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Pokharel P, Pandey U, Sedai S, Khanal K, Shrestha M. Chronic kidney disease on the background of bardet-biedl syndrome: a case report and review of literature. Ann Med Surg (Lond) 2024; 86:1131-1134. [PMID: 38333249 PMCID: PMC10849371 DOI: 10.1097/ms9.0000000000001626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/06/2023] [Indexed: 02/10/2024] Open
Abstract
Introduction Bardet-Biedl syndrome (BBS) is a rare autosomal recessive multisystem disorder characterized by retinal dystrophy, obesity, postaxial polydactyly, renal dysfunction, learning difficulties, and hypogonadism. In this case report, the authors present the clinical course and management of a patient with BBS who developed chronic kidney disease (CKD). Case presentation An 18-year-old male presented to the emergency department with chief complaints of fever, cough, vomiting, and decreased urine output for 7 days. Parents complained that the child had a delay in development compared to other children of the same age group. On examination, the patient had tachypnea, periorbital and pedal edema, expiratory wheeze with bilateral basal crackles, polydactyly, central obesity, microtestes, and delayed developmental milestones. Ultrasonography revealed bilateral small kidneys with increased cortical echotexture and loss of corticomedullary differentiation. Based on clinical features, the patient was diagnosed with CKD in the background of BBS. Hemodialysis was initiated after the diagnosis. Discussion The management of CKD in the background of BBS poses unique challenges due to the complex multisystem involvement of this genetic disorder. There should be early reorganization and management of this condition so that the patient can have a better quality of life. Moreover, in developing countries like Nepal, genetic testing and diagnosis should be made easily accessible for better patient outcome. Conclusion Multidisciplinary approach involving nephrologists, ophthalmologists, endocrinologists, and geneticists is important to optimize the treatment and long-term management of Badet Biedel patients.
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Affiliation(s)
| | - Uday Pandey
- Maharajgunj Medical Campus, Institute of Medicine, Tribhuvan University
| | - Samir Sedai
- Maharajgunj Medical Campus, Institute of Medicine, Tribhuvan University
| | - Kapil Khanal
- Maharajgunj Medical Campus, Institute of Medicine, Tribhuvan University
| | - Midhan Shrestha
- Department of Nephrology and Kidney Transplant Medicine, Tribhuvan University Teaching Hospital, Kathmandu Nepal
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Kalot R, Sentell Z, Kitzler TM, Torban E. Primary cilia and actin regulatory pathways in renal ciliopathies. FRONTIERS IN NEPHROLOGY 2024; 3:1331847. [PMID: 38292052 PMCID: PMC10824913 DOI: 10.3389/fneph.2023.1331847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024]
Abstract
Ciliopathies are a group of rare genetic disorders caused by defects to the structure or function of the primary cilium. They often affect multiple organs, leading to brain malformations, congenital heart defects, and anomalies of the retina or skeletal system. Kidney abnormalities are among the most frequent ciliopathic phenotypes manifesting as smaller, dysplastic, and cystic kidneys that are often accompanied by renal fibrosis. Many renal ciliopathies cause chronic kidney disease and often progress to end-stage renal disease, necessitating replacing therapies. There are more than 35 known ciliopathies; each is a rare hereditary condition, yet collectively they account for a significant proportion of chronic kidney disease worldwide. The primary cilium is a tiny microtubule-based organelle at the apex of almost all vertebrate cells. It serves as a "cellular antenna" surveying environment outside the cell and transducing this information inside the cell to trigger multiple signaling responses crucial for tissue morphogenesis and homeostasis. Hundreds of proteins and unique cellular mechanisms are involved in cilia formation. Recent evidence suggests that actin remodeling and regulation at the base of the primary cilium strongly impacts ciliogenesis. In this review, we provide an overview of the structure and function of the primary cilium, focusing on the role of actin cytoskeleton and its regulators in ciliogenesis. We then describe the key clinical, genetic, and molecular aspects of renal ciliopathies. We highlight what is known about actin regulation in the pathogenesis of these diseases with the aim to consider these recent molecular findings as potential therapeutic targets for renal ciliopathies.
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Affiliation(s)
- Rita Kalot
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Zachary Sentell
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Thomas M. Kitzler
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- McGill University Health Center, Montreal, QC, Canada
| | - Elena Torban
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
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3
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Freke GM, Martins T, Davies RJ, Beyer T, Seda M, Peskett E, Haq N, Prasai A, Otto G, Jeyabalan Srikaran J, Hernandez V, Diwan GD, Russell RB, Ueffing M, Huranova M, Boldt K, Beales PL, Jenkins D. De-Suppression of Mesenchymal Cell Identities and Variable Phenotypic Outcomes Associated with Knockout of Bbs1. Cells 2023; 12:2662. [PMID: 37998397 PMCID: PMC10670506 DOI: 10.3390/cells12222662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/31/2023] [Accepted: 11/01/2023] [Indexed: 11/25/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is an archetypal ciliopathy caused by dysfunction of primary cilia. BBS affects multiple tissues, including the kidney, eye and hypothalamic satiety response. Understanding pan-tissue mechanisms of pathogenesis versus those which are tissue-specific, as well as gauging their associated inter-individual variation owing to genetic background and stochastic processes, is of paramount importance in syndromology. The BBSome is a membrane-trafficking and intraflagellar transport (IFT) adaptor protein complex formed by eight BBS proteins, including BBS1, which is the most commonly mutated gene in BBS. To investigate disease pathogenesis, we generated a series of clonal renal collecting duct IMCD3 cell lines carrying defined biallelic nonsense or frameshift mutations in Bbs1, as well as a panel of matching wild-type CRISPR control clones. Using a phenotypic screen and an unbiased multi-omics approach, we note significant clonal variability for all assays, emphasising the importance of analysing panels of genetically defined clones. Our results suggest that BBS1 is required for the suppression of mesenchymal cell identities as the IMCD3 cell passage number increases. This was associated with a failure to express epithelial cell markers and tight junction formation, which was variable amongst clones. Transcriptomic analysis of hypothalamic preparations from BBS mutant mice, as well as BBS patient fibroblasts, suggested that dysregulation of epithelial-to-mesenchymal transition (EMT) genes is a general predisposing feature of BBS across tissues. Collectively, this work suggests that the dynamic stability of the BBSome is essential for the suppression of mesenchymal cell identities as epithelial cells differentiate.
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Affiliation(s)
- Grace Mercedes Freke
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Tiago Martins
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Rosalind Jane Davies
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Tina Beyer
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076 Tübingen, Germany; (T.B.); (M.U.); (K.B.)
| | - Marian Seda
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Emma Peskett
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Naila Haq
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Avishek Prasai
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, 14220 Prague, Czech Republic (M.H.)
| | - Georg Otto
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Jeshmi Jeyabalan Srikaran
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Victor Hernandez
- Life Sciences Department, CHMLS, Brunel University London, Kingston Lane, Uxbridge UB8 3PH, UK;
| | - Gaurav D. Diwan
- BioQuant, University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany; (G.D.D.); (R.B.R.)
- Biochemistry Center (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Robert B. Russell
- BioQuant, University of Heidelberg, Im Neuenheimer Feld 267, 69120 Heidelberg, Germany; (G.D.D.); (R.B.R.)
- Biochemistry Center (BZH), University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076 Tübingen, Germany; (T.B.); (M.U.); (K.B.)
| | - Martina Huranova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, 14220 Prague, Czech Republic (M.H.)
| | - Karsten Boldt
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Strasse 7, 72076 Tübingen, Germany; (T.B.); (M.U.); (K.B.)
| | - Philip L. Beales
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
| | - Dagan Jenkins
- Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK; (G.M.F.); (T.M.); (M.S.); (E.P.); (N.H.); (G.O.); (J.J.S.); (P.L.B.)
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Rasel M, Istiak A, Saiara A, Al‐Jubair A, Matin S, Roy GC. Bardet-Biedl syndrome: Delayed diagnosis in a 14-year-old child with end-stage renal disease. Clin Case Rep 2023; 11:e7649. [PMID: 37415582 PMCID: PMC10319965 DOI: 10.1002/ccr3.7649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/02/2023] [Accepted: 06/19/2023] [Indexed: 07/08/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathic disorder. Because of its low prevalence and wide spectrum of clinical features, many patients remain undiagnosed. We report a case of a 14-year-old boy with a typical phenotype of BBS who remains undiagnosed until the development of end-stage renal disease.
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Affiliation(s)
- Mohammad Rasel
- Shaheed Suhrawardy Medical College HospitalDhakaBangladesh
- Bangladesh College of Physicians and SurgeonsDhakaBangladesh
| | - Ashif Istiak
- Shaheed Suhrawardy Medical College HospitalDhakaBangladesh
- Bangladesh College of Physicians and SurgeonsDhakaBangladesh
| | - Afra Saiara
- Shaheed Suhrawardy Medical College HospitalDhakaBangladesh
- Bangladesh College of Physicians and SurgeonsDhakaBangladesh
| | | | - Shariful Matin
- Shaheed Suhrawardy Medical College HospitalDhakaBangladesh
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Adipose tissue function and insulin sensitivity in syndromic obesity of Bardet-Biedl syndrome. Int J Obes (Lond) 2023; 47:382-390. [PMID: 36807608 DOI: 10.1038/s41366-023-01280-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/22/2023]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare autosomal recessive syndromic obesity of childhood onset among many other features. To date, the excess risk of metabolic complications of severe early-onset obesity in BBS remains controversial. In-depth investigation of adipose tissue structure and function with detailed metabolic phenotype has not been investigated yet. OBJECTIVE To investigate adipose tissue function in BBS. DESIGN A prospective cross-sectional study. MAIN OUTCOME MEASURE To determine if there are differences in insulin resistance, metabolic profile, adipose tissue function and gene expression in patients with BBS compared to BMI-matched polygenic obese controls. METHOD 9 adults with BBS and 10 controls were recruited from the national centre for BBS, Birmingham, UK. An in-depth study of adipose tissue structure and function along with insulin sensitivity was performed using hyperinsulinemic-euglycemic clamp studies, adipose tissue microdialysis, histology and RNA sequencing, and measurement of circulating adipokines and inflammatory biomarkers. RESULTS Adipose tissue structure, gene expression and in vivo functional analysis between BBS and polygenic obesity cohorts were similar. Using hyperinsulinemic-euglycemic clamp and surrogate markers of insulin resistance, we found no significant differences in insulin sensitivity between BBS and obese controls. Furthermore, no significant changes were noted in an array of adipokines, cytokines, pro-inflammatory markers and adipose tissue RNA transcriptomic. CONCLUSION Although childhood-onset extreme obesity is a feature of BBS, detailed studies of insulin sensitivity and adipose tissue structure and function are similar to common polygenic obesity. This study adds to the literature by suggesting that it is the quality and quantity of adiposity not the duration that drives the metabolic phenotype.
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Melluso A, Secondulfo F, Capolongo G, Capasso G, Zacchia M. Bardet-Biedl Syndrome: Current Perspectives and Clinical Outlook. Ther Clin Risk Manag 2023; 19:115-132. [PMID: 36741589 PMCID: PMC9896974 DOI: 10.2147/tcrm.s338653] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/20/2023] [Indexed: 02/04/2023] Open
Abstract
The Bardet Biedl syndrome (BBS) is a rare inherited disorder considered a model of non-motile ciliopathy. It is in fact caused by mutations of genes encoding for proteins mainly localized to the base of the cilium. Clinical features of BBS patients are widely shared with patients suffering from other ciliopathies, especially autosomal recessive syndromic disorders; moreover, mutations in cilia-related genes can cause different clinical ciliopathy entities. Besides the best-known clinical features, as retinal degeneration, learning disabilities, polydactyly, obesity and renal defects, several additional clinical signs have been reported in BBS, expanding our understanding of the complexity of its clinical spectrum. The present review aims to describe the current knowledge of BBS i) pathophysiology, ii) clinical manifestations, highlighting both the most common and the less described features, iii) current and future perspective for treatment.
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Affiliation(s)
- Andrea Melluso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Floriana Secondulfo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovanna Capolongo
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Biogem Scarl, Ariano Irpino, AV, 83031, Italy
| | - Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy,Correspondence: Miriam Zacchia, Via Pansini 5, Naples, 80131, Italy, Tel +39 081 566 6650, Fax +39 081 566 6671, Email
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Caba L, Florea L, Braha EE, Lupu VV, Gorduza EV. Monitoring and Management of Bardet-Biedl Syndrome: What the Multi-Disciplinary Team Can Do. J Multidiscip Healthc 2022; 15:2153-2167. [PMID: 36193191 PMCID: PMC9526427 DOI: 10.2147/jmdh.s274739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 09/16/2022] [Indexed: 11/23/2022] Open
Abstract
Bardet – Biedl syndrome is a rare autosomal recessive multisystem non-motile ciliopathy. It has heterogeneous clinical manifestations. It is caused by mutations in 26 genes encoding BBSome proteins, chaperonines, and IFT complex. The main clinical features are: retinal cone-rod dystrophy, central obesity, postaxial polydactyly, cognitive impairment, hypogonadism and genitourinary anomalies, and kidney disease. The onset of clinical manifestations is variable which makes the diagnosis difficult in some patients. Because of the multiple system involvement, a multidisciplinary approach is necessary. The purpose of this review is to provide monitoring and management directions for a better approach to these patients.
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Affiliation(s)
- Lavinia Caba
- Department of Mother and Child Medicine – Medical Genetics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
- Correspondence: Lavinia Caba, Department of Medical Genetics, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 16 University Street, Iasi, 700115, Romania, Email
| | - Laura Florea
- Department of Nephrology - Internal Medicine, Faculty of Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, Iasi, Romania
| | | | - Valeriu Vasile Lupu
- Department of Mother and Child Medicine – Pediatrics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
| | - Eusebiu Vlad Gorduza
- Department of Mother and Child Medicine – Medical Genetics, “Grigore T. Popa” University of Medicine and Pharmacy, Iaşi, Romania
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Chang KJ, Wu HY, Yarmishyn AA, Li CY, Hsiao YJ, Chi YC, Lo TC, Dai HJ, Yang YC, Liu DH, Hwang DK, Chen SJ, Hsu CC, Kao CL. Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology. Int J Mol Sci 2022; 23:ijms23179707. [PMID: 36077104 PMCID: PMC9456058 DOI: 10.3390/ijms23179707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet–Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus–Merzbacher disease), transcriptional deregulation diseases (Mowat–Wilson disease, Pitt–Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.
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Affiliation(s)
- Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yu Wu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Cheng-Yi Li
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chun Chi
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tzu-Chen Lo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - He-Jhen Dai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chiang Yang
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Ding-Hao Liu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
| | - Chung-Lan Kao
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
- Correspondence: (C.-C.H.); (C.-L.K.); Tel.: +886-2-287-573-25 (C.-C.H.); +886-2-287-573-63 (C.-L.K.)
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Woon PY, Chien JY, Wang JH, Chou YY, Lin MC, Huang SP. Prevalence and associated relating factors in patients with hereditary retinal dystrophy: a nationwide population-based study in Taiwan. BMJ Open 2022; 12:e054111. [PMID: 35396285 PMCID: PMC8995947 DOI: 10.1136/bmjopen-2021-054111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE To investigate the prevalence, incidence and relating factors that are associated with hereditary retinal dystrophy (HRD) in Taiwan from 2000 to 2013. DESIGN, SETTING AND PARTICIPANTS This is a nationwide, population-based, retrospective case-control study using National Health Insurance Database. Study groups are patients with HRD as case group; age-matched patients without any diagnosis of HRD as control group. We enrolled 2418 study subjects, of which 403 were HRD patients. Important relating factors such as hypertension, diabetes, coronary artery disease, autoimmune disease, cancer, liver cirrhosis, chronic kidney disease, stroke, hyperlipidaemia, asthma, depression and dementia are also included. EXPOSURE Patients diagnosed with HRD were retrieved from National Health Insurance Database. MAIN OUTCOMES AND MEASURES OR calculated between the relating factors and HRD for objects and stratified by age and sex group between 2000 and 2013. RESULTS Four hundred and three patients were included in the study group and 2015 in the control group. The incidence of HRD was 3.29/100 000, and the prevalence of HRD was 40.5/100 000 persons. The tendency of study group to have more cataract, cystoid macula oedema (CME) as compared with the control group. Among the subgroup with comorbidities, the relating factors such as hypertension, diabetes and chronic kidney disease was significantly higher among HRD patients with age 55 and above. CONCLUSIONS 74% of the diagnosed HRD are retinitis pigmentosa. Population-based data suggested an increased incidence of cataract in younger patients, whereas older HRD patients are more susceptible to develop CME. Further work is needed to elucidate the mechanism between these ophthalmological disorders and HRD.
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Affiliation(s)
- Peng Yeong Woon
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Jia-Ying Chien
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Jen-Hung Wang
- Department of Medical Research, Hualien Tzu Chi Medical Center, Hualien, Taiwan
| | - Yu-Yau Chou
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Mei-Chen Lin
- College of Medicine, China Medical University, Taichung, Taiwan
- Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan
| | - Shun-Ping Huang
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
- Department of Ophthalmology, Taichung Tzu Chi Hospital, Taichung, Taiwan
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Abstract
The BBSome is an octameric protein complex involved in Bardet-Biedl syndrome (BBS), a human pleiotropic, autosomal recessive condition. Patients with BBS display various clinical features including obesity, hypertension, and renal abnormalities. Association studies have also linked the BBS genes to hypertension and other cardiovascular risks in the general population. The BBSome was originally associated with the function of cilia, a highly specialized organelle that extend from the cell membrane of most vertebrate cells. However, subsequent studies have implicated the BBSome in the control of a myriad of other cellular processes not related to cilia including cell membrane localization of receptors and gene expression. The development of animal models of BBS such as mouse lines lacking various components of the BBSome and associated proteins has facilitated studying their role in the control of cardiovascular function and deciphering the pathophysiological mechanisms responsible for the cardiovascular aberrations associated with BBS. These studies revealed the importance of the neuronal, renal, vascular, and cardiac BBSome in the regulation of blood pressure, renal function, vascular reactivity, and cardiac development. The BBSome has also emerged as a critical regulator of key systems involved in cardiovascular control including the renin-angiotensin system. Better understanding of the influence of the BBSome on the molecular and physiological processes relevant to cardiovascular health and disease has the potential of identifying novel mechanisms underlying hypertension and other cardiovascular risks.
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Affiliation(s)
- Yuying Zhao
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Human Toxicology Graduate Program, University of Iowa Graduate College, Iowa City, IA, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Obesity Research and Educational Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Iowa City VA Health Care System, Iowa City, IA, USA,Corresponding author: Kamal Rahmouni, Ph.D., Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA, , Tel: 319 353 5256, Fax: 319 353 5350
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11
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Zacchia M, Blanco FDV, Torella A, Raucci R, Blasio G, Onore ME, Marchese E, Trepiccione F, Vitagliano C, Iorio VD, Alessandra P, Simonelli F, Nigro V, Capasso G, Viggiano D. Urine concentrating defect as presenting sign of progressive renal failure in Bardet-Biedl syndrome patients. Clin Kidney J 2021; 14:1545-1551. [PMID: 34084454 PMCID: PMC8162863 DOI: 10.1093/ckj/sfaa182] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 07/06/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Urine concentrating defect is a common dysfunction in ciliopathies, even though its underlying mechanism and its prognostic meaning are largely unknown. This study assesses renal function in a cohort of 54 Bardet-Biedl syndrome (BBS) individuals and analyses whether renal hyposthenuria is the result of specific tubule dysfunction and predicts renal disease progression. METHODS The estimated glomerular filtration rate (eGFR), urine albumin:creatinine ratio (ACR) and maximum urine osmolality (max-Uosm) were measured in all patients. Genetic analysis was conducted in 43 patients. Annual eGFR decline (ΔeGFR) was measured in patients with a median follow-up period of 6.5 years. Urine aquaporin-2 (uAQP2) excretion was measured and the furosemide test was performed in patients and controls. RESULTS At baseline, 33 (61.1%), 12 (22.2%) and 9 (16.7%) patients showed an eGFR >90, 60-90 and <60 mL/min/1.73 m2, respectively; 27.3% showed an ACR >30 mg/g and 55.8% of patients showed urine concentrating defect in the absence of renal insufficiency. Baseline eGFR, but not max-Uosm, correlated negatively with age. Conversely, truncating mutations affected max-Uosm and showed a trend towards a reduction in eGFR. Max-Uosm correlated with ΔeGFR (P < 0.005), suggesting that urine concentrating defect may predict disease progression. uAQP2 excretion and Na+ and Cl- fractional excretion after furosemide did not differ between hyposthenuric patients and controls, suggesting that specific collecting duct and thick ascending limb dysfunctions are unlikely to play a central role in the pathogenesis of hyposthenuria. CONCLUSIONS Hyposthenuria is a warning sign predicting poor renal outcome in BBS. The pathophysiology of this defect is most likely beyond defective tubular function.
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Affiliation(s)
- Miriam Zacchia
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | | | - Annalaura Torella
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Raffaele Raucci
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Giancarlo Blasio
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Maria Elena Onore
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Emanuela Marchese
- Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
- CEINGE, Advanced Biotechnologies, Naples, Italy
| | - Francesco Trepiccione
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Biogem Scarl, Ariano Irpino, Italy
| | - Caterina Vitagliano
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Valentina Di Iorio
- Multidisciplinary Department of Medical, Eye Clinic, Surgical and Dental Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Perna Alessandra
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Francesca Simonelli
- Multidisciplinary Department of Medical, Eye Clinic, Surgical and Dental Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Vincenzo Nigro
- Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Giovambattista Capasso
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Biogem Scarl, Ariano Irpino, Italy
| | - Davide Viggiano
- Department of Translational Medical Sciences, University of Campania “Luigi Vanvitelli”, Naples, Italy
- Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
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12
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Tsegaw A, Teshome T. Bardet-Biedl Syndrome in an Ethiopian. Int Med Case Rep J 2021; 14:177-181. [PMID: 33776488 PMCID: PMC7989368 DOI: 10.2147/imcrj.s299421] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 03/08/2021] [Indexed: 11/23/2022] Open
Abstract
Bardet–Biedl syndrome (BBS) is a rare familial and multi-system disorder with an autosomal recessive pattern of inheritance and wide range of clinical variability. Its main manifestations are progressive retinal dystrophy, renal dysfunction, post-axial polydactyly, central obesity, mental retardation, and hypogonadism. Renal failure is known to be the main cause of death in patients with BBS. Retinal dystrophy and other eye diseases seen in patients with BBS can cause severe visual impairment and blindness at an early age. After written consent was obtained from the patient, we report the clinical and laboratory data of the first case from Ethiopia of an 18-year-old boy with multi-system manifestations of the Bardet–Biedl Syndrome. We discuss the main clinical manifestations of the syndrome including its potentially blinding and fatal features. We emphasize the need for diagnosis of this syndrome at an early age as possible so that proper and multidisciplinary medical care can be given for such patients to prevent unnecessary morbidity and early mortality.
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Affiliation(s)
- Asamere Tsegaw
- Department of Ophthalmology, School of Medicine, University of Gondar, Gondar, Ethiopia
| | - Tiliksew Teshome
- Department of Ophthalmology, Faculty of Medicine, Addis Ababa University, Addis Ababa, Ethiopia
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13
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Beigi F, Del Pozo-Valero M, Martin-Merida I, Perea-Romero I, Manaviat MR, Ayuso C, Ghasemi N. Apparent but unconfirmed digenism in an Iranian consanguineous family with syndromic Retinal Disease. Exp Eye Res 2021; 207:108533. [PMID: 33741323 DOI: 10.1016/j.exer.2021.108533] [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: 10/25/2020] [Revised: 02/23/2021] [Accepted: 02/28/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome is an autosomal recessive disease characterized by rod-cone dystrophy, postaxial polydactyly, kidney defects, obesity, mental retardation and hypogonadism. Here, we report different genotypes in two Bardet-Biedl syndrome affected sisters with a different clinical phenotype regarding severity. MATERIALS AND METHODS The proband of the family was examined by Next Generation Sequencing (NGS) using clinical exome and filtering by syndromic and non-syndromic genes associated with retinal dystrophies. RESULTS Targeted NGS revealed two novel variants in the MKKS and CEP290 genes in homozygosis state in the proband. Segregation analysis revealed the presence of the same MKKS homozygous variant in her younger affected sister but not the CEP290 variant. Both sisters presented different clinical manifestation, at different ages, with a more severe renal and retinal defect in the case of the sister carrying mutations in both genes. Another unaffected sister showed only homozygosity for the CEP290 variant, thus supporting the non-pathogenic role of this mutation in BBS phenotype. CONCLUSIONS In this study, NGS proved to be a powerful and efficient sequencing method to identify causal variants in different genes. However, it remarks the importance of the segregation analysis and clinical information to establish the pathogenicity of new variants. The two affected sisters present different genotypes and clinical manifestation, suggesting that the novel CEP290 variant could be acting as a modifier, making the phenotype more severe in the sister homozygote for MKKS and CEP290 genes. On the other hand, the difference in the age of both sisters highlight the important role of monitoring disease progression also to confirm the modifier role of genetic variants.
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Affiliation(s)
- Fahimeh Beigi
- Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Marta Del Pozo-Valero
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Inmaculada Martin-Merida
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Irene Perea-Romero
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Masoud Reza Manaviat
- Department of Ophthalmology, Shahid Sadoughi University of Medical Science, Yazd Diabetes Research Center, Yazd, Iran
| | - Carmen Ayuso
- Department of Clinical Genetics and Genomics, University Hospital Fundacion Jimenez Diaz, Health Research Institute Fundacion Jimenez Diaz (IIS-FJD, UAM), Madrid, Spain; CIBERER (Biomedical Research Network Centre for Rare Diseases), ISCIII, Madrid, Spain
| | - Nasrin Ghasemi
- Abortion Research Centre, Reproductive Sciences Institute, Yazd Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran.
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14
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Tsyklauri O, Niederlova V, Forsythe E, Prasai A, Drobek A, Kasparek P, Sparks K, Trachtulec Z, Prochazka J, Sedlacek R, Beales P, Huranova M, Stepanek O. Bardet-Biedl Syndrome ciliopathy is linked to altered hematopoiesis and dysregulated self-tolerance. EMBO Rep 2021; 22:e50785. [PMID: 33426789 DOI: 10.15252/embr.202050785] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 12/04/2020] [Accepted: 12/09/2020] [Indexed: 12/19/2022] Open
Abstract
Bardet-Biedl Syndrome (BBS) is a pleiotropic genetic disease caused by the dysfunction of primary cilia. The immune system of patients with ciliopathies has not been investigated. However, there are multiple indications that the impairment of the processes typically associated with cilia may have influence on the hematopoietic compartment and immunity. In this study, we analyze clinical data of BBS patients and corresponding mouse models carrying mutations in Bbs4 or Bbs18. We find that BBS patients have a higher prevalence of certain autoimmune diseases. Both BBS patients and animal models have altered red blood cell and platelet compartments, as well as elevated white blood cell levels. Some of the hematopoietic system alterations are associated with BBS-induced obesity. Moreover, we observe that the development and homeostasis of B cells in mice is regulated by the transport complex BBSome, whose dysfunction is a common cause of BBS. The BBSome limits canonical WNT signaling and increases CXCL12 levels in bone marrow stromal cells. Taken together, our study reveals a connection between a ciliopathy and dysregulated immune and hematopoietic systems.
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Affiliation(s)
- Oksana Tsyklauri
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Veronika Niederlova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Elizabeth Forsythe
- Genetics and Genomic Medicine Programme, University College London Great Ormond Street Institute of Child Health, London, UK.,National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, UK
| | - Avishek Prasai
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ales Drobek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Petr Kasparek
- Laboratory of Transgenic Models of Diseases, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic.,Czech Centre for Phenogenomics, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Kathryn Sparks
- National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, UK
| | - Zdenek Trachtulec
- Laboratory of Germ Cell Development, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Prochazka
- Laboratory of Transgenic Models of Diseases, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic.,Czech Centre for Phenogenomics, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Radislav Sedlacek
- Laboratory of Transgenic Models of Diseases, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic.,Czech Centre for Phenogenomics, Division BIOCEV, Institute of Molecular Genetics of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Philip Beales
- Genetics and Genomic Medicine Programme, University College London Great Ormond Street Institute of Child Health, London, UK.,National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, UK
| | - Martina Huranova
- 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
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15
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Sablok A, Thakur S, Sharma A, Kaul A. Prenatal Diagnosis of Bardet-Biedl Syndrome: A Case Study and Review of Literature. JOURNAL OF FETAL MEDICINE 2020. [DOI: 10.1007/s40556-020-00278-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Deletion in the Bardet-Biedl Syndrome Gene TTC8 Results in a Syndromic Retinal Degeneration in Dogs. Genes (Basel) 2020; 11:genes11091090. [PMID: 32962042 PMCID: PMC7565673 DOI: 10.3390/genes11091090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023] Open
Abstract
In golden retriever dogs, a 1 bp deletion in the canine TTC8 gene has been shown to cause progressive retinal atrophy (PRA), the canine equivalent of retinitis pigmentosa. In humans, TTC8 is also implicated in Bardet–Biedl syndrome (BBS). To investigate if the affected dogs only exhibit a non-syndromic PRA or develop a syndromic ciliopathy similar to human BBS, we recruited 10 affected dogs to the study. The progression of PRA for two of the dogs was followed for 2 years, and a rigorous clinical characterization allowed a careful comparison with primary and secondary characteristics of human BBS. In addition to PRA, the dogs showed a spectrum of clinical and morphological signs similar to primary and secondary characteristics of human BBS patients, such as obesity, renal anomalies, sperm defects, and anosmia. We used Oxford Nanopore long-read cDNA sequencing to characterize retinal full-length TTC8 transcripts in affected and non-affected dogs, the results of which suggest that three isoforms are transcribed in the retina, and the 1 bp deletion is a loss-of-function mutation, resulting in a canine form of Bardet–Biedl syndrome with heterogeneous clinical signs.
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17
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Bahmanpour Z, Daneshmandpour Y, Kazeminasab S, Khalil Khalili S, Alehabib E, Chapi M, Soosanabadi M, Darvish H, Emamalizadeh B. A novel splice site mutation in the SDCCAG8 gene in an Iranian family with Bardet-Biedl syndrome. Int Ophthalmol 2020; 41:389-397. [PMID: 32926352 DOI: 10.1007/s10792-020-01588-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 09/01/2020] [Indexed: 01/08/2023]
Abstract
PURPOSE Bardet-Biedl syndrome (BBS: OMIM 209,900) is a rare ciliopathic human genetic disorder that affects many parts of the body systems. BBS is a genetically heterogeneous disorder with a wide spectrum of clinical manifestations which makes its diagnosis and management more challenging. RetNet reports 18 genes that cause BBS and each of genes has had several known mutations. Genetic studies suggesting that serologically defined colon cancer antigen 8 (SDCCAG8) gene mutations are a major cause of BBS. MATERIALS AND METHODS In this section, we investigated the consanguineous Iranian family members with BBS. Whole-exome sequencing and Sanger sequencing, were performed to screen and confirm the suspicious pathogenic mutations. The identified mutation was investigated using bioinformatics tools to predict the effect of the mutation on protein structure. RESULTS Sequential analysis identified a novel splice site mutation c.1221 + 2 T > A in the SDCCAG8 gene in BBS patients. Structure-based approaches have predicted significant structural alterations in SDCCAG8 protein. CONCLUSIONS This study was conducted to show the aberrant alternative splicing as one of the single splicing mutations identified can cause BBS by affecting the function of SDCCAG8 protein.
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Affiliation(s)
- Zahra Bahmanpour
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yousef Daneshmandpour
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Somayeh Kazeminasab
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Soudabeh Khalil Khalili
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Elham Alehabib
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Marjan Chapi
- Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohsen Soosanabadi
- Department of Medical Genetics, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Hossein Darvish
- Cancer Research Center, Semnan University of Medical Sciences, Semnan, Iran. .,Department of Medical Genetics, School of Medicine, Semnan University of Medical Sciences, Semnan, Iran.
| | - Babak Emamalizadeh
- Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. .,Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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18
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Abstract
The liver and kidneys are often similarly affected by a single disease. This is the case in metabolic, immunological, toxic, and infectious diseases, and in the different congenital malformation syndromes. Also, an enzymatic defect in an otherwise healthy liver or the consequences of advanced liver disease by itself can cause kidney disease as a secondary phenomenon. In this review, we describe numerous pathogenic mechanisms leading to dysfunction or malformations of the liver and kidneys in children. We encourage multidisciplinary management for optimal care. A combined liver-kidney transplantation is sometimes needed.
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19
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Forsythe E, Kenny J, Bacchelli C, Beales PL. Managing Bardet-Biedl Syndrome-Now and in the Future. Front Pediatr 2018; 6:23. [PMID: 29487844 PMCID: PMC5816783 DOI: 10.3389/fped.2018.00023] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/25/2018] [Indexed: 11/13/2022] Open
Abstract
Bardet-Biedl syndrome is a rare autosomal recessive multisystem disorder caused by defects in genes encoding for proteins that localize to the primary cilium/basal body complex. Twenty-one disease-causing genes have been identified to date. It is one of the most well-studied conditions in the family of diseases caused by defective cilia collectively known as ciliopathies. In this review, we provide an update on diagnostic developments, clinical features, and progress in the management of Bardet-Biedl syndrome. Advances in diagnostic technologies including exome and whole genome sequencing are expanding the spectrum of patients who are diagnosed with Bardet-Biedl syndrome and increasing the number of cases with diagnostic uncertainty. As a result of the diagnostic developments, a small number of patients with only one or two clinical features of Bardet-Biedl syndrome are being diagnosed. Our understanding of the syndrome-associated renal disease has evolved and is reviewed here. Novel interventions are developing at a rapid pace and are explored in this review including genetic therapeutics such as gene therapy, exon skipping therapy, nonsense suppression therapy, and gene editing. Other non-genetic therapies such as gene repurposing, targeted therapies, and non-pharmacological interventions are also discussed.
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Affiliation(s)
- Elizabeth Forsythe
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Joanna Kenny
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Chiara Bacchelli
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Philip L Beales
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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20
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Cronjé L. Bardet–Biedl syndrome: expect the unexpected, suspect the unsuspected. SOUTHERN AFRICAN JOURNAL OF ANAESTHESIA AND ANALGESIA 2017. [DOI: 10.1080/22201181.2017.1379719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Larissa Cronjé
- Perioperative Research Group, Department of Anaesthesiology and Critical Care, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, King Edward VIII Hospital, Durban, South Africa
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21
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Zacchia M, Di Iorio V, Trepiccione F, Caterino M, Capasso G. The Kidney in Bardet-Biedl Syndrome: Possible Pathogenesis of Urine Concentrating Defect. KIDNEY DISEASES 2017; 3:57-65. [PMID: 28868293 DOI: 10.1159/000475500] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/05/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND The ciliopathies are a growing number of disorders caused by mutations in genes involved in the function of the primary cilium. Bardet-Biedl syndrome (BBS) belongs to this group of disorders. In this setting, kidney dysfunction is highly variable, and urine concentrating defect, a common feature of multiple ciliopathies, has been described as the most frequent defect. Here we review the mechanism of urine concentration and describe the possible mechanism underling this defect in ciliopathies and especially BBS, based on the current body of literature. SUMMARY Active Na+ absorption along the thick ascending limb of the loop of Henle (TAL) is critical for generating the corticomedullary osmotic gradient, and the countercurrent anatomical arrangement of the 2 branches of the loop of Henle enhances this gradient. The vasa recta, paralleling the loop of Henle, operate into the countercurrent mechanism, minimizing washout of solutes from the interstitium. Final water reabsorption is mediated by the aquaporin 2 (AQP2) water channels along the distal nephron, and it is under hormonal control. Several studies demonstrated that hyposthenuria in BBS patients relies on kidney resistance to desmopressin, suggesting a renal origin. We recently showed that the majority of hyposthenuric BBS patients have also a defect regarding maximal urine dilution. Independent studies showed that BBS10 deficiency caused AQP2 mistrafficking in vitro; accordingly, we demonstrated impaired urinary AQP2 excretion in BBS patients with combined concentrating and diluting defect. Whether receptor signaling pathways or downstream events cause AQP2 deregulation is still unclear. In addition, reduced urinary uromodulin excretion in BBS patients opens the possibility that TAL dysfunction may also play a pathogenic role. KEY MESSAGE Impaired water handling in BBS is associated with AQP2 mistrafficking. The potential role of additional factors, such as the dissipation of the medullary osmotic gradient due to TAL dysfunction and/or structural anomalies, remains to be elucidated.
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Affiliation(s)
- Miriam Zacchia
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical, and Dental Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Francesco Trepiccione
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
| | - Marianna Caterino
- Department of Molecular Biology and Medical Biotechnologies, Università degli Studi di Napoli "Federico II," Naples, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Cardiothoracic and Respiratory Sciences, University of Campania "Luigi Vanvitelli," Naples, Italy
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22
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Forsythe E, Sparks K, Best S, Borrows S, Hoskins B, Sabir A, Barrett T, Williams D, Mohammed S, Goldsmith D, Milford DV, Bockenhauer D, Foggensteiner L, Beales PL. Risk Factors for Severe Renal Disease in Bardet-Biedl Syndrome. J Am Soc Nephrol 2017; 28:963-970. [PMID: 27659767 PMCID: PMC5328148 DOI: 10.1681/asn.2015091029] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 08/07/2016] [Indexed: 01/06/2023] Open
Abstract
Bardet-Biedl syndrome is a rare autosomal recessive, multisystem disease characterized by retinal dystrophy, renal malformation, obesity, intellectual disability, polydactyly, and hypogonadism. Nineteen disease-causing genes (BBS1-19) have been identified, of which mutations in BBS1 are most common in North America and Europe. A hallmark of the disease, renal malformation is heterogeneous and is a cause of morbidity and mortality through the development of CKD. We studied the prevalence and severity of CKD in 350 patients with Bardet-Biedl syndrome-related renal disease attending the United Kingdom national Bardet-Biedl syndrome clinics to further elucidate the phenotype and identify risk indicators of CKD. Overall, 31% of children and 42% of adults had CKD; 6% of children and 8% of adults had stage 4-5 CKD. In children, renal disease was often detected within the first year of life. Analysis of the most commonly mutated disease-associated genes revealed that, compared with two truncating mutations, two missense mutations associated with less severe CKD in adults. Moreover, compared with mutations in BBS10, mutations in BBS1 associated with less severe CKD or lack of CKD in adults. Finally, 51% of patients with available ultrasounds had structural renal abnormalities, and 35% of adults were hypertensive. The presence of structural abnormalities or antihypertensive medication also correlated statistically with stage 3b-5 CKD. This study describes the largest reported cohort of patients with renal disease in Bardet-Biedl syndrome and identifies risk factors to be considered in genetic counseling.
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Affiliation(s)
- Elizabeth Forsythe
- Genetics and Genomic Medicine Program, University College London Great Ormond Street Institute of Child Health,
- National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, United Kingdom
| | - Kathryn Sparks
- National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, United Kingdom
| | - Sunayna Best
- Genetics and Genomic Medicine Program, University College London Great Ormond Street Institute of Child Health
| | - Sarah Borrows
- Nephrology Unit, Queen Elizabeth II Hospital, Birmingham, United Kingdom
| | - Bethan Hoskins
- National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, United Kingdom
| | | | - Timothy Barrett
- Department of Endocrinology, Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Denise Williams
- Clinical Genetics Unit, Birmingham Women's Hospital, Birmingham, United Kingdom; and
| | | | | | | | - Detlef Bockenhauer
- University College Hospital Center for Nephrology, Great Ormond Street Hospital, London, United Kingdom
| | | | - Philip L Beales
- Genetics and Genomic Medicine Program, University College London Great Ormond Street Institute of Child Health
- National Bardet-Biedl Syndrome Service, Department of Clinical Genetics, Great Ormond Street Hospital, London, United Kingdom
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23
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Esposito G, Testa F, Zacchia M, Crispo AA, Di Iorio V, Capolongo G, Rinaldi L, D'Antonio M, Fioretti T, Iadicicco P, Rossi S, Franzè A, Marciano E, Capasso G, Simonelli F, Salvatore F. Genetic characterization of Italian patients with Bardet-Biedl syndrome and correlation to ocular, renal and audio-vestibular phenotype: identification of eleven novel pathogenic sequence variants. BMC MEDICAL GENETICS 2017; 18:10. [PMID: 28143435 PMCID: PMC5286791 DOI: 10.1186/s12881-017-0372-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 01/21/2017] [Indexed: 12/14/2022]
Abstract
Background Bardet-Biedl syndrome (BBS) is a rare genetic disorder that features retinal degeneration, obesity, polydactyly, learning disabilities and renal abnormalities. The diagnosis is often missed at birth, the median age at diagnosis being 9 years. In the attempt to shed light on BBS and improve its diagnosis and treatment, we evaluated the genotype-phenotype relationship in patients with a molecular diagnosis of BBS. Methods We analyzed three common BBS genes, BBS1, BBS10 and BBS2, in 25 Italian patients fulfilling the clinical criteria of BBS. In 12 patients, we identified gene-specific biallelic variants and thus correlated genotype to the ophthalmic, renal and audio-vestibular phenotypes. Results At least one sequence variant was found in 60% of patients. The most common mutated gene was BBS1 followed by BBS10. Of the 17 sequence variants we found, 11 have not previously been associated with BBS. In 12 patients, we identified biallelic pathogenic variants; they had retinitis pigmentosa with early onset of visual impairment. However, retinal dystrophy was less severe in patients with BBS1 than in those with BBS10 variants. Overall, we found a high prevalence of renal dysmorphism and dysfunction. Notably, patients with BBS10 variants had the most severe renal impairment, which resulted in a critical decline in renal function. All the patients who underwent audio-vestibular evaluation had dysfunction of the cochlear outer hair cells, thus confirming the presence of hearing defects. Conclusion BBS1, BBS2 and BBS10 are major causative genes in Italian BBS patients. BBS10 was associated with the worse outcome in terms of the renal, ocular and audiovestibular phenotypes. Cochlear dysfunction should be included among the hallmarks of BBS. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0372-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gabriella Esposito
- CEINGE-Biotecnologie Avanzate s.c.a r.l., Via Gaetano Salvatore 486, I-80145, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Miriam Zacchia
- Department of Nephrology, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Anna Alessia Crispo
- CEINGE-Biotecnologie Avanzate s.c.a r.l., Via Gaetano Salvatore 486, I-80145, Naples, Italy
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Giovanna Capolongo
- Department of Nephrology, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Luca Rinaldi
- Department of Nephrology, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Marcella D'Antonio
- CEINGE-Biotecnologie Avanzate s.c.a r.l., Via Gaetano Salvatore 486, I-80145, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Tiziana Fioretti
- IRCCS-Fondazione SDN Naples, Via Emanuele Gianturco 113, I-80143, Naples, Italy
| | - Pasquale Iadicicco
- Area of Audiology, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Settimio Rossi
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Annamaria Franzè
- CEINGE-Biotecnologie Avanzate s.c.a r.l., Via Gaetano Salvatore 486, I-80145, Naples, Italy.,Area of Audiology, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Elio Marciano
- Area of Audiology, Department of Neurosciences, Reproductive and Odontostomatological Sciences, University of Naples Federico II, Via Sergio Pansini 5, I-80131, Naples, Italy
| | - Giovanbattista Capasso
- Department of Nephrology, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy.
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Second University of Naples, Via Sergio Pansini 5, I-80131, Naples, Italy.
| | - Francesco Salvatore
- CEINGE-Biotecnologie Avanzate s.c.a r.l., Via Gaetano Salvatore 486, I-80145, Naples, Italy. .,IRCCS-Fondazione SDN Naples, Via Emanuele Gianturco 113, I-80143, Naples, Italy.
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Oud MM, Lamers IJC, Arts HH. Ciliopathies: Genetics in Pediatric Medicine. J Pediatr Genet 2016; 6:18-29. [PMID: 28180024 DOI: 10.1055/s-0036-1593841] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/08/2016] [Indexed: 12/15/2022]
Abstract
Ciliary disorders, which are also referred to as ciliopathies, are a group of hereditary disorders that result from dysfunctional cilia. The latter are cellular organelles that stick up from the apical plasma membrane. Cilia have important roles in signal transduction and facilitate communications between cells and their surroundings. Ciliary disruption can result in a wide variety of clinically and genetically heterogeneous disorders with overlapping phenotypes. Because cilia occur widespread in our bodies many organs and sensory systems can be affected when they are dysfunctional. Ciliary disorders may be isolated or syndromic, and common features are cystic liver and/or kidney disease, blindness, neural tube defects, brain anomalies and intellectual disability, skeletal abnormalities ranging from polydactyly to abnormally short ribs and limbs, ectodermal defects, obesity, situs inversus, infertility, and recurrent respiratory tract infections. In this review, we summarize the features, frequency, morbidity, and mortality of each of the different ciliopathies that occur in pediatrics. The importance of genetics and the occurrence of genotype-phenotype correlations are indicated, and advances in gene identification are discussed. The use of next-generation sequencing by which a gene panel or all genes can be screened in a single experiment is highlighted as this technology significantly lowered costs and time of the mutation detection process in the past. We discuss the challenges of this new technology and briefly touch upon the use of whole-exome sequencing as a diagnostic test for ciliary disorders. Finally, a perspective on the future of genetics in the context of ciliary disorders is provided.
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Affiliation(s)
- Machteld M Oud
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ideke J C Lamers
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Heleen H Arts
- Department of Human Genetics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Department of Biochemistry, University of Western Ontario, London, Ontario, Canada
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25
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Renal transplantation in Bardet-Biedl Syndrome. Pediatr Nephrol 2016; 31:2153-61. [PMID: 27245600 DOI: 10.1007/s00467-016-3415-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 05/03/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Renal anomalies are common in patients with Bardet-Biedl syndrome (BBS), a renal cystic ciliopathy with multi-systemic features. Renal transplantation is indicated in cases of end-stage renal disease (ESRD), but transplant centers may be hesitant to perform the necessary transplant in light of the multitude of metabolic comorbidities these patients often face with the potential to complicate outcomes. METHODS Data from the Clinical Registry Investigating BBS (CRIBBS) were used to investigate renal transplant outcomes in the largest BBS cohort described to date. RESULTS Of the 206 patients enrolled in the CRIBBS, 21 children (10.2 %; 16 girls, 5 boys; median age 8.4 years) had been diagnosed with ESRD. Renal transplantation was performed in 18 of these individuals between 1982 and 2015, including repeat transplantation in some cases, for a total of 22 kidneys. Overall graft survival was 81.6 % at 1 year post-transplantation, 75.7 % at 5 years, 59 % at 10 years, and 49.2 % at 25 years. Patient survival was 94.4 % at 1 year post-transplantation, 87.2 % at 8 years, and 79.3 % at 25 years. CONCLUSIONS At a median follow-up time of 97 months, relatively few complications of renal transplantation were reported in the patients of this study. However, body mass index was significantly elevated in transplanted individuals compared to non-transplanted individuals participating in CRIBBS at the most recent follow-up. Although the frequency of obesity and other manifestations of the metabolic syndrome warrant meticulous management in this high-risk population, favorable long-term outcomes suggest that renal transplantation is a viable option for patients with BBS and ESRD.
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Zacchia M, Zacchia E, Zona E, Capolongo G, Raiola I, Rinaldi L, Trepiccione F, Ingrosso D, Perna A, Di Iorio V, Simonelli F, Moe OW, Capasso G. Renal phenotype in Bardet-Biedl syndrome: a combined defect of urinary concentration and dilution is associated with defective urinary AQP2 and UMOD excretion. Am J Physiol Renal Physiol 2016; 311:F686-F694. [PMID: 27488999 PMCID: PMC5142239 DOI: 10.1152/ajprenal.00224.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/22/2016] [Indexed: 11/22/2022] Open
Abstract
The renal phenotype in Bardet-Biedl syndrome (BBS) is highly variable. The present study describes renal findings in 41 BBS patients and analyzes the pathogenesis of hyposthenuria, the most common renal dysfunction. Five of 41 patients (12%) showed an estimated glomerular filtration rate < 60 ml·min-1·1.73 m-2 Urine protein and urine albumin-to-creatinine ratio were over 200 and 30 mg/g in 9/24 and 7/23 patients, respectively. Four of 41 patients showed no renal anomalies on ultrasound. Twenty of 34 patients had hyposthenuria in the absence of renal insufficiency. In all 8 of the hyposthenuric patients studied, dDAVP failed to elevate urine osmolality (Uosm), suggesting a nephrogenic origin. Interestingly, water loading (WL) did not result in a significant reduction of Uosm, indicating combined concentrating and diluting defects. dDAVP infusion induced a significant increase of plasma Factor VIII and von Willebrand Factor levels, supporting normal function of the type 2 vasopressin receptor at least in endothelial cells. While urinary aquaporin 2 (u-AQP2) abundance was not different between patients and controls at baseline, the dDAVP-induced increased u-AQP2 and the WL-induced reduction of u-AQP2 were blunted in patients with a combined concentrating and diluting defect, suggesting a potential role of AQP2 in the defective regulation of water absorption. Urine Uromodulin excretion was reduced in all hyposthenuric patients, suggesting a thick ascending limb defect. Interestingly, renal Na, Cl, Ca, but not K handling was impaired after acute WL but not at basal. In summary, BBS patients show combined urinary concentration and dilution defects; a thick ascending limb and collecting duct tubulopathy may underlie impaired water handling.
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Affiliation(s)
- Miriam Zacchia
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy;
| | - Enza Zacchia
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy; Institute of Genetics and Biophysics of the National Research Council (CNR), Naples, Italy
| | - Enrica Zona
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy; Institute of Genetics and Biophysics of the National Research Council (CNR), Naples, Italy
| | - Giovanna Capolongo
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
| | - Ilaria Raiola
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
| | - Luca Rinaldi
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
| | - Francesco Trepiccione
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
| | - Diego Ingrosso
- Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy
| | - Alessandra Perna
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences-Second University of Naples, Naples, Italy; and
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences-Second University of Naples, Naples, Italy; and
| | - Orson W Moe
- Departments of Internal Medicine and Physiology and the Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Giovambattista Capasso
- Section of Nephrology, Department of Cardiothoracic and Respiratory Sciences-Second University of Naples, Naples, Italy
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Smith BB, Barbara DW, Hyder JA, Smith MM. Anesthetic considerations for patients with Bardet-Biedl syndrome: a case series and review of the literature. Paediatr Anaesth 2016; 26:429-37. [PMID: 26804322 DOI: 10.1111/pan.12848] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/16/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare genetic condition with manifestations that can impact anesthetic and perioperative care. There is a void of literature describing the perioperative anesthetic management in this complex patient population. OBJECTIVES The purpose of this retrospective series was to describe the perioperative care of patients diagnosed with BBS at a large academic tertiary referral center with experience in caring for these patients. METHODS All patients receiving anesthesia during the time between July 10, 1997 and Jan 1, 2015 were identified. Anesthetic and perioperative records were reviewed in detail for demographic, echocardiographic, preoperative, intraoperative, and postoperative data. RESULTS We identified 12 patients with BBS undergoing 40 anesthetics at our institution. The study identified a high risk for difficult airway with need for advanced airway techniques (67% of patient's ≥ 18 years of age required either awake fiberoptic or video laryngoscopy techniques), cardiac abnormalities, renal impairment, morbid obesity, and intellectual disability as the main syndrome manifestations of interest to the anesthesiologist. No patient had perioperative complications directly related to BBS; however, each underwent thorough perioperative evaluation with emphasis on the systemic comorbidities associated with the syndrome. This report illustrates that patients with BBS can safely undergo anesthesia, but a detailed and often multidisciplinary preoperative evaluation is prudent.
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Affiliation(s)
| | - David W Barbara
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Joseph A Hyder
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
| | - Mark M Smith
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
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Ece Solmaz A, Onay H, Atik T, Aykut A, Cerrah Gunes M, Ozalp Yuregir O, Bas VN, Hazan F, Kirbiyik O, Ozkinay F. Targeted multi-gene panel testing for the diagnosis of Bardet Biedl syndrome: Identification of nine novel mutations across BBS1, BBS2, BBS4, BBS7, BBS9, BBS10 genes. Eur J Med Genet 2015; 58:689-94. [DOI: 10.1016/j.ejmg.2015.10.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 12/19/2022]
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Cramer MT, Guay-Woodford LM. Cystic kidney disease: a primer. Adv Chronic Kidney Dis 2015; 22:297-305. [PMID: 26088074 DOI: 10.1053/j.ackd.2015.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 04/05/2015] [Accepted: 04/06/2015] [Indexed: 02/07/2023]
Abstract
Renal cystic diseases encompass a broad group of disorders with variable phenotypic expression. Cystic disorders can present during infancy, childhood, or adulthood. Often, but not always, they can be distinguished by the clinical features including age at presentation, renal imaging characteristics, including cyst distribution, and the presence/distribution of extrarenal manifestations. It is important to take the clinical context into consideration when assessing renal cystic disease in children and adults. For example, solitary kidney cysts may be completely benign when they develop during adulthood but may represent early polycystic kidney disease when observed during childhood. In this review, we have categorized renal cystic disease according to inherited single-gene disorders, for example, autosomal recessive polycystic kidney disease; syndromic disorders associated with kidney cysts, for example, tuberous sclerosis complex; and nongenetic forms of renal cystic disease, for example, simple kidney cysts. We present an overview of the clinical characteristics, genetics (when appropriate), and molecular pathogenesis and the diagnostic evaluation and management of each renal cystic disease. We also provide an algorithm that distinguishes kidney cysts based on their clinical features and may serve as a helpful diagnostic tool for practitioners. A review of Autosomal Dominant Polycystic Disease was excluded as this disorder was reviewed in this journal in March 2010, volume 17, issue 2.
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Starks RD, Beyer AM, Guo DF, Boland L, Zhang Q, Sheffield VC, Rahmouni K. Regulation of Insulin Receptor Trafficking by Bardet Biedl Syndrome Proteins. PLoS Genet 2015; 11:e1005311. [PMID: 26103456 PMCID: PMC4478011 DOI: 10.1371/journal.pgen.1005311] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/29/2015] [Indexed: 01/06/2023] Open
Abstract
Insulin and its receptor are critical for the regulation of metabolic functions, but the mechanisms underlying insulin receptor (IR) trafficking to the plasma membrane are not well understood. Here, we show that Bardet Biedl Syndrome (BBS) proteins are necessary for IR localization to the cell surface. We demonstrate that the IR interacts physically with BBS proteins, and reducing the expression of BBS proteins perturbs IR expression in the cell surface. We show the consequence of disrupting BBS proteins for whole body insulin action and glucose metabolism using mice lacking different BBS genes. These findings demonstrate the importance of BBS proteins in underlying IR cell surface expression. Our data identify defects in trafficking and localization of the IR as a novel mechanism accounting for the insulin resistance commonly associated with human BBS. This is supported by the reduced surface expression of the IR in fibroblasts derived from patients bearing the M390R mutation in the BBS1 gene. A main function of the hormone insulin in the body is to regulate metabolism of glucose. The hormone causes body cells in different organs and tissues to utilize glucose from the bloodstream, storing the excess amount. Insulin resistance which reflects the inability of insulin to properly regulate glucose metabolism is common in people with obesity and/or type 2 diabetes. This insulin resistance is strongly associated with cardiovascular disease and increases the risk of death. However, the reasons that account for this insulin resistance phenomenon are currently not well understood. Here, we show that Bardet Biedl Syndrome proteins are required for proper action of insulin. We found that cells or animals that are deficient in Bardet Biedl Syndrome proteins are unable to respond to insulin. These results provide an explanation why patients that carry mutations in the Bardet Biedl Syndrome genes are insulin resistant, and will potentially contribute to understand common human forms of insulin resistance.
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Affiliation(s)
- Rachel D. Starks
- Department of Pharmacology, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
| | - Andreas M. Beyer
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
| | - Deng Fu Guo
- Department of Pharmacology, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
| | - Lauren Boland
- Department of Pharmacology, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
| | - Qihong Zhang
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
| | - Val C. Sheffield
- Department of Pediatrics, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- Howard Hughes Medical Institute, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- * E-mail: (VCS); (KR)
| | - Kamal Rahmouni
- Department of Pharmacology, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- Department of Internal Medicine, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- FOE Diabetes Research Center, University of Iowa College of Medicine, Iowa City, Iowa, United States of America
- * E-mail: (VCS); (KR)
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Kurschat CE, Müller RU, Franke M, Maintz D, Schermer B, Benzing T. An approach to cystic kidney diseases: the clinician's view. Nat Rev Nephrol 2014; 10:687-99. [DOI: 10.1038/nrneph.2014.173] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Al-Hamed MH, van Lennep C, Hynes AM, Chrystal P, Eley L, Al-Fadhly F, El Sayed R, Simms RJ, Meyer B, Sayer JA. Functional modelling of a novel mutation in BBS5. Cilia 2014; 3:3. [PMID: 24559376 PMCID: PMC3931281 DOI: 10.1186/2046-2530-3-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 02/04/2014] [Indexed: 12/22/2022] Open
Abstract
Background Bardet-Biedl syndrome (BBS) is an autosomal recessive ciliopathy disorder with 18 known causative genes (BBS1-18). The primary clinical features are renal abnormalities, rod-cone dystrophy, post-axial polydactyly, learning difficulties, obesity and male hypogonadism. Results We describe the clinical phenotype in three Saudi siblings in whom we have identified a novel mutation in exon 12 of BBS5 (c.966dupT; p.Ala323CysfsX57). This single nucleotide duplication creates a frame shift results in a predicted elongated peptide. Translation blocking Morpholino oligonucleotides were used to create zebrafish bbs5 morphants. Morphants displayed retinal layering defects, abnormal cardiac looping and dilated, cystic pronephric ducts with reduced cilia expression. Morphants also displayed significantly reduced dextran clearance via the pronephros compared to wildtype embryos, suggesting reduced renal function in morphants. The eye, kidney and heart defects reported in morphant zebrafish resemble the human phenotype of BBS5 mutations. The pathogenicity of the novel BBS5 mutation was determined. Mutant mRNA was unable to rescue pleiotropic phenotypes of bbs5 morphant zebrafish and in cell culture we demonstrate a mislocalisation of mutant BBS5 protein which fails to localise discretely with the basal body. Conclusions We conclude that this novel BBS5 mutation has a deleterious function that accounts for the multisystem ciliopathy phenotype seen in affected human patients.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - John A Sayer
- International Centre for Life, Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK.
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Bush A, Hogg C. Primary ciliary dyskinesia: recent advances in epidemiology, diagnosis, management and relationship with the expanding spectrum of ciliopathy. Expert Rev Respir Med 2014; 6:663-82. [DOI: 10.1586/ers.12.60] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Büscher AK, Cetiner M, Büscher R, Wingen AM, Hauffa BP, Hoyer PF. Obesity in patients with Bardet-Biedl syndrome: influence of appetite-regulating hormones. Pediatr Nephrol 2012; 27:2065-2071. [PMID: 22669322 DOI: 10.1007/s00467-012-2220-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/11/2012] [Accepted: 05/11/2012] [Indexed: 12/22/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a genetic disorder with obesity as one of the major phenotypic criterion, which is proposed to be of neuroendocrine origin. Therefore, disturbances in appetite-regulating hormones have been considered as causative factors. Acyl ghrelin is an orexigenic hormone, whereas its desacylated form, obestatin, and leptin have the opposite functions. Ghrelin is negatively regulated in relation to nutritional status. The aim of this study was to evaluate the impact of hormone alterations on obesity development in BBS patients. METHODS Total and acylated ghrelin, obestatin, leptin and adiponectin were measured in eight children with BBS. The results were analyzed in relation to auxological parameters [body mass index (BMI), height]. RESULTS The mean BMI was significantly increased in BBS patients compared to the controls. Plasma levels of acylated ghrelin, total ghrelin and obestatin were slightly elevated in BBS patients compared to controls, as was the acyl/total ghrelin ratio. Leptin levels were significantly elevated in BBS patients. CONCLUSION BBS patients lack the negative regulatory mechanisms of appetite-regulating hormones with respect to nutritional status and exhibit resistance to anorexigenic leptin. This results in a shift towards the orexigenic effects of this self-regulating system. These alterations may in part be responsible for the disturbed appetite regulation in BBS patients.
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Affiliation(s)
- Anja K Büscher
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany. .,Paediatrics II, Children's Hospital, University of Duisburg-Essen, Hufelandstraße 55, 45122, Essen, Germany.
| | - Metin Cetiner
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany
| | - Rainer Büscher
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany
| | - Anne-Margret Wingen
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany
| | - Berthold P Hauffa
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany
| | - Peter F Hoyer
- Department of Paediatrics II, Paediatric Nephrology, Endocrinology, Gastroenterology and Transplant Medicine, Children's Hospital, University of Duisburg-Essen, Essen, Germany
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Cox KF, Kerr NC, Kedrov M, Nishimura D, Jennings BJ, Stone EM, Sheffield VC, Iannaccone A. Phenotypic expression of Bardet-Biedl syndrome in patients homozygous for the common M390R mutation in the BBS1 gene. Vision Res 2012; 75:77-87. [PMID: 22940089 DOI: 10.1016/j.visres.2012.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 08/07/2012] [Accepted: 08/08/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE To characterize the phenotype of Bardet-Biedl syndrome (BBS) patients homozygous for the BBS1 M390R mutation. METHODS Three patients [PT1, F, 27 years old (yo) at last examination, 14-year follow-up (F/U) PT2, F, 15-yo PT3, M, 15-yo, both 1-year F/U] underwent eye exams, Goldmann visual fields (GVFs), dark- (DA) and light-adapted (LA) electroretinograms (ERGs), spectral domain optical coherence tomography (SD-OCT) and fundus autofluorescence (FAF). Vision and systemic history were also collected. RESULTS All patients had night blindness, hyperopic astigmatism, ptosis or mild blepharospasm, foot polydactyly, 5th finger clinodactyly, history of headaches, and variable, diet-responsive obesity. Two had asthma, PT1 was developmentally delayed, PT2 had Asperger-like symptoms, and PT3 had normal cognition. At age 14, acuity was 20/100 in PT1, who had nystagmus since age 2, 20/40 in PT2 and 20/30 in PT3. By 27yo PT1 progressed to 20/320, by 15 yo PT2 was 20/60 and PT3 remained stable. PT1 had well preserved peripheral GVFs, with minimal progression over 10 years of F/U. PT2 and PT3 presented with ring scotomas and I4e<5°. All patients had severe generalized visual sensitivity depression. ERGs were consistently recordable (also rod ERG in PT3 after 60 min DA), but progressed to non-recordable in PT1. Mixed DA ERGs exhibited electronegativity. In PT3, this was partly due to a bleaching effect during bright-flash DA averaging, partly to ON≫OFF LA response compromise. PT2 and 3 had, on SD-OCTs, generalized macular thinning, normal retinal lamination, and widespread photoreceptor outer/inner segment attenuation except foveally, and multiple rings of abnormal FAF configuring a complex bull's eye-pattern. PT1 had macular atrophy. All patients also had peripapillary nerve fiber layer thickening. CONCLUSIONS The observed phenotype matches very closely that reported in patients by Azari et al. (IOVS 2006) and in the Bbs1-M390R knock-in mouse model, and expands it to the characterization of important ERG response characteristics that provide insight in the pathogenesis of retinopathy in these patients. Our findings confirm the consistent pathogenicity of the BBS1 M390R mutation.
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Affiliation(s)
- Kyle F Cox
- University of Tennessee Health Science Center, Hamilton Eye Institute, Memphis, TN 38163, USA
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Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive ciliopathy characterised by retinal dystrophy, obesity, post-axial polydactyly, renal dysfunction, learning difficulties and hypogonadism. Many associated minor features can be helpful in making a diagnosis and are important in the clinical management of BBS. The diagnosis is based on clinical findings and can be confirmed by sequencing of known disease-causing genes in 80% of patients. BBS genes encode proteins that localise to the cilia and basal body and are involved in cilia biogenesis and function. Mutations lead to defective cilia accounting in part for the pleiotropic effects observed in BBS. We provide an overview of BBS including the clinical findings, current understanding of cilia biology, and a practical approach to diagnosis, genetic counselling and up-to-date management.
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Affiliation(s)
- Elizabeth Forsythe
- Molecular Medicine Unit, Institute of Child Health, University College London, London, UK
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Putoux A, Attie-Bitach T, Martinovic J, Gubler MC. Phenotypic variability of Bardet-Biedl syndrome: focusing on the kidney. Pediatr Nephrol 2012; 27:7-15. [PMID: 21246219 DOI: 10.1007/s00467-010-1751-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 11/26/2010] [Accepted: 11/30/2010] [Indexed: 12/12/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a multisystemic developmental disorder diagnosed on the basis of the presence of obesity, retinal defects, polydactyly, hypogonadism, renal dysfunction, and learning disabilities. The syndrome is genetically heterogeneous with 14 BBS genes identified to date. Since the cloning of the first gene in 2000, a combination of genetic, in vitro, and in vivo studies have highlighted ciliary dysfunction as a primary cause of BBS pathology. Pleiotropy of ciliopathy phenotypes and complex genetic interactions between causal and modifying alleles of ciliary genes contribute to phenotypic variability. In particular, kidney disease in BBS is clinically heterogeneous, but is now recognized as a cardinal feature and a major cause of mortality in BBS.
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Affiliation(s)
- Audrey Putoux
- INSERM U-781, Hôpital Necker-Enfants Malades, Paris, France
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Mihai CM, Marshall JD, Stoicescu RM. Bardet-Biedl syndrome with end-stage kidney disease in a four-year-old Romanian boy: a case report. J Med Case Rep 2011; 5:378. [PMID: 21843323 PMCID: PMC3174128 DOI: 10.1186/1752-1947-5-378] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 08/15/2011] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Bardet-Biedl syndrome is a significant genetic cause of chronic kidney disease in children. Kidney abnormalities are a major cause of morbidity and mortality in Bardet-Biedl syndrome, but the onset of end-stage renal disease at an early age and continuous ambulatory peritoneal dialysis, however, are not commonly mentioned in the literature. CASE PRESENTATION We present the case of a four-year-old Romanian boy who presented to our department with 'febrile seizures'. After an initial evaluation, we diagnosed our patient as having hypertension, severe anemia and end-stage renal disease. He met the major and minor criteria for the diagnosis of Bardet-Biedl syndrome and underwent continuous ambulatory peritoneal dialysis. CONCLUSIONS Close follow-up for renal involvement in patients with Bardet-Biedl syndrome and Alström syndrome from an early age is highly recommended to prevent end-stage renal disease and so renal replacement therapy can be started immediately.
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Affiliation(s)
- Cristina M Mihai
- Faculty of Medicine, "Ovidius" University, 145 Tomis Blvd, Constanta 900591, Romania
| | - Jan D Marshall
- The Jackson Laboratory 600 Main Street Bar Harbor, Maine 04609 USA
| | - Ramona M Stoicescu
- Faculty of Pharmacy, "Ovidius" University, 145 Tomis Blvd, Constanta 900591, Romania
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Waters AM, Beales PL. Ciliopathies: an expanding disease spectrum. Pediatr Nephrol 2011; 26:1039-56. [PMID: 21210154 PMCID: PMC3098370 DOI: 10.1007/s00467-010-1731-7] [Citation(s) in RCA: 491] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2010] [Revised: 11/02/2010] [Accepted: 11/03/2010] [Indexed: 01/17/2023]
Abstract
Ciliopathies comprise a group of disorders associated with genetic mutations encoding defective proteins, which result in either abnormal formation or function of cilia. As cilia are a component of almost all vertebrate cells, cilia dysfunction can manifest as a constellation of features that include characteristically, retinal degeneration, renal disease and cerebral anomalies. Additional manifestations include congenital fibrocystic diseases of the liver, diabetes, obesity and skeletal dysplasias. Ciliopathic features have been associated with mutations in over 40 genes to date. However, with over 1,000 polypeptides currently identified within the ciliary proteome, several other disorders associated with this constellation of clinical features will likely be ascribed to mutations in other ciliary genes. The mechanisms underlying many of the disease phenotypes associated with ciliary dysfunction have yet to be fully elucidated. Several elegant studies have crucially demonstrated the dynamic ciliary localisation of components of the Hedgehog and Wnt signalling pathways during signal transduction. Given the critical role of the cilium in transducing "outside-in" signals, it is not surprising therefore, that the disease phenotypes consequent to ciliary dysfunction are a manifestation of aberrant signal transduction. Further investigation is now needed to explore the developmental and physiological roles of aberrant signal transduction in the manifestation of ciliopathy phenotypes. Utilisation of conditional and inducible murine models to delete or overexpress individual ciliary genes in a spatiotemporal and organ/cell-specific manner should help clarify some of the functional roles of ciliary proteins in the manifestation of phenotypic features.
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Affiliation(s)
- Aoife M. Waters
- Department of Nephro-Urology, Great Ormond Street Hospital, London, WC1N 3JH UK ,Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Philip L. Beales
- Molecular Medicine Unit, Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
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Dervisoglu E, Isgoren S, Kasgari D, Demir H, Yilmaz A. Obesity control and low protein diet preserve or even improve renal functions in Bardet-Biedl syndrome: a report of two cases. Med Sci Monit 2011; 17:CS12-14. [PMID: 21169913 PMCID: PMC3524693 DOI: 10.12659/msm.881320] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Bardet-Biedl syndrome (BBS) is a rare autosomal-recessive disorder characterized by abdominal obesity, mental retardation, dysmorphic extremities, retinal dystrophy, hypogonadism, and kidney structural abnormalities or functional impairment. It is now considered a significant cause of chronic and end-stage renal disease in children. To the best of our knowledge there have been no previous studies on the role of diet in the management of renal functions in patients with BBS. Case Reports Two siblings, aged 32 and 27 years, with BBS are presented. On admission both patients were obese, with body mass indexes (BMI) of 40 and 39 kg/m2. Their creatinine clearances (CrCl) were 41 and 24 mL/min. After 2 years of follow-up with a diet consisting of 0.6 g/kg/day protein and 1400 kcal/day energy, their BMI’s were decreased to 29 and 27 kg/m2, whereas their CrCl’s were increased to 44 and 32 mL/min, respectively. 99mTc-MAG3 scintigraphy also revealed improved renal function. Conclusions Since this syndrome most likely results in end-stage renal disease, follow-up of renal dysfunction is essential. Low protein diet and/or obesity control may slow the progression of renal failure in patients with BBS.
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Affiliation(s)
- Erkan Dervisoglu
- Department of Nephrology, School of Medicine, Kocaeli University, Kocaeli, Turkey.
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Bardet-Biedl syndrome highlights the major role of the primary cilium in efficient water reabsorption. Kidney Int 2011; 79:1013-25. [PMID: 21270763 DOI: 10.1038/ki.2010.538] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Studies of the primary cilium, now known to be present in all cells, have undergone a revolution, in part, because mutation of many of its proteins causes a large number of diseases, including cystic kidney disease. Bardet-Biedl syndrome (BBS) is an inherited ciliopathy characterized, among other dysfunctions, by renal defects for which the precise role of the cilia in kidney function remains unclear. We studied a cohort of patients with BBS where we found that these patients had a urinary concentration defect even when kidney function was near normal and in the absence of major cyst formation. Subsequent in vitro analysis showed that renal cells in which a BBS gene was knocked down were unciliated, but did not exhibit cell cycle defects. As the vasopressin receptor 2 is located in the primary cilium, we studied BBS-derived unciliated renal epithelial cells and found that they were unable to respond to luminal arginine vasopressin treatment and activate their luminal aquaporin 2. The ability to reabsorb water was restored by treating these unciliated renal epithelial cells with forskolin, a receptor-independent adenylate cyclase activator, showing that the intracellular machinery for water absorption was present but not activated. These findings suggest that the luminal receptor located on the primary cilium may be important for efficient transepithelial water absorption.
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42
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Imhoff O, Marion V, Stoetzel C, Durand M, Holder M, Sigaudy S, Sarda P, Hamel CP, Brandt C, Dollfus H, Moulin B. Bardet-Biedl syndrome: a study of the renal and cardiovascular phenotypes in a French cohort. Clin J Am Soc Nephrol 2011; 6:22-9. [PMID: 20876674 PMCID: PMC3022245 DOI: 10.2215/cjn.03320410] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 08/24/2010] [Indexed: 11/23/2022]
Abstract
BACKGROUND AND OBJECTIVES Bardet-Biedl Syndrome (BBS) is a rare autosomal recessive ciliopathy with a wide spectrum of clinical features including obesity, retinitis pigmentosa, polydactyly, mental retardation, hypogonadism, and renal abnormalities. The molecular genetic profile of BBS is currently being investigated after the recent identification of 14 BBS genes involved in primary cilia-linked disease. This study aims to characterize the renal and cardiovascular presentations and to analyze possible relationships between genotypes and clinical phenotypes. DESIGN, SETTING, PARTICIPANTS & MEASUREMENTS This clinical study was performed in a national cohort of 33 BBS patients, 22 men and 11 women, all aged >16 years (mean age 26.3 years). RESULTS Renal abnormalities, including impairment of renal function and signs of chronic interstitial nephropathy of dysplastic nature, were documented in 82% of the patients. Cardiovascular evaluations revealed that this group of young patients had significant cardiovascular risk factors. Hypertension was found in >30% of the patients and hyperlipidemia in >60%, and almost 50% had other metabolic abnormalities. Overt diabetes was present in only 6%. With regard to genotype-phenotype correlation, patients with a mutation in the BBS6, BBS10, or BBS12 gene (10 of 33 patients) had more severe renal disease. CONCLUSIONS Our study results confirm the frequent occurrence of renal involvement in patients with BBS, underscore the high risk of cardiovascular disease in these patients, and provide new information on a possible genotype-phenotype correlation.
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Affiliation(s)
| | - Vincent Marion
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Myriam Durand
- Service de Génétique Médicale, Fédération de Génétique
| | - Muriel Holder
- Service de Génétique Médicale, Hôpitaux Universitaires de Lille, Lille, France
| | - Sabine Sigaudy
- Département de Génétique Médicale, Hôpital Timone Enfant, Marseille, France; and
| | | | - Christian P. Hamel
- Service d'Ophtalmologie, Hôpitaux Universitaires de Montpellier, Montpellier, France
| | - Christian Brandt
- Service de Cardiologie, and
- Centre d'Investigation et de Recherche Clinique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Hélène Dollfus
- Service de Génétique Médicale, Fédération de Génétique
- Laboratoire de Physiopathologie et Épidémiologie des Syndromes Génétiques Rares, EA 3944, Avenir INSERM, Faculté de Médecine de Strasbourg, Strasbourg, France
| | - Bruno Moulin
- Service de Néphrologie et Transplantation Rénale
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Abstract
The combined occurrence of diabetes mellitus (DM) and retinitis pigmentosa (RP) is rare. It has been reported in the form of four different syndromes that are inherited in an autosomal recessive fashion. We describe two cases of DM and RP occurring together. The first case was a 35-year-old male who presented with insulin-treated diabetes, obesity, hypertension, polydactyly, normal cognitive functions, an ataxic gait, blindness secondary to RP, dyslipidemia, impaired renal function, and multiple renal cysts. He was diagnosed clinically as having Bardet-Biedl syndrome. The second case was a 34-year-old male who presented with insulin-resistant diabetes, hypertension, blindness secondary to RP, deafness, normal cognitive functions, primary infertility, renal, and liver impairment. He was diagnosed clinically as having Alström syndrome. Because of overlapping clinical manifestations and the cost and time involved in genetic studies, clinical criteria can be used for diagnosis and as a guide for genetic mapping in these patients.
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Affiliation(s)
- Afaf Al-Adsani
- Department of Medicine, Al-Sabah Hospital, PO Box 4078 Safat, 13041, Sualibikhat, Kuwait 90801, Kuwait.
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Gunay-Aygun M. Liver and kidney disease in ciliopathies. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2009; 151C:296-306. [PMID: 19876928 PMCID: PMC2919058 DOI: 10.1002/ajmg.c.30225] [Citation(s) in RCA: 170] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Hepatorenal fibrocystic diseases (HRFCDs) are among the most common inherited human disorders. The discovery that proteins defective in the autosomal dominant and recessive polycystic kidney diseases (ADPKD and ARPKD) localize to the primary cilia and the recognition of the role these organelles play in the pathogenesis of HRFCDs led to the term "ciliopathies." While ADPKD and ARPKD are the most common ciliopathies associated with both liver and kidney disease, variable degrees of renal and/or hepatic involvement occur in many other ciliopathies, including Joubert, Bardet-Biedl, Meckel-Gruber, and oral-facial-digital syndromes. The ductal plate malformation (DPM), a developmental abnormality of the portobiliary system, is the basis of the liver disease in ciliopathies that manifest congenital hepatic fibrosis (CHF), Caroli syndrome (CS), and polycystic liver disease (PLD). Hepatocellular function remains relatively preserved in ciliopathy-associated liver diseases. The major morbidity associated with CHF is portal hypertension (PH), often leading to esophageal varices and hypersplenism. In addition, CD predisposes to recurrent cholangitis. PLD is not typically associated with PH, but may result in complications due to mass effects. The kidney pathology in ciliopathies ranges from non-functional cystic dysplastic kidneys to an isolated urinary concentration defect; the disorders contributing to this pathology, in addition to ADPKD and ARPKD, include nephronophithisis (NPHP), glomerulocystic kidney disease and medullary sponge kidneys. Decreased urinary concentration ability, resulting in polyuria and polydypsia, is the first and most common renal symptom in ciliopathies. While the majority of ADPKD, ARPKD, and NPHP patients require renal transplantation, the frequency and rate of progression to renal failure varies considerably in other ciliopathies. This review focuses on the kidney and liver disease found in the different ciliopathies.
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Affiliation(s)
- Meral Gunay-Aygun
- Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, 10 Center Dr., Bldg 10, Rm. 10C103, Bethesda, MD 20892-1851, USA.
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Webb MP, Dicks EL, Green JS, Moore SJ, Warden GM, Gamberg JS, Davidson WS, Young TL, Parfrey PS. Autosomal recessive Bardet-Biedl syndrome: first-degree relatives have no predisposition to metabolic and renal disorders. Kidney Int 2009; 76:215-23. [PMID: 19367329 DOI: 10.1038/ki.2009.116] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Bardet-Biedl Syndrome (BBS) is an autosomal recessive, multisystem, genetically heterogeneous, ciliopathic condition caused by mutations in multiple genes. Here we sought to determine if inheritance of a single BBS mutation increased the risks of frequent disorders of this syndrome such as obesity, hypertension, and diabetes. Various metabolic and renal diseases in a cohort of 46 patients with BBS, prospectively followed for up to 28 years, were compared to recent assessments of these factors in 96 relatives with a heterozygote mutation (carriers) and 37 relatives without a contributing mutation (non-carriers). Ten mutations in 6 genes causing this syndrome were identified in 21 families from whom DNA was obtained. The body mass index or the incidences of hypertension, diabetes, or stage 3 chronic kidney diseases were found to be similar between carriers and non-carriers but were all significantly less than those of family members with BBS. Similarly, the median age of onset of hypertension or diagnosis of stage 3 kidney disease, or the diagnosis of diabetes by age 70 were all significantly lower in those with BBS than in gene carriers or non-carriers. While our study shows that metabolic and renal events occurred frequently and at an early age in BBS, the heterozygous inheritance of any of the 10 described BBS mutations did not predispose family members to obesity, diabetes, hypertension, or renal impairment.
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Affiliation(s)
- Michael P Webb
- Clinical Epidemiology Unit, Department of Medicine, Memorial University, St John's, Newfoundland and Labrador, Canada
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Transient ciliogenesis involving Bardet-Biedl syndrome proteins is a fundamental characteristic of adipogenic differentiation. Proc Natl Acad Sci U S A 2009; 106:1820-5. [PMID: 19190184 DOI: 10.1073/pnas.0812518106] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is an inherited ciliopathy generally associated with severe obesity, but the underlying mechanism remains hypothetical and is generally proposed to be of neuroendocrine origin. In this study, we show that while the proliferating preadipocytes or mature adipocytes are nonciliated in culture, a typical primary cilium is present in differentiating preadipocytes. This transient cilium carries receptors for Wnt and Hedgehog pathways, linking this organelle to previously described regulatory pathways of adipogenesis. We also show that the BBS10 and BBS12 proteins are located within the basal body of this primary cilium and inhibition of their expression impairs ciliogenesis, activates the glycogen synthase kinase 3 pathway, and induces peroxisome proliferator-activated receptor nuclear accumulation, hence favoring adipogenesis. Moreover, adipocytes derived from BBS-patients' dermal fibroblasts in culture exhibit higher propensity for fat accumulation when compared to controls. This strongly suggests that a peripheral primary dysfunction of adipogenesis participates to the pathogenesis of obesity in BBS.
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van de Louw J, Vorstenbosch R, Vinck L, Penning C, Evenhuis H. Prevalence of hypertension in adults with intellectual disability in the Netherlands. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2009; 53:78-84. [PMID: 19054271 DOI: 10.1111/j.1365-2788.2008.01130.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
BACKGROUND Literature on the prevalence of hypertension in people with intellectual disability (ID) is mostly based on file studies or on measurements limited to the age group below 50 years. We measured and calculated the prevalence of hypertension in adults with ID and studied the distribution of hypertension in relation to age, gender, diagnosis of Down's syndrome and level of ID. METHODS In an observational cross-sectional study, standardized blood pressure measurements were obtained from 258 randomly selected adult clients of three Dutch care providers for people with ID. Hypertension was defined as a mean systolic blood pressure above 140 mm Hg on repeated measurements. RESULTS The overall prevalence rate of hypertension was 17.4% (95% CI 12.28-22.46). This was comparable to the prevalence in the general Dutch population. No accurate blood pressure measurement could be performed in 28.4% of people with severe and profound ID owing to repetitive physical activity or resistance. Hypertension was significantly related to older age and absence of Down's syndrome; no correlation with gender or level of ID could be shown. RECOMMENDATION The risk factor hypertension should be detected and treated in the same manner as in the general population following national guidelines.
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Rooryck C, Lacombe D. [Bardet-Biedl syndrome]. ANNALES D'ENDOCRINOLOGIE 2008; 69:463-71. [PMID: 19019343 DOI: 10.1016/j.ando.2008.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Indexed: 10/21/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a ciliopathy causing multivisceral abnormalities. Its prevalence in Europe is from 1/125,000 to 1/175,000. This disorder is defined by a combination of clinical signs: obesity, pigmentary retinopathy, post-axial polydactyly, polycystic kidneys, hypogenitalism, and learning disabilities, many of which appearing after several years of evolution. Individual clinical phenotype is highly variable. Most signs are present in a majority of patients but only pigmentary retinopathy is constant after infancy. There are many other associated minor clinical signs including diabetes, blood hypertension, congenital cardiopathy or Hirschsprung disease. This broad clinical spectrum is associated to a great genetic heterogeneity, with mainly an autosomal recessive transmission and, sometimes cases of oligogenism. To date, mutations in 12 different genes (BBS1 to BBS12) are responsible for this phenotype. These genes code for proteins involved in the development and function of primary cilia. Absent or non functional BBS proteins affect cilia in certain organs such as kidney or eye. However, some symptoms are still not clearly related to cilia dysfunction. BB syndrome has to be recognized because a molecular diagnosis is possible and will lead to familial genetic counseling and possibly prenatal diagnosis. Patients with BBS will need a multidisciplinary medical care. The renal abnormalities are the main life-threatening features because they can lead to end-stage renal failure and renal transplantation. Retinal dystrophy leading to progressive vision loss, moderate mental retardation, and obesity will affect social life of these patients.
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Affiliation(s)
- C Rooryck
- Laboratoire de Génétique Humaine, Université Victor-Segalen, Bordeaux cedex, France.
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Drugowick RM, Da Rós Gonçalves L, Barrôso AS, Feres-Filho EJ, Maia LC. Treatment of Gingival Overgrowth in a Child With Bardet-Biedl Syndrome. J Periodontol 2007; 78:1159-63. [PMID: 17539732 DOI: 10.1902/jop.2007.060378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a rare, heterogeneous, autosomal recessive condition, primarily characterized by polydactyly, obesity, mental retardation, hypogonadism, retinopathy, and renal failure. Dental anomalies, regarded as secondary manifestations, include hypodontia, microdontia, short roots, and deep palate. Few reports in the literature have described the oral manifestations of BBS. This article reports a case of BBS in a boy who presented some typical oral manifestations added to a generalized gingival overgrowth, an anomaly that had not been reported previously in patients with this syndrome. METHODS A 12-year-old white male presented with a diagnosis of BBS and chief complaint of gingival enlargement in the anterior segment of both arcades. The treatment plan included surgical removal of the overgrown gingiva followed by orthodontic therapy. The excised tissues were submitted to histologic analysis. RESULTS There was no sign of recurrence 1 year after gingivectomy. Histopathology revealed a dense connective tissue with a mild inflammatory infiltrate, irregularly arranged fiber bundles, and epithelial acanthosis, which is characteristic of gingival overgrowth. CONCLUSIONS The gingival overgrowth was treated successfully by gingivectomy. The periodontal surgery minimized the functional, social, and emotional consequences of the oral manifestation associated with the syndrome.
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Affiliation(s)
- Rayen Millanao Drugowick
- Department of Pediatric Dentistry and Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, RJ, Brazil
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50
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Abstract
The Bardet-Biedl syndrome (BBS) is a significant genetic cause of chronic and end-stage renal failure in children. Despite being a relatively rare recessive condition, BBS has come to prominence during the past few years owing to revelations of primary cilia dysfunction underlying pathogenesis. The study of this multi-system disorder, which includes obesity, cognitive impairment, genito-urinary tract malformations and limb deformities, is beginning to reveal insights into several aspects of mammalian development and organogenesis. Involvement of BBS proteins in disparate pathways such as the non-canonical Wnt and Sonic Hedgehog pathways is highlighting their interplay in disease pathogenesis. Here we review the recent developments in this emerging field, with the emphasis on the renal component of the syndrome and potential future directions.
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Affiliation(s)
- Jonathan L. Tobin
- Molecular Medicine Unit, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
| | - Philip L. Beales
- Molecular Medicine Unit, UCL Institute of Child Health, 30 Guilford Street, London, WC1N 1EH UK
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