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Tomlinson JW. Bardet-Biedl syndrome: A focus on genetics, mechanisms and metabolic dysfunction. Diabetes Obes Metab 2024; 26 Suppl 2:13-24. [PMID: 38302651 DOI: 10.1111/dom.15480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
Bardet-Biedl syndrome (BBS) is a rare, monogenic, multisystem disorder characterized by retinal dystrophy, renal abnormalities, polydactyly, learning disabilities, as well as metabolic dysfunction, including obesity and an increased risk of type 2 diabetes. It is a primary ciliopathy, and causative mutations in more than 25 different genes have been described. Multiple cellular mechanisms contribute to the development of the metabolic phenotype associated with BBS, including hyperphagia as a consequence of altered hypothalamic appetite signalling as well as alterations in adipocyte biology promoting adipocyte proliferation and adipogenesis. Within this review, we describe in detail the metabolic phenotype associated with BBS and discuss the mechanisms that drive its evolution. In addition, we review current approaches to the metabolic management of patients with BBS, including the use of weight loss medications and bariatric surgery. Finally, we evaluate the potential of targeting hypothalamic appetite signalling to limit hyperphagia and induce clinically significant weight loss.
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Affiliation(s)
- Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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2
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Deitch I, Itskov S, Panneman D, Abu Shtaya A, Saban T, Goldberg Y, Ehrenberg M, Cremers FPM, Roosing S, Ben-Yosef T. Autosomal Recessive Rod-Cone Dystrophy with Mild Extra-Ocular Manifestations Due to a Splice-Affecting Variant in BBS9. Curr Issues Mol Biol 2024; 46:2566-2575. [PMID: 38534779 DOI: 10.3390/cimb46030163] [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: 02/05/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/28/2024] Open
Abstract
Bardet-Biedl syndrome (BBS), one of the most common forms of syndromic inherited retinal diseases (IRDs), is characterized by the combination of retinal degeneration with additional extra-ocular manifestations, including obesity, intellectual disability, kidney disease, polydactyly and other skeletal abnormalities. We observed an Israeli patient with autosomal recessive apparently non-syndromic rod-cone dystrophy (RCD). Extra-ocular findings were limited to epilepsy and dental problems. Genetic analysis with a single molecule molecular inversion probes-based panel that targets the exons and splice sites of 113 genes associated with retinitis pigmentosa and Leber congenital amaurosis revealed a homozygous rare missense variant in the BBS9 gene (c.263C>T;p.(Ser88Leu)). This variant, which affects a highly conserved amino acid, is also located in the last base of Exon 3, and predicted to be splice-altering. An in vitro minigene splice assay demonstrated that this variant leads to the partial aberrant splicing of Exon 3. Therefore, we suggest that this variant is likely hypomorphic. This is in agreement with the relatively mild phenotype observed in the patient. Hence, the findings in our study expand the phenotypic spectrum associated with BBS9 variants and indicate that variants in this gene should be considered not only in BBS patients but also in individuals with non-syndromic IRD or IRD with very mild extra-ocular manifestations.
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Affiliation(s)
- Iris Deitch
- Rabin Medical Center, Department of Ophthalmology, Petach Tikva 4941492, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Sofia Itskov
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
| | - Daan Panneman
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Aasem Abu Shtaya
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva 4941492, Israel
- Unit of Gastroenterology, Carmel Medical Center, Haifa 3436212, Israel
| | - Tal Saban
- Rabin Medical Center, Department of Ophthalmology, Petach Tikva 4941492, Israel
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yael Goldberg
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Hospital, Petach Tikva 4941492, Israel
| | - Miriam Ehrenberg
- Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Schneider Children's Medical Center of Israel, Department of Ophthalmology, Petach Tikva 4920235, Israel
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands
| | - Tamar Ben-Yosef
- Ruth & Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3109601, Israel
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3
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Khan S, Focșa IO, Budișteanu M, Stoica C, Nedelea F, Bohîlțea L, Caba L, Butnariu L, Pânzaru M, Rusu C, Jurcă C, Chirita-Emandi A, Bănescu C, Abbas W, Sadeghpour A, Baig SM, Bălgrădean M, Davis EE. Exome sequencing in a Romanian Bardet-Biedl syndrome cohort revealed an overabundance of causal BBS12 variants. Am J Med Genet A 2023; 191:2376-2391. [PMID: 37293956 PMCID: PMC10524726 DOI: 10.1002/ajmg.a.63322] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/16/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023]
Abstract
Bardet-Biedl syndrome (BBS), is an emblematic ciliopathy hallmarked by pleiotropy, phenotype variability, and extensive genetic heterogeneity. BBS is a rare (~1/140,000 to ~1/160,000 in Europe) autosomal recessive pediatric disorder characterized by retinal degeneration, truncal obesity, polydactyly, cognitive impairment, renal dysfunction, and hypogonadism. Twenty-eight genes involved in ciliary structure or function have been implicated in BBS, and explain the molecular basis for ~75%-80% of individuals. To investigate the mutational spectrum of BBS in Romania, we ascertained a cohort of 24 individuals in 23 families. Following informed consent, we performed proband exome sequencing (ES). We detected 17 different putative disease-causing single nucleotide variants or small insertion-deletions and two pathogenic exon disruptive copy number variants in known BBS genes in 17 pedigrees. The most frequently impacted genes were BBS12 (35%), followed by BBS4, BBS7, and BBS10 (9% each) and BBS1, BBS2, and BBS5 (4% each). Homozygous BBS12 p.Arg355* variants were present in seven pedigrees of both Eastern European and Romani origin. Our data show that although the diagnostic rate of BBS in Romania is likely consistent with other worldwide cohorts (74%), we observed a unique distribution of causal BBS genes, including overrepresentation of BBS12 due to a recurrent nonsense variant, that has implications for regional diagnostics.
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Affiliation(s)
- Sheraz Khan
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Ina Ofelia Focșa
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Cytogenomic Medical Laboratory, Bucharest, Romania
| | - Magdalena Budișteanu
- Psychiatry Research Laboratory, "Prof. Dr. Alexandru Obregia" Clinical Hospital of Psychiatry, Bucharest, Romania
- Medical Genetic Laboratory, "Victor Babeș" National Institute of Pathology, Bucharest, Romania
- Department of Medical Genetics, Faculty of Medicine, "Titu Maiorescu" University, Bucharest, Romania
| | - Cristina Stoica
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics, Clinical Institute Fundeni, Bucharest, Romania
| | - Florina Nedelea
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Genetics Department, Clinical Hospital Filantropia, Bucharest, Romania
| | | | - Lavinia Caba
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
| | - Lăcrămioara Butnariu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Monica Pânzaru
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Cristina Rusu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Claudia Jurcă
- Department of Genetics, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
- Department of Pediatrics, "Dr. Gavril Curteanu" Municipal Clinical Hospital, Oradea, Romania
| | - Adela Chirita-Emandi
- Emergency Hospital for Children Louis Turcanu, Regional Center of Medical Genetics Timis, Timisoara, Romania
- Victor Babes University of Medicine and Pharmacy Timisoara, Department of Microscopic Morphology Genetics, Center for Genomic Medicine, Timisoara, Romania
| | - Claudia Bănescu
- "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology, Târgu Mureş, Romania
| | - Wasim Abbas
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina, USA
- Duke Precision Medicine Program, Department of Medicine, Division of General Internal Medicine, Duke University Medical Center, Durham, NC, USA
| | - Shahid Mahmood Baig
- Pakistan Science Foundation (PSF), Islamabad, Pakistan
- Department of Biological and Biomedical Sciences, Agha Khan University Karachi, Karachi, Pakistan
| | - Mihaela Bălgrădean
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children "Maria Skłodowska Curie", Bucharest, Romania
| | - Erica E Davis
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Department of Pediatrics and Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Tian X, Zhao H, Zhou J. Organization, functions, and mechanisms of the BBSome in development, ciliopathies, and beyond. eLife 2023; 12:e87623. [PMID: 37466224 DOI: 10.7554/elife.87623] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
The BBSome is an octameric protein complex that regulates ciliary transport and signaling. Mutations in BBSome subunits are closely associated with ciliary defects and lead to ciliopathies, notably Bardet-Biedl syndrome. Over the past few years, there has been significant progress in elucidating the molecular organization and functions of the BBSome complex. An improved understanding of BBSome-mediated biological events and molecular mechanisms is expected to help advance the development of diagnostic and therapeutic approaches for BBSome-related diseases. Here, we review the current literature on the structural assembly, transport regulation, and molecular functions of the BBSome, emphasizing its roles in cilium-related processes. We also provide perspectives on the pathological role of the BBSome in ciliopathies as well as how these can be exploited for therapeutic benefit.
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Affiliation(s)
- Xiaoyu Tian
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Huijie Zhao
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, China
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D’Antona L, Amato R, Brescia C, Rocca V, Colao E, Iuliano R, Blazer-Yost BL, Perrotti N. Kinase Inhibitors in Genetic Diseases. Int J Mol Sci 2023; 24:ijms24065276. [PMID: 36982349 PMCID: PMC10048847 DOI: 10.3390/ijms24065276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/02/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Over the years, several studies have shown that kinase-regulated signaling pathways are involved in the development of rare genetic diseases. The study of the mechanisms underlying the onset of these diseases has opened a possible way for the development of targeted therapies using particular kinase inhibitors. Some of these are currently used to treat other diseases, such as cancer. This review aims to describe the possibilities of using kinase inhibitors in genetic pathologies such as tuberous sclerosis, RASopathies, and ciliopathies, describing the various pathways involved and the possible targets already identified or currently under study.
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Affiliation(s)
- Lucia D’Antona
- Department of Health Sciences, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
| | - Rosario Amato
- Department of Health Sciences, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
| | - Carolina Brescia
- Department of Health Sciences, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
| | - Valentina Rocca
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
- Department of Experimental and Clinical Medicine, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
| | - Emma Colao
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
| | - Rodolfo Iuliano
- Department of Health Sciences, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
| | - Bonnie L. Blazer-Yost
- Department of Biology, Indiana University Purdue University, Indianapolis, IN 46202, USA
| | - Nicola Perrotti
- Department of Health Sciences, University “Magna Graecia” at Catanzaro, 88100 Catanzaro, Italy
- Medical Genetics Unit, University Hospital “Mater Domini” at Catanzaro, 88100 Catanzaro, Italy
- Correspondence:
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Bardet–Biedl syndrome associated with novel compound heterozygous variants in BBS12 gene. Doc Ophthalmol 2022; 146:165-171. [PMID: 36574078 DOI: 10.1007/s10633-022-09915-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 12/13/2022] [Indexed: 12/28/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy characterized by 6 primary features of rod-cone dystrophy, central obesity, polydactyly, cognitive impairment, hypogonadism and/or genitourinary malformations, and kidney abnormalities. At least 21 genes associated with BBS have been reported. To date, BBS associated with BBS12 variants has never been described in the Japanese population. We report a Japanese infant female with BBS with compound heterozygous BBS12 variants. METHODS In addition to the pediatric examination, fundus photography, full-field electroretinogram(ffERG) and whole exome sequencing (WES) were underwent. RESULTS The infant exhibited obesity, polydactyly, cognitive impairment, genitourinary malformations, and kidney dysfunction. At the age of 2 years, ffERG revealed severe reduction in both rod- and cone-mediated electroretinographic responses consistent with a severe form of rod-cone dystrophy, with minimal retinal abnormalities. WES revealed novel compound heterozygous BBS12 variants (c.591T > A, p.Tyr197* and c.1372dupA, p.Thr458Asnfs*5) in the infant. Her parents carried each of the variants, as confirmed by Sanger sequencing. CONCLUSIONS The current observations will contribute to an expanded understanding of genotype-phenotype associations in BBS12-associated BBS.
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Nasser F, Kohl S, Kurtenbach A, Kempf M, Biskup S, Zuleger T, Haack TB, Weisschuh N, Stingl K, Zrenner E. Ophthalmic and Genetic Features of Bardet Biedl Syndrome in a German Cohort. Genes (Basel) 2022; 13:genes13071218. [PMID: 35886001 PMCID: PMC9322102 DOI: 10.3390/genes13071218] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/29/2022] [Accepted: 07/02/2022] [Indexed: 12/04/2022] Open
Abstract
The aim of this study was to characterize the ophthalmic and genetic features of Bardet Biedl (BBS) syndrome in a cohort of patients from a German specialized ophthalmic care center. Sixty-one patients, aged 5−56 years, underwent a detailed ophthalmic examination including visual acuity and color vision testing, electroretinography (ERG), visually evoked potential recording (VEP), fundus examination, and spectral domain optical coherence tomography (SD-OCT). Adaptive optics flood illumination ophthalmoscopy was performed in five patients. All patients had received diagnostic genetic testing and were selected upon the presence of apparent biallelic variants in known BBS-associated genes. All patients had retinal dystrophy with morphologic changes of the retina. Visual acuity decreased from ~0.2 (decimal) at age 5 to blindness 0 at 50 years. Visual field examination could be performed in only half of the patients and showed a concentric constriction with remaining islands of function in the periphery. ERG recordings were mostly extinguished whereas VEP recordings were reduced in about half of the patients. The cohort of patients showed 51 different likely biallelic mutations—of which 11 are novel—in 12 different BBS-associated genes. The most common associated genes were BBS10 (32.8%) and BBS1 (24.6%), and by far the most commonly observed variants were BBS10 c.271dup;p.C91Lfs*5 (21 alleles) and BBS1 c.1169T>G;p.M390R (18 alleles). The phenotype associated with the different BBS-associated genes and genotypes in our cohort is heterogeneous, with diverse features without genotype−phenotype correlation. The results confirm and expand our knowledge of this rare disease.
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Affiliation(s)
- Fadi Nasser
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
- Department of Ophthalmology, University of Leipzig, 04103 Leipzig, Germany
- Correspondence:
| | - Susanne Kohl
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
| | - Anne Kurtenbach
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
| | - Melanie Kempf
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tuebingen, Germany
| | | | - Theresia Zuleger
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tuebingen, Germany; (T.Z.); (T.B.H.)
| | - Tobias B. Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tuebingen, Germany; (T.Z.); (T.B.H.)
| | - Nicole Weisschuh
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
| | - Katarina Stingl
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
- Center for Rare Eye Diseases, University of Tübingen, 72076 Tuebingen, Germany
| | - Eberhart Zrenner
- Centre for Ophthalmology, University of Tübingen, 72076 Tuebingen, Germany; (S.K.); (A.K.); (M.K.); (N.W.); (K.S.); (E.Z.)
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, 72076 Tuebingen, Germany
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Gupta N, D'Acierno M, Zona E, Capasso G, Zacchia M. Bardet-Biedl syndrome: The pleiotropic role of the chaperonin-like BBS6, 10, and 12 proteins. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:9-19. [PMID: 35373910 PMCID: PMC9325507 DOI: 10.1002/ajmg.c.31970] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 02/08/2022] [Accepted: 03/27/2022] [Indexed: 12/11/2022]
Abstract
Bardet–Biedl syndrome (BBS) is a rare pleiotropic disorder known as a ciliopathy. Despite significant genetic heterogeneity, BBS1 and BBS10 are responsible for major diagnosis in western countries. It is well established that eight BBS proteins, namely BBS1, 2, 4, 5, 7, 8, 9, and 18, form the BBSome, a multiprotein complex serving as a regulator of ciliary membrane protein composition. Less information is available for BBS6, BBS10, and BBS12, three proteins showing sequence homology with the CCT/TRiC family of group II chaperonins. Even though their chaperonin function is debated, scientific evidence demonstrated that they are required for initial BBSome assembly in vitro. Recent studies suggest that genotype may partially predict clinical outcomes. Indeed, patients carrying truncating mutations in any gene show the most severe phenotype; moreover, mutations in chaperonin‐like BBS proteins correlated with severe kidney impairment. This study is a critical review of the literature on genetics, expression level, cellular localization and function of BBS proteins, focusing primarily on the chaperonin‐like BBS proteins, and aiming to provide some clues to understand the pathomechanisms of disease in this setting.
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Affiliation(s)
- Neha Gupta
- Unit of Nephrology, Department of Translational Medical Sciences, University of Campania L. Vanvitelli, Naples, Italy.,BioGem S.C.A.R.L., Benevento, Benevento Province, Italy
| | - Mariavittoria D'Acierno
- Unit of Nephrology, Department of Translational Medical Sciences, University of Campania L. Vanvitelli, Naples, Italy.,BioGem S.C.A.R.L., Benevento, Benevento Province, Italy
| | - Enrica Zona
- Unit of Nephrology, Department of Translational Medical Sciences, University of Campania L. Vanvitelli, Naples, Italy
| | | | - Miriam Zacchia
- Unit of Nephrology, Department of Translational Medical Sciences, University of Campania L. Vanvitelli, Naples, Italy
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9
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Chandra B, Tung ML, Hsu Y, Scheetz T, Sheffield VC. Retinal ciliopathies through the lens of Bardet-Biedl Syndrome: Past, present and future. Prog Retin Eye Res 2021; 89:101035. [PMID: 34929400 DOI: 10.1016/j.preteyeres.2021.101035] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The primary cilium is a highly specialized and evolutionary conserved organelle in eukaryotes that plays a significant role in cell signaling and trafficking. Over the past few decades tremendous progress has been made in understanding the physiology of cilia and the underlying pathomechanisms of various ciliopathies. Syndromic ciliopathies consist of a group of disorders caused by ciliary dysfunction or abnormal ciliogenesis. These disorders have multiorgan involvement in addition to retinal degeneration underscoring the ubiquitous distribution of primary cilia in different cell types. Genotype-phenotype correlation is often challenging due to the allelic heterogeneity and pleiotropy of these disorders. In this review, we discuss the clinical and genetic features of syndromic ciliopathies with a focus on Bardet-Biedl syndrome (BBS) as a representative disorder. We discuss the structure and function of primary cilia and their role in retinal photoreceptors. We describe the progress made thus far in understanding the functional and genetic characterization including expression quantitative trait locus (eQTL) analysis of BBS genes. In the future directions section, we discuss the emerging technologies, such as gene therapy, as well as anticipated challenges and their implications in therapeutic development for ciliopathies.
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Affiliation(s)
- Bharatendu Chandra
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Moon Ley Tung
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Hsu
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Todd Scheetz
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Val C Sheffield
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA.
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10
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Focșa IO, Budișteanu M, Burloiu C, Khan S, Sadeghpour A, Bohîlțea LC, Davis EE, Bălgrădean M. A case of Bardet-Biedl syndrome caused by a recurrent variant in BBS12: A case report. Biomed Rep 2021; 15:103. [PMID: 34760276 PMCID: PMC8567465 DOI: 10.3892/br.2021.1479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/29/2021] [Indexed: 12/30/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogenous disorder that manifests as a result of primary cilia impairment. Cilia are present on most cell types, thus BBS is a multisystemic condition involving the majority of organ systems. The core features of the syndrome include retinal degeneration, obesity, polydactyly, cognitive impairment, renal anomalies and urogenital malformations. To date, pathogenic variants in 26 genes have been shown to be involved in the molecular basis of this rare ciliopathy. Of these causal loci, BBS12 accounts for ~8% of all cases. In this case report, an individual with BBS caused by a rare recurrent variant in BBS12 (NM_152618.3: c.1063C>T; p.Arg355*) is described and compared with others with the same DNA variant, placing this finding in the context of the current literature.
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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.,Medical Genetic Laboratory, 'Victor Babeș' National Institute of Pathology, 050096 Bucharest, Romania.,Department of Medical Genetics, Titu Maiorescu University, 040441 Bucharest, Romania
| | - Carmen Burloiu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania
| | - Sheraz Khan
- National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan Institute of Engineering and Applied Sciences, Islamabad 38000, Pakistan.,Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA.,Duke Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Laurențiu C Bohîlțea
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Erica E Davis
- Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA.,Departments of Pediatrics and Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mihaela Bălgrădean
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children 'Maria Skłodowska Curie', 077120 Bucharest, Romania.,Department of Pediatrics, University of Medicine and Pharmacy 'Carol Davila', 077120 Bucharest, Romania
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11
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Yamakawa D, Katoh D, Kasahara K, Shiromizu T, Matsuyama M, Matsuda C, Maeno Y, Watanabe M, Nishimura Y, Inagaki M. Primary cilia-dependent lipid raft/caveolin dynamics regulate adipogenesis. Cell Rep 2021; 34:108817. [PMID: 33691104 DOI: 10.1016/j.celrep.2021.108817] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/28/2020] [Accepted: 02/11/2021] [Indexed: 12/14/2022] Open
Abstract
Primary cilia play a pivotal role in signal transduction and development and are known to serve as signaling hubs. Recent studies have shown that primary cilium dysfunction influences adipogenesis, but the mechanisms are unclear. Here, we show that mesenchymal progenitors C3H10T1/2 depleted of trichoplein, a key regulator of cilium formation, have significantly longer cilia than control cells and fail to differentiate into adipocytes. Mechanistically, the elongated cilia prevent caveolin-1- and/or GM3-positive lipid rafts from being assembled around the ciliary base where insulin receptor proteins accumulate, thereby inhibiting the insulin-Akt signaling. We further generate trichoplein knockout mice, in which adipogenic progenitors display elongated cilia and impair the lipid raft dynamics. The knockout mice on an extended high-fat diet exhibit reduced body fat and smaller adipocytes than wild-type (WT) mice. Overall, our results suggest a role for primary cilia in regulating adipogenic signal transduction via control of the lipid raft dynamics around cilia.
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Affiliation(s)
- Daishi Yamakawa
- Department of Physiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Daisuke Katoh
- Department of Physiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan; Department of Pathology and Matrix Biology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Kousuke Kasahara
- Department of Physiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Takashi Shiromizu
- Department of Integrative Pharmacology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Makoto Matsuyama
- Division of Molecular Genetics, Shigei Medical Research Institute, 2117 Yamada, Minami-ku, Okayama 701-0202, Japan
| | - Chise Matsuda
- Department of Oncologic Pathology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Yumi Maeno
- Department of Physiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Masatoshi Watanabe
- Department of Oncologic Pathology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Yuhei Nishimura
- Department of Integrative Pharmacology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan
| | - Masaki Inagaki
- Department of Physiology, Mie University Graduate School of Medicine, Tsu, Mie 514-8507, Japan.
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12
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The Neurochaperonopathies: Anomalies of the Chaperone System with Pathogenic Effects in Neurodegenerative and Neuromuscular Disorders. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11030898] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The chaperone (or chaperoning) system (CS) constitutes molecular chaperones, co-chaperones, and chaperone co-factors, interactors and receptors, and its canonical role is protein quality control. A malfunction of the CS may cause diseases, known as the chaperonopathies. These are caused by qualitatively and/or quantitatively abnormal molecular chaperones. Since the CS is ubiquitous, chaperonopathies are systemic, affecting various tissues and organs, playing an etiologic-pathogenic role in diverse conditions. In this review, we focus on chaperonopathies involved in the pathogenic mechanisms of diseases of the central and peripheral nervous systems: the neurochaperonopathies (NCPs). Genetic NCPs are linked to pathogenic variants of chaperone genes encoding, for example, the small Hsp, Hsp10, Hsp40, Hsp60, and CCT-BBS (chaperonin-containing TCP-1- Bardet–Biedl syndrome) chaperones. Instead, the acquired NCPs are associated with malfunctional chaperones, such as Hsp70, Hsp90, and VCP/p97 with aberrant post-translational modifications. Awareness of the chaperonopathies as the underlying primary or secondary causes of disease will improve diagnosis and patient management and open the possibility of investigating and developing chaperonotherapy, namely treatment with the abnormal chaperone as the main target. Positive chaperonotherapy would apply in chaperonopathies by defect, i.e., chaperone insufficiency, and consist of chaperone replacement or boosting, whereas negative chaperonotherapy would be pertinent when a chaperone actively participates in the initiation and progression of the disease and must be blocked and eliminated.
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13
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Novel Compound Heterozygous BBS2 and Homozygous MKKS Variants Detected in Chinese Families with Bardet-Biedl Syndrome. J Ophthalmol 2021; 2021:6751857. [PMID: 33520300 PMCID: PMC7817241 DOI: 10.1155/2021/6751857] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 10/23/2020] [Accepted: 12/19/2020] [Indexed: 11/29/2022] Open
Abstract
Background Bardet–Biedl syndrome (BBS) is a rare multisystem developmental disorder. In this study, we report the genetic causes and clinical manifestations in two Chinese families with BBS. Materials and Methods Two families were recruited in this study. Family A was a four-generation family with four affected and 15 unaffected members participating in the study, and family B was a consanguineous family with one affected and three unaffected members participating. Whole exome sequencing was performed in the two families, followed by a multistep bioinformatics analysis. Sanger sequencing was used to verify the variants and to perform a segregation analysis. Comprehensive ocular and systemic examinations were also conducted. Results Novel compound heterozygous variants c.235T > G (p.T79P) and c.534 + 1G > T were detected in the BBS2 gene in family A, and known homozygous variant c.748G > A (p.G250R) was detected in the MKKS gene in family B. Both families presented with retinitis pigmentosa; however, except for polydactyly, all other systemic manifestations were different. All of the affected family members in family A were overweight with a high body mass index (range from 26.5 to 41.9) and high blood pressure. Family A also presented with a delay in the onset of secondary sex characteristics and genital anomalies, while other systemic abnormalities were absent in family B. Conclusions This study presents one family with two novel BBS2 variants, expanding the variant spectrum of BBS, and one family with a known homozygous MKKS variant. The different phenotypes seen between the families with BBS2 and MKKS variants will contribute to the literature and our overall understanding of BBS.
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14
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Dehani M, Zare-Abdollahi D, Bushehri A, Dehghani A, Effati J, Miratashi SAM, Khorram Khorshid HR. Identification of a Novel Homozygous Mutation in BBS10 Gene in an Iranian Family with Bardet-Biedl Syndrome. Avicenna J Med Biotechnol 2021; 13:230-233. [PMID: 34900151 PMCID: PMC8606112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/03/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Bardet-Biedl Syndrome (BBS) is a rare pleiotropic autosomal recessive disease related to ciliopathies with approximately 25 causative genes. BBS is a multisystemic disorder with wide spectrum of manifestations including truncal obesity, retinal dystrophy, male hypogenitalism, postaxial polydactyly, learning difficulties, and renal abnormalities. METHODS A consanguineous Iranian family with a 28-year-old daughter affected with BBS, resulting from a first cousin marriage, was examined. After clinical examination, Whole Exome Sequencing (WES) was applied. Following the analysis of exome data, Sanger sequencing was used to confirm as well as to co-segregate the candidate variant with the phenotype. RESULTS A novel homozygous variant [c. 2035G>A (p.E679K)] in exon 2 of the BBS10 gene was found which was categorized as likely pathogenic based on American College of Medical Genetics and Genomics (ACMG) guidelines and criteria. In this study, the variant was fully co-segregated with the phenotype in the family. CONCLUSION Despite overlapping with other ciliopathies in terms of the phenotype, the BBS has high genetic heterogeneity and clinical variability even among affected members of a family. The symptoms observed in patients are largely related to the genes involved and the type of mutations in the BBS. In this study, in addition to phenotype description of the proband harboring a novel disease-causing variant in BBS10 gene, the spectrum of BBS symptoms was expanded. The findings of this study can be useful in genetic counseling, especially for risk estimation and prenatal diagnosis.
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Affiliation(s)
- Mohammad Dehani
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Davood Zare-Abdollahi
- Fetal Health Research Center, Hope Generation Foundation, Tehran, Iran,Corresponding author: Davood Zare-Abdollahi, Ph.D., Fetal Health Research Center, Hope Generation Foundation, Tehran, Iran, Tel: +98 9138502360, Fax: +98 21 22180138, E-mail:
| | - Ata Bushehri
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Azadeh Dehghani
- Medical Biotechnology Research Center, Ashkezar Branch, Islamic Azad University, Ashkezar, Iran
| | - Jalil Effati
- Meybod Genetic Research Center, State Welfare Organization, Yazd, Iran
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15
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Kousi M, Söylemez O, Ozanturk A, Mourtzi N, Akle S, Jungreis I, Muller J, Cassa CA, Brand H, Mokry JA, Wolf MY, Sadeghpour A, McFadden K, Lewis RA, Talkowski ME, Dollfus H, Kellis M, Davis EE, Sunyaev SR, Katsanis N. Evidence for secondary-variant genetic burden and non-random distribution across biological modules in a recessive ciliopathy. Nat Genet 2020; 52:1145-1150. [PMID: 33046855 PMCID: PMC8272915 DOI: 10.1038/s41588-020-0707-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 08/31/2020] [Indexed: 11/08/2022]
Abstract
The influence of genetic background on driver mutations is well established; however, the mechanisms by which the background interacts with Mendelian loci remain unclear. We performed a systematic secondary-variant burden analysis of two independent cohorts of patients with Bardet-Biedl syndrome (BBS) with known recessive biallelic pathogenic mutations in one of 17 BBS genes for each individual. We observed a significant enrichment of trans-acting rare nonsynonymous secondary variants in patients with BBS compared with either population controls or a cohort of individuals with a non-BBS diagnosis and recessive variants in the same gene set. Strikingly, we found a significant over-representation of secondary alleles in chaperonin-encoding genes-a finding corroborated by the observation of epistatic interactions involving this complex in vivo. These data indicate a complex genetic architecture for BBS that informs the biological properties of disease modules and presents a model for secondary-variant burden analysis in recessive disorders.
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Affiliation(s)
- Maria Kousi
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA, USA
| | - Onuralp Söylemez
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Aysegül Ozanturk
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Niki Mourtzi
- Advanced Center for Translational and Genetic Medicine, Lurie Children's Hospital, Chicago, IL, USA
| | - Sebastian Akle
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Boston, MA, USA
| | - Irwin Jungreis
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA, USA
| | - Jean Muller
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
- Laboratoire de Diagnostic Génétique, Institut de Génétique Médicale d'Alsace, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Christopher A Cassa
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Harrison Brand
- Molecular Neurogenetics Unit and Psychiatric and Neurodevelopmental Genetics Unit, Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Program in Population and Medical Genetics and Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jill Anne Mokry
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Maxim Y Wolf
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA, USA
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Kelsey McFadden
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Richard A Lewis
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Michael E Talkowski
- Molecular Neurogenetics Unit and Psychiatric and Neurodevelopmental Genetics Unit, Center for Genomic Medicine and Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
- Program in Population and Medical Genetics and Genomics Platform, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Program in Bioinformatics and Integrative Genomics, Division of Medical Sciences, Harvard Medical School, Boston, MA, USA
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Manolis Kellis
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- MIT Computer Science and Artificial Intelligence Laboratory, Cambridge, MA, USA
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
- Advanced Center for Translational and Genetic Medicine, Lurie Children's Hospital, Chicago, IL, USA
| | - Shamil R Sunyaev
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Division of Genetics, Brigham and Women's Hospital, Boston, MA, USA
- Department of Medicine, Harvard Medical School, Boston, MA, USA
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA.
- Advanced Center for Translational and Genetic Medicine, Lurie Children's Hospital, Chicago, IL, USA.
- Departments of Pediatrics and Cellular and Molecular Biology, Northwestern University School of Medicine, Chicago, IL, USA.
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16
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Tian JL, Gomeshtapeh FI. Potential Roles of O-GlcNAcylation in Primary Cilia- Mediated Energy Metabolism. Biomolecules 2020; 10:biom10111504. [PMID: 33139642 PMCID: PMC7693894 DOI: 10.3390/biom10111504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/26/2022] Open
Abstract
The primary cilium, an antenna-like structure on most eukaryotic cells, functions in transducing extracellular signals into intracellular responses via the receptors and ion channels distributed along it membrane. Dysfunction of this organelle causes an array of human diseases, known as ciliopathies, that often feature obesity and diabetes; this indicates the primary cilia's active role in energy metabolism, which it controls mainly through hypothalamic neurons, preadipocytes, and pancreatic β-cells. The nutrient sensor, O-GlcNAc, is widely involved in the regulation of energy homeostasis. Not only does O-GlcNAc regulate ciliary length, but it also modifies many components of cilia-mediated metabolic signaling pathways. Therefore, it is likely that O-GlcNAcylation (OGN) plays an important role in regulating energy homeostasis in primary cilia. Abnormal OGN, as seen in cases of obesity and diabetes, may play an important role in primary cilia dysfunction mediated by these pathologies.
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Affiliation(s)
- Jie L. Tian
- Complex Carbohydrate Research Center, Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-583-5551
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17
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Prasai A, Schmidt Cernohorska M, Ruppova K, Niederlova V, Andelova M, Draber P, Stepanek O, Huranova M. The BBSome assembly is spatially controlled by BBS1 and BBS4 in human cells. J Biol Chem 2020; 295:14279-14290. [PMID: 32759308 DOI: 10.1074/jbc.ra120.013905] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/04/2020] [Indexed: 12/18/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a pleiotropic ciliopathy caused by dysfunction of primary cilia. More than half of BBS patients carry mutations in one of eight genes encoding for subunits of a protein complex, the BBSome, which mediates trafficking of ciliary cargoes. In this study, we elucidated the mechanisms of the BBSome assembly in living cells and how this process is spatially regulated. We generated a large library of human cell lines deficient in a particular BBSome subunit and expressing another subunit tagged with a fluorescent protein. We analyzed these cell lines utilizing biochemical assays, conventional and expansion microscopy, and quantitative fluorescence microscopy techniques: fluorescence recovery after photobleaching and fluorescence correlation spectroscopy. Our data revealed that the BBSome formation is a sequential process. We show that the pre-BBSome is nucleated by BBS4 and assembled at pericentriolar satellites, followed by the translocation of the BBSome into the ciliary base mediated by BBS1. Our results provide a framework for elucidating how BBS-causative mutations interfere with the biogenesis of the BBSome.
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Affiliation(s)
- Avishek Prasai
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marketa Schmidt Cernohorska
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Klara Ruppova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Veronika Niederlova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Monika Andelova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Peter Draber
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Stepanek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Huranova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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18
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Engle SE, Bansal R, Antonellis PJ, Berbari NF. Cilia signaling and obesity. Semin Cell Dev Biol 2020; 110:43-50. [PMID: 32466971 DOI: 10.1016/j.semcdb.2020.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/11/2022]
Abstract
An emerging number of rare genetic disorders termed ciliopathies are associated with pediatric obesity. It is becoming clear that the mechanisms associated with cilia dysfunction and obesity in these syndromes are complex. In addition to ciliopathic syndromic forms of obesity, several cilia-associated signaling gene mutations also lead to morbid obesity. While cilia have critical and diverse functions in energy homeostasis including their roles in centrally mediated food intake as well as in peripheral tissues, many questions remain. Here, we briefly discuss the syndromic ciliopathies and monoallelic cilia signaling gene mutations associated with obesity. We also describe potential ways cilia may be involved in common obesity. We discuss how neuronal cilia impact food intake potentially through leptin signaling and changes in ciliary G protein-coupled receptor (GPCR) signaling. We highlight several recent studies that have implicated the potential for cilia in peripheral tissues such as adipose and the pancreas to contribute to metabolic dysfunction. Then we discuss the potential for cilia to impact energy homeostasis through their roles in both development and adult tissue homeostasis. The studies discussed in this review highlight how a comprehensive understanding of the requirement of cilia for the regulation of diverse biological functions will contribute to our understanding of common forms of obesity.
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Affiliation(s)
- Staci E Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Patrick J Antonellis
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA; Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, USA; Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
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19
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Goyal S, Singh IR, Vanita V. Novel mutation in MKKS/BBS6 linked with arRP and polydactyly in a family of North Indian origin. Clin Exp Ophthalmol 2020; 48:343-355. [PMID: 31989739 DOI: 10.1111/ceo.13719] [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: 04/11/2019] [Revised: 11/12/2019] [Accepted: 11/20/2019] [Indexed: 11/28/2022]
Abstract
BACKGROUND To identify the underlying genetic defect in a fourth-generation autosomal recessive retinitis pigmentosa (arRP) family. Detailed family history and clinical data were collected from nine members, including three affected, from an arRP family. METHODS Whole-exome sequencing (WES) was performed on DNA sample of an affected individual IV: 2. Variants obtained by WES were annotated using Ion Reporter Software (ver. 5.2). Potential pathogenic variants detected in an affected member were validated in other affected and unaffected family members by Sanger sequencing. Further 150 ethnically-matched controls were tested for the variant that co-segregated completely with disease in the family, so as to exclude it as a polymorphism. Various web-based bioinformatics tools were also applied to access pathogenic potential of the observed variant. RESULTS All the three patients had RP with polydactyly of both hands and feet, however, they did not show other symptoms of Bardet-Biedl syndrome (BBS) or McKusick-Kaufmann Syndrome (MKKS). A novel missense mutation, that is, c.518A>C (p.His173Pro) was identified in MKKS/BBS6 that co-segregated completely with the disease phenotype in all the three affected members and was not observed in six unaffected members of the family. Also the c.518A>C change was not observed in 150 ethnically matched controls (300 chromosomes), hence excluding it as a polymorphism. CONCLUSIONS Present study is the second report of identifying a novel mutation in MKKS/BBS6 that is linked with arRP in association with polydactyly, however, with no other signs of BBS or MKKS. These findings further expand the mutation spectrum of MKKS/BBS6 for arRP with polydactyly.
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Affiliation(s)
- Shiwali Goyal
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, India
| | | | - Vanita Vanita
- Department of Human Genetics, Guru Nanak Dev University, Amritsar, India
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20
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A novel missense variant in the BBS7 gene underlying Bardet-Biedl syndrome in a consanguineous Pakistani family. Clin Dysmorphol 2020; 29:17-23. [DOI: 10.1097/mcd.0000000000000294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Ludlam WG, Aoba T, Cuéllar J, Bueno-Carrasco MT, Makaju A, Moody JD, Franklin S, Valpuesta JM, Willardson BM. Molecular architecture of the Bardet-Biedl syndrome protein 2-7-9 subcomplex. J Biol Chem 2019; 294:16385-16399. [PMID: 31530639 DOI: 10.1074/jbc.ra119.010150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/10/2019] [Indexed: 02/04/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a genetic disorder characterized by malfunctions in primary cilia resulting from mutations that disrupt the function of the BBSome, an 8-subunit complex that plays an important role in protein transport in primary cilia. To better understand the molecular basis of BBS, here we used an integrative structural modeling approach consisting of EM and chemical cross-linking coupled with MS analyses, to analyze the structure of a BBSome 2-7-9 subcomplex consisting of three homologous BBS proteins, BBS2, BBS7, and BBS9. The resulting molecular model revealed an overall structure that resembles a flattened triangle. We found that within this structure, BBS2 and BBS7 form a tight dimer through a coiled-coil interaction and that BBS9 associates with the dimer via an interaction with the α-helical domain of BBS2. Interestingly, a BBS-associated mutation of BBS2 (R632P) is located in its α-helical domain at the interface between BBS2 and BBS9, and binding experiments indicated that this mutation disrupts the BBS2-BBS9 interaction. This finding suggests that BBSome assembly is disrupted by the R632P substitution, providing molecular insights that may explain the etiology of BBS in individuals harboring this mutation.
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Affiliation(s)
- W Grant Ludlam
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| | - Takuma Aoba
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| | - Jorge Cuéllar
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - M Teresa Bueno-Carrasco
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Aman Makaju
- Department of Internal Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah 84112
| | - James D Moody
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
| | - Sarah Franklin
- Department of Internal Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, Utah 84112
| | - José M Valpuesta
- Centro Nacional de Biotecnología (CNB-CSIC), Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Barry M Willardson
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602
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22
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Kretschmer V, Patnaik SR, Kretschmer F, Chawda MM, Hernandez-Hernandez V, May-Simera HL. Progressive Characterization of Visual Phenotype in Bardet-Biedl Syndrome Mutant Mice. Invest Ophthalmol Vis Sci 2019; 60:1132-1143. [PMID: 30901771 DOI: 10.1167/iovs.18-25210] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Bardet-Biedl syndrome (BBS) is an archetypical ciliopathy caused by defective ciliary trafficking and consequent function. Insights gained from BBS mouse models are applicable to other syndromic and nonsyndromic retinal diseases. This progressive characterization of the visual phenotype in three BBS mouse models sets a baseline for testing therapeutic interventions. Methods Longitudinal acquisition of electroretinograms, optical coherence tomography scans, and visual acuity using the optomotor reflex in Bbs6/Mkks, Bbs8/Ttc8, and Bbs5 knockout mice. Gene and protein expression analysis in vivo and in vitro. Results Complete loss of BBS5, BBS6, or BBS8 leads to different rates of retinal degeneration and visual function over time. BBS8-deficient mice showed the fastest rate of degeneration, and BBS8 seems to be required for cone photoreceptors to reach functional maturity. In contrast, the loss of BBS5 (a further BBSome component) showed very little degeneration. Loss of BBS8 versus BBS5 resulted in different physiologic responses both in vivo and in vitro. BBS6-deficient mice show a slower rate of degeneration with both rod and cone function reducing at a similar rate. Conclusions The mouse models analyzed show distinct and diverging courses of degeneration upon loss of BBS5, BBS6, or BBS8, which can be used as a benchmark to test therapeutic interventions. Close consideration of the different phenotypes reveal subtle but important differences relating to their function. Because we also see differences in terms of phenotype depending on the type of visual assessment used, our data highlight the importance of using a combinatorial approach for assessment of visual function.
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Affiliation(s)
- Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg University, Mainz, Germany
| | - Sarita Rani Patnaik
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg University, Mainz, Germany
| | - Friedrich Kretschmer
- Scientific Computing Facility, Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Mira Manilal Chawda
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Victor Hernandez-Hernandez
- Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom.,Department of Life Sciences, College of Health and Life Sciences, Brunel University London, London, United Kingdom
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes Gutenberg University, Mainz, Germany
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23
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Barrell WB, Griffin JN, Harvey JL, Danovi D, Beales P, Grigoriadis AE, Liu KJ. Induction of Neural Crest Stem Cells From Bardet-Biedl Syndrome Patient Derived hiPSCs. Front Mol Neurosci 2019; 12:139. [PMID: 31293383 PMCID: PMC6598745 DOI: 10.3389/fnmol.2019.00139] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 05/13/2019] [Indexed: 11/13/2022] Open
Abstract
Neural crest cells arise in the embryo from the neural plate border and migrate throughout the body, giving rise to many different tissue types such as bones and cartilage of the face, smooth muscles, neurons, and melanocytes. While studied extensively in animal models, neural crest development and disease have been poorly described in humans due to the challenges in accessing embryonic tissues. In recent years, patient-derived human induced pluripotent stem cells (hiPSCs) have become easier to generate, and several streamlined protocols have enabled robust differentiation of hiPSCs to the neural crest lineage. Thus, a unique opportunity is offered for modeling neurocristopathies using patient specific stem cell lines. In this work, we make use of hiPSCs derived from patients affected by the Bardet-Biedl Syndrome (BBS) ciliopathy. BBS patients often exhibit subclinical craniofacial dysmorphisms that are likely to be associated with the neural crest-derived facial skeleton. We focus on hiPSCs carrying variants in the BBS10 gene, which encodes a protein forming part of a chaperonin-like complex associated with the cilium. Here, we establish a pipeline for profiling hiPSCs during differentiation toward the neural crest stem cell fate. This can be used to characterize the differentiation properties of the neural crest-like cells. Two different BBS10 mutant lines showed a reduction in expression of the characteristic neural crest gene expression profile. Further analysis of both BBS10 mutant lines highlighted the inability of these mutant lines to differentiate toward a neural crest fate, which was also characterized by a decreased WNT and BMP response. Altogether, our study suggests a requirement for wild-type BBS10 in human neural crest development. In the long term, approaches such as the one we describe will allow direct comparison of disease-specific cell lines. This will provide valuable insights into the relationships between genetic background and heterogeneity in cellular models. The possibility of integrating laboratory data with clinical phenotypes will move us toward precision medicine approaches.
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Affiliation(s)
- William B. Barrell
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - John N. Griffin
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
| | - Jessica-Lily Harvey
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
- School of Psychology and Neuroscience, University of St Andrews, St Andrews, United Kingdom
| | - Davide Danovi
- Centre for Stem Cells & Regenerative Medicine, King’s College London, London, United Kingdom
| | - Philip Beales
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | | | - Karen J. Liu
- Centre for Craniofacial and Regenerative Biology, King’s College London, London, United Kingdom
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24
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Manara E, Paolacci S, D’Esposito F, Abeshi A, Ziccardi L, Falsini B, Colombo L, Iarossi G, Pilotta A, Boccone L, Guerri G, Monica M, Marta B, Maltese PE, Buzzonetti L, Rossetti L, Bertelli M. Mutation profile of BBS genes in patients with Bardet-Biedl syndrome: an Italian study. Ital J Pediatr 2019; 45:72. [PMID: 31196119 PMCID: PMC6567512 DOI: 10.1186/s13052-019-0659-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/16/2019] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare inherited multisystemic disorder with autosomal recessive or complex digenic triallelic inheritance. There is currently no treatment for BBS, but some morbidities can be managed. Accurate molecular diagnosis is often crucial for the definition of appropriate patient management and for the development of a potential personalized therapy. METHODS We developed a next-generation-sequencing (NGS) protocol for the screening of the 18 most frequently mutated genes to define the genotype and clarify the mutation spectrum of a cohort of 20 BBS Italian patients. RESULTS We defined the causative variants in 60% of patients; four of those are novel. 33% of patients also harboured variants in additional gene/s, suggesting possible oligogenic inheritance. To explore the function of different genes, we looked for correlations between genotype and phenotype in our cohort. Hypogonadism was more frequently detected in patients with variants in BBSome proteins, while renal abnormalities in patients with variations in BBSome chaperonin genes. CONCLUSIONS NGS is a powerful tool that can help understanding BBS patients' phenotype through the identification of mutations that could explain differences in phenotype severity and could provide insights for the development of targeted therapy. Furthermore, our results support the existence of additional BBS loci yet to be identified.
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Affiliation(s)
| | | | - Fabiana D’Esposito
- Magi Euregio, Bolzano, Italy
- Imperial College Ophthalmic Research Unit, Western Eye Hospital, Imperial College Healthcare NHS Trust, London, UK
- Eye Clinic, Department of Neurosciences, Reproductive Sciences and Dentistry, Federico II University, Naples, Italy
| | | | | | - Benedetto Falsini
- Institute of Ophthalmology, Università Cattolica del Sacro Cuore, Rome, Italy
- Fondazione Policlinico Universitario “A. Gemelli”, IRCCS, Rome, Italy
| | - Leonardo Colombo
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Milan, Italy
| | - Giancarlo Iarossi
- Department of Ophthalmology, Bambino Gesù IRCCS Children’s Hospital, Rome, Italy
| | - Alba Pilotta
- Special Unit of Auxoendocrinology, Diabetology and Pediatric Genetics, University of Brescia, Spedali Civili di Brescia, Brescia, Italy
| | - Loredana Boccone
- Microcitemic Regional Hospital, Brotzu Hospital, Cagliari, Italy
| | | | - Marica Monica
- Microcitemic Regional Hospital, Brotzu Hospital, Cagliari, Italy
| | - Balzarini Marta
- Microcitemic Regional Hospital, Brotzu Hospital, Cagliari, Italy
| | | | - Luca Buzzonetti
- Department of Ophthalmology, Bambino Gesù IRCCS Children’s Hospital, Rome, Italy
| | - Luca Rossetti
- Department of Ophthalmology, San Paolo Hospital, University of Milan, Milan, Italy
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25
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Chang T, Wei J, Wang X, Miao J, Xu L, Zhang L, Gao X, Chen Y, Li J, Gao H. A rapid and efficient linear mixed model approach using the score test and its application to GWAS. Livest Sci 2019. [DOI: 10.1016/j.livsci.2018.12.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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27
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Ladino LY, Galvis J, Yasnó D, Ramírez A, Beltrán OI. A pathogenic homozygous variant of the BBS10 gene in a patient with Bardet Biedl syndrome. BIOMEDICA : REVISTA DEL INSTITUTO NACIONAL DE SALUD 2018; 38:308-320. [PMID: 30335236 DOI: 10.7705/biomedica.v38i4.4199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 03/23/2018] [Accepted: 04/02/2018] [Indexed: 06/08/2023]
Abstract
The Bardet-Biedl syndrome is an autosomal recessive hereditary disorder with vast locus heterogeneity that belongs to the so-called ciliopathies, whose proteins are localized in the primary cilia and present functional deficiency. The multisystemic features of the disease include ocular, renal, cognitive, skeletal, as well as gonadal involvement and obesity, among others, with high inter- and intrafamilial variability. We describe the clinical case of an adolescent male patient with Bardet-Biedl syndrome, including the approach, the results from a 22-gene sequencing panel, and the analysis of updated scientific literature. We collected the clinical data of the patient and, after obtaining the informed consent, we conducted a multigenic sequencing panel oriented to known implicated genes. The patient was born to consanguineous parents and was the first affected member of the family. He presented with postaxial polydactyly, obesity, micropenis, retinitis pigmentosa, and learning disability. The multigenic panel allowed the identification of the homozygous pathogenic variant c.39_46del in the BBS10 gene and in other BBS genes variants associated with obesity. As the Bardet-Biedl syndrome is a rare disease, it is challenging to interpret its pleiotropism and gene/allelic heterogeneity. Its confirmation by molecular tests allows an adequate approach, follow-up, and genetic counseling of the patient and the family.
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Affiliation(s)
- Luz Yaqueline Ladino
- Departamento de Genética, Grupo de Investigación GenHOMI, Fundación Hospital Pediátrico La Misericordia-HOMI, Bogotá, D.C., Colombia Maestría en Genética Humana, Universidad Nacional de Colombia, Bogotá, D.C., Colombia.
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28
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An B, Xia J, Chang T, Wang X, Miao J, Xu L, Zhang L, Gao X, Chen Y, Li J, Gao H. Genome-wide association study identifies loci and candidate genes for internal organ weights in Simmental beef cattle. Physiol Genomics 2018; 50:523-531. [DOI: 10.1152/physiolgenomics.00022.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cattle internal organs as accessible raw materials have a long history of being widely used in beef processing, feed and pharmaceutical industry. These traits not only are of economic interest to breeders, but they are intrinsically linked to many valuable traits, such as growth, health, and productivity. Using the Illumina Bovine HD 770K SNP array, we performed a genome-wide association study for heart weight, liver weight, spleen weight, lung weight, and kidney weight in 1,217 Simmental cattle. In our research, 38 significant single nucleotide polymorphisms (SNPs) ( P < 1.49 × 10−6) were identified for five internal organ weight traits. These SNPs are within or near 13 genes, and some of them have been reported previously, including NDUFAF4, LCORL, BT.94996, SLIT2, FAM184B, LAP3, BBS12, MECOM, CD300LF, HSD17B3, TLR4, MXI1, and MB21D2. In addition, we detected four haplotype blocks on BTA6 containing 18 significant SNPs associated with spleen weight. Our results offer worthy insights into understanding the genetic mechanisms of internal organs' development, with potential application in breeding programs of Simmental beef cattle.
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Affiliation(s)
- Bingxing An
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Jiangwei Xia
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Tianpeng Chang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Xiaoqiao Wang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Jian Miao
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Lingyang Xu
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Lupei Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Xue Gao
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Yan Chen
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Junya Li
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
| | - Huijiang Gao
- Institute of Animal Science, Chinese Academy of Agricultural Science, Beijing, People’s Republic of China
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29
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Sheffield ID, McGee MA, Glenn SJ, Baek DY, Coleman JM, Dorius BK, Williams C, Rose BJ, Sanchez AE, Goodman MA, Daines JM, Eggett DL, Sheffield VC, Suli A, Kooyman DL. Osteoarthritis-Like Changes in Bardet-Biedl Syndrome Mutant Ciliopathy Mice ( Bbs1M390R/M390R): Evidence for a Role of Primary Cilia in Cartilage Homeostasis and Regulation of Inflammation. Front Physiol 2018; 9:708. [PMID: 29971011 PMCID: PMC6018413 DOI: 10.3389/fphys.2018.00708] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 05/22/2018] [Indexed: 12/22/2022] Open
Abstract
Osteoarthritis (OA) is a debilitating inflammation related disease characterized by joint pain and effusion, loss of mobility, and deformity that may result in functional joint failure and significant impact on quality of life. Once thought of as a simple “wear and tear” disease, it is now widely recognized that OA has a considerable metabolic component and is related to chronic inflammation. Defects associated with primary cilia have been shown to be cause OA-like changes in Bardet–Biedl mice. We examined the role of dysfunctional primary cilia in OA in mice through the regulation of the previously identified degradative and pro-inflammatory molecular pathways common to OA. We observed an increase in the presence of pro-inflammatory markers TGFβ-1 and HTRA1 as well as cartilage destructive protease MMP-13 but a decrease in DDR-2. We observed a morphological difference in cartilage thickness in Bbs1M390R/M390R mice compared to wild type (WT). We did not observe any difference in OARSI or Mankin scores between WT and Bbs1M390R/M390R mice. Primary cilia appear to be involved in the upregulation of biomarkers, including pro-inflammatory markers common to OA.
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Affiliation(s)
- Isaac D Sheffield
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Mercedes A McGee
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Steven J Glenn
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Da Young Baek
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Joshua M Coleman
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Bradley K Dorius
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Channing Williams
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Brandon J Rose
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Anthony E Sanchez
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Michael A Goodman
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - John M Daines
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Dennis L Eggett
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - Val C Sheffield
- Departments of Pediatrics and Ophthalmology, University of Iowa, Iowa City, IA, United States
| | - Arminda Suli
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
| | - David L Kooyman
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, United States
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30
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Zebrafish Models of Rare Hereditary Pediatric Diseases. Diseases 2018; 6:diseases6020043. [PMID: 29789451 PMCID: PMC6023479 DOI: 10.3390/diseases6020043] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/17/2018] [Accepted: 05/19/2018] [Indexed: 12/12/2022] Open
Abstract
Recent advances in sequencing technologies have made it significantly easier to find the genetic roots of rare hereditary pediatric diseases. These novel methods are not panaceas, however, and they often give ambiguous results, highlighting multiple possible causative mutations in affected patients. Furthermore, even when the mapping results are unambiguous, the affected gene might be of unknown function. In these cases, understanding how a particular genotype can result in a phenotype also needs carefully designed experimental work. Model organism genetics can offer a straightforward experimental setup for hypothesis testing. Containing orthologs for over 80% of the genes involved in human diseases, zebrafish (Danio rerio) has emerged as one of the top disease models over the past decade. A plethora of genetic tools makes it easy to create mutations in almost any gene of the zebrafish genome and these mutant strains can be used in high-throughput preclinical screens for active molecules. As this small vertebrate species offers several other advantages as well, its popularity in biomedical research is bound to increase, with “aquarium to bedside” drug development pipelines taking a more prevalent role in the near future.
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31
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Mujahid S, Hunt KF, Cheah YS, Forsythe E, Hazlehurst JM, Sparks K, Mohammed S, Tomlinson JW, Amiel SA, Carroll PV, Beales PL, Huda MSB, McGowan BM. The Endocrine and Metabolic Characteristics of a Large Bardet-Biedl Syndrome Clinic Population. J Clin Endocrinol Metab 2018; 103:1834-1841. [PMID: 29409041 DOI: 10.1210/jc.2017-01459] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 01/26/2018] [Indexed: 01/03/2023]
Abstract
CONTEXT Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder in which previous reports have described obesity and a metabolic syndrome. OBJECTIVE We describe the endocrine and metabolic characteristics of a large BBS population compared with matched control subjects. DESIGN We performed a case-control study. SETTING This study was performed at a hospital clinic. PATIENTS Study patients had a clinical or genetic diagnosis of BBS. MAIN OUTCOME MEASUREMENTS Our study determined the prevalence of a metabolic syndrome in our cohort. RESULTS A total of 152 subjects were studied. Eighty-four (55.3%) were male. Mean (± standard deviation) age was 33.2 ± 1.0 years. Compared with age-, sex-, and body mass index-matched control subjects, fasting glucose and insulin levels were significantly higher in subjects with BBS (glucose: BBS, 5.2 ± 1.2 mmol/L vs control, 4.9 ± 0.9 mmol/L, P = 0.04; insulin: BBS, 24.2 ± 17.0 pmol/L vs control, 14.2 ± 14.8 pmol/L, P < 0.001). Serum triglycerides were significantly higher in subjects with BBS (2.0 ± 1.2 mmol/L) compared with control subjects (1.3 ± 0.8 mmol/L; P < 0.001), but total cholesterol, high-density lipoprotein, and low-density lipoprotein were similar in both groups. Systolic blood pressure was higher in the BBS group (BBS, 135 ± 18 mm Hg vs control subjects, 129 ± 16 mm Hg; P = 0.02). Alanine transaminase was raised in 34 (26.8%) subjects with BBS, compared with five (8.9%) control subjects (P = 0.01). The rate of metabolic syndrome, determined using International Diabetes Federation criteria, was significantly higher in the BBS group (54.3%) compared with control subjects (26% P < 0.001). Twenty-six (19.5%) of male subjects with BBS were hypogonadal (serum testosterone, 9.9 ± 5.3 mmol/L), but significant pituitary abnormalities were uncommon. Subclinical hypothyroidism was present in 24 of 125 (19.4%) patients with BBS, compared with 3 of 65 (4.6%) control subjects (P = 0.01). CONCLUSIONS Insulin resistance and the metabolic syndrome are increased in adult patients with BBS compared with matched control subjects. Increased subclinical hypothyroidism in the BBS cohort needs further investigation.
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Affiliation(s)
- Safa Mujahid
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Katharine F Hunt
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | - Yee S Cheah
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | | | - Jonathan M Hazlehurst
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- University Hospitals, Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Kathryn Sparks
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Shehla Mohammed
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, United Kingdom
- University Hospitals, Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Stephanie A Amiel
- King's Diabetes Research Group, King's College London, London, United Kingdom
| | - Paul V Carroll
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Phillip L Beales
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
| | - Mohammed S B Huda
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom
- King's Diabetes Research Group, King's College London, London, United Kingdom
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Nikkhah E, Safaralizadeh R, Mohammadiasl J, Tahmasebi Birgani M, Hosseinpour Feizi MA, Golchin N. Identification of A Novel Compound Heterozygous Mutation in BBS12 in An Iranian Family with Bardet-Biedl Syndrome Using Targeted Next Generation Sequencing. CELL JOURNAL 2018; 20:284-289. [PMID: 29633607 PMCID: PMC5893301 DOI: 10.22074/cellj.2018.5012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 03/21/2017] [Indexed: 01/27/2023]
Abstract
Bardet-Biedl syndrome (BBS) is a pleiotropic and multisystemic disorder characterized by rod-cone dystrophy, polydactyly,
learning difficulties, renal abnormalities, obesity and hypogonadism. This disorder is genetically heterogeneous. Until
now, a total of nineteen genes have been identified for BBS whose mutations explain more than 80% of diagnosed
cases. Recently, the development of next generation sequencing (NGS) technology has accelerated mutation screening
of target genes, resulting in lower cost and less time consumption. Here, we screened the most common BBS genes
(BBS1-BBS13) using NGS in an Iranian family of a proposita displaying symptoms of BBS. Among the 18 mutations
identified in the proposita, one (BBS12 c.56T>G and BBS12 c.1156C>T) was novel. This compound heterozygosity
was confirmed by Sanger sequencing in the proposita and her parents. Although our data were presented as a case
report, however, we suggest a new probable genetic mechanism other than the conventional autosomal recessive
inheritance of BBS. Additionally, given that in some Iranian provinces, like Khuzestan, consanguineous marriages
are common, designing mutational panels for genetic diseases is strongly recommended, especially for those with an
autosomal recessive inheritance pattern.
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Affiliation(s)
- Emad Nikkhah
- Department of Animal Biology, Faculty of Natural Science, University of Tabriz, Tabriz, Iran
| | - Reza Safaralizadeh
- Department of Animal Biology, Faculty of Natural Science, University of Tabriz, Tabriz, Iran.
| | - Javad Mohammadiasl
- Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Maryam Tahmasebi Birgani
- Department of Medical Genetics, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
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Bujakowska KM, Liu Q, Pierce EA. Photoreceptor Cilia and Retinal Ciliopathies. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028274. [PMID: 28289063 DOI: 10.1101/cshperspect.a028274] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Photoreceptors are sensory neurons designed to convert light stimuli into neurological responses. This process, called phototransduction, takes place in the outer segments (OS) of rod and cone photoreceptors. OS are specialized sensory cilia, with analogous structures to those present in other nonmotile cilia. Deficient morphogenesis and/or dysfunction of photoreceptor sensory cilia (PSC) caused by mutations in a variety of photoreceptor-specific and common cilia genes can lead to inherited retinal degenerations (IRDs). IRDs can manifest as isolated retinal diseases or syndromic diseases. In this review, we describe the structure and composition of PSC and different forms of ciliopathies with retinal involvement. We review the genetics of the IRDs, which are monogenic disorders but genetically diverse with regard to causality.
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Affiliation(s)
- Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Qin Liu
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
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Griffith JF, DeBenedictis MJ, Traboulsi EI. A novel dominant CRX mutation causes adult-onset macular dystrophy. Ophthalmic Genet 2017; 39:120-124. [DOI: 10.1080/13816810.2017.1373831] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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35
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Weihbrecht K, Goar WA, Pak T, Garrison JE, DeLuca AP, Stone EM, Scheetz TE, Sheffield VC. Keeping an Eye on Bardet-Biedl Syndrome: A Comprehensive Review of the Role of Bardet-Biedl Syndrome Genes in the Eye. MEDICAL RESEARCH ARCHIVES 2017; 5. [PMID: 29457131 DOI: 10.18103/mra.v5i9.1526] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Upwards of 90% of individuals with Bardet-Biedl syndrome (BBS) display rod-cone dystrophy with early macular involvement. BBS is an autosomal recessive, genetically heterogeneous, pleiotropic ciliopathy for which 21 causative genes have been discovered to date. In addition to retinal degeneration, the cardinal features of BBS include obesity, cognitive impairment, renal anomalies, polydactyly, and hypogonadism. Here, we review the genes, proteins, and protein complexes involved in BBS and the BBS model organisms available for the study of retinal degeneration. We include comprehensive lists for all known BBS genes, their known phenotypes, and the model organisms available. We also review the molecular mechanisms believed to lead to retinal degeneration. We provide an overview of the mode of inheritance and describe the relationships between BBS genes and Joubert syndrome, Leber Congenital Amaurosis, Senior-Løken syndrome, and non-syndromic retinitis pigmentosa. Finally, we propose ways that new advances in technology will allow us to better understand the role of different BBS genes in retinal formation and function.
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Affiliation(s)
- Katie Weihbrecht
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Wesley A Goar
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Thomas Pak
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Janelle E Garrison
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Adam P DeLuca
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Edwin M Stone
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Todd E Scheetz
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Val C Sheffield
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
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36
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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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Álvarez-Satta M, Castro-Sánchez S, Valverde D. Bardet-Biedl Syndrome as a Chaperonopathy: Dissecting the Major Role of Chaperonin-Like BBS Proteins (BBS6-BBS10-BBS12). Front Mol Biosci 2017; 4:55. [PMID: 28824921 PMCID: PMC5534436 DOI: 10.3389/fmolb.2017.00055] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 07/13/2017] [Indexed: 01/01/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a rare genetic disorder that belongs to the group of ciliopathies, defined as diseases caused by defects in cilia structure and/or function. The six diagnostic features considered for this syndrome include retinal dystrophy, obesity, polydactyly, cognitive impairment and renal and urogenital anomalies. Furthermore, three of the 21 genes currently known to be involved in BBS encode chaperonin-like proteins (MKKS/BBS6, BBS10, and BBS12), so BBS can be also considered a member of the growing group of chaperonopathies. Remarkably, up to 50% of clinically-diagnosed BBS families can harbor disease-causing variants in these three genes, which highlights the importance of chaperone defects as pathogenic factors even for genetically heterogeneous syndromes such as BBS. In addition, it is interesting to note that BBS families with deleterious variants in MKKS/BBS6, BBS10 or BBS12 genes generally display more severe phenotypes than families with changes in other BBS genes. The chaperonin-like BBS proteins have structural homology to the CCT family of group II chaperonins, although they are believed to conserve neither the ATP-dependent folding activity of canonical CCT chaperonins nor the ability to form CCT-like oligomeric complexes. Thus, they play an important role in the initial steps of assembly of the BBSome, which is a multiprotein complex essential for mediating the ciliary trafficking activity. In this review, we present a comprehensive review of those genetic, functional and evolutionary aspects concerning chaperonin-like BBS proteins, trying to provide a new perspective that expands the classical conception of BBS only from a ciliary point of view.
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Affiliation(s)
- María Álvarez-Satta
- Grupo de Biomarcadores Moleculares, Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de VigoVigo, Spain.,Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGOVigo, Spain.,Centro de Investigaciones Biomédicas (Centro Singular de Investigación de Galicia 2016-2019), Universidad de VigoVigo, Spain
| | - Sheila Castro-Sánchez
- Grupo de Biomarcadores Moleculares, Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de VigoVigo, Spain.,Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGOVigo, Spain.,Centro de Investigaciones Biomédicas (Centro Singular de Investigación de Galicia 2016-2019), Universidad de VigoVigo, Spain
| | - Diana Valverde
- Grupo de Biomarcadores Moleculares, Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de VigoVigo, Spain.,Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGOVigo, Spain.,Centro de Investigaciones Biomédicas (Centro Singular de Investigación de Galicia 2016-2019), Universidad de VigoVigo, Spain
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Ullah A, Umair M, Yousaf M, Khan SA, Nazim-ud-din M, Shah K, Ahmad F, Azeem Z, Ali G, Alhaddad B, Rafique A, Jan A, Haack TB, Strom TM, Meitinger T, Ghous T, Ahmad W. Sequence variants in four genes underlying Bardet-Biedl syndrome in consanguineous families. Mol Vis 2017; 23:482-494. [PMID: 28761321 PMCID: PMC5524433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 07/19/2017] [Indexed: 12/03/2022] Open
Abstract
PURPOSE To investigate the molecular basis of Bardet-Biedl syndrome (BBS) in five consanguineous families of Pakistani origin. METHODS Linkage in two families (A and B) was established to BBS7 on chromosome 4q27, in family C to BBS8 on chromosome 14q32.1, and in family D to BBS10 on chromosome 12q21.2. Family E was investigated directly with exome sequence analysis. RESULTS Sanger sequencing revealed two novel mutations and three previously reported mutations in the BBS genes. These mutations include two deletions (c.580_582delGCA, c.1592_1597delTTCCAG) in the BBS7 gene, a missense mutation (p.Gln449His) in the BBS8 gene, a frameshift mutation (c.271_272insT) in the BBS10 gene, and a nonsense mutation (p.Ser40*) in the MKKS (BBS6) gene. CONCLUSIONS Two novel mutations and three previously reported variants, identified in the present study, further extend the body of evidence implicating BBS6, BBS7, BBS8, and BBS10 in causing BBS.
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Affiliation(s)
- Asmat Ullah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Muhammad Umair
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan,Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany,Institute of Human Genetics, Helmholtz Zentrum Munchen, Neuherberg, Germany
| | - Maryam Yousaf
- Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
| | - Sher Alam Khan
- Kohat University of Science and Technology (KUST), Khyber Pakhtunkhwa Province, Pakistan
| | - Muhammad Nazim-ud-din
- Department of Biotechnology, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
| | - Khadim Shah
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Farooq Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Zahid Azeem
- Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
| | - Ghazanfar Ali
- Department of Biotechnology, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
| | - Bader Alhaddad
- Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany,Institute of Human Genetics, Helmholtz Zentrum Munchen, Neuherberg, Germany
| | - Afzal Rafique
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
| | - Abid Jan
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan,Kohat University of Science and Technology (KUST), Khyber Pakhtunkhwa Province, Pakistan
| | - Tobias B. Haack
- Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany,Institute of Human Genetics, Helmholtz Zentrum Munchen, Neuherberg, Germany
| | - Tim M. Strom
- Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany,Institute of Human Genetics, Helmholtz Zentrum Munchen, Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Technische Universitat Munchen, Munchen, Germany,Institute of Human Genetics, Helmholtz Zentrum Munchen, Neuherberg, Germany
| | - Tahseen Ghous
- Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
| | - Wasim Ahmad
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan
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Qi Z, Shen Y, Fu Q, Li W, Yang W, Xu W, Chu P, Zhang Y, Wang H. Whole-exome sequencing identified compound heterozygous variants in MMKS in a Chinese pedigree with Bardet-Biedl syndrome. SCIENCE CHINA-LIFE SCIENCES 2017. [PMID: 28624958 DOI: 10.1007/s11427-017-9085-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a genetically heterogeneous disorder characterized by retinal dystrophy, polydactyly, obesity, developmental delay, and renal defects. At least 21 candidate BBS-associated genes (BBS1-19, NPHP1, and IFT172) have previously been identified, and all of them play important roles in ciliary function. Here, we collected a BBS pedigree with four members and performed whole-exome sequencing on the proband. The variants were analyzed and evaluated to confirm their pathogenicity. We found compound heterozygous variants (c.1192C>T, p.Q398* and c.1175C>T, p.T392M) in MKKS in both the siblings, and these were likely to be pathogenic variants. We also found a missense variant (c.2029G>C, p.E677Q) in NPHP1 and a missense variant (c.2470C>T, p.R824C) in BBS9 in the proband only, which are variants of uncertain significance. The compound heterozygous variants were probably responsible for the BBS phenotype in this Chinese pedigree and the missense mutations in NPHP1 and BBS9 might contribute to the mutation load.
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Affiliation(s)
- Zhan Qi
- Beijing Key Laboratory for Genetics of Birth Defects, Key Laboratory of Major Diseases in Children of Ministry of Education, Center for Medical Genetics, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Ying Shen
- Beijing Key Laboratory for Chronic Renal Disease and Blood Purification, Key Laboratory of Major Diseases in Children of Ministry of Education; Nephrology Department, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Qian Fu
- Beijing Key Laboratory for Chronic Renal Disease and Blood Purification, Key Laboratory of Major Diseases in Children of Ministry of Education; Nephrology Department, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Wei Li
- Beijing Key Laboratory for Genetics of Birth Defects, Key Laboratory of Major Diseases in Children of Ministry of Education, Center for Medical Genetics, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Wei Yang
- Beijing Key Laboratory for Genetics of Birth Defects, Key Laboratory of Major Diseases in Children of Ministry of Education, Center for Medical Genetics, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Wenshan Xu
- Beijing Key Laboratory for Genetics of Birth Defects, Key Laboratory of Major Diseases in Children of Ministry of Education, Center for Medical Genetics, Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Ping Chu
- Beijing Key Laboratory for Pediatric Disease of Otolaryngology, Head and Neck Surgery, Key Laboratory of Major Diseases in Children of Ministry of Education; Beijing Pediatric Research Institute; Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China
| | - Yaxin Zhang
- School of Pediatrics, Capital Medical University, Beijing, 100069, China
| | - Hui Wang
- Beijing Key Laboratory for Chronic Renal Disease and Blood Purification, Key Laboratory of Major Diseases in Children of Ministry of Education; Nephrology Department, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, 100045, China.
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40
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Kaur Y, de Souza RJ, Gibson WT, Meyre D. A systematic review of genetic syndromes with obesity. Obes Rev 2017; 18:603-634. [PMID: 28346723 DOI: 10.1111/obr.12531] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/01/2017] [Accepted: 02/02/2017] [Indexed: 11/29/2022]
Abstract
Syndromic monogenic obesity typically follows Mendelian patterns of inheritance and involves the co-presentation of other characteristics, such as mental retardation, dysmorphic features and organ-specific abnormalities. Previous reviews on obesity have reported 20 to 30 syndromes but no systematic review has yet been conducted on syndromic obesity. We searched seven databases using terms such as 'obesity', 'syndrome' and 'gene' to conduct a systematic review of literature on syndromic obesity. Our literature search identified 13,719 references. After abstract and full-text review, 119 relevant papers were eligible, and 42 papers were identified through additional searches. Our analysis of these 161 papers found that 79 obesity syndromes have been reported in literature. Of the 79 syndromes, 19 have been fully genetically elucidated, 11 have been partially elucidated, 27 have been mapped to a chromosomal region and for the remaining 22, neither the gene(s) nor the chromosomal location(s) have yet been identified. Interestingly, 54.4% of the syndromes have not been assigned a name, whereas 13.9% have more than one name. We report on organizational inconsistencies (e.g. naming discrepancies and syndrome classification) and provide suggestions for improvements. Overall, this review illustrates the need for increased clinical and genetic research on syndromes with obesity.
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Affiliation(s)
- Y Kaur
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - R J de Souza
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - W T Gibson
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada.,British Columbia Children's Hospital Research Institute, Vancouver, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
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Jones AV, Tilley M, Gutteridge A, Hyde C, Nagle M, Ziemek D, Gorman D, Fauman EB, Chen X, Miller MR, Tian C, Hu Y, Hinds DA, Cox P, Scollen S. GWAS of self-reported mosquito bite size, itch intensity and attractiveness to mosquitoes implicates immune-related predisposition loci. Hum Mol Genet 2017; 26:1391-1406. [PMID: 28199695 PMCID: PMC5390679 DOI: 10.1093/hmg/ddx036] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 01/23/2017] [Indexed: 12/31/2022] Open
Abstract
Understanding the interaction between humans and mosquitoes is a critical area of study due to the phenomenal burdens on public health from mosquito-transmitted diseases. In this study, we conducted the first genome-wide association studies (GWAS) of self-reported mosquito bite reaction size (n = 84,724), itchiness caused by bites (n = 69,057), and perceived attractiveness to mosquitoes (n = 16,576). In total, 15 independent significant (P < 5×10−8) associations were identified. These loci were enriched for immunity-related genes that are involved in multiple cytokine signalling pathways. We also detected suggestive enrichment of these loci in enhancer regions that are active in stimulated T-cells, as well as within loci previously identified as controlling central memory T-cell levels. Egger regression analysis between the traits suggests that perception of itchiness and attractiveness to mosquitoes is driven, at least in part, by the genetic determinants of bite reaction size. Our findings illustrate the complex genetic and immunological landscapes underpinning human interactions with mosquitoes.
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Affiliation(s)
- Amy V. Jones
- Pfizer WRD, Human Genetics and Computational Biomedicine, The Portway Building, Granta Park, Cambridge CB21 6GS, UK
| | - Mera Tilley
- Pfizer WRD, Pharmatherapeutics Clinical R&D, Precision Medicine, 300 Technology Square Fl #3, Cambridge, MA 02139, USA
| | - Alex Gutteridge
- Pfizer WRD, Computational Sciences CoE, The Portway Building, Granta Park, Cambridge CB21 6GS, UK
| | - Craig Hyde
- Pfizer WRD, Research Statistics, 558 Eastern Point Rd, Groton, CT 06340, USA
| | - Michael Nagle
- Pfizer WRD, Human Genetics and Computational Biomedicine, 610 Main Street S, Cambridge, MA 02139, USA
| | - Daniel Ziemek
- Pfizer WRD, Computational Sciences CoE, Linkstraße 10, 10785 Berlin, Germany
| | - Donal Gorman
- Pfizer WRD, Research Statistics, The Portway Building, Granta Park, Cambridge CB21 6GS, UK
| | - Eric B. Fauman
- Pfizer WRD, Computational Sciences CoE, 610 Main Street S, Cambridge, MA 02139, USA
| | - Xing Chen
- Pfizer WRD, Research Statistics, 558 Eastern Point Rd, Groton, CT 06340, USA
| | - Melissa R. Miller
- Pfizer WRD, Human Genetics and Computational Biomedicine, 610 Main Street S, Cambridge, MA 02139, USA
| | - Chao Tian
- 23andMe, Inc, 899 W Evelyn Avenue, Mountain View, California, CA 94043, USA
| | - Youna Hu
- 23andMe, Inc, 899 W Evelyn Avenue, Mountain View, California, CA 94043, USA
| | - David A. Hinds
- 23andMe, Inc, 899 W Evelyn Avenue, Mountain View, California, CA 94043, USA
| | - Peter Cox
- Pfizer Ltd, Neuroscience and Pain Research Unit, The Portway Building, Granta Park, Cambridge CB21 6GS, UK
| | - Serena Scollen
- Pfizer WRD, Human Genetics and Computational Biomedicine, The Portway Building, Granta Park, Cambridge CB21 6GS, UK
- To whom correspondence should be addressed at: ELIXIR Hub, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SD, UK. Tel: +44 1223494322; Fax: +44 (0)1223 484696;
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Recent progress in genetics, epigenetics and metagenomics unveils the pathophysiology of human obesity. Clin Sci (Lond) 2017; 130:943-86. [PMID: 27154742 DOI: 10.1042/cs20160136] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/24/2016] [Indexed: 12/19/2022]
Abstract
In high-, middle- and low-income countries, the rising prevalence of obesity is the underlying cause of numerous health complications and increased mortality. Being a complex and heritable disorder, obesity results from the interplay between genetic susceptibility, epigenetics, metagenomics and the environment. Attempts at understanding the genetic basis of obesity have identified numerous genes associated with syndromic monogenic, non-syndromic monogenic, oligogenic and polygenic obesity. The genetics of leanness are also considered relevant as it mirrors some of obesity's aetiologies. In this report, we summarize ten genetically elucidated obesity syndromes, some of which are involved in ciliary functioning. We comprehensively review 11 monogenic obesity genes identified to date and their role in energy maintenance as part of the leptin-melanocortin pathway. With the emergence of genome-wide association studies over the last decade, 227 genetic variants involved in different biological pathways (central nervous system, food sensing and digestion, adipocyte differentiation, insulin signalling, lipid metabolism, muscle and liver biology, gut microbiota) have been associated with polygenic obesity. Advances in obligatory and facilitated epigenetic variation, and gene-environment interaction studies have partly accounted for the missing heritability of obesity and provided additional insight into its aetiology. The role of gut microbiota in obesity pathophysiology, as well as the 12 genes associated with lipodystrophies is discussed. Furthermore, in an attempt to improve future studies and merge the gap between research and clinical practice, we provide suggestions on how high-throughput '-omic' data can be integrated in order to get closer to the new age of personalized medicine.
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Nahum N, Forti E, Aksanov O, Birk R. Insulin regulates Bbs4 during adipogenesis. IUBMB Life 2017; 69:489-499. [PMID: 28371235 DOI: 10.1002/iub.1626] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Accepted: 03/12/2017] [Indexed: 01/08/2023]
Abstract
Bardet-Biedl syndrome (BBS) is a pleiotropic autosomal recessive disorder associated with marked obesity, increased susceptibility to insulin resistance and type 2 diabetes. However, it is unknown whether the link between BBS and diabetes is indirect or direct. Adipogenesis and adipocyte function are regulated by hormonal stimuli, with insulin and insulin growth factor (IGF) playing an important role both in normal and impaired conditions. We have previously shown augmented transcript levels of BBS genes upon induction of adipogenesis. The aim of this study was to investigate the role of insulin in BBS. Through in vitro studies in adipocytes in which Bbs4 expression was either silenced (SiBbs4) or overexpressed (OEBbs4), we showed that insulin and IGF dose- and time-dependently decrease transcription and protein expression of BBS genes during adipogenesis. Silencing of Bbs4 expression in adipocytes significantly impaired and reduced glucose uptake. This effect was reversed by Bbs4 overexpression. Inhibition of PI 3-kinase resulted in upregulation of Bbs transcripts, suggesting that the PI3K pathway is involved in the regulation of these genes. In conclusion, we showed that insulin is a direct regulator of Bbs1, 2, 4 and 6. This hormonal regulation might indicate a metabolic link of these genes to obesity and metabolic syndrome. © 2017 IUBMB Life, 69(7):489-499, 2017.
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Affiliation(s)
- Netta Nahum
- Department of Biotechnology and Epidemiology, Ben-Gurion University, Beer-Sheva, Israel.,Department of Nutrition, School of Health Science, Ariel University, Ariel, Israel
| | - Efrat Forti
- Department of Biotechnology and Epidemiology, Ben-Gurion University, Beer-Sheva, Israel
| | - Olga Aksanov
- Department of Biotechnology and Epidemiology, Ben-Gurion University, Beer-Sheva, Israel
| | - Ruth Birk
- Department of Nutrition, School of Health Science, Ariel University, Ariel, Israel
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Abstract
Nephronophthisis-related ciliopathies (NPHP-RC) are a group of inherited diseases that affect genes encoding proteins that localize to primary cilia or centrosomes. With few exceptions, ciliopathies are inherited in an autosomal recessive manner, and affected individuals manifest early during childhood or adolescence. NPHP-RC are genetically very heterogeneous, and, currently, mutations in more than 90 genes have been described as single-gene causes. The phenotypes of NPHP-RC are very diverse, and include cystic-fibrotic kidney disease, brain developmental defects, retinal degeneration, skeletal deformities, facial dimorphism, and, in some cases, laterality defects, and congenital heart disease. Mutations in the same gene can give rise to diverse phenotypes depending on the mutated allele. At the same time, there is broad phenotypic overlap between different monogenic genes. The identification of monogenic causes of ciliopathies has furthered the understanding of molecular mechanism and cellular pathways involved in the pathogenesis.
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Lindstrand A, Frangakis S, Carvalho C, Richardson E, McFadden K, Willer J, Pehlivan D, Liu P, Pediaditakis I, Sabo A, Lewis R, Banin E, Lupski J, Davis E, Katsanis N. Copy-Number Variation Contributes to the Mutational Load of Bardet-Biedl Syndrome. Am J Hum Genet 2016; 99:318-36. [PMID: 27486776 DOI: 10.1016/j.ajhg.2015.04.023] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/13/2016] [Indexed: 12/15/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a defining ciliopathy, notable for extensive allelic and genetic heterogeneity, almost all of which has been identified through sequencing. Recent data have suggested that copy-number variants (CNVs) also contribute to BBS. We used a custom oligonucleotide array comparative genomic hybridization (aCGH) covering 20 genes that encode intraflagellar transport (IFT) components and 74 ciliopathy loci to screen 92 unrelated individuals with BBS, irrespective of their known mutational burden. We identified 17 individuals with exon-disruptive CNVs (18.5%), including 13 different deletions in eight BBS genes (BBS1, BBS2, ARL6/BBS3, BBS4, BBS5, BBS7, BBS9, and NPHP1) and a deletion and a duplication in other ciliopathy-associated genes (ALMS1 and NPHP4, respectively). By contrast, we found a single heterozygous exon-disruptive event in a BBS-associated gene (BBS9) in 229 control subjects. Superimposing these data with resequencing revealed CNVs to (1) be sufficient to cause disease, (2) Mendelize heterozygous deleterious alleles, and (3) contribute oligogenic alleles by combining point mutations and exonic CNVs in multiple genes. Finally, we report a deletion and a splice site mutation in IFT74, inherited under a recessive paradigm, defining a candidate BBS locus. Our data suggest that CNVs contribute pathogenic alleles to a substantial fraction of BBS-affected individuals and highlight how either deletions or point mutations in discrete splice isoforms can induce hypomorphic mutations in genes otherwise intolerant to deleterious variation. Our data also suggest that CNV analyses and resequencing studies unbiased for previous mutational burden is necessary to delineate the complexity of disease architecture.
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Srilekha S, Rao B, Rao DM, Sudha D, Chandrasekar SP, Pandian AJ, Soumittra N, Sripriya S. Strategies for Gene Mapping in Inherited Ophthalmic Diseases. Asia Pac J Ophthalmol (Phila) 2016; 5:282-92. [PMID: 27488070 DOI: 10.1097/apo.0000000000000228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Gene mapping of inherited ophthalmic diseases such as congenital cataracts, retinal degeneration, glaucoma, age-related macular degeneration, myopia, optic atrophy, and eye malformations has shed more light on the disease pathology, identified targets for research on therapeutics, earlier detection, and treatment options for disease management and patient care. This article details the different approaches to gene identification for both Mendelian and complex eye disorders.
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Affiliation(s)
- Sundar Srilekha
- From the SNONGC Department of Genetics and Molecular Biology, Kamal Nayan Bajaj Institute for Research in Vision and Ophthalmology (KNBIRVO), Chennai, Tamil Nadu, India
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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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Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive genetic disorder. It is characterized by heterogeneous clinical manifestations including primary features of the disease (rod-cone dystrophy, polydactyly, obesity, genital abnormalities, renal defects, and learning difficulties) and secondary BBS characteristics (developmental delay, speech deficit, brachydactyly or syndactyly, dental defects, ataxia or poor coordination, olfactory deficit, diabetes mellitus, congenital heart disease, etc.); most of these symptoms may not be present at birth but appear and progressively worsen during the first and second decades of life. At least 20 BBS genes have already been identified, and all of them are involved in primary cilia functioning. Genetic diagnosis of BBS is complicated due to lack of gene-specific disease symptoms; however, it is gradually becoming more accessible with the invention of multigene sequencing technologies. Clinical management of BBS is largely limited to a symptomatic treatment. Mouse experiments demonstrate that the most debilitating complication of BBS, blindness, can be rescued by topical gene therapy. There is a published case report describing the delay of BBS symptoms by nutritional compensation of the disease-related biochemical deficiencies. Progress in DNA testing technologies is likely to rapidly resolve all limitations in BBS diagnosis; however, much slower improvement is expected with regard to BBS treatment.
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Affiliation(s)
- Evgeny N Suspitsin
- N.N. Petrov Institute of Oncology, St. Petersburg, Russia; St. Petersburg Pediatric Medical University, St. Petersburg, Russia
| | - Evgeny N Imyanitov
- N.N. Petrov Institute of Oncology, St. Petersburg, Russia; St. Petersburg Pediatric Medical University, St. Petersburg, Russia; I.I. Mechnikov North-Western Medical University, St. Petersburg, Russia; St. Petersburg State University, St. Petersburg, Russia
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Heon E, Kim G, Qin S, Garrison JE, Tavares E, Vincent A, Nuangchamnong N, Scott CA, Slusarski DC, Sheffield VC. Mutations in C8ORF37 cause Bardet Biedl syndrome (BBS21). Hum Mol Genet 2016; 25:2283-2294. [PMID: 27008867 DOI: 10.1093/hmg/ddw096] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/17/2016] [Indexed: 01/18/2023] Open
Abstract
Bardet Biedl syndrome (BBS) is a multisystem genetically heterogeneous ciliopathy that most commonly leads to obesity, photoreceptor degeneration, digit anomalies, genito-urinary abnormalities, as well as cognitive impairment with autism, among other features. Sequencing of a DNA sample from a 17-year-old female affected with BBS did not identify any mutation in the known BBS genes. Whole-genome sequencing identified a novel loss-of-function disease-causing homozygous mutation (K102*) in C8ORF37, a gene coding for a cilia protein. The proband was overweight (body mass index 29.1) with a slowly progressive rod-cone dystrophy, a mild learning difficulty, high myopia, three limb post-axial polydactyly, horseshoe kidney, abnormally positioned uterus and elevated liver enzymes. Mutations in C8ORF37 were previously associated with severe autosomal recessive retinal dystrophies (retinitis pigmentosa RP64 and cone-rod dystrophy CORD16) but not BBS. To elucidate the functional role of C8ORF37 in a vertebrate system, we performed gene knockdown in Danio rerio and assessed the cardinal features of BBS and visual function. Knockdown of c8orf37 resulted in impaired visual behavior and BBS-related phenotypes, specifically, defects in the formation of Kupffer's vesicle and delays in retrograde transport. Specificity of these phenotypes to BBS knockdown was shown with rescue experiments. Over-expression of human missense mutations in zebrafish also resulted in impaired visual behavior and BBS-related phenotypes. This is the first functional validation and association of C8ORF37 mutations with the BBS phenotype, which identifies BBS21. The zebrafish studies hereby show that C8ORF37 variants underlie clinically diagnosed BBS-related phenotypes as well as isolated retinal degeneration.
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Affiliation(s)
- Elise Heon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, M5G 1X8 Canada Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, M5G 1X8 Canada Program of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, M5G 1X8 Canada
| | - Gunhee Kim
- Department of Pediatrics, Division of Medical Genetics, Wynn Institute for Vision Research, Carver College of Medicine
| | - Sophie Qin
- Program of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, M5G 1X8 Canada
| | - Janelle E Garrison
- Department of Pediatrics, Division of Medical Genetics, Wynn Institute for Vision Research, Carver College of Medicine
| | - Erika Tavares
- Program of Genetics and Genomic Biology, The Hospital for Sick Children, Toronto, M5G 1X8 Canada
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, Toronto, M5G 1X8 Canada Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, M5G 1X8 Canada
| | | | - C Anthony Scott
- Department of Biology, University of Iowa, Iowa City, IA 52242, USA
| | | | - Val C Sheffield
- Department of Pediatrics, Division of Medical Genetics, Wynn Institute for Vision Research, Carver College of Medicine
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Song Z, Zhang X, Jia S, Yelick PC, Zhao C. Zebrafish as a Model for Human Ciliopathies. J Genet Genomics 2016; 43:107-20. [DOI: 10.1016/j.jgg.2016.02.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/22/2022]
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