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Ruehle MD, Li S, Agard DA, Pearson CG. Poc1 bridges basal body inner junctions to promote triplet microtubule integrity and connections. J Cell Biol 2024; 223:e202311104. [PMID: 38743010 PMCID: PMC11094743 DOI: 10.1083/jcb.202311104] [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] [Received: 11/27/2023] [Revised: 03/15/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Basal bodies (BBs) are conserved eukaryotic structures that organize cilia. They are comprised of nine, cylindrically arranged, triplet microtubules (TMTs) connected to each other by inter-TMT linkages which stabilize the structure. Poc1 is a conserved protein important for BB structural integrity in the face of ciliary forces transmitted to BBs. To understand how Poc1 confers BB stability, we identified the precise position of Poc1 in the Tetrahymena BB and the effect of Poc1 loss on BB structure. Poc1 binds at the TMT inner junctions, stabilizing TMTs directly. From this location, Poc1 also stabilizes inter-TMT linkages throughout the BB, including the cartwheel pinhead and the inner scaffold. The full localization of the inner scaffold protein Fam161A requires Poc1. As ciliary forces are increased, Fam161A is reduced, indicative of a force-dependent molecular remodeling of the inner scaffold. Thus, while not essential for BB assembly, Poc1 promotes BB interconnections that establish an architecture competent to resist ciliary forces.
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Affiliation(s)
- Marisa D. Ruehle
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sam Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A. Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Institute for Advanced Biological Imaging, Redwood Shores, CA, USA
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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2
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Kumari A, Caliz AD, Yoo HJ, Kant S, Vertii A. TNF-alpha promotes cilia elongation via mixed lineage kinases signaling in mouse fibroblasts and human RPE-1 cells. Cytoskeleton (Hoboken) 2024. [PMID: 38767050 DOI: 10.1002/cm.21873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 04/10/2024] [Accepted: 04/30/2024] [Indexed: 05/22/2024]
Abstract
The primary cilium is a characteristic feature of most non-immune cells and functions as an environmental signal transduction sensor. The defects in primary cilium have profound effects on the developmental program, including the maturation of retinal epithelium. The ciliary length is tightly regulated during ciliogenesis, but the impact of inflammation on ciliary length remains elusive. The current study investigates the outcome of inflammatory stimuli for the primary cilium length in retinal epithelium cells and mouse embryonic fibroblasts. Here, we report that exposure to the pro-inflammatory cytokine TNF-alpha elongates cilia in a mixed-lineage kinase (MLK)-dependent manner. Pro-inflammatory stimuli such as bacterial LPS and interferon-gamma have similar effects on ciliary length. In contrast, febrile condition-mimicking heat stress dramatically reduced the number of ciliated cells regardless of TNF-alpha exposure but did not shorten TNF-induced elongation, suggesting distinct but rapid effects of inflammatory stresses on ciliogenesis.
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Affiliation(s)
- Amrita Kumari
- Molecular, Cell and Cancer Biology Department, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
| | - Amada D Caliz
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Hyung-Jin Yoo
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Shashi Kant
- Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Anastassiia Vertii
- Molecular, Cell and Cancer Biology Department, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA
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3
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Alzahem TA, AlTheeb A, Ba-Abbad R. Phenotypic and genotypic features of POC1B-associated cone dystrophy. Ophthalmic Genet 2024; 45:72-77. [PMID: 37246743 DOI: 10.1080/13816810.2023.2204361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 04/14/2023] [Indexed: 05/30/2023]
Abstract
PURPOSE Patients with cone dystrophy (CD) can present with virtually normal retinal appearance, which may delay diagnosis. This study describes the inconspicuous clinical features of POC1B-associated CD in two Saudi families. METHODS This is a retrospective case study. Clinical data analyzed included multimodal retinal imaging and electroretinography of the affected individuals. Genetic analysis was done for all probands. RESULTS Three affected males from two Saudi families with POC1B-associated CD were included. The ages at presentation ranged from 18 to 34 years. Ophthalmic examination showed decreased Snellen visual acuities (range: 20/100-20/300) and color vision bilaterally. Fundus examination showed only mild vascular attenuation. Macular optical coherence tomography showed reduced reflectivity of the external limiting membrane, ellipsoid, and interdigitation zones. Full-field electroretinography demonstrated undetectable light-adapted responses and normal dark-adapted responses in all patients. Next-generation sequencing showed one proband to be homozygous for a previously unpublished nonsense variant in POC1B (NM_172240):c.672C>G; p(Tyr224*). Whole exome sequencing for the second proband showed a novel homozygous frameshifting variant in POC1B: c.991del; p(Arg331Glufs*13). CONCLUSION We described two novel variants in POC1B and the associated subtle, yet significant retinal features. POC1B-associated CD is a rare cause of visual loss in patients with relatively normal fundus appearance. Deep phenotyping is necessary in formulating appropriate differential diagnosis.
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Affiliation(s)
- Tariq A Alzahem
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
- Ophthalmology Department, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Abdulwahab AlTheeb
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Rola Ba-Abbad
- Ocular Genetics Service, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
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4
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Cheng T, Agwu C, Shim K, Wang B, Jain S, Mahjoub MR. Aberrant centrosome biogenesis disrupts nephron and collecting duct progenitor growth and fate resulting in fibrocystic kidney disease. Development 2023; 150:dev201976. [PMID: 37982452 PMCID: PMC10753588 DOI: 10.1242/dev.201976] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023]
Abstract
Mutations that disrupt centrosome biogenesis or function cause congenital kidney developmental defects and fibrocystic pathologies. Yet how centrosome dysfunction results in the kidney disease phenotypes remains unknown. Here, we examined the consequences of conditional knockout of the ciliopathy gene Cep120, essential for centrosome duplication, in the nephron and collecting duct progenitor niches of the mouse embryonic kidney. Cep120 loss led to reduced abundance of both cap mesenchyme and ureteric bud populations, due to a combination of delayed mitosis, increased apoptosis and premature differentiation of progenitor cells. These defects resulted in dysplastic kidneys at birth, which rapidly formed cysts, displayed increased interstitial fibrosis and decline in kidney function. RNA sequencing of embryonic and postnatal kidneys from Cep120-null mice identified changes in the pathways essential for development, fibrosis and cystogenesis. Our study defines the cellular and developmental defects caused by centrosome dysfunction during kidney morphogenesis and identifies new therapeutic targets for patients with renal centrosomopathies.
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Affiliation(s)
- Tao Cheng
- Department of Medicine, Division of Nephrology, Washington University in St Louis, St. Louis, MO 63110, USA
| | - Chidera Agwu
- Department of Medicine, Division of Nephrology, Washington University in St Louis, St. Louis, MO 63110, USA
| | - Kyuhwan Shim
- Department of Medicine, Division of Nephrology, Washington University in St Louis, St. Louis, MO 63110, USA
| | - Baolin Wang
- Department of Genetic Medicine, Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Sanjay Jain
- Department of Medicine, Division of Nephrology, Washington University in St Louis, St. Louis, MO 63110, USA
| | - Moe R. Mahjoub
- Department of Medicine, Division of Nephrology, Washington University in St Louis, St. Louis, MO 63110, USA
- Department of Cell Biology and Physiology, Washington University in St Louis, St. Louis, MO 63110, USA
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5
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Ruehle MD, Li S, Agard DA, Pearson CG. Poc1 is a basal body inner junction protein that promotes triplet microtubule integrity and interconnections. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567593. [PMID: 38014135 PMCID: PMC10680851 DOI: 10.1101/2023.11.17.567593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Basal bodies (BBs) are conserved eukaryotic structures that organize motile and primary cilia. The BB is comprised of nine, cylindrically arranged, triplet microtubules (TMTs) that are connected to each other by inter-TMT linkages which maintain BB structure. During ciliary beating, forces transmitted to the BB must be resisted to prevent BB disassembly. Poc1 is a conserved BB protein important for BBs to resist ciliary forces. To understand how Poc1 confers BB stability, we identified the precise position of Poc1 binding in the Tetrahymena BB and the effect of Poc1 loss on BB structure. Poc1 binds at the TMT inner junctions, stabilizing TMTs directly. From this location, Poc1 also stabilizes inter-TMT linkages throughout the BB, including the cartwheel pinhead and the inner scaffold. Moreover, we identify a molecular response to ciliary forces via a molecular remodeling of the inner scaffold, as determined by differences in Fam161A localization. Thus, while not essential for BB assembly, Poc1 promotes BB interconnections that establish an architecture competent to resist ciliary forces.
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Affiliation(s)
- Marisa D. Ruehle
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sam Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - David A. Agard
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Institute for Advanced Biological Imaging, 3400 Bridge Parkway, Redwood Shores, CA, USA
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Abdel-Salam GMH, Hellmuth S, Gradhand E, Käseberg S, Winter J, Pabst AS, Eid MM, Thiele H, Nürnberg P, Budde BS, Toliat MR, Brecht IB, Schroeder C, Gschwind A, Ossowski S, Häuser F, Rossmann H, Abdel-Hamid MS, Hegazy I, Mohamed AG, Schneider DT, Bertoli-Avella A, Bauer P, Pearring JN, Pfundt R, Hoischen A, Gilissen C, Strand D, Zechner U, Tashkandi SA, Faqeih EA, Stemmann O, Strand S, Bolz HJ. Biallelic MAD2L1BP (p31comet) mutation is associated with mosaic aneuploidy and juvenile granulosa cell tumors. JCI Insight 2023; 8:e170079. [PMID: 37796616 PMCID: PMC10721328 DOI: 10.1172/jci.insight.170079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023] Open
Abstract
MAD2L1BP-encoded p31comet mediates Trip13-dependent disassembly of Mad2- and Rev7-containing complexes and, through this antagonism, promotes timely spindle assembly checkpoint (SAC) silencing, faithful chromosome segregation, insulin signaling, and homology-directed repair (HDR) of DNA double-strand breaks. We identified a homozygous MAD2L1BP nonsense variant, R253*, in 2 siblings with microcephaly, epileptic encephalopathy, and juvenile granulosa cell tumors of ovary and testis. Patient-derived cells exhibited high-grade mosaic variegated aneuploidy, slowed-down proliferation, and instability of truncated p31comet mRNA and protein. Corresponding recombinant p31comet was defective in Trip13, Mad2, and Rev7 binding and unable to support SAC silencing or HDR. Furthermore, C-terminal truncation abrogated an identified interaction of p31comet with tp53. Another homozygous truncation, R227*, detected in an early-deceased patient with low-level aneuploidy, severe epileptic encephalopathy, and frequent blood glucose elevations, likely corresponds to complete loss of function, as in Mad2l1bp-/- mice. Thus, human mutations of p31comet are linked to aneuploidy and tumor predisposition.
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Affiliation(s)
- Ghada M. H. Abdel-Salam
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | | | - Elise Gradhand
- Senckenberg Institute of Pathology, University Hospital Frankfurt, Frankfurt, Germany
| | - Stephan Käseberg
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
| | - Jennifer Winter
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
| | - Ann-Sophie Pabst
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
| | - Maha M. Eid
- Human Cytogenetics Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | | | - Peter Nürnberg
- Cologne Center for Genomics and
- Center for Molecular Medicine Cologne, University Hospital of Cologne, University of Cologne, Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | | | | | - Ines B. Brecht
- Paediatric Haematology/Oncology, Department of Paediatrics, University Hospital Tübingen, Tübingen, Germany
| | - Christopher Schroeder
- Institute of Medical Genetics and Applied Genomics, Eberhard-Karls University, Tübingen, Germany
| | - Axel Gschwind
- Institute of Medical Genetics and Applied Genomics, Eberhard-Karls University, Tübingen, Germany
| | - Stephan Ossowski
- Institute of Medical Genetics and Applied Genomics, Eberhard-Karls University, Tübingen, Germany
| | - Friederike Häuser
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Mainz, Germany
| | - Heidi Rossmann
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Mainz, Germany
| | - Mohamed S. Abdel-Hamid
- Medical Molecular Department, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Ibrahim Hegazy
- Department of Clinical Genetics, Human Genetics and Genome Research Institute, National Research Centre, Cairo, Egypt
| | - Ahmed G. Mohamed
- Pediatrics Department, Faculty of Medicine, Cairo University, Cairo, Egypt
| | | | | | | | - Jillian N. Pearring
- Department of Ophthalmology and Visual Sciences and
- Department of Cell and Developmental Biology, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Rolph Pfundt
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences and
| | - Alexander Hoischen
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences and
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, Netherlands
| | - Christian Gilissen
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences and
| | - Dennis Strand
- Department of Internal Medicine I, University Medical Center Mainz, Mainz, Germany
| | - Ulrich Zechner
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
| | - Soha A. Tashkandi
- Cytogenetics Laboratory, Pathology and Clinical Laboratory Medicine Administration (PCLMA), King Fahad Medical City, Second Central Healthcare Cluster (C2), Riyadh, Saudi Arabia
| | - Eissa A. Faqeih
- Section of Medical Genetics, Children’s Specialist Hospital, King Fahad Medical City, Riyadh, Saudi Arabia
| | - Olaf Stemmann
- Chair of Genetics, University of Bayreuth, Bayreuth, Germany
| | - Susanne Strand
- Department of Internal Medicine I, University Medical Center Mainz, Mainz, Germany
| | - Hanno J. Bolz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
- Institute of Human Genetics, University Hospital of Cologne, University of Cologne, Cologne, Germany
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7
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Jones MK, Orozco LD, Qin H, Truong T, Caplazi P, Elstrott J, Modrusan Z, Chaney SY, Jeanne M. Integration of human stem cell-derived in vitro systems and mouse preclinical models identifies complex pathophysiologic mechanisms in retinal dystrophy. Front Cell Dev Biol 2023; 11:1252547. [PMID: 37691820 PMCID: PMC10483287 DOI: 10.3389/fcell.2023.1252547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 08/14/2023] [Indexed: 09/12/2023] Open
Abstract
Rare DRAM2 coding variants cause retinal dystrophy with early macular involvement via unknown mechanisms. We found that DRAM2 is ubiquitously expressed in the human eye and expression changes were observed in eyes with more common maculopathy such as Age-related Macular Degeneration (AMD). To gain insights into pathogenicity of DRAM2-related retinopathy, we used a combination of in vitro and in vivo models. We found that DRAM2 loss in human pluripotent stem cell (hPSC)-derived retinal organoids caused the presence of additional mesenchymal cells. Interestingly, Dram2 loss in mice also caused increased proliferation of cells from the choroid in vitro and exacerbated choroidal neovascular lesions in vivo. Furthermore, we observed that DRAM2 loss in human retinal pigment epithelial (RPE) cells resulted in increased susceptibility to stress-induced cell death in vitro and that Dram2 loss in mice caused age-related photoreceptor degeneration. This highlights the complexity of DRAM2 function, as its loss in choroidal cells provided a proliferative advantage, whereas its loss in post-mitotic cells, such as photoreceptor and RPE cells, increased degeneration susceptibility. Different models such as human pluripotent stem cell-derived systems and mice can be leveraged to study and model human retinal dystrophies; however, cell type and species-specific expression must be taken into account when selecting relevant systems.
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Affiliation(s)
- Melissa K. Jones
- Department of Neuroscience, Genentech Inc., South San Francisco, CA, United States
- Product Development Clinical Science Ophthalmology, Genentech Inc., South San Francisco, CA, United States
| | - Luz D. Orozco
- Department of Bioinformatics, Genentech Inc., South San Francisco, CA, United States
| | - Han Qin
- Department of Neuroscience, Genentech Inc., South San Francisco, CA, United States
| | - Tom Truong
- Department of Translational Immunology, Genentech Inc., South San Francisco, CA, United States
| | - Patrick Caplazi
- Department of Research Pathology, Genentech Inc., South San Francisco, CA, United States
| | - Justin Elstrott
- Department of Translational Imaging, Genentech Inc., South San Francisco, CA, United States
| | - Zora Modrusan
- Department of Microchemistry, Proteomics, Lipidomics and Next-Generation Sequencing, Genentech Inc., South San Francisco, CA, United States
| | - Shawnta Y. Chaney
- Department of Translational Immunology, Genentech Inc., South San Francisco, CA, United States
| | - Marion Jeanne
- Department of Neuroscience, Genentech Inc., South San Francisco, CA, United States
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8
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Hayashi T, Mizobuchi K, Kameya S, Ueno S, Matsuura T, Nakano T. A mild form of POC1B-associated retinal dystrophy with relatively preserved cone system function. Doc Ophthalmol 2023:10.1007/s10633-023-09936-9. [PMID: 37227616 DOI: 10.1007/s10633-023-09936-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 05/04/2023] [Indexed: 05/26/2023]
Abstract
PURPOSE Biallelic variants in POC1B are rare causes of autosomal recessive cone dystrophy associated with generalized cone system dysfunction. In this report, we describe the clinical characteristics of a Japanese male patient with POC1B-associated retinopathy with relatively preserved cone system function. METHODS We performed whole-exome sequencing (WES) to identify the disease-causing variants and a comprehensive ophthalmic examination, including full-field and multifocal electroretinography (ffERG and mfERG). RESULTS Our WES analysis identified novel compound heterozygous POC1B variants (p.Arg106Gln and p.Arg452Ter) in the patient. His unaffected mother carried the p.Arg452Ter variant heterozygously. The patient experienced decreased visual acuity in his 50s. At the age of 63, his corrected visual acuity was 20/22 in the right and 20/20 in the left eye. Fundus and fundus autofluorescence images for each eye showed no remarkable finding, except for a subtle hyperautofluorescent spot in the fovea of the left eye. Cross-sectional optical coherence tomography demonstrated blurred but a relatively preserved ellipsoid zone. The ffERG showed that amplitudes of rod and standard-flash responses were within the reference range, whereas the cone and light-adapted 30-Hz flicker amplitudes were close to, or slightly below, the reference range. The mfERG revealed substantially reduced responses with relative preservation of central function. CONCLUSIONS We reported the case of an older patient with POC1B-associated retinopathy, demonstrating late-onset visual decrease, good visual acuity, and relatively preserved cone system function. The disease condition was much milder than previously reported in patients with POC1B-associated retinopathy.
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Affiliation(s)
- Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, 105-8461, Japan.
- Department of Ophthalmology, Katsushika Medical Center, The Jikei University School of Medicine, 6-41-2 Aoto, Katsushika-Ku, Tokyo, 125-8506, Japan.
| | - Kei Mizobuchi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Shuhei Kameya
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, 270-1694, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, 466-8550, Japan
| | - Tomokazu Matsuura
- Department of Laboratory Medicine, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
| | - Tadashi Nakano
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, 105-8461, Japan
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9
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Nuzhat N, Van Schil K, Liakopoulos S, Bauwens M, Rey AD, Käseberg S, Jäger M, Willer JR, Winter J, Truong HM, Gruartmoner N, Van Heetvelde M, Wolf J, Merget R, Grasshoff-Derr S, Van Dorpe J, Hoorens A, Stöhr H, Mansard L, Roux AF, Langmann T, Dannhausen K, Rosenkranz D, Wissing KM, Van Lint M, Rossmann H, Häuser F, Nürnberg P, Thiele H, Zechner U, Pearring JN, De Baere E, Bolz HJ. CEP162 deficiency causes human retinal degeneration and reveals a dual role in ciliogenesis and neurogenesis. J Clin Invest 2023; 133:e161156. [PMID: 36862503 PMCID: PMC10104899 DOI: 10.1172/jci161156] [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: 04/18/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023] Open
Abstract
Defects in primary or motile cilia result in a variety of human pathologies, and retinal degeneration is frequently associated with these so-called ciliopathies. We found that homozygosity for a truncating variant in CEP162, a centrosome and microtubule-associated protein required for transition zone assembly during ciliogenesis and neuronal differentiation in the retina, caused late-onset retinitis pigmentosa in 2 unrelated families. The mutant CEP162-E646R*5 protein was expressed and properly localized to the mitotic spindle, but it was missing from the basal body in primary and photoreceptor cilia. This impaired recruitment of transition zone components to the basal body and corresponded to complete loss of CEP162 function at the ciliary compartment, reflected by delayed formation of dysmorphic cilia. In contrast, shRNA knockdown of Cep162 in the developing mouse retina increased cell death, which was rescued by expression of CEP162-E646R*5, indicating that the mutant retains its role for retinal neurogenesis. Human retinal degeneration thus resulted from specific loss of the ciliary function of CEP162.
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Affiliation(s)
- Nafisa Nuzhat
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Kristof Van Schil
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sandra Liakopoulos
- Cologne Image Reading Center, Department of Ophthalmology, University Hospital of Cologne, Cologne, Germany
- Department of Ophthalmology, Goethe University, Frankfurt, Germany
| | - Miriam Bauwens
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Alfredo Dueñas Rey
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Stephan Käseberg
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
| | - Melanie Jäger
- Department of Ophthalmology, Justus-Liebig-University Giessen, Giessen, Germany
- Augenarztpraxis Bad Brückenau, Bad Brückenau, Germany
| | | | - Jennifer Winter
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
| | - Hanh M. Truong
- Cell and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Nuria Gruartmoner
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Mattias Van Heetvelde
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | | | | | | | - Jo Van Dorpe
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
- Department of Pathology, Ghent University Hospital, Ghent, Belgium
| | - Anne Hoorens
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
- Department of Pathology, Ghent University Hospital, Ghent, Belgium
| | - Heidi Stöhr
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Luke Mansard
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Anne-Françoise Roux
- Laboratoire de Génétique Moléculaire, CHU de Montpellier, Université de Montpellier, Montpellier, France
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Katharina Dannhausen
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - David Rosenkranz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
| | | | - Michel Van Lint
- Department of Ophthalmology, Brussels University Hospital, Jette, Belgium
| | - Heidi Rossmann
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Mainz, Germany
| | - Friederike Häuser
- Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center Mainz, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Ulrich Zechner
- Institute of Human Genetics, University Medical Center Mainz, Mainz, Germany
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
| | - Jillian N. Pearring
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Department of Ophthalmology and
- Cell and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, USA
| | - Elfride De Baere
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Hanno J. Bolz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
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Cheng T, Agwu C, Shim K, Wang B, Jain S, Mahjoub MR. Aberrant centrosome biogenesis disrupts nephron progenitor cell renewal and fate resulting in fibrocystic kidney disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.04.535568. [PMID: 37066373 PMCID: PMC10104032 DOI: 10.1101/2023.04.04.535568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Mutations that disrupt centrosome structure or function cause congenital kidney developmental defects and fibrocystic pathologies. Yet, it remains unclear how mutations in proteins essential for centrosome biogenesis impact embryonic kidney development. Here, we examined the consequences of conditional deletion of a ciliopathy gene, Cep120 , in the two nephron progenitor niches of the embryonic kidney. Cep120 loss led to reduced abundance of both metanephric mesenchyme and ureteric bud progenitor populations. This was due to a combination of delayed mitosis, increased apoptosis, and premature differentiation of progenitor cells. These defects resulted in dysplastic kidneys at birth, which rapidly formed cysts, displayed increased interstitial fibrosis, and decline in filtration function. RNA sequencing of embryonic and postnatal kidneys from Cep120-null mice identified changes in pathways essential for branching morphogenesis, cystogenesis and fibrosis. Our study defines the cellular and developmental defects caused by centrosome dysfunction during kidney development, and identifies new therapeutic targets for renal centrosomopathies. Highlights Defective centrosome biogenesis in nephron progenitors causes:Reduced abundance of metanephric mesenchyme and premature differentiation into tubular structuresAbnormal branching morphogenesis leading to reduced nephron endowment and smaller kidneysChanges in cell-autonomous and paracrine signaling that drive cystogenesis and fibrosisUnique cellular and developmental defects when compared to Pkd1 knockout models.
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Clinical-genetic findings in a group of subjects with macular dystrophies due to mutations in rare inherited retinopathy genes. Graefes Arch Clin Exp Ophthalmol 2023; 261:353-365. [PMID: 35947183 DOI: 10.1007/s00417-022-05786-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 07/03/2022] [Accepted: 07/22/2022] [Indexed: 01/25/2023] Open
Abstract
PURPOSE To describe the results of clinical and molecular analyses in a group of patients suffering from inherited macular dystrophies, in which next-generation sequencing (NGS) efficiently detected rare causative mutations. METHODS A total of eight unrelated Mexican subjects with a clinical and multimodal imaging diagnosis of macular dystrophy were included. Visual assessment methods included best corrected visual acuity, color fundus photography, Goldmann visual field tests, kinetic perimetry, dark/light adapted chromatic perimetry, full-field electroretinography, autofluorescence imaging, and spectral domain-optical coherence tomography imaging. Genetic screening was performed by means of whole exome sequencing with subsequent Sanger sequencing validation of causal variants. RESULTS All patients exhibited a predominantly macular or cone-dominant disease. Patients' ages ranged from 12 to 60 years. Three cases had mutations in genes associated with autosomal dominant inheritance (UNC119 and PRPH2) while the remaining five cases had mutations in genes associated with autosomal recessive inheritance (CNGA3, POC1B, BEST1, CYP2U1, and PROM1). Of the total of 11 different pathogenic alleles identified, three were previously unreported disease-causing variants. CONCLUSIONS Macular dystrophies can be caused by defects in genes that are not routinely analyzed or not included in NGS gene panels. In this group of patients, whole exome sequencing efficiently detected rare genetic causes of hereditary maculopathies, and our findings contribute to expanding the current knowledge of the clinical and mutational spectrum associated with these disorders.
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Batu Oto B, Ağırbaşlı D, Kılıçarslan O, Celik G, Kalayci Yigin A, Seven M, Yetik H. Pigmentary retinopathy with perivascular sparing in a SOFT syndrome patient with a novel homozygous splicing variant in POC1A gene. Ophthalmic Genet 2023; 44:70-73. [PMID: 35930384 DOI: 10.1080/13816810.2022.2103837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
PURPOSE SOFT syndrome is an extremely rare inherited dwarfism syndrome. The syndrome has four major clinical manifestations: short stature, onychodysplasia, facial dysmorphism, and hypotrichosis. Herein, we report a unique case of a SOFT syndrome with findings of pigmentary retinopathy. METHODS Case report. RESULTS A 3-year boy was referred to our clinic for ophthalmologic examination from Genetic Diseases Diagnosis Center. In ophthalmic examination, anterior segment was normal bilaterally in biomicroscopy. Fundus examination revealed bilateral yellow-white punctate retinal pigment epithelium lesions located in the midperipheral retina. Macula optical coherence tomography was bilaterally normal. Whole exome sequencing (WES) analysis revealed a homozygous intronic splice site variant (c.103 + 1 G>T) in POC1A, hemizygous intronic splice site variant (c.459-5T>A) in TBX22, and a heterozygous missense variant (c.2254 C>T) in DDR2 genes. CONCLUSION There is a limited number of reported cases with SOFT syndrome and, though retinal findings in SOFT syndrome have been reported in two cases previously, none were given in detail. According to our findings, perivascular and macula sparing midperipheral retina pigment epithelium changes could be observed in patients with SOFT syndrome.
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Affiliation(s)
- Bilge Batu Oto
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
| | - Deniz Ağırbaşlı
- Department of Medical Genetics, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
| | - Oğuzhan Kılıçarslan
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
| | - Gökhan Celik
- Department of Ophthalmology, ROP Screening, Treatment and Training Center, Zeynep Kamil Maternity and Children's Disease Training and Research Hospital, Istanbul, Turkey
| | - Aysel Kalayci Yigin
- Department of Medical Genetics, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
| | - Mehmet Seven
- Department of Medical Genetics, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
| | - Hüseyin Yetik
- Department of Ophthalmology, Cerrahpasa Medical Faculty, Istanbul University- Cerrahpasa, Istanbul, Turkey
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Yanık Ö, Batıoğlu F, Sahin Y, Demirel S, Özmert E. Seroreactivity against retinal proteins in a case of POC1B gene associated cone dystrophy with normal funduscopic appearance: a systematic approach to diagnosis. Ophthalmic Genet 2022:1-7. [PMID: 36094084 DOI: 10.1080/13816810.2022.2121842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
PURPOSE To report a case of cone dystrophy, associated with autosomal recessive homozygote POC1B gene variant, mimicking autoimmune retinopathy. CASE A 45-year-old female presented with a complaint of decreased vision in both eyes. Her best corrected visual acuity was 20/32 in the right eye and 20/50 in the left eye. Anterior segment and dilated fundus examinations were unremarkable. Spectral domain optical coherence tomography showed a subfoveal blurred dome-shaped ellipsoid zone and an extinguished interdigitation zone affecting the entire macula. Full field electroretinography revealed reduced cone responses. The differential diagnosis included inflammatory chorioretinopathies, autoimmune retinopathies (paraneoplastic or nonparaneoplastic), and hereditary retinal dystrophies. No remarkable finding was observed on combined fluorescein and indocyanine green angiographies. Paraneoplastic autoimmune antibody panel revealed nothing; however, aldolase, enolase, pyruvate kinase M2, and glyceraldehyde-3-phosphate dehydrogenase antibodies were positive on autoimmune retinopathy panel. To exclude hereditary retinal dystrophies, whole-exome sequencing (WES) was applied. WES identified an autosomal recessive homozygote POC1B gene variant (c.680A>G, p.His227Arg). Cone dystrophy diagnosis was given. CONCLUSION Cone dystrophy associated with POC1B gene variant may present without visible fundus abnormalities. It should be kept in mind that retinal autoantibodies may be positive in such a hereditary dystrophy case due to long-term exposure of the immune system to self-antigens. Therefore, autoimmune retinopathy is a diagnosis of exclusion and should not be diagnosed until all other causes, including hereditary dystrophies, have been ruled out.
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Affiliation(s)
- Özge Yanık
- Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey
| | - Figen Batıoğlu
- Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey
| | | | - Sibel Demirel
- Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey
| | - Emin Özmert
- Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey
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Chang KJ, Wu HY, Yarmishyn AA, Li CY, Hsiao YJ, Chi YC, Lo TC, Dai HJ, Yang YC, Liu DH, Hwang DK, Chen SJ, Hsu CC, Kao CL. Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology. Int J Mol Sci 2022; 23:ijms23179707. [PMID: 36077104 PMCID: PMC9456058 DOI: 10.3390/ijms23179707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet–Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus–Merzbacher disease), transcriptional deregulation diseases (Mowat–Wilson disease, Pitt–Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.
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Affiliation(s)
- Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yu Wu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Cheng-Yi Li
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chun Chi
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tzu-Chen Lo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - He-Jhen Dai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chiang Yang
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Ding-Hao Liu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
| | - Chung-Lan Kao
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
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Gana S, Serpieri V, Valente EM. Genotype-phenotype correlates in Joubert syndrome: A review. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:72-88. [PMID: 35238134 PMCID: PMC9314610 DOI: 10.1002/ajmg.c.31963] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/04/2022] [Accepted: 02/15/2022] [Indexed: 01/20/2023]
Abstract
Joubert syndrome (JS) is a genetically heterogeneous primary ciliopathy characterized by a pathognomonic cerebellar and brainstem malformation, the “molar tooth sign,” and variable organ involvement. Over 40 causative genes have been identified to date, explaining up to 94% of cases. To date, gene‐phenotype correlates have been delineated only for a handful of genes, directly translating into improved counseling and clinical care. For instance, JS individuals harboring pathogenic variants in TMEM67 have a significantly higher risk of liver fibrosis, while pathogenic variants in NPHP1, RPGRIP1L, and TMEM237 are frequently associated to JS with renal involvement, requiring a closer monitoring of liver parameters, or renal functioning. On the other hand, individuals with causal variants in the CEP290 or AHI1 need a closer surveillance for retinal dystrophy and, in case of CEP290, also for chronic kidney disease. These examples highlight how an accurate description of the range of clinical symptoms associated with defects in each causative gene, including the rare ones, would better address prognosis and help guiding a personalized management. This review proposes to address this issue by assessing the available literature, to confirm known, as well as to propose rare gene‐phenotype correlates in JS.
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Affiliation(s)
- Simone Gana
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy
| | | | - Enza Maria Valente
- Neurogenetics Research Center, IRCCS Mondino Foundation, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
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16
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Focșa IO, Budișteanu M, Bălgrădean M. Clinical and genetic heterogeneity of primary ciliopathies (Review). Int J Mol Med 2021; 48:176. [PMID: 34278440 PMCID: PMC8354309 DOI: 10.3892/ijmm.2021.5009] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/28/2021] [Indexed: 01/11/2023] Open
Abstract
Ciliopathies comprise a group of complex disorders, with involvement of the majority of organs and systems. In total, >180 causal genes have been identified and, in addition to Mendelian inheritance, oligogenicity, genetic modifications, epistatic interactions and retrotransposon insertions have all been described when defining the ciliopathic phenotype. It is remarkable how the structural and functional impairment of a single, minuscule organelle may lead to the pathogenesis of highly pleiotropic diseases. Thus, combined efforts have been made to identify the genetic substratum and to determine the pathophysiological mechanism underlying the clinical presentation, in order to diagnose and classify ciliopathies. Yet, predicting the phenotype, given the intricacy of the genetic cause and overlapping clinical characteristics, represents a major challenge. In the future, advances in proteomics, cell biology and model organisms may provide new insights that could remodel the field of ciliopathies.
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Affiliation(s)
- Ina Ofelia Focșa
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Magdalena Budișteanu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania
| | - Mihaela Bălgrădean
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children 'Maria Skłodowska Curie', 077120 Bucharest, Romania
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17
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Clinical Characteristics of POC1B-Associated Retinopathy and Assignment of Pathogenicity to Novel Deep Intronic and Non-Canonical Splice Site Variants. Int J Mol Sci 2021; 22:ijms22105396. [PMID: 34065499 PMCID: PMC8160832 DOI: 10.3390/ijms22105396] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 12/13/2022] Open
Abstract
Mutations in POC1B are a rare cause of inherited retinal degeneration. In this study, we present a thorough phenotypic and genotypic characterization of three individuals harboring putatively pathogenic variants in the POC1B gene. All patients displayed a similar, slowly progressive retinopathy (cone dystrophy or cone-rod dystrophy) with normal funduscopy but disrupted outer retinal layers on optical coherence tomography and variable age of onset. Other symptoms were decreased visual acuity and photophobia. Whole genome sequencing revealed a novel homozygous frameshift variant in one patient. Another patient was shown to harbor a novel deep intronic variant in compound heterozygous state with a previously reported canonical splice site variant. The third patient showed a novel nonsense variant and a novel non-canonical splice site variant. We aimed to validate the effect of the deep intronic variant and the non-canonical splice site variant by means of in vitro splice assays. In addition, direct RNA analysis was performed in one patient. Splicing analysis revealed that the non-canonical splice site variant c.561-3T>C leads to exon skipping while the novel deep intronic variant c.1033-327T>A causes pseudoexon activation. Our data expand the genetic landscape of POC1B mutations and confirm the benefit of genome sequencing in combination with downstream functional validation using minigene assays for the analysis of putative splice variants. In addition, we provide clinical multimodal phenotyping of the affected individuals.
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18
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Baldridge D, Wangler MF, Bowman AN, Yamamoto S, Schedl T, Pak SC, Postlethwait JH, Shin J, Solnica-Krezel L, Bellen HJ, Westerfield M. Model organisms contribute to diagnosis and discovery in the undiagnosed diseases network: current state and a future vision. Orphanet J Rare Dis 2021; 16:206. [PMID: 33962631 PMCID: PMC8103593 DOI: 10.1186/s13023-021-01839-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 04/23/2021] [Indexed: 12/12/2022] Open
Abstract
Decreased sequencing costs have led to an explosion of genetic and genomic data. These data have revealed thousands of candidate human disease variants. Establishing which variants cause phenotypes and diseases, however, has remained challenging. Significant progress has been made, including advances by the National Institutes of Health (NIH)-funded Undiagnosed Diseases Network (UDN). However, 6000-13,000 additional disease genes remain to be identified. The continued discovery of rare diseases and their genetic underpinnings provides benefits to affected patients, of whom there are more than 400 million worldwide, and also advances understanding the mechanisms of more common diseases. Platforms employing model organisms enable discovery of novel gene-disease relationships, help establish variant pathogenicity, and often lead to the exploration of underlying mechanisms of pathophysiology that suggest new therapies. The Model Organism Screening Center (MOSC) of the UDN is a unique resource dedicated to utilizing informatics and functional studies in model organisms, including worm (Caenorhabditis elegans), fly (Drosophila melanogaster), and zebrafish (Danio rerio), to aid in diagnosis. The MOSC has directly contributed to the diagnosis of challenging cases, including multiple patients with complex, multi-organ phenotypes. In addition, the MOSC provides a framework for how basic scientists and clinicians can collaborate to drive diagnoses. Customized experimental plans take into account patient presentations, specific genes and variant(s), and appropriateness of each model organism for analysis. The MOSC also generates bioinformatic and experimental tools and reagents for the wider scientific community. Two elements of the MOSC that have been instrumental in its success are (1) multidisciplinary teams with expertise in variant bioinformatics and in human and model organism genetics, and (2) mechanisms for ongoing communication with clinical teams. Here we provide a position statement regarding the central role of model organisms for continued discovery of disease genes, and we advocate for the continuation and expansion of MOSC-type research entities as a Model Organisms Network (MON) to be funded through grant applications submitted to the NIH, family groups focused on specific rare diseases, other philanthropic organizations, industry partnerships, and other sources of support.
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Affiliation(s)
- Dustin Baldridge
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - Michael F Wangler
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, 77030, USA.
- Department of Pediatrics, BCM, Houston, TX, 77030, USA.
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA.
- Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX, 77030, USA.
| | - Angela N Bowman
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Center of Regenerative Medicine, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Shinya Yamamoto
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
- Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX, 77030, USA
- Department of Neuroscience, BCM, Houston, TX, 77030, USA
| | - Tim Schedl
- Center of Regenerative Medicine, Washington University in St. Louis, St. Louis, MO, 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Stephen C Pak
- Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | | | - Jimann Shin
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Lilianna Solnica-Krezel
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO, 63110, USA
- Center of Regenerative Medicine, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine (BCM), Houston, TX, 77030, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, 77030, USA
- Development, Disease Models & Therapeutics Graduate Program, BCM, Houston, TX, 77030, USA
- Department of Neuroscience, BCM, Houston, TX, 77030, USA
- Howard Hughes Medical Institute, Houston, TX, 77030, USA
| | - Monte Westerfield
- Institute of Neuroscience, University of Oregon, Eugene, OR, 97403, USA
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Zebrafish Models of Autosomal Recessive Ataxias. Cells 2021; 10:cells10040836. [PMID: 33917666 PMCID: PMC8068028 DOI: 10.3390/cells10040836] [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: 03/09/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 12/11/2022] Open
Abstract
Autosomal recessive ataxias are much less well studied than autosomal dominant ataxias and there are no clearly defined systems to classify them. Autosomal recessive ataxias, which are characterized by neuronal and multisystemic features, have significant overlapping symptoms with other complex multisystemic recessive disorders. The generation of animal models of neurodegenerative disorders increases our knowledge of their cellular and molecular mechanisms and helps in the search for new therapies. Among animal models, the zebrafish, which shares 70% of its genome with humans, offer the advantages of being small in size and demonstrating rapid development, making them optimal for high throughput drug and genetic screening. Furthermore, embryo and larval transparency allows to visualize cellular processes and central nervous system development in vivo. In this review, we discuss the contributions of zebrafish models to the study of autosomal recessive ataxias characteristic phenotypes, behavior, and gene function, in addition to commenting on possible treatments found in these models. Most of the zebrafish models generated to date recapitulate the main features of recessive ataxias.
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20
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Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
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Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
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21
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Peturson AMC, Noel NCL, MacDonald IM. A homozygous POC1B variant causes recessive cone-rod dystrophy. Ophthalmic Genet 2021; 42:349-353. [PMID: 33657974 DOI: 10.1080/13816810.2021.1894460] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Purpose: To report a case of initial cone dystrophy that advanced to a cone-rod dystrophy with homozygous variants in the POC1B gene.Methods: Retinal structure and visual function assessments were performed using fundoscopy, spectral-domain optical coherence tomography, full field electroretinography, semi-kinetic perimetry, and Ishihara plate testing. A DNA sample was collected and sent for diagnostic molecular genetic testing with a cone-rod dystrophy panel.Results: Clinical examination and electroretinography confirmed a clinical diagnosis of cone dystrophy. Molecular genetic testing revealed homozygous variants in POC1B (c.1355 G > A, p.(Arg452Gln)). Follow-up three years later showed progression to a cone-rod dystrophy.Conclusion: Our case describes an ophthalmological phenotype associated with a homozygous POC1B missense variant and provides clinical support for variant classification.
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Affiliation(s)
- Ann-Marie C Peturson
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Nicole C L Noel
- Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - Ian M MacDonald
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
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22
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Nuovo S, Fuiano L, Micalizzi A, Battini R, Bertini E, Borgatti R, Caridi G, D'Arrigo S, Fazzi E, Fischetto R, Ghiggeri GM, Giordano L, Leuzzi V, Romaniello R, Signorini S, Stringini G, Zanni G, Romani M, Valente EM, Emma F. Impaired urinary concentration ability is a sensitive predictor of renal disease progression in Joubert syndrome. Nephrol Dial Transplant 2020; 35:1195-1202. [PMID: 30403813 PMCID: PMC7417010 DOI: 10.1093/ndt/gfy333] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 09/26/2018] [Indexed: 11/29/2022] Open
Abstract
Background Joubert syndrome (JS) is an inherited ciliopathy characterized by a complex midbrain–hindbrain malformation and multiorgan involvement. Renal disease, mainly juvenile nephronophthisis (NPH), was reported in 25–30% patients although only ∼18% had a confirmed diagnosis of chronic kidney disease (CKD). NPH often remains asymptomatic for many years, resulting in delayed diagnosis. The aim of the study was to identify a biomarker able to quantify the risk of progressive CKD in young children with JS. Methods Renal features were investigated in 93 Italian patients, including biochemical tests, ultrasound and 1-deamino-8D-arginine vasopressin test in children with reduced basal urine osmolality. A subset of patients was followed-up over time. Results At last examination, 27 of 93 subjects (29%) presented with CKD, ranging from isolated urinary concentration defect (UCD) to end-stage renal disease. Both normal and pathological urine osmolality levels remained stable over time, even when obtained at very early ages. Follow-up data showed that the probability of developing CKD can be modelled as a function of the urine osmolality value, exceeding 75% for levels <600 mOsm/kg H2O, and significantly increased in patients with an early diagnosis of isolated UCD. Conclusions We conclude that the frequency of CKD in JS increases with age and is higher than previously reported. Urine osmolality represents an early sensitive quantitative biomarker of the risk of CKD progression.
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Affiliation(s)
- Sara Nuovo
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Laura Fuiano
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | | | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy.,Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Enrico Bertini
- Laboratory of Molecular Medicine, Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Renato Borgatti
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Gianluca Caridi
- Laboratory of Molecular Nephrology, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - Stefano D'Arrigo
- Developmental Neurology Division, Foundation IRCCS Neurological Institute Carlo Besta, Milan, Italy
| | - Elisa Fazzi
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy.,Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy
| | - Rita Fischetto
- Clinical Genetics Unit, Department of Paediatric Medicine, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Gian Marco Ghiggeri
- Laboratory of Molecular Nephrology, Istituto Giannina Gaslini IRCCS, Genoa, Italy
| | - Lucio Giordano
- Child and Adolescent Neurology and Psychiatry Unit, Children Hospital, ASST Spedali Civili of Brescia, Brescia, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Sabrina Signorini
- Unit of Child Neurology and Psychiatry, IRCCS C. Mondino Foundation, Pavia, Italy
| | - Gilda Stringini
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Ginevra Zanni
- Laboratory of Molecular Medicine, Unit of Neuromuscular and Neurodegenerative Disorders, Department of Neurosciences, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Marta Romani
- Molecular Genetics Laboratory, Eurofins GENOMA Group, Rome, Italy
| | - Enza Maria Valente
- Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy.,Deparment of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Francesco Emma
- Department of Nephrology and Urology, Unit of Nephrology and Dialysis, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
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23
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Gliem M, Müller PL, Birtel J, Herrmann P, McGuinness MB, Holz FG, Charbel Issa P. Quantitative Fundus Autofluorescence and Genetic Associations in Macular, Cone, and Cone-Rod Dystrophies. Ophthalmol Retina 2020; 4:737-749. [PMID: 32646556 DOI: 10.1016/j.oret.2020.02.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/06/2020] [Accepted: 02/19/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate quantitatively lipofuscin-associated fundus autofluorescence in patients with macular and cone/cone-rod dystrophies (MD/CCRDs). DESIGN Prospective, single-center, case-control study. PARTICIPANTS Two hundred thirty patients with MD/CCRDs who had undergone genetic testing and 110 control participants without any eye disease. METHODS Participants were examined using quantitative fundus autofluorescence (qAF) imaging with a modified confocal scanning laser ophthalmoscope equipped with an internal fluorescent reference (modified Spectralis HRA-OCT; Heidelberg Engineering, Heidelberg, Germany). Mean qAF values were obtained by averaging measurements from an 8-segment ring centered on the fovea (qAF8) and compared with controls. MAIN OUTCOME MEASURES The qAF8 levels. RESULTS Elevated qAF8 values were a frequent finding (n = 105 [45%]) and associated with ABCA4 (n = 73 [70%]), PRPH2 (n = 9 [9%]), CERKL (n = 3 [3%]), PROM1 (n = 2 [2%]), CRX (n = 1 [1%]), and CDHR1 (n = 1 [1%]) mutations. Reduced qAF8 values were rare (n = 15 [7%]) and found predominantly among patients with MERTK (n = 3 [20%]) and RDH5 (n = 2 [13%]) mutations. Patients with normal qAF8 values (n = 110 [48%]) showed high genotypic heterogeneity. For various genes including ABCA4, PRPH2, CDHR1, and PROM1, higher qAF8 measures were associated with specific phenotypes and genotypes. For instance, qAF8 values were normal in PRPH2-related central areolar chorioretinal dystrophy but increased in PRPH2-related Stargardt-like retinopathy. Accordingly, high qAF8 levels were associated with specific genetic causes and mutation detection rates in characteristic but genetically heterogenous clinical phenotypes, such as a Stargardt-like flecked fundus, bull's eye maculopathy, or pattern dystrophy. In genetically unsolved cases (16 with elevated, 35 with normal, 7 with reduced qAF values), qAF8 was used to support or reject ambiguous results of genetic testing, to suggest underlying pathogenic pathways, and to predict disease in otherwise healthy participants. CONCLUSIONS Quantitative fundus autofluorescence imaging revealed characteristic qAF levels in association with certain gene mutations and in participants without detected mutations. These findings indicate that qAF may facilitate differential diagnostics of MD/CCRDs and may offer novel pathogenetic insights that may be of particular value for the assessment of future treatment approaches.
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Affiliation(s)
- Martin Gliem
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, and Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Department of Ophthalmology, University Hospital of Bonn, Bonn, Germany; Centre for Rare Diseases Bonn (ZSEB), University of Bonn, Bonn, Germany
| | - Philipp L Müller
- Department of Ophthalmology, University Hospital of Bonn, Bonn, Germany; Centre for Rare Diseases Bonn (ZSEB), University of Bonn, Bonn, Germany; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Johannes Birtel
- Department of Ophthalmology, University Hospital of Bonn, Bonn, Germany; Centre for Rare Diseases Bonn (ZSEB), University of Bonn, Bonn, Germany
| | - Philipp Herrmann
- Department of Ophthalmology, University Hospital of Bonn, Bonn, Germany; Centre for Rare Diseases Bonn (ZSEB), University of Bonn, Bonn, Germany
| | - Myra B McGuinness
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Frank G Holz
- Department of Ophthalmology, University Hospital of Bonn, Bonn, Germany; Centre for Rare Diseases Bonn (ZSEB), University of Bonn, Bonn, Germany
| | - Peter Charbel Issa
- Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, and Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
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24
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Kameya S, Fujinami K, Ueno S, Hayashi T, Kuniyoshi K, Ideta R, Kikuchi S, Kubota D, Yoshitake K, Katagiri S, Sakuramoto H, Kominami T, Terasaki H, Yang L, Fujinami-Yokokawa Y, Liu X, Arno G, Pontikos N, Miyake Y, Iwata T, Tsunoda K. Phenotypical Characteristics of POC1B-Associated Retinopathy in Japanese Cohort: Cone Dystrophy With Normal Funduscopic Appearance. Invest Ophthalmol Vis Sci 2019; 60:3432-3446. [PMID: 31390656 DOI: 10.1167/iovs.19-26650] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Cone/cone-rod dystrophy is a large group of retinal disorders with both phonotypic and genetic heterogeneity. The purpose of this study was to characterize the phenotype of eight patients from seven families harboring POC1B mutations in a cohort of the Japan Eye Genetics Consortium (JEGC). Methods Whole-exome sequencing with targeted analyses identified homozygous or compound heterozygous mutations of the POC1B gene in 7 of 548 families in the JEGC database. Ophthalmologic examinations including the best-corrected visual acuity, perimetry, fundus photography, fundus autofluorescence imaging, optical coherence tomography, and full-field and multifocal electroretinography (ERGs) were performed. Results There were four men and four women whose median age at the onset of symptoms was 15.6 years (range, 6-23 years) and that at the time of examination was 40.3 years (range, 22-67 years). The best-corrected visual acuity ranged from -0.08 to 1.52 logMAR units. The funduscopic appearance was normal in all the cases except in one case with faint mottling in the fovea. Optical coherence tomography revealed an absence of the interdigitation zone and blurred ellipsoid zone in the posterior pole, but the foveal structures were preserved in three cases. The full-field photopic ERGs were reduced or extinguished with normal scotopic responses. The central responses of the multifocal ERGs were preserved in two cases. The diagnosis was either generalized cone dystrophy in five cases or cone dystrophy with foveal sparing in three cases. Conclusions Generalized or peripheral cone dystrophy with normal funduscopic appearance is the representative phenotype of POC1B-associated retinopathy in our cohort.
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Affiliation(s)
- Shuhei Kameya
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan
| | - Kaoru Fujinami
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,UCL Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Shinji Ueno
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazuki Kuniyoshi
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| | | | - Sachiko Kikuchi
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan.,Department of Ophthalmology, Chiba, Japan
| | - Daiki Kubota
- Department of Ophthalmology, Nippon Medical School Chiba Hokusoh Hospital, Chiba, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Satoshi Katagiri
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroyuki Sakuramoto
- Department of Ophthalmology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Taro Kominami
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Hiroko Terasaki
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Aichi, Japan
| | - Lizhu Yang
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Yu Fujinami-Yokokawa
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Graduate School of Health Management, Keio University, Kanagawa, Japan.,Division of Public Health, Yokokawa Clinic, Osaka, Japan
| | - Xiao Liu
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan.,Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Gavin Arno
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,UCL Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom.,North East Thames Regional Genetics Service, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Nikolas Pontikos
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,UCL Institute of Ophthalmology, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | | | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
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25
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Bachmann-Gagescu R, Dempsey JC, Bulgheroni S, Chen ML, D'Arrigo S, Glass IA, Heller T, Héon E, Hildebrandt F, Joshi N, Knutzen D, Kroes HY, Mack SH, Nuovo S, Parisi MA, Snow J, Summers AC, Symons JM, Zein WM, Boltshauser E, Sayer JA, Gunay-Aygun M, Valente EM, Doherty D. Healthcare recommendations for Joubert syndrome. Am J Med Genet A 2019; 182:229-249. [PMID: 31710777 DOI: 10.1002/ajmg.a.61399] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/02/2019] [Accepted: 10/09/2019] [Indexed: 12/19/2022]
Abstract
Joubert syndrome (JS) is a recessive neurodevelopmental disorder defined by a characteristic cerebellar and brainstem malformation recognizable on axial brain magnetic resonance imaging as the "Molar Tooth Sign". Although defined by the neurological features, JS is associated with clinical features affecting many other organ systems, particularly progressive involvement of the retina, kidney, and liver. JS is a rare condition; therefore, many affected individuals may not have easy access to subspecialty providers familiar with JS (e.g., geneticists, neurologists, developmental pediatricians, ophthalmologists, nephrologists, hepatologists, psychiatrists, therapists, and educators). Expert recommendations can enable practitioners of all types to provide quality care to individuals with JS and know when to refer for subspecialty care. This need will only increase as precision treatments targeting specific genetic causes of JS emerge. The goal of these recommendations is to provide a resource for general practitioners, subspecialists, and families to maximize the health of individuals with JS throughout the lifespan.
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Affiliation(s)
- Ruxandra Bachmann-Gagescu
- Institute of Molecular Life Sciences, University of Zurich, Zurich, Switzerland.,Institute of Medical Genetics, University of Zurich, Schlieren, Switzerland
| | - Jennifer C Dempsey
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Sara Bulgheroni
- Developmental Neurology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Maida L Chen
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Division of Pulmonary and Sleep Medicine, Seattle Children's Hospital, Seattle, Washington
| | - Stefano D'Arrigo
- Developmental Neurology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Ian A Glass
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington
| | - Theo Heller
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Elise Héon
- Department of Surgery, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Ophthalmology and Vision Science, University of Toronto, Toronto, Ontario, Canada
| | - Friedhelm Hildebrandt
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts.,Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts
| | - Nirmal Joshi
- Department of Anesthesia, Deaconess Hospital, Evansville, Indiana.,Anesthesia Dynamics, LLC, Evansville, Indiana
| | - Dana Knutzen
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas.,The Children's Hospital of San Antonio, San Antonio, Texas
| | - Hester Y Kroes
- Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Stephen H Mack
- Joubert Syndrome and Related Disorders Foundation, Petaluma, California
| | - Sara Nuovo
- Neurogenetics Lab, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Medicine and Surgery, University of Salerno, Salerno, Italy
| | - Melissa A Parisi
- Intellectual and Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Joseph Snow
- Office of the Clinical Director, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Angela C Summers
- Office of the Clinical Director, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.,Department of Psychology, Fordham University, Bronx, New York
| | - Jordan M Symons
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Division of Nephrology, Seattle Children's Hospital, Seattle, Washington
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Eugen Boltshauser
- Department of Pediatric Neurology (emeritus), Children's University Hospital, Zürich, Switzerland
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Renal Services, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK
| | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland.,Department of Pediatrics and McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Enza Maria Valente
- Neurogenetics Lab, IRCCS Santa Lucia Foundation, Rome, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Dan Doherty
- Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington.,Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
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26
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Preising MN, Görg B, Friedburg C, Qvartskhava N, Budde BS, Bonus M, Toliat MR, Pfleger C, Altmüller J, Herebian D, Beyer M, Zöllner HJ, Wittsack HJ, Schaper J, Klee D, Zechner U, Nürnberg P, Schipper J, Schnitzler A, Gohlke H, Lorenz B, Häussinger D, Bolz HJ. Biallelic mutation of human SLC6A6 encoding the taurine transporter TAUT is linked to early retinal degeneration. FASEB J 2019; 33:11507-11527. [PMID: 31345061 DOI: 10.1096/fj.201900914rr] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We previously reported that inactivation of the transmembrane taurine transporter (TauT or solute carrier 6a6) causes early retinal degeneration in mice. Compatible with taurine's indispensability for cell volume homeostasis, protein stabilization, cytoprotection, antioxidation, and immuno- and neuromodulation, mice develop multisystemic dysfunctions (hearing loss; liver fibrosis; and behavioral, heart, and skeletal muscle abnormalities) later on. Here, by genetic, cell biologic, in vivo 1H-magnetic resonance spectroscopy and molecular dynamics simulation studies, we conducted in-depth characterization of a novel disorder: human TAUT deficiency. Loss of TAUT function due to a homozygous missense mutation caused panretinal degeneration in 2 brothers. TAUTp.A78E still localized in the plasma membrane but is predicted to impact structural stabilization. 3H-taurine uptake by peripheral blood mononuclear cells was reduced by 95%, and taurine levels were severely reduced in plasma, skeletal muscle, and brain. Extraocular dysfunctions were not yet detected, but significantly increased urinary excretion of 8-oxo-7,8-dihydroguanosine indicated generally enhanced (yet clinically unapparent) oxidative stress and RNA oxidation, warranting continuous broad surveillance.-Preising, M. N., Görg, B., Friedburg, C., Qvartskhava, N., Budde, B. S., Bonus, M., Toliat, M. R., Pfleger, C., Altmüller, J., Herebian, D., Beyer, M., Zöllner, H. J., Wittsack, H.-J., Schaper, J., Klee, D., Zechner, U., Nürnberg, P., Schipper, J., Schnitzler, A., Gohlke, H., Lorenz, B., Häussinger, D., Bolz, H. J. Biallelic mutation of human SLC6A6 encoding the taurine transporter TAUT is linked to early retinal degeneration.
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Affiliation(s)
- Markus N Preising
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
| | - Boris Görg
- Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Christoph Friedburg
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
| | - Natalia Qvartskhava
- Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Birgit S Budde
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Michele Bonus
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Mohammad R Toliat
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Christopher Pfleger
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Diran Herebian
- Department of General Pediatrics, Neonatology, and Pediatric Cardiology, Medical Faculty, University Hospital Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Mila Beyer
- Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Helge J Zöllner
- Institute of Clinical Neuroscience and Medical Psychology, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Hans-Jörg Wittsack
- Department of Diagnostic and Interventional Radiology, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jörg Schaper
- Department of Diagnostic and Interventional Radiology, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Dirk Klee
- Department of Diagnostic and Interventional Radiology, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Ulrich Zechner
- Senckenberg Centre for Human Genetics, Frankfurt on the Main, Germany.,Institute of Human Genetics, Mainz University Medical Center, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jörg Schipper
- Klinik für Hals-Nasen-Ohren Heilkunde, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,John von Neumann Institute for Computing (NIC)-Jülich Supercomputing Centre (JSC)-Structural Biochemistry, Institute of Complex Systems (ICS 6), Research Centre Jülich, Jülich, Germany
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
| | - Dieter Häussinger
- Department of Gastroenterology, Hepatology, and Infectious Diseases, University Hospital of Düsseldorf-Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Hanno J Bolz
- Institute of Human Genetics, University of Cologne, Cologne, Germany.,Senckenberg Centre for Human Genetics, Frankfurt on the Main, Germany
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27
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Parisi MA. The molecular genetics of Joubert syndrome and related ciliopathies: The challenges of genetic and phenotypic heterogeneity. ACTA ACUST UNITED AC 2019; 4:25-49. [PMID: 31763177 PMCID: PMC6864416 DOI: 10.3233/trd-190041] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Joubert syndrome (JS; MIM PS213300) is a rare, typically autosomal recessive disorder characterized by cerebellar vermis hypoplasia and a distinctive malformation of the cerebellum and brainstem identified as the “molar tooth sign” on brain MRI. Other universal features include hypotonia with later ataxia and intellectual disability/developmental delay, with additional features consisting of oculomotor apraxia and abnormal respiratory pattern. Notably, other, more variable features include renal cystic disease, typically nephronophthisis, retinal dystrophy, and congenital hepatic fibrosis; skeletal changes such as polydactyly and findings consistent with short-rib skeletal dysplasias are also seen in many subjects. These pleiotropic features are typical of a number of disorders of the primary cilium, and make the identification of causal genes challenging given the significant overlap between JS and other ciliopathy conditions such as nephronophthisis and Meckel, Bardet-Biedl, and COACH syndromes. This review will describe the features of JS, characterize the 35 known genes associated with the condition, and describe some of the genetic conundrums of JS, such as the heterogeneity of founder effects, lack of genotype-phenotype correlations, and role of genetic modifiers. Finally, aspects of JS and related ciliopathies that may pave the way for development of therapeutic interventions, including gene therapy, will be described.
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Affiliation(s)
- Melissa A Parisi
- Chief, Intellectual & Developmental Disabilities Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Bethesda, MD, USA
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Li S, Fernandez JJ, Marshall WF, Agard DA. Electron cryo-tomography provides insight into procentriole architecture and assembly mechanism. eLife 2019; 8:43434. [PMID: 30741631 PMCID: PMC6384029 DOI: 10.7554/elife.43434] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 02/10/2019] [Indexed: 01/03/2023] Open
Abstract
Centriole is an essential structure with multiple functions in cellular processes. Centriole biogenesis and homeostasis is tightly regulated. Using electron cryo-tomography (cryoET) we present the structure of procentrioles from Chlamydomonas reinhardtii. We identified a set of non-tubulin components attached to the triplet microtubule (MT), many are at the junctions of tubules likely to reinforce the triplet. We describe structure of the A-C linker that bridges neighboring triplets. The structure infers that POC1 is likely an integral component of A-C linker. Its conserved WD40 β-propeller domain provides attachment sites for other A-C linker components. The twist of A-C linker results in an iris diaphragm-like motion of the triplets in the longitudinal direction of procentriole. Finally, we identified two assembly intermediates at the growing ends of procentriole allowing us to propose a model for the procentriole assembly. Our results provide a comprehensive structural framework for understanding the molecular mechanisms underpinning procentriole biogenesis and assembly.
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Affiliation(s)
- Sam Li
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | | | - Wallace F Marshall
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
| | - David A Agard
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
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Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
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Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
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Review of Ocular Manifestations of Joubert Syndrome. Genes (Basel) 2018; 9:genes9120605. [PMID: 30518138 PMCID: PMC6315342 DOI: 10.3390/genes9120605] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/13/2018] [Accepted: 11/27/2018] [Indexed: 12/13/2022] Open
Abstract
Joubert syndrome is a group of rare disorders that stem from defects in a sensory organelle, the primary cilia. Affected patients often present with disorders involving multiple organ systems, including the brain, eyes, and kidneys. Common symptoms include breathing abnormalities, mental developmental delays, loss of voluntary muscle coordination, and abnormal eye movements, with a diagnostic “molar tooth” sign observed by magnetic resonance imaging (MRI) of the midbrain. We reviewed the ocular phenotypes that can be found in patients with Joubert syndrome. Ocular motor apraxia is the most frequent (80% of patients), followed by strabismus (74%) and nystagmus (72%). A minority of patients also present with ptosis (43%), chorioretinal coloboma (30%), and optic nerve atrophy (22%). Although mutations in 34 genes have been found to be associated with Joubert syndrome, retinal degeneration has been reported in only 38% of patients. Mutations in AHI1 and CEP290, genes critical to primary cilia function, have been linked to retinal degeneration. In conclusion, Joubert syndrome is a rare pleiotropic group of disorders with variable ocular presentations.
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Mégarbané A, Hmaimess G, Bizzari S, El-Bazzal L, Al-Ali MT, Stora S, Delague V, El-Hayek S. A novel PDE6D mutation in a patient with Joubert syndrome type 22 (JBTS22). Eur J Med Genet 2018; 62:103576. [PMID: 30423442 DOI: 10.1016/j.ejmg.2018.11.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 10/02/2018] [Accepted: 11/09/2018] [Indexed: 10/27/2022]
Abstract
Joubert syndrome (JS) is an autosomal or X-linked recessive syndrome principally characterized by hypotonia, ataxia, cognitive impairment, and a specific finding on brain imaging called a "molar tooth sign" (MTS), which can be isolated or in conjunction with variable organ involvement. The genetic basis of JS is heterogeneous, with over 35 ciliary genes being implicated in its pathogenesis. However, some of these genes (such as PDE6D) have been associated to JS only in single families, seeking confirmation. Here we report a boy, born to first cousin parents, presenting with developmental delay, hypotonia, microcephaly, post axial polydactyly, oculomotor apraxia, and MTS. Whole exome sequencing revealed the presence of a novel homozygous truncating variant in the PDE6D gene: NM_002601.3:c.367_368insG [p.(Leu123Cysfs*13)]. The variant was confirmed by Sanger sequencing and found at the heterozygous state in both parents. A review of the literature pertaining to the role of PDE6D in JS is discussed.
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Affiliation(s)
| | | | - Sami Bizzari
- Centre for Arab Genomic Studies, Dubai, United Arab Emirates
| | - Lara El-Bazzal
- Aix Marseille Univ, Inserm, MMG, U 1251, Marseille, France
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Clinical and genetic characteristics of 251 consecutive patients with macular and cone/cone-rod dystrophy. Sci Rep 2018; 8:4824. [PMID: 29555955 PMCID: PMC5859282 DOI: 10.1038/s41598-018-22096-0] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 02/16/2018] [Indexed: 12/14/2022] Open
Abstract
Macular and cone/cone-rod dystrophies (MD/CCRD) demonstrate a broad genetic and phenotypic heterogeneity, with retinal alterations solely or predominantly involving the central retina. Targeted next-generation sequencing (NGS) is an efficient diagnostic tool for identifying mutations in patient with retinitis pigmentosa, which shows similar genetic heterogeneity. To detect the genetic causes of disease in patients with MD/CCRD, we implemented a two-tier procedure consisting of Sanger sequencing and targeted NGS including genes associated with clinically overlapping conditions. Disease-causing mutations were identified in 74% of 251 consecutive MD/CCRD patients (33% of the variants were novel). Mutations in ABCA4, PRPH2 and BEST1 accounted for 57% of disease cases. Further mutations were identified in CDHR1, GUCY2D, PROM1, CRX, GUCA1A, CERKL, MT-TL1, KIF11, RP1L1, MERTK, RDH5, CDH3, C1QTNF5, CRB1, JAG1, DRAM2, POC1B, NPHP1 and RPGR. We provide detailed illustrations of rare phenotypes, including autofluorescence and optical coherence tomography imaging. Targeted NGS also identified six potential novel genotype-phenotype correlations for FAM161A, INPP5E, MERTK, FBLN5, SEMA4A and IMPDH1. Clinical reassessment of genetically unsolved patients revealed subgroups with similar retinal phenotype, indicating a common molecular disease cause in each subgroup.
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Weisz Hubshman M, Broekman S, van Wijk E, Cremers F, Abu-Diab A, Khateb S, Tzur S, Lagovsky I, Smirin-Yosef P, Sharon D, Haer-Wigman L, Banin E, Basel-Vanagaite L, de Vrieze E. Whole-exome sequencing reveals POC5 as a novel gene associated with autosomal recessive retinitis pigmentosa. Hum Mol Genet 2017; 27:614-624. [DOI: 10.1093/hmg/ddx428] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 12/08/2017] [Indexed: 01/01/2023] Open
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Kominami A, Ueno S, Kominami T, Nakanishi A, Ito Y, Fujinami K, Tsunoda K, Hayashi T, Kikuchi S, Kameya S, Iwata T, Terasaki H. Case of cone dystrophy with normal fundus appearance associated with biallelic POC1B variants. Ophthalmic Genet 2017; 39:255-262. [PMID: 29220607 DOI: 10.1080/13816810.2017.1408846] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Biallelic variants of POC1B were recently reported to cause autosomal recessive non-syndromic cone dystrophy. However, the number of studies supporting this is limited, and the clinical phenotypes of cone dystrophy have not been definitively determined. The purpose of this study was to report the phenotype of a case of POC1B-associated cone dystrophy. MATERIALS AND METHODS The medical chart of one case diagnosed with cone dystrophy was reviewed. RESULTS The patient was a 20-year-old Japanese man whose chief complaint was a progressive decrease in his central vision. His decimal best-corrected visual acuity was 0.2 for the right and 0.3 for the left. Fundus examinations showed no abnormalities. The photopic electroretinograms were nonrecordable, but the scotopic electroretinograms were within normal limits. Optical coherence tomography detected a blurry line in the region of the external limiting membrane and ellipsoid zone. Adaptive optics images showed sparsely distributed cone cells around the fovea. The patient was initially diagnosed with incomplete achromatopsia. Whole-exome sequence with targeted analysis identified new compound heterozygous mutations of c.G1355A (p R452Q) and c.C987A (pY329X) in the POC1B gene. The patient was then diagnosed with cone dystrophy. CONCLUSIONS The cone dystrophy associated with POC1B variants has features similar to achromatopsia, and genetic analyses is useful in discriminating these two diseases.
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Affiliation(s)
- Azusa Kominami
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
| | - Shinji Ueno
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
| | - Taro Kominami
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
| | - Ayami Nakanishi
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
| | - Yasuki Ito
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
| | - Kaoru Fujinami
- b National Institute of Sensor Organs, National Hospital Organization Tokyo Medical Center , Tokyo , Japan
| | - Kazushige Tsunoda
- b National Institute of Sensor Organs, National Hospital Organization Tokyo Medical Center , Tokyo , Japan
| | - Takaaki Hayashi
- c Department of Ophthalmology , The Jikei University School of Medicine , Tokyo , Japan
| | - Sachiko Kikuchi
- d Department of Ophthalmology , Nippon Medical School Chiba Hokusoh Hospital , Chiba , Japan
| | - Shuhei Kameya
- d Department of Ophthalmology , Nippon Medical School Chiba Hokusoh Hospital , Chiba , Japan
| | - Takeshi Iwata
- b National Institute of Sensor Organs, National Hospital Organization Tokyo Medical Center , Tokyo , Japan
| | - Hiroko Terasaki
- a Department of Ophthalmology , Nagoya University Graduate School of Medicine , Nagoya , Japan
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Unraveling the genetic cause of a consanguineous family with unilateral coloboma and retinoschisis: expanding the phenotypic variability of RAX mutations. Sci Rep 2017; 7:9064. [PMID: 28831107 PMCID: PMC5567291 DOI: 10.1038/s41598-017-09276-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 07/25/2017] [Indexed: 01/08/2023] Open
Abstract
Ocular coloboma is a common eye malformation arising from incomplete closure of the human optic fissure during development. Multiple genetic mutations contribute to the disease process, showing extensive genetic heterogeneity and complexity of coloboma spectrum diseases. In this study, we aimed to unravel the genetic cause of a consanguineous family with unilateral coloboma and retinoschisis. The subjects were recruited and underwent specialized ophthalmologic clinical examination. A combination of whole exome sequencing (WES), homozygosity mapping, and comprehensive variant analyses was performed to uncover the causative mutation. Only one homozygous mutation (c.113 T > C, p.I38T) in RAX gene survived our strict variant filtering process, consistent with an autosomal recessive inheritance pattern. This mutation segregated perfectly in the family and is located in a highly conserved functional domain. Crystal structure modeling indicated that I38T affected the protein structure. We describe a patient from a consanguineous Chinese family with unusual coloboma, proven to harbor a novel RAX mutation (c.113 T > C, p.I38T, homozygous), expanding the phenotypic variability of ocular coloboma and RAX mutations.
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Castro-Sánchez S, Álvarez-Satta M, Tohamy MA, Beltran S, Derdak S, Valverde D. Whole exome sequencing as a diagnostic tool for patients with ciliopathy-like phenotypes. PLoS One 2017; 12:e0183081. [PMID: 28800606 PMCID: PMC5553726 DOI: 10.1371/journal.pone.0183081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/29/2017] [Indexed: 12/13/2022] Open
Abstract
Ciliopathies are a group of rare disorders characterized by a high genetic and phenotypic variability, which complicates their molecular diagnosis. Hence the need to use the latest powerful approaches to faster identify the genetic defect in these patients. We applied whole exome sequencing to six consanguineous families clinically diagnosed with ciliopathy-like disease, and for which mutations in predominant Bardet-Biedl syndrome (BBS) genes had previously been excluded. Our strategy, based on first applying several filters to ciliary variants and using many of the bioinformatics tools available, allowed us to identify causal mutations in BBS2, ALMS1 and CRB1 genes in four families, thus confirming the molecular diagnosis of ciliopathy. In the remaining two families, after first rejecting the presence of pathogenic variants in common cilia-related genes, we adopted a new filtering strategy combined with prioritisation tools to rank the final candidate genes for each case. Thus, we propose CORO2B, LMO7 and ZNF17 as novel candidate ciliary genes, but further functional studies will be needed to confirm their role. Our data show the usefulness of this strategy to diagnose patients with unclear phenotypes, and therefore the success of applying such technologies to achieve a rapid and reliable molecular diagnosis, improving genetic counselling for these patients. In addition, the described pipeline also highlights the common pitfalls associated to the large volume of data we have to face and the difficulty of assigning a functional role to these changes, hence the importance of designing the most appropriate strategy according to each case.
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Affiliation(s)
- Sheila Castro-Sánchez
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - María Álvarez-Satta
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
| | - Mohamed A. Tohamy
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Sergi Beltran
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Sophia Derdak
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Diana Valverde
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
- Research Group of Rare Diseases & Pediatric Medicine, Instituto de Investigación Sanitaria Galicia Sur (IISGS), SERGAS-UVIGO, Hospital Álvaro Cunqueiro, Vigo, Spain
- Centro de Investigaciones Biomédicas (CINBIO) (Centro Singular de Investigación de Galicia), Universidad de Vigo, Vigo, Spain
- * E-mail:
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37
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Genetic characterization and disease mechanism of retinitis pigmentosa; current scenario. 3 Biotech 2017; 7:251. [PMID: 28721681 DOI: 10.1007/s13205-017-0878-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 07/10/2017] [Indexed: 12/21/2022] Open
Abstract
Retinitis pigmentosa is a group of genetically transmitted disorders affecting 1 in 3000-8000 individual people worldwide ultimately affecting the quality of life. Retinitis pigmentosa is characterized as a heterogeneous genetic disorder which leads by progressive devolution of the retina leading to a progressive visual loss. It can occur in syndromic (with Usher syndrome and Bardet-Biedl syndrome) as well as non-syndromic nature. The mode of inheritance can be X-linked, autosomal dominant or autosomal recessive manner. To date 58 genes have been reported to associate with retinitis pigmentosa most of them are either expressed in photoreceptors or the retinal pigment epithelium. This review focuses on the disease mechanisms and genetics of retinitis pigmentosa. As retinitis pigmentosa is tremendously heterogeneous disorder expressing a multiplicity of mutations; different variations in the same gene might induce different disorders. In recent years, latest technologies including whole-exome sequencing contributing effectively to uncover the hidden genesis of retinitis pigmentosa by reporting new genetic mutations. In future, these advancements will help in better understanding the genotype-phenotype correlations of disease and likely to develop new therapies.
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A deep intronic CLRN1 (USH3A) founder mutation generates an aberrant exon and underlies severe Usher syndrome on the Arabian Peninsula. Sci Rep 2017; 7:1411. [PMID: 28469144 PMCID: PMC5431179 DOI: 10.1038/s41598-017-01577-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/29/2017] [Indexed: 12/04/2022] Open
Abstract
Deafblindness is mostly due to Usher syndrome caused by recessive mutations in the known genes. Mutation-negative patients therefore either have distinct diseases, mutations in yet unknown Usher genes or in extra-exonic parts of the known genes – to date a largely unexplored possibility. In a consanguineous Saudi family segregating Usher syndrome type 1 (USH1), NGS of genes for Usher syndrome, deafness and retinal dystrophy and subsequent whole-exome sequencing each failed to identify a mutation. Genome-wide linkage analysis revealed two small candidate regions on chromosome 3, one containing the USH3A gene CLRN1, which has never been associated with Usher syndrome in Saudi Arabia. Whole-genome sequencing (WGS) identified a homozygous deep intronic mutation, c.254–649T > G, predicted to generate a novel donor splice site. CLRN1 minigene-based analysis confirmed the splicing of an aberrant exon due to usage of this novel motif, resulting in a frameshift and a premature termination codon. We identified this mutation in an additional two of seven unrelated mutation-negative Saudi USH1 patients. Locus-specific markers indicated that c.254–649T > GCLRN1 represents a founder allele that may significantly contribute to deafblindness in this population. Our finding underlines the potential of WGS to uncover atypically localized, hidden mutations in patients who lack exonic mutations in the known disease genes.
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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Blanco-Sánchez B, Clément A, Phillips JB, Westerfield M. Zebrafish models of human eye and inner ear diseases. Methods Cell Biol 2016; 138:415-467. [PMID: 28129854 DOI: 10.1016/bs.mcb.2016.10.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Eye and inner ear diseases are the most common sensory impairments that greatly impact quality of life. Zebrafish have been intensively employed to understand the fundamental mechanisms underlying eye and inner ear development. The zebrafish visual and vestibulo-acoustic systems are very similar to these in humans, and although not yet mature, they are functional by 5days post-fertilization (dpf). In this chapter, we show how the zebrafish has significantly contributed to the field of biomedical research and how researchers, by establishing disease models and meticulously characterizing their phenotypes, have taken the first steps toward therapies. We review here models for (1) eye diseases, (2) ear diseases, and (3) syndromes affecting eye and/or ear. The use of new genome editing technologies and high-throughput screening systems should increase considerably the speed at which knowledge from zebrafish disease models is acquired, opening avenues for better diagnostics, treatments, and therapies.
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Affiliation(s)
| | - A Clément
- University of Oregon, Eugene, OR, United States
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41
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Roosing S, Rosti RO, Rosti B, de Vrieze E, Silhavy JL, van Wijk E, Wakeling E, Gleeson JG. Identification of a homozygous nonsense mutation in KIAA0556 in a consanguineous family displaying Joubert syndrome. Hum Genet 2016; 135:919-921. [PMID: 27245168 DOI: 10.1007/s00439-016-1689-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 05/22/2016] [Indexed: 10/21/2022]
Abstract
Joubert Syndrome (JS) is an inherited ciliopathy associated with mutations in genes essential in primary cilium function. Whole exome sequencing in a multiplex consanguineous family from India revealed a KIAA0556 homozygous single base pair deletion mutation (c.4420del; p.Met1474Cysfs*11). Knockdown of the gene in zebrafish resulted in a ciliopathy phenotype, rescued by co-injection of wildtype cDNA. Affected siblings present a mild and classical form of Joubert syndrome allowing for further delineation of the JS associated genotypic spectrum.
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Affiliation(s)
- Susanne Roosing
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Rasim O Rosti
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Basak Rosti
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Erik de Vrieze
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jennifer L Silhavy
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Emma Wakeling
- North West Thames Regional Genetic Service, North West London Hospitals, NHS Trust, London, United Kingdom
| | - Joseph G Gleeson
- Laboratory for Pediatric Brain Disease, Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA
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42
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Marshall RA, Osborn DPS. Zebrafish: a vertebrate tool for studying basal body biogenesis, structure, and function. Cilia 2016; 5:16. [PMID: 27168933 PMCID: PMC4862167 DOI: 10.1186/s13630-016-0036-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/01/2016] [Indexed: 02/27/2023] Open
Abstract
Understanding the role of basal bodies (BBs) during development and disease has been largely overshadowed by research into the function of the cilium. Although these two organelles are closely associated, they have specific roles to complete for successful cellular development. Appropriate development and function of the BB are fundamental for cilia function. Indeed, there are a growing number of human genetic diseases affecting ciliary development, known collectively as the ciliopathies. Accumulating evidence suggests that BBs establish cell polarity, direct ciliogenesis, and provide docking sites for proteins required within the ciliary axoneme. Major contributions to our knowledge of BB structure and function have been provided by studies in flagellated or ciliated unicellular eukaryotic organisms, specifically Tetrahymena and Chlamydomonas. Reproducing these and other findings in vertebrates has required animal in vivo models. Zebrafish have fast become one of the primary organisms of choice for modeling vertebrate functional genetics. Rapid ex-utero development, proficient egg laying, ease of genetic manipulation, and affordability make zebrafish an attractive vertebrate research tool. Furthermore, zebrafish share over 80 % of disease causing genes with humans. In this article, we discuss the merits of using zebrafish to study BB functional genetics, review current knowledge of zebrafish BB ultrastructure and mechanisms of function, and consider the outlook for future zebrafish-based BB studies.
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Affiliation(s)
- Ryan A Marshall
- Cell Sciences and Genetics Research Centre, St George's University of London, London, SW17 0RE UK
| | - Daniel P S Osborn
- Cell Sciences and Genetics Research Centre, St George's University of London, London, SW17 0RE UK
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43
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Zaki MS, Heller R, Thoenes M, Nürnberg G, Stern-Schneider G, Nürnberg P, Karnati S, Swan D, Fateen E, Nagel-Wolfrum K, Mostafa MI, Thiele H, Wolfrum U, Baumgart-Vogt E, Bolz HJ. PEX6 is Expressed in Photoreceptor Cilia and Mutated in Deafblindness with Enamel Dysplasia and Microcephaly. Hum Mutat 2015; 37:170-4. [PMID: 26593283 DOI: 10.1002/humu.22934] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 11/12/2015] [Indexed: 02/06/2023]
Abstract
Deafblindness is part of several genetic disorders. We investigated a consanguineous Egyptian family with two siblings affected by congenital hearing loss and retinal degeneration, initially diagnosed as Usher syndrome type 1. At teenage, severe enamel dysplasia, developmental delay, and microcephaly became apparent. Genome-wide homozygosity mapping and whole-exome sequencing detected a homozygous missense mutation, c.1238G>T (p.Gly413Val), affecting a highly conserved residue of peroxisomal biogenesis factor 6, PEX6. Biochemical profiling of the siblings revealed abnormal and borderline plasma phytanic acid concentration, and cerebral imaging revealed white matter disease in both. We show that Pex6 localizes to the apical extensions of secretory ameloblasts and differentiated odontoblasts at early stages of dentin synthesis in mice, and to cilia of retinal photoreceptor cells. We propose PEX6, and possibly other peroxisomal genes, as candidate for the rare cooccurrence of deafblindness and enamel dysplasia. Our study for the first time links peroxisome biogenesis disorders to retinal ciliopathies.
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Affiliation(s)
- Maha S Zaki
- Department of Clinical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Raoul Heller
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Michaela Thoenes
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Gudrun Nürnberg
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Gabi Stern-Schneider
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany.,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Srikanth Karnati
- Institute for Anatomy and Cell Biology, Justus Liebig University, Giessen, Germany
| | - Daniel Swan
- Computational Biology Group, Oxford Gene Technology, Oxford, United Kingdom
| | - Ekram Fateen
- Department of Biochemical Genetics, Human Genetics and Genome Research Division, National Research Centre, Cairo, Egypt
| | - Kerstin Nagel-Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Mostafa I Mostafa
- Department of Orodental Genetics, Orodental Research Division, National Research Centre, Cairo, Egypt
| | - Holger Thiele
- Cologne Center for Genomics (CCG) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
| | - Uwe Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | | | - Hanno J Bolz
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany.,Bioscientia Center for Human Genetics, Ingelheim, Germany
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Geister KA, Brinkmeier ML, Cheung LY, Wendt J, Oatley MJ, Burgess DL, Kozloff KM, Cavalcoli JD, Oatley JM, Camper SA. LINE-1 Mediated Insertion into Poc1a (Protein of Centriole 1 A) Causes Growth Insufficiency and Male Infertility in Mice. PLoS Genet 2015; 11:e1005569. [PMID: 26496357 PMCID: PMC4619696 DOI: 10.1371/journal.pgen.1005569] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 09/15/2015] [Indexed: 11/19/2022] Open
Abstract
Skeletal dysplasias are a common, genetically heterogeneous cause of short stature that can result from disruptions in many cellular processes. We report the identification of the lesion responsible for skeletal dysplasia and male infertility in the spontaneous, recessive mouse mutant chagun. We determined that Poc1a, encoding protein of the centriole 1a, is disrupted by the insertion of a processed Cenpw cDNA, which is flanked by target site duplications, suggestive of a LINE-1 retrotransposon-mediated event. Mutant fibroblasts have impaired cilia formation and multipolar spindles. Male infertility is caused by defective spermatogenesis early in meiosis and progressive germ cell loss. Spermatogonial stem cell transplantation studies revealed that Poc1a is essential for normal function of both Sertoli cells and germ cells. The proliferative zone of the growth plate is small and disorganized because chondrocytes fail to re-align after cell division and undergo increased apoptosis. Poc1a and several other genes associated with centrosome function can affect the skeleton and lead to skeletal dysplasias and primordial dwarfisms. This mouse mutant reveals how centrosome dysfunction contributes to defects in skeletal growth and male infertility.
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Affiliation(s)
- Krista A. Geister
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Michelle L. Brinkmeier
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Leonard Y. Cheung
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jennifer Wendt
- Roche NimbleGen, Inc., Research and Development, Madison, Wisconsin, United States of America
| | - Melissa J. Oatley
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, United States of America
| | - Daniel L. Burgess
- Roche NimbleGen, Inc., Research and Development, Madison, Wisconsin, United States of America
| | - Kenneth M. Kozloff
- Department of Orthopedic Surgery, University of Michigan, Ann Arbor, Michigan, United States of America
| | - James D. Cavalcoli
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jon M. Oatley
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington, United States of America
| | - Sally A. Camper
- Graduate Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, United States of America
- * E-mail:
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45
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Stephen LA, Tawamie H, Davis GM, Tebbe L, Nürnberg P, Nürnberg G, Thiele H, Thoenes M, Boltshauser E, Uebe S, Rompel O, Reis A, Ekici AB, McTeir L, Fraser AM, Hall EA, Mill P, Daudet N, Cross C, Wolfrum U, Jamra RA, Davey MG, Bolz HJ. TALPID3 controls centrosome and cell polarity and the human ortholog KIAA0586 is mutated in Joubert syndrome (JBTS23). eLife 2015; 4. [PMID: 26386247 PMCID: PMC4641851 DOI: 10.7554/elife.08077] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 09/19/2015] [Indexed: 12/30/2022] Open
Abstract
Joubert syndrome (JBTS) is a severe recessive neurodevelopmental ciliopathy which can affect several organ systems. Mutations in known JBTS genes account for approximately half of the cases. By homozygosity mapping and whole-exome sequencing, we identified a novel locus, JBTS23, with a homozygous splice site mutation in KIAA0586 (alias TALPID3), a known lethal ciliopathy locus in model organisms. Truncating KIAA0586 mutations were identified in two additional patients with JBTS. One mutation, c.428delG (p.Arg143Lysfs*4), is unexpectedly common in the general population and may be a major contributor to JBTS. We demonstrate KIAA0586 protein localization at the basal body in human and mouse photoreceptors, as is common for JBTS proteins, and also in pericentriolar locations. We show that loss of TALPID3 (KIAA0586) function in animal models causes abnormal tissue polarity, centrosome length and orientation, and centriolar satellites. We propose that JBTS and other ciliopathies may in part result from cell polarity defects. DOI:http://dx.doi.org/10.7554/eLife.08077.001 Joubert syndrome is a rare and severe neurodevelopmental disease in which two parts of the brain called the cerebellar vermis and brainstem do not develop properly. The disease is caused by defects in the formation of small projections from the surface of cells, called cilia, which are essential for signalling processes inside cells. Mutations in at least 25 genes are known to cause Joubert syndrome, and all encode proteins that create or maintain cilia. However, these mutations account for only half of the cases that have been studied, which indicates that mutations in other genes may also cause Joubert syndrome. Here, Stephen et al. used genetic techniques called ‘homozygosity mapping’ and ‘whole-exome sequencing’ to search for other mutations that might cause the disease. They found that mutations in a gene encoding a protein called KIAA0586 also cause Joubert syndrome in humans. One of these mutations (c.428delG) is unexpectedly common in the healthy human population. It might be a major contributor to Joubert syndrome, and the manifestation of Joubert syndrome in individuals with this mutation might depend on the presence and nature of other mutations in KIAA0586 and in other genes. The TALPID3 protein in chickens and other ‘model’ animals is the equivalent of human KIAA0586. A loss of TALPID3 protein in animals has been shown to stop cilia from forming. This protein is found in a structure called the basal body, which is part of a larger structure called the centrosome that anchors cilia to the cell. Here, Stephen et al. show that this is also true in mouse and human eye cells. Further experiments using chicken embryos show that a loss of the TALPID3 protein alters the location of centrosomes inside cells. TALPID3 is also required for cells and organs to develop the correct polarity, that is, directional differences in their structure and shape. The centrosomes of chicken brain cells that lacked TALPID3 were poorly positioned at the cell surface and abnormally long, which is likely responsible for the cilia failing to form. Stephen et al.'s findings suggest that KIAA0586 is also important for human development through its ability to control the centrosome. Defects in TALPID3 have a more severe effect on animal models than many of the identified KIAA0586 mutations have on humans. Therefore, the next step in this research is to find a more suitable animal in which to study the role of this protein, which may inform efforts to develop treatments for Joubert syndrome. DOI:http://dx.doi.org/10.7554/eLife.08077.002
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Affiliation(s)
- Louise A Stephen
- Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Hasan Tawamie
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Gemma M Davis
- Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Lars Tebbe
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany.,Cologne Cluster of Excellence, University of Cologne, Cologne, Germany
| | - Gudrun Nürnberg
- Cologne Center for Genomics, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics, Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Michaela Thoenes
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Eugen Boltshauser
- Department of Paediatric Neurology, University Children's Hospital Zurich, Zurich, Switzerland
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Oliver Rompel
- Institute of Radiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Lynn McTeir
- Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Amy M Fraser
- Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Emma A Hall
- Medical Research Council Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Pleasantine Mill
- Medical Research Council Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Nicolas Daudet
- UCL Ear Institute, University College London, London, United Kingdom
| | - Courtney Cross
- School of Osteopathic Medicine, A.T. Still University, Mesa, United States
| | - Uwe Wolfrum
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Centogene, Rostock, Germany.,Institute of Human Genetics, Leipzig University, Leipzig, Germany
| | - Megan G Davey
- Division of Developmental Biology, The Roslin Institute, University of Edinburgh, Edinburgh, United Kingdom
| | - Hanno J Bolz
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany.,Bioscientia Center for Human Genetics, Bioscientia International Business, Ingelheim am Rhein, Germany
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46
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Vertii A, Bright A, Delaval B, Hehnly H, Doxsey S. New frontiers: discovering cilia-independent functions of cilia proteins. EMBO Rep 2015; 16:1275-87. [PMID: 26358956 DOI: 10.15252/embr.201540632] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/17/2015] [Indexed: 12/11/2022] Open
Abstract
In most vertebrates, mitotic spindles and primary cilia arise from a common origin, the centrosome. In non-cycling cells, the centrosome is the template for primary cilia assembly and, thus, is crucial for their associated sensory and signaling functions. During mitosis, the duplicated centrosomes mature into spindle poles, which orchestrate mitotic spindle assembly, chromosome segregation, and orientation of the cell division axis. Intriguingly, both cilia and spindle poles are centrosome-based, functionally distinct structures that require the action of microtubule-mediated, motor-driven transport for their assembly. Cilia proteins have been found at non-cilia sites, where they have distinct functions, illustrating a diverse and growing list of cellular processes and structures that utilize cilia proteins for crucial functions. In this review, we discuss cilia-independent functions of cilia proteins and re-evaluate their potential contributions to "cilia" disorders.
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Affiliation(s)
- Anastassiia Vertii
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Alison Bright
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | | | - Heidi Hehnly
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Stephen Doxsey
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
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47
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Zhang C, Zhang Q, Wang F, Liu Q. Knockdown of poc1b causes abnormal photoreceptor sensory cilium and vision impairment in zebrafish. Biochem Biophys Res Commun 2015; 465:651-7. [PMID: 26188096 DOI: 10.1016/j.bbrc.2015.06.083] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 06/12/2015] [Indexed: 01/26/2023]
Abstract
Proteomic analysis of the mouse photoreceptor sensory cilium identified a set of cilia proteins, including Poc1 centriolar protein b (Poc1b). Previous functional studies in human cells and zebrafish embryos implicated that Poc1b plays important roles in centriole duplication and length control, as well as ciliogenesis. To study the function of Poc1b in photoreceptor sensory cilia and other primary cilia, we expressed a tagged recombinant Poc1b protein in cultured renal epithelial cells and rat retina. Poc1b was localized to the centrioles and spindle bundles during cell cycle progression, and to the basal body of photoreceptor sensory cilia. A morpholino knockdown and complementation assay of poc1b in zebrafish showed that loss of poc1b led to a range of morphological anomalies of cilia commonly associated with human ciliopathies. In the retina, the development of retinal laminae was significantly delayed and the length of photoreceptor outer segments was shortened. Visual behavior studies revealed impaired visual function in the poc1b morphants. In addition, ciliopathy-associated developmental defects, such as small eyes, curved body axis, heart defects, and shortened cilia in Kupffer's vesicle, were observed as well. These data suggest that poc1b is required for normal development and ciliogenesis of retinal photoreceptor sensory cilia and other cilia. Furthermore, this conclusion is supported by recent findings that mutations in POC1B gene have been identified in patients with inherited retinal dystrophy and syndromic retinal ciliopathy.
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Affiliation(s)
- Conghui Zhang
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China
| | - Qi Zhang
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Fang Wang
- Department of Ophthalmology, Shanghai Tenth People's Hospital, Tongji University, Shanghai, China.
| | - Qin Liu
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA; Berman-Gund Laboratory for the Study of Retinal Degenerations, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA.
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48
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Roosing S, Hofree M, Kim S, Scott E, Copeland B, Romani M, Silhavy JL, Rosti RO, Schroth J, Mazza T, Miccinilli E, Zaki MS, Swoboda KJ, Milisa-Drautz J, Dobyns WB, Mikati MA, İncecik F, Azam M, Borgatti R, Romaniello R, Boustany RM, Clericuzio CL, D'Arrigo S, Strømme P, Boltshauser E, Stanzial F, Mirabelli-Badenier M, Moroni I, Bertini E, Emma F, Steinlin M, Hildebrandt F, Johnson CA, Freilinger M, Vaux KK, Gabriel SB, Aza-Blanc P, Heynen-Genel S, Ideker T, Dynlacht BD, Lee JE, Valente EM, Kim J, Gleeson JG. Functional genome-wide siRNA screen identifies KIAA0586 as mutated in Joubert syndrome. eLife 2015; 4:e06602. [PMID: 26026149 PMCID: PMC4477441 DOI: 10.7554/elife.06602] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/28/2015] [Indexed: 12/14/2022] Open
Abstract
Defective primary ciliogenesis or cilium stability forms the basis of human ciliopathies, including Joubert syndrome (JS), with defective cerebellar vermis development. We performed a high-content genome-wide small interfering RNA (siRNA) screen to identify genes regulating ciliogenesis as candidates for JS. We analyzed results with a supervised-learning approach, using SYSCILIA gold standard, Cildb3.0, a centriole siRNA screen and the GTex project, identifying 591 likely candidates. Intersection of this data with whole exome results from 145 individuals with unexplained JS identified six families with predominantly compound heterozygous mutations in KIAA0586. A c.428del base deletion in 0.1% of the general population was found in trans with a second mutation in an additional set of 9 of 163 unexplained JS patients. KIAA0586 is an orthologue of chick Talpid3, required for ciliogenesis and Sonic hedgehog signaling. Our results uncover a relatively high frequency cause for JS and contribute a list of candidates for future gene discoveries in ciliopathies. DOI:http://dx.doi.org/10.7554/eLife.06602.001 Joubert syndrome is a rare disorder that affects the brain and causes physical, mental, and sometimes visual impairments. In individuals with this condition, two parts of the brain called the cerebellar vermis and the brainstem do not develop properly. This is thought to be due to defects in the development and maintenance of tiny hair-like structures called cilia, which are found on the surface of cells. Currently, mutations in 25 different genes are known to be able to cause Joubert syndrome. However, these mutations only account for around 50% of the cases that have been studied, and the ‘unexplained’ cases suggest that mutations in other genes may also cause the disease. Here, Roosing et al. used a technique called a ‘genome-wide siRNA screen’ to identify other genes regulating the formation of cilia that might also be connected with Joubert syndrome. This approach identified almost 600 candidate genes. The data from the screen were combined with gene sequence data from 145 individuals with unexplained Joubert syndrome. Roosing et al. found that individuals with Joubert syndrome from 15 different families had mutations in a gene called KIAA0586. In chickens and mice, this gene—known as Talpid3—is required for the formation of cilia. Roosing et al.'s findings reveal a new gene that is involved in Joubert syndrome and also provides a list of candidate genes for future studies of other conditions caused by defects in the formation of cilia. The next challenges are to find out what causes the remaining unexplained cases of the disease and to understand what roles the genes identified in this study play in cilia. DOI:http://dx.doi.org/10.7554/eLife.06602.002
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Affiliation(s)
- Susanne Roosing
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Matan Hofree
- Department of Computer Science and Engineering, University of California, San Diego, San Diego, United States
| | - Sehyun Kim
- Department of Pathology and Cancer Institute, Smilow Research Center, New York University School of Medicine, New York, United States
| | - Eric Scott
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Brett Copeland
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Marta Romani
- IRCCS Casa Sollievo della Sofferenza, Mendel Institute, San Giovanni Rotondo, Italy
| | - Jennifer L Silhavy
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Rasim O Rosti
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Jana Schroth
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Tommaso Mazza
- IRCCS Casa Sollievo della Sofferenza, Mendel Institute, San Giovanni Rotondo, Italy
| | - Elide Miccinilli
- IRCCS Casa Sollievo della Sofferenza, Mendel Institute, San Giovanni Rotondo, Italy
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Center, Cairo, Egypt
| | - Kathryn J Swoboda
- Departments of Neurology and Pediatrics, University of Utah School of Medicine, Salt Lake City, United States
| | - Joanne Milisa-Drautz
- Department of Pediatric Genetics, University of New Mexico, Albuquerque, United States
| | - William B Dobyns
- Center for Integrative Brain Research, Seattle Children's Hospital, Seattle, United States
| | - Mohamed A Mikati
- Division of Pediatric Neurology, Department of Pediatrics, Duke Institute for Brain Sciences, Duke University Medical Center, Durham, United States
| | - Faruk İncecik
- Department of Pediatric Neurology, Cukurova University Medical Faculty, Balcali, Turkey
| | - Matloob Azam
- Department of Pediatrics and Child Neurology, Wah Medical College, Wah Cantt, Pakistan
| | - Renato Borgatti
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute IRCCS Eugenio Medea, Bosisio Parini, Italy
| | - Rose-Mary Boustany
- Departments of Pediatrics, Adolescent Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Carol L Clericuzio
- Division of Genetics/Dysmorphology, Department Pediatrics, University of New Mexico, Albuquerque, United States
| | - Stefano D'Arrigo
- Developmental Neurology Division, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Petter Strømme
- Women and Children's Division, Oslo University Hospital, Oslo, Norway
| | - Eugen Boltshauser
- Department of Pediatric Neurology, University Children's Hospital, Zurich, Switzerland
| | - Franco Stanzial
- Department of Pediatrics, Genetic Counselling Service, Regional Hospital of Bolzano, Bolzano, Italy
| | - Marisol Mirabelli-Badenier
- Child Neuropsychiatry Unit, Department of Neurosciences and Rehabilitation, Istituto G. Gaslini, Genoa, Italy
| | - Isabella Moroni
- Unit of Child Neurology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Research Hospital, IRCCS, Rome, Italy
| | - Francesco Emma
- Division of Nephrology and Dialysis, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - Colin A Johnson
- Section of Ophthalmology and Neurosciences, Wellcome Trust Brenner Building, Leeds Institute of Molecular Medicine, University of Leeds, St. James's University Hospital, Leeds, United Kingdom
| | - Michael Freilinger
- Neuropediatric group, Department of Paediatrics and Adolescent Medicine, Medical University Vienna, Vienna, Austria
| | - Keith K Vaux
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Stacey B Gabriel
- Broad Institute of Harvard and Massachusetts Institute of Technology, Cambridge, United States
| | - Pedro Aza-Blanc
- High Content Screening Systems, Sanford-Burnham Institute, La Jolla, United States
| | - Susanne Heynen-Genel
- High Content Screening Systems, Sanford-Burnham Institute, La Jolla, United States
| | - Trey Ideker
- Department of Computer Science and Engineering, University of California, San Diego, San Diego, United States
| | - Brian D Dynlacht
- Department of Pathology and Cancer Institute, Smilow Research Center, New York University School of Medicine, New York, United States
| | - Ji Eun Lee
- Samsung Genome Institute, Department of Health Sciences and Technology, Samsung Advanced Institute of Health Sciences and Technology, Sungkyunkwan University, Seoul, Republic of Korea
| | - Enza Maria Valente
- IRCCS Casa Sollievo della Sofferenza, Mendel Institute, San Giovanni Rotondo, Italy
| | - Joon Kim
- Korea Advanced Institute of Science and Technology, School of Medical Science and Engineering, Daejeon, Republic of Korea
| | - Joseph G Gleeson
- Laboratory for Pediatric Brain Disease, New York Genome Center, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
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Elsayed SM, Phillips JB, Heller R, Thoenes M, Elsobky E, Nürnberg G, Nürnberg P, Seland S, Ebermann I, Altmüller J, Thiele H, Toliat M, Körber F, Hu XJ, Wu YD, Zaki MS, Abdel-Salam G, Gleeson J, Boltshauser E, Westerfield M, Bolz HJ. Non-manifesting AHI1 truncations indicate localized loss-of-function tolerance in a severe Mendelian disease gene. Hum Mol Genet 2015; 24:2594-603. [PMID: 25616960 DOI: 10.1093/hmg/ddv022] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/21/2015] [Indexed: 01/21/2023] Open
Abstract
Determination of variant pathogenicity represents a major challenge in the era of high-throughput sequencing. Erroneous categorization may result if variants affect genes that are in fact dispensable. We demonstrate that this also applies to rare, apparently unambiguous truncating mutations of an established disease gene. By whole-exome sequencing (WES) in a consanguineous family with congenital non-syndromic deafness, we unexpectedly identified a homozygous nonsense variant, p.Arg1066*, in AHI1, a gene associated with Joubert syndrome (JBTS), a severe recessive ciliopathy. None of four homozygotes expressed any signs of JBTS, and one of them had normal hearing, which also ruled out p.Arg1066* as the cause of deafness. Homozygosity mapping and WES in the only other reported JBTS family with a homozygous C-terminal truncation (p.Trp1088Leufs*16) confirmed AHI1 as disease gene, but based on a more N-terminal missense mutation impairing WD40-repeat formation. Morpholinos against N-terminal zebrafish Ahi1, orthologous to where human mutations cluster, produced a ciliopathy, but targeting near human p.Arg1066 and p.Trp1088 did not. Most AHI1 mutations in JBTS patients result in truncated protein lacking WD40-repeats and the SH3 domain; disease was hitherto attributed to loss of these protein interaction modules. Our findings indicate that normal development does not require the C-terminal SH3 domain. This has far-reaching implications, considering that variants like p.Glu984* identified by preconception screening ('Kingsmore panel') do not necessarily indicate JBTS carriership. Genomes of individuals with consanguineous background are enriched for homozygous variants that may unmask dispensable regions of disease genes and unrecognized false positives in diagnostic large-scale sequencing and preconception carrier screening.
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Affiliation(s)
- Solaf M Elsayed
- Medical Genetics Center, Cairo 11566, Egypt, Children's Hospital, Ain Shams University, Cairo 11566, Egypt
| | | | - Raoul Heller
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Michaela Thoenes
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Ezzat Elsobky
- Medical Genetics Center, Cairo 11566, Egypt, Children's Hospital, Ain Shams University, Cairo 11566, Egypt
| | - Gudrun Nürnberg
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
| | - Saskia Seland
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Inga Ebermann
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Janine Altmüller
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany, Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Mohammad Toliat
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Friederike Körber
- Department of Radiology, University of Cologne, 50937 Cologne, Germany
| | - Xue-Jia Hu
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518000 Shenzhen, P. R. China
| | - Yun-Dong Wu
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518000 Shenzhen, P. R. China, College of Chemistry, Peking University, 100871 Beijing, P. R. China
| | - Maha S Zaki
- Department of Clinical Genetics, National Research Centre, Cairo 11566, Egypt
| | - Ghada Abdel-Salam
- Department of Clinical Genetics, National Research Centre, Cairo 11566, Egypt
| | - Joseph Gleeson
- Laboratory of Neurogenetics, Howard Hughes Medical Institute, Department of Neurosciences, University of California, La Jolla, San Diego, CA 92093, USA
| | - Eugen Boltshauser
- Department of Paediatric Neurology, University Children's Hospital of Zurich, 8032 Zurich, Switzerland and
| | - Monte Westerfield
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Hanno J Bolz
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany, Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
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50
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Wang Y, Hu XJ, Zou XD, Wu XH, Ye ZQ, Wu YD. WDSPdb: a database for WD40-repeat proteins. Nucleic Acids Res 2014; 43:D339-44. [PMID: 25348404 PMCID: PMC4383882 DOI: 10.1093/nar/gku1023] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
WD40-repeat proteins, as one of the largest protein families, often serve as platforms to assemble functional complexes through the hotspot residues on their domain surfaces, and thus play vital roles in many biological processes. Consequently, it is highly required for researchers who study WD40 proteins and protein-protein interactions to obtain structural information of WD40 domains. Systematic identification of WD40-repeat proteins, including prediction of their secondary structures, tertiary structures and potential hotspot residues responsible for protein-protein interactions, may constitute a valuable resource upon this request. To achieve this goal, we developed a specialized database WDSPdb (http://wu.scbb.pkusz.edu.cn/wdsp/) to provide these details of WD40-repeat proteins based on our recently published method WDSP. The WDSPdb contains 63,211 WD40-repeat proteins identified from 3383 species, including most well-known model organisms. To better serve the community, we implemented a user-friendly interactive web interface to browse, search and download the secondary structures, 3D structure models and potential hotspot residues provided by WDSPdb.
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Affiliation(s)
- Yang Wang
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Xue-Jia Hu
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Xu-Dong Zou
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Xian-Hui Wu
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Zhi-Qiang Ye
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China
| | - Yun-Dong Wu
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, P. R. China College of Chemistry, Peking University, Beijing, 100871, P. R. China
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