when improved facilities and treatment increased the survival rate of premature infants. Although its incidence and severity have been decreasing in developed countries over the past two decades, both are increasing in developing nations. ROP is consequently targeted as an important but avoidable disease. This review provides an updated summary and discussion of much of the work that has been produced through population, animal, cell culture, and genetic research. The authors examine the prevalence, risk factors, and possible causes of the disease with a particular focus on genetic studies. They conclude that while significant reductions in the disease have occurred in developed countries, further research is required to fully understand and prevent the disease. In the meantime, development and implementation of appropriate screening and treatment strategies will be critical in reducing blindness in developing countries.
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Affiliation(s)
- C M Wheatley
- Discipline of Biochemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
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42
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Wheatley CM, Dickinson JL, Mackey DA, Craig JE, Sale MM. Retinopathy of prematurity: recent advances in our understanding. Br J Ophthalmol 2002; 86:696-700. [PMID: 12034695 PMCID: PMC1771164 DOI: 10.1136/bjo.86.6.696] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Retinopathy of prematurity (ROP) has been recognised as an important cause of childhood visual impairment and blindness since the 1940s when improved facilities and treatment increased the survival rate of premature infants. Although its incidence and severity have been decreasing in developed countries over the past two decades, both are increasing in developing nations. ROP is consequently targeted as an important but avoidable disease. This review provides an updated summary and discussion of much of the work that has been produced through population, animal, cell culture, and genetic research. The authors examine the prevalence, risk factors, and possible causes of the disease with a particular focus on genetic studies. They conclude that while significant reductions in the disease have occurred in developed countries, further research is required to fully understand and prevent the disease. In the meantime, development and implementation of appropriate screening and treatment strategies will be critical in reducing blindness in developing countries.
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Affiliation(s)
- C M Wheatley
- Discipline of Biochemistry, University of Tasmania, Hobart, Tasmania, Australia
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43
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Sazgar M, Leonard NJ, Renaud DL, Bhargava R, Sinclair DB. Intracranial calcification, retinopathy, and osteopenia: a new syndrome? Pediatr Neurol 2002; 26:324-8. [PMID: 11992766 DOI: 10.1016/s0887-8994(01)00398-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We describe two brothers with bilateral exudative retinopathy, intracranial calcifications, a sclerotic bony disorder, and normal intelligence. The younger brother also has osteopenia, mild splenomegaly, and pancytopenia. We review the literature with emphasis on the unique features of these patients.
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Affiliation(s)
- Mona Sazgar
- Department of Medicine, Division of Neurology, University of Alberta Hospital, Edmonton, Canada
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44
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Smith SD. Relationships between neurologic disorders and hereditary hearing loss. Semin Pediatr Neurol 2001; 8:147-59. [PMID: 11575844 DOI: 10.1053/spen.2001.26448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hearing loss is a common disorder that often has a neurologic etiology. Recently, there has been significant progress in the discovery of the genes that cause sensorineural hearing loss, and this has led to increased understanding of the pathophysiology of both syndromic and nonsyndromic hearing problems. These genes cover the range of processes involved in neurologic development and function, including structural genes, transcription factors, and tumor suppressors; genes involved in signal transduction processes, such as ion homeostasis and intracellular transport; and mitochondrial genes responsible for oxidative phosphorylation and energy production. Interactions between genes as well as between genes and environmental factors have also been documented. Understanding of these processes should lead to earlier and more accurate diagnosis and more effective treatment for neurologic disorders and hearing loss.
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Affiliation(s)
- S D Smith
- Department of Pediatrics, Center for Human Molecular Genetics, Munroe Meyer Institute, University of Nebraska Medical Center, Omaha 68198-5455, USA
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45
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Yamada K, Limprasert P, Ratanasukon M, Tengtrisorn S, Yingchareonpukdee J, Vasiknanonte P, Kitaoka T, Ghadami M, Niikawa N, Kishino T. Two Thai families with Norrie disease (ND): association of two novel missense mutations with severe ND phenotype, seizures, and a manifesting carrier. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 100:52-5. [PMID: 11337749 DOI: 10.1002/1096-8628(20010415)100:1<52::aid-ajmg1214>3.0.co;2-b] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We describe two Thai families with Norrie disease (ND) in three generations, including 10 affected males and one manifesting female. All affected males in each family had severely defective eye development with complete loss of vision. In addition, three male patients (one from family 1 and two from family 2) suffered from epilepsy, and one female carrier from one family manifested blindness with phthisis bulbi in her right eye. Mutation analysis of the ND gene (NDP) revealed two different novel missense mutations (L16P and S75P) that co-segregated with ND in each family, suggesting that the newly appearing proline at codon 16 or codon 75 alters the conformation of the ND protein and contributes to the severe phenotype of ND in each family. Other studies suggest that epileptic seizures or growth retardation that is associated with ND is the consequence of loss of contiguous genes, because most such patients had deletions extending beyond the Norrie locus. Our finding that the three affected males in the two families with the missense mutations had epilepsy does not support a contiguous gene effect, but favors the pleiotropism of NDP, at least as far as the epileptic manifestation is concerned. The unilateral blindness in the female carrier may have been due to non-random X-inactivation.
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Affiliation(s)
- K Yamada
- Department of Human Genetics, Nagasaki University School of Medicine, Nagasaki, Japan.
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46
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Darling RJ, Wilken JA, Ruddon RW, Bedows E. Intracellular folding pathway of the cystine knot-containing glycoprotein hormone alpha-subunit. Biochemistry 2001; 40:577-85. [PMID: 11148053 DOI: 10.1021/bi002046a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Three of the five disulfide bonds in the glycoprotein hormone alpha-subunit (GPH-alpha) form a cystine knot motif that stabilizes a three-loop antiparallel structure. Previously, we described a mutant (alpha(k)) that contained only the three knot disulfide bonds and demonstrated that the cystine knot was necessary and sufficient for efficient GPH-alpha folding and secretion. In this study, we used alpha(k) as a model to study the intracellular GPH-alpha folding pathway. Cystine knot formation proceeded through a 1-disulfide intermediate that contained the 28-82 disulfide bond. Formation of disulfide bond 10-60, then disulfide bond 32-84, followed the formation of 28-82. Whether the two non-cystine knot bonds 7-31 and 59-87 could form independent of the knot was also tested. Disulfide bond 7-31 formed rapidly, whereas 59-87 did not form when all cysteine residues of the cystine knot were converted to alanine, suggesting that 7-31 forms early in the folding pathway and that 59-87 forms during or after cystine knot formation. Finally, loop 2 of GPH-alpha has been shown to be very flexible, suggesting that loop 2 does not actively drive GPH-alpha folding. To test this, we replaced residues 36-55 in the flexible loop 2 with an artificially flexible glycine chain. Consistent with our hypothesis, folding and secretion were unaffected when loop 2 was replaced with the glycine chain. Based on these findings, we describe a model for the intracellular folding pathway of GPH-alpha and discuss how these findings may provide insight into the folding mechanisms of other cystine knot-containing proteins.
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MESH Headings
- Amino Acid Motifs/genetics
- Cell Line
- Chorionic Gonadotropin, beta Subunit, Human/chemistry
- Chorionic Gonadotropin, beta Subunit, Human/metabolism
- Cysteine/chemistry
- Cysteine/genetics
- Cysteine/metabolism
- Cystine/chemistry
- Cystine/genetics
- Cystine/metabolism
- Dithiothreitol/pharmacology
- Glycoprotein Hormones, alpha Subunit/chemistry
- Glycoprotein Hormones, alpha Subunit/genetics
- Glycoprotein Hormones, alpha Subunit/metabolism
- Humans
- Intracellular Fluid/chemistry
- Mutagenesis, Site-Directed
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Protein Folding
- Protein Structure, Secondary/genetics
- Protein Structure, Tertiary/genetics
- Reducing Agents/pharmacology
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Affiliation(s)
- R J Darling
- Department of Pharmacology, Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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Rehm HL, Gutiérrez-Espeleta GA, Garcia R, Jiménez G, Khetarpal U, Priest JM, Sims KB, Keats BJ, Morton CC. Norrie disease gene mutation in a large Costa Rican kindred with a novel phenotype including venous insufficiency. Hum Mutat 2000; 9:402-8. [PMID: 9143918 DOI: 10.1002/(sici)1098-1004(1997)9:5<402::aid-humu4>3.0.co;2-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A large Costa Rican kindred has been identified with 15 males affected with congenital blindness, progressive bearing loss, and venous insufficiency. Due to ophthalmological and audio-otological findings, including bilateral retinal dysplasia and detachment, progressive bilateral sensorineural hearing loss, and an X-linked pattern of inheritance, a tentative diagnosis of Norrie disease was considered. However, venous insufficiency is a clinical finding not reportedly associated with Norrie disease. Genetic linkage analysis using microsatellite repeat markers demonstrated linkage to Xp11.23-11.4 (z = 2.723 at theta = 0.0). A candidate gene approach using the Norrie disease gene (NDP), which maps to Xp11.3, revealed a point mutation in the third exon resulting in substitution of phenylalanine for leucine at position 61. The precise function of the gene product, norrin, has yet to be elucidated; however, it has been postulated to be involved in the regulation of neural cell differentiation and proliferation, although hypotheses have been considered for its role in vascular development in the eye. The finding of a mutation in NDP in association with peripheral vascular disease may provide valuable insight into the potential role of this gene in cellular processes.
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Affiliation(s)
- H L Rehm
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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48
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Shastry BS, Hejtmancik JF, Trese MT. Identification of novel missense mutations in the Norrie disease gene associated with one X-linked and four sporadic cases of familial exudative vitreoretinopathy. Hum Mutat 2000; 9:396-401. [PMID: 9143917 DOI: 10.1002/(sici)1098-1004(1997)9:5<396::aid-humu3>3.0.co;2-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
X-linked Familial Exudative Vitreoretinopathy (XLFEVR) is a hereditary eye disorder that affects both the retina and the vitreous body. It is characterized by an abnormal vascularization of the peripheral retina. It has been previously shown by linkage and candidate gene analysis that XLFEVR and Norrie disease are allelic. In this report we describe four novel mutations (R41K, H42R, K58N, and Y120C) in the Norrie disease gene associated with one X-linked and four sporadic cases of FEVR. One mutation (H42R) was found to be segregating with the disease in three generations (X-linked family), and the others are sporadic. These sequence alterations changed the encoded amino acids in the Norrie disease protein and were not found in 17 unaffected family members or in 36 randomly selected normal individuals. This study provides additional evidence that mutations in the same gene can result in FEVR and Norrie disease. It also demonstrates that it may be beneficial for clinical diagnosis to screen for mutations in the Norrie disease gene in sporadic FEVR cases.
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Affiliation(s)
- B S Shastry
- Eye Research Institute, Oakland University, Rochester, Michigan 48309-4401, USA
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Darling RJ, Ruddon RW, Perini F, Bedows E. Cystine knot mutations affect the folding of the glycoprotein hormone alpha-subunit. Differential secretion and assembly of partially folded intermediates. J Biol Chem 2000; 275:15413-21. [PMID: 10809777 DOI: 10.1074/jbc.275.20.15413] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The common glycoprotein hormone alpha-subunit (GPH-alpha) contains five intramolecular disulfide bonds, three of which form a cystine knot motif (10-60, 28-82, and 32-84). By converting each pair of cysteine residues of a given disulfide bond to alanine, we have studied the role of individual disulfide bonds in GPH-alpha folding and have related folding ability to secretion and assembly with the human chorionic gonadotropin beta-subunit (hCG-beta). Mutation of non-cystine knot disulfide bond 7-31, bond 59-87, or both (leaving only the cystine knot) resulted in an efficiently secreted folding form that was indistinguishable from wild type. Conversely, the cystine knot mutants were inefficiently secreted (<25%). Furthermore, mutation of the cystine knot disulfide bonds resulted in multiple folding intermediates containing 1, 2, or 4 disulfide bonds. High performance liquid chromatographic separation of intracellular and secreted forms of the folding intermediates demonstrated that the most folded forms were preferentially secreted and combined with hCG-beta. From these studies we conclude that: (i) the cystine knot of GPH-alpha is necessary and sufficient for folding and (ii) there is a direct correlation between the extent of GPH-alpha folding, its ability to be secreted, and its ability to heterodimerize with hCG-beta.
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Affiliation(s)
- R J Darling
- Eppley Institute for Research in Cancer and Allied Diseases and the Department of Pharmacology, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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50
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Hartzer MK, Cheng M, Liu X, Shastry BS. Localization of the Norrie disease gene mRNA by in situ hybridization. Brain Res Bull 1999; 49:355-8. [PMID: 10452356 DOI: 10.1016/s0361-9230(99)00071-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Norrie disease is a rare X-linked recessive neurodevelopmental disorder. The affected males manifest congenital blindness, which is often associated with hearing loss, mental retardation and psychiatric problems. Genetic linkage studies have localized the gene to the short arm of the X-chromosome and the gene has been isolated recently. The encoded protein is a member of the superfamily of growth factors containing a cystine knot motif and may be involved in cell adhesion and neurodevelopment. Molecular genetic analysis revealed a large number of missense, nonsense, deletion, and splice-site mutations among Norrie patients. In order to further determine the role of the Norrie disease gene, we studied the distribution pattern of its mRNA in the retina and in brain by in situ hybridization. The results show abundant hybridization signals in outer nuclear, inner nuclear, and ganglion cell layers of the retina in all three species (mice, rabbit, and human) examined. There was no significant expression in the vitreous body, lens, and rod outer segment. High expression levels were also observed in the cerebellar granular layer, hippocampus, olfactory bulb, cortex, and epithelium of the rabbit brain. These data suggest that the Norrie disease gene could play a critical role in the differentiation or maintenance of the differentiated state of the retina.
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Affiliation(s)
- M K Hartzer
- Eye Research Institute, Oakland University, Rochester, MI 48309, USA
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