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Qasba RK, Bucharles ACF, Piccoli MVF, Sharma P, Banga A, Kamaraj B, Nawaz FA, Kumar HJ, Happy MA, Qasba RK, Kogilathota Jagirdhar GS, Essar MY, Garg P, Reddy ST, Rama K, Surani S, Kashyap R. Bartter Syndrome: A Systematic Review of Case Reports and Case Series. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1638. [PMID: 37763757 PMCID: PMC10537044 DOI: 10.3390/medicina59091638] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023]
Abstract
Background and Objectives: Bartter syndrome (BS) is a rare group of autosomal-recessive disorders that usually presents with hypokalemic metabolic alkalosis, occasionally with hyponatremia and hypochloremia. The clinical presentation of BS is heterogeneous, with a wide variety of genetic variants. The aim of this systematic review was to examine the available literature and provide an overview of the case reports and case series on BS. Materials and Methods: Case reports/series published from April 2012 to April 2022 were searched through Pubmed, JSTOR, Cochrane, ScienceDirect, and DOAJ. Subsequently, the information was extracted in order to characterize the clinical presentation, laboratory results, treatment options, and follow-up of the patients with BS. Results: Overall, 118 patients, 48 case reports, and 9 case series (n = 70) were identified. Out of these, the majority of patients were male (n = 68). A total of 21 patients were born from consanguineous marriages. Most cases were reported from Asia (73.72%) and Europe (15.25%). In total, 100 BS patients displayed the genetic variants, with most of these being reported as Type III (n = 59), followed by Type II (n = 19), Type I (n = 14), Type IV (n = 7), and only 1 as Type V. The most common symptoms included polyuria, polydipsia, vomiting, and dehydration. Some of the commonly used treatments were indomethacin, potassium chloride supplements, and spironolactone. The length of the follow-up time varied from 1 month to 14 years. Conclusions: Our systematic review was able to summarize the clinical characteristics, presentation, and treatment plans of BS patients. The findings from this review can be effectively applied in the diagnosis and patient management of individuals with BS, rendering it a valuable resource for nephrologists in their routine clinical practice.
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Affiliation(s)
| | - Anna Carolina Flumignan Bucharles
- Department of Medicine, Faculty of Health Sciences, Universidade Positivo, R. Professor Pedro Viriato Parigot de Souza, Curitiba 5300, Brazil
| | - Maria Victoria Ferreira Piccoli
- Department of Medicine, Faculty of Health Sciences, Universidade Positivo, R. Professor Pedro Viriato Parigot de Souza, Curitiba 5300, Brazil
| | | | - Akshat Banga
- Sawai Man Singh Medical College, Jaipur 302004, Rajasthan, India
| | | | - Faisal A. Nawaz
- Emirates Health Services, Al Amal Psychiatric Hospital, Dubai 345055, United Arab Emirates
| | | | | | - Ruman K. Qasba
- Sher-I-Kashmir Institute of Medical Sciences, Srinagar 190001, Jammu and Kashmir, India
| | | | | | - Piyush Garg
- JJM Medical College, Davanagere 577004, Karnataka, India
| | | | - Kaanthi Rama
- Gandhi Medical College, Secunderabad 500025, Telangana, India
| | - Salim Surani
- Department of Medicine & Pharmacology, Texas A&M University, College Station, TX 79016, USA
| | - Rahul Kashyap
- Critical Care Medicine, Department of Anesthesiology, Mayo Clinic, Rochester, MN 55905, USA
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2
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Guo W, Ji P, Xie Y. Genetic diagnosis and treatment of hereditary renal tubular disease with hypokalemia and alkalosis. J Nephrol 2023; 36:575-591. [PMID: 35994232 DOI: 10.1007/s40620-022-01428-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/29/2022] [Indexed: 10/15/2022]
Abstract
Renal tubules play an important role in maintaining water, electrolyte, and acid-base balance. Renal tubule dysfunction can cause electrolyte disorders and acid-base imbalance. Clinically, hypokalemic renal tubular disease is the most common tubule disorder. With the development of molecular genetics and gene sequencing technology, hereditary renal tubular diseases have attracted attention, and an increasing number of pathogenic genes related to renal tubular diseases have been discovered and reported. Inherited renal tubular diseases mainly occur due to mutations in genes encoding various specific transporters or ion channels expressed on the tubular epithelial membrane, leading to dysfunctional renal tubular reabsorption, secretion, and excretion. An in-depth understanding of the molecular genetic basis of hereditary renal tubular disease will help to understand the physiological function of renal tubules, the mechanism by which the kidney maintains water, electrolyte, and acid-base balance, and the relationship between the kidney and other systems in the body. Meanwhile, understanding these diseases also improves our understanding of the pathogenesis of hypokalemia, alkalosis and other related diseases and ultimately promotes accurate diagnostics and effective disease treatment. The present review summarizes the most common hereditary renal tubular diseases (Bartter syndrome, Gitelman syndrome, EAST syndrome and Liddle syndrome) characterized by hypokalemia and alkalosis. Further detailed explanations are provided for pathogenic genes and functional proteins, clinical manifestations, intrinsic relationship between genotype and clinical phenotype, diagnostic clues, differential diagnosis, and treatment strategies for these diseases.
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Affiliation(s)
- Wenkai Guo
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, 100853, People's Republic of China
- School of Medicine, Nankai University, Tianjin, 300071, People's Republic of China
| | - Pengcheng Ji
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, 100853, People's Republic of China
| | - Yuansheng Xie
- Department of Nephrology, First Medical Center of Chinese PLA General Hospital, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Beijing, 100853, People's Republic of China.
- School of Medicine, Nankai University, Tianjin, 300071, People's Republic of China.
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3
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London S, Levine MA, Li D, Spiegel R, Lebel A, Halevy R, Tenenbaum-Rakover Y. Hypocalcemia as the Initial Presentation of Type 2 Bartter Syndrome: A Family Report. J Clin Endocrinol Metab 2022; 107:e1679-e1688. [PMID: 34751387 DOI: 10.1210/clinem/dgab821] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Bartter syndrome (BS) is a group of rare autosomal-recessive tubulopathies characterized by hypokalemic, hypochloremic metabolic alkalosis in which the primary defect is a deficiency of transporters involved in sodium chloride reabsorption. Type 2 BS results from a defect in the renal outer medullary potassium channel encoded by the KCNJ1 gene. Type 2 BS presents with polyhydramnios, intrauterine growth retardation, prematurity, failure to thrive, polyuria, hypercalciuria, and life-threatening episodes of dehydration. Hypocalcemia is a very rare presenting symptom of BS, with only a few published cases reporting it as the initial manifestation of type 2 BS. OBJECTIVE To describe a child who presented with hypocalcemic seizure at the age of 2.3 years that was first related to vitamin D deficiency and high-phosphate soft drink consumption. METHODS Whole exome sequencing (WES) was used to evaluate the biochemical abnormalities of the proband. RESULTS We identified a previously described homozygous missense mutation c.212C>T, p.T71M in the KCNJ1 gene associated with type 2 BS. Six additional family members with the same mutation and diagnosed clinically with BS are also reported, 2 presenting with hypocalcemia associated with vitamin D deficiency. CONCLUSION This report expands the clinical spectrum associated with KCNJ1 mutations and emphasizes the role of WES in unsolved cases of hypocalcemia when genetic disease is suspected. It also highlights the hazardous effects of phosphate-containing soft drinks on calcium metabolism.
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Affiliation(s)
- Shira London
- Pediatric Endocrine Institute, Ha'Emek Medical Center, Afula, Israel
- Armon Child Health Center, Clalit Health Services, Haifa, Israel
| | - Michael A Levine
- Division of Endocrinology and Diabetes, Center for Bone Health, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Dong Li
- Center for Applied Genomics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Ronen Spiegel
- Pediatric Ward B, Ha'Emek Medical Center, Afula, Israel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
| | - Asaf Lebel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
- Pediatric Nephrology Unit, Ha'Emek Medical Center, Afula, Israel
| | - Rephael Halevy
- Pediatric Nephrology Unit, Ha'Emek Medical Center, Afula, Israel
| | - Yardena Tenenbaum-Rakover
- Pediatric Endocrine Institute, Ha'Emek Medical Center, Afula, Israel
- The Rappaport Faculty of Medicine, Technion Institute of Technology, Haifa, Israel
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4
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Marcoux AA, Tremblay LE, Slimani S, Fiola MJ, Mac-Way F, Haydock L, Garneau AP, Isenring P. Anatomophysiology of the Henle's Loop: Emphasis on the Thick Ascending Limb. Compr Physiol 2021; 12:3119-3139. [PMID: 34964111 DOI: 10.1002/cphy.c210021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The loop of Henle plays a variety of important physiological roles through the concerted actions of ion transport systems in both its apical and basolateral membranes. It is involved most notably in extracellular fluid volume and blood pressure regulation as well as Ca2+ , Mg2+ , and acid-base homeostasis because of its ability to reclaim a large fraction of the ultrafiltered solute load. This nephron segment is also involved in urinary concentration by energizing several of the steps that are required to generate a gradient of increasing osmolality from cortex to medulla. Another important role of the loop of Henle is to sustain a process known as tubuloglomerular feedback through the presence of specialized renal tubular cells that lie next to the juxtaglomerular arterioles. This article aims at describing these physiological roles and at discussing a number of the molecular mechanisms involved. It will also report on novel findings and uncertainties regarding the realization of certain processes and on the pathophysiological consequences of perturbed salt handling by the thick ascending limb of the loop of Henle. Since its discovery 150 years ago, the loop of Henle has remained in the spotlight and is now generating further interest because of its role in the renal-sparing effect of SGLT2 inhibitors. © 2022 American Physiological Society. Compr Physiol 12:1-21, 2022.
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Affiliation(s)
- Andrée-Anne Marcoux
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Laurence E Tremblay
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Samira Slimani
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Marie-Jeanne Fiola
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Fabrice Mac-Way
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Ludwig Haydock
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
| | - Alexandre P Garneau
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada.,Cardiometabolic Axis, School of Kinesiology and Physical Activity Sciences, University of Montréal, Montréal, QC, Canada
| | - Paul Isenring
- Nephrology Research Group, Department of Medicine, Laval University, Québec, QC, Canada
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5
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Nuñez-Gonzalez L, Carrera N, Garcia-Gonzalez MA. Molecular Basis, Diagnostic Challenges and Therapeutic Approaches of Bartter and Gitelman Syndromes: A Primer for Clinicians. Int J Mol Sci 2021; 22:11414. [PMID: 34768847 PMCID: PMC8584233 DOI: 10.3390/ijms222111414] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 12/18/2022] Open
Abstract
Gitelman and Bartter syndromes are rare inherited diseases that belong to the category of renal tubulopathies. The genes associated with these pathologies encode electrolyte transport proteins located in the nephron, particularly in the Distal Convoluted Tubule and Ascending Loop of Henle. Therefore, both syndromes are characterized by alterations in the secretion and reabsorption processes that occur in these regions. Patients suffer from deficiencies in the concentration of electrolytes in the blood and urine, which leads to different systemic consequences related to these salt-wasting processes. The main clinical features of both syndromes are hypokalemia, hypochloremia, metabolic alkalosis, hyperreninemia and hyperaldosteronism. Despite having a different molecular etiology, Gitelman and Bartter syndromes share a relevant number of clinical symptoms, and they have similar therapeutic approaches. The main basis of their treatment consists of electrolytes supplements accompanied by dietary changes. Specifically for Bartter syndrome, the use of non-steroidal anti-inflammatory drugs is also strongly supported. This review aims to address the latest diagnostic challenges and therapeutic approaches, as well as relevant recent research on the biology of the proteins involved in disease. Finally, we highlight several objectives to continue advancing in the characterization of both etiologies.
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Affiliation(s)
- Laura Nuñez-Gonzalez
- Grupo de Xenetica e Bioloxia do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxia (No. 11), Instituto de Investigacion Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain;
- Grupo de Medicina Xenomica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
| | - Noa Carrera
- Grupo de Xenetica e Bioloxia do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxia (No. 11), Instituto de Investigacion Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain;
- Grupo de Medicina Xenomica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
- RedInRen (Red en Investigación Renal) RETIC (Redes Temáticas de Investigación Cooperativa en Salud), ISCIII (Instituto de Salud Carlos III), 28029 Madrid, Spain
| | - Miguel A. Garcia-Gonzalez
- Grupo de Xenetica e Bioloxia do Desenvolvemento das Enfermidades Renais, Laboratorio de Nefroloxia (No. 11), Instituto de Investigacion Sanitaria de Santiago (IDIS), Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain;
- Grupo de Medicina Xenomica, Complexo Hospitalario de Santiago de Compostela (CHUS), 15706 Santiago de Compostela, Spain
- RedInRen (Red en Investigación Renal) RETIC (Redes Temáticas de Investigación Cooperativa en Salud), ISCIII (Instituto de Salud Carlos III), 28029 Madrid, Spain
- Fundación Pública Galega de Medicina Xenomica—SERGAS, Complexo Hospitalario de Santiago de Compotela (CHUS), 15706 Santiago de Compostela, Spain
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6
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Mani S, Nair J, Handa D. Antenatal Bartter syndrome: a new compound heterozygous mutation in exon 2 of KCNJ1 gene. BMJ Case Rep 2021; 14:e244685. [PMID: 34663630 PMCID: PMC8524263 DOI: 10.1136/bcr-2021-244685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2021] [Indexed: 11/03/2022] Open
Abstract
A 30+6/7-week infant was born by vaginal delivery to a 21-year-old primigravida with pregnancy complicated by polyhydramnios. The infant developed polyuria and significant weight loss in the first 2 weeks of life despite appropriate fluid management. He developed hyponatraemia, hypochloraemia, transient hyperkalaemia and prerenal azotaemia with metabolic acidosis. On further evaluation, he had elevated plasma renin and aldosterone levels. Bartter syndrome was considered in the differential diagnosis. Bartter syndrome gene panel revealed a rare compound heterozygous mutation in exon 2 of the KCNJ1 gene (Lys186Glu/Thr71Met), suggesting antenatal Bartter syndrome (type 2). The infant developed late-onset hypokalaemia and metabolic alkalosis by week 4 of life. He regained birth weight by week 3 of life but failed to thrive (10-20 g/kg/day) despite high caloric intake (140 kcal/kg/day). His electrolyte abnormalities gradually improved, and he was discharged home without the need for electrolyte supplements or medications.
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Affiliation(s)
- Srinivasan Mani
- Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Jayasree Nair
- Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
| | - Deepali Handa
- Pediatrics, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, Buffalo, New York, USA
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7
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Marcoux A, Tremblay LE, Slimani S, Fiola M, Mac‐Way F, Garneau AP, Isenring P. Molecular characteristics and physiological roles of Na + -K + -Cl - cotransporter 2. J Cell Physiol 2021; 236:1712-1729. [PMID: 32776569 PMCID: PMC7818487 DOI: 10.1002/jcp.29997] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/28/2020] [Accepted: 07/24/2020] [Indexed: 12/23/2022]
Abstract
Na+ -K+ -Cl- cotransporter 2 (NKCC2; SLC12A1) is an integral membrane protein that comes as three splice variants and mediates the cotranslocation of Na+ , K+ , and Cl- ions through the apical membrane of the thick ascending loop of Henle (TALH). In doing so, and through the involvement of other ion transport systems, it allows this nephron segment to reclaim a large fraction of the ultrafiltered Na+ , Cl- , Ca2+ , Mg2+ , and HCO3- loads. The functional relevance of NKCC2 in human is illustrated by the many abnormalities that result from the inactivation of this transport system through the use of loop diuretics or in the setting of inherited disorders. The following presentation aims at discussing the physiological roles and molecular characteristics of Na+ -K+ -Cl- cotransport in the TALH and those of the individual NKCC2 splice variants more specifically. Many of the historical and recent data that have emerged from the experiments conducted will be outlined and their larger meaning will also be placed into perspective with the aid of various hypotheses.
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Affiliation(s)
- Andree‐Anne Marcoux
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
| | - Laurence E. Tremblay
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
| | - Samira Slimani
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
| | - Marie‐Jeanne Fiola
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
| | - Fabrice Mac‐Way
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
| | - Alexandre P. Garneau
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQuebecCanada
| | - Paul Isenring
- Department of Medicine, Nephrology Research GroupLaval UniversityQuebec CityQuébecCanada
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8
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Konrad M, Nijenhuis T, Ariceta G, Bertholet-Thomas A, Calo LA, Capasso G, Emma F, Schlingmann KP, Singh M, Trepiccione F, Walsh SB, Whitton K, Vargas-Poussou R, Bockenhauer D. Diagnosis and management of Bartter syndrome: executive summary of the consensus and recommendations from the European Rare Kidney Disease Reference Network Working Group for Tubular Disorders. Kidney Int 2021; 99:324-335. [PMID: 33509356 DOI: 10.1016/j.kint.2020.10.035] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/30/2020] [Accepted: 10/29/2020] [Indexed: 12/13/2022]
Abstract
Bartter syndrome is a rare inherited salt-losing renal tubular disorder characterized by secondary hyperaldosteronism with hypokalemic and hypochloremic metabolic alkalosis and low to normal blood pressure. The primary pathogenic mechanism is defective salt reabsorption predominantly in the thick ascending limb of the loop of Henle. There is significant variability in the clinical expression of the disease, which is genetically heterogenous with 5 different genes described to date. Despite considerable phenotypic overlap, correlations of specific clinical characteristics with the underlying molecular defects have been demonstrated, generating gene-specific phenotypes. As with many other rare disease conditions, there is a paucity of clinical studies that could guide diagnosis and therapeutic interventions. In this expert consensus document, the authors have summarized the currently available knowledge and propose clinical indicators to assess and improve quality of care.
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Affiliation(s)
- Martin Konrad
- Department of General Pediatrics, University Hospital Münster, Münster, Germany.
| | - Tom Nijenhuis
- Department of Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Gema Ariceta
- Pediatric Nephrology, Hospital Universitari Vall d'Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | | | - Lorenzo A Calo
- Department of Medicine (DIMED), Nephrology, Dialysis, Transplantation, University of Padova, Padua, Italy
| | - Giovambattista Capasso
- Division of Nephrology, Department of Translational Medical Sciences, School of Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Francesco Emma
- Division of Nephrology, Department of Pediatric Subspecialties, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - Karl P Schlingmann
- Department of General Pediatrics, University Hospital Münster, Münster, Germany
| | - Mandeep Singh
- Fetal Medicine Centre, Southend University Hospital NHS Foundation Trust, Essex, UK
| | - Francesco Trepiccione
- Division of Nephrology, Department of Translational Medical Sciences, School of Medicine, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Stephen B Walsh
- Department of Renal Medicine, University College London, London, United Kingdom
| | | | - Rosa Vargas-Poussou
- Hôpital Européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Centre d'Investigation Clinique, Paris, France; Centre de Référence des Maladies Rénales Héréditaires de l'Enfant et de l'Adulte, Paris, France
| | - Detlef Bockenhauer
- Department of Renal Medicine, University College London, London, United Kingdom; Department of Pediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
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9
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Hanukoglu A, Vargas-Poussou R, Landau Z, Yosovich K, Hureaux M, Zennaro MC. Renin-aldosterone system evaluation over four decades in an extended family with autosomal dominant pseudohypoaldosteronism due to a deletion in the NR3C2 gene. J Steroid Biochem Mol Biol 2020; 204:105755. [PMID: 33017655 DOI: 10.1016/j.jsbmb.2020.105755] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
Abstract
Renal pseudohypoaldosteronism (PHA1) is a mild form of an aldosterone-resistance syndrome caused by mutations in the NR3C2 gene that codes for the mineralocorticoid receptor (MR). The disease is inherited as an autosomal dominant trait characterized by signs and symptoms of salt-losing in infancy. Disease manifestations could be severe in infancy but improve after the age of 1-3 years. Some affected members are asymptomatic and remain so life-long. In this study, we report the identification of a large deletion in the NR3C2 gene (c.1897+1_1898-1)_(c.*2955+?)del in renal PHA1 patients from an extended family spanning four generations. We prospectively evaluated the plasma renin activity and serum aldosterone profiles over four decades in symptomatic and asymptomatic affected family members. The benefits of early diagnosis on the clinical outcome were assessed as well. The long-term follow-up showed an age-dependent decrease in both plasma renin activity and serum aldosterone levels over the years. However, aldosterone levels remain high life-long. Thus, levels of aldosterone are a reliable marker to detect asymptomatic family members. The diagnosis of the proposita led to early diagnosis and therapy in other affected family members, significantly mitigating the clinical course. Despite the extremely elevated serum aldosterone levels during pregnancy, affected pregnant women did not experience any ill effects. However, this should be verified by observations in other adult patients.
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Affiliation(s)
- Aaron Hanukoglu
- Division of Pediatric Endocrinology, E. Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel.
| | - Rosa Vargas-Poussou
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France; Centre de Références de Maladies Rénales Rares de l'Enfant et d'Adulte (MARHEA)
| | - Zohar Landau
- Division of Pediatric Endocrinology, E. Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Keren Yosovich
- Molecular Genetics Lab, Wolfson Medical Center, Holon, Israel
| | - Marguerite Hureaux
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France; Inserm, PARCC, Université de Paris, F-75015 Paris, France
| | - Maria-Christina Zennaro
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France; Inserm, PARCC, Université de Paris, F-75015 Paris, France
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10
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Zuo J, Guo W, Wang S, Lang Y, Wang S, Shi X, Zhang R, Zhao X, Han Y, Shao L. Eight novel KCNJ1 variants and parathyroid hormone overaction or resistance in 5 probands with Bartter syndrome type 2. Clin Chim Acta 2020; 511:248-254. [PMID: 33058840 DOI: 10.1016/j.cca.2020.10.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/07/2020] [Accepted: 10/02/2020] [Indexed: 01/19/2023]
Abstract
PURPOSE Bartter syndrome type 2 (BS2) is an autosomal recessive renal tubular disorder, which is caused by the mutations in KCNJ1. This study was designed to analyze and describe the genotype and clinical features of five Chinese probands with BS2. METHODS Identify KCNJ1 gene variants by the next generation sequencing and evaluate their mutation effects according to 2015 American College of Medical Genetics and Genomics (ACMG) standards and guidelines. RESULTS Ten variants including eight novel ones of KCNJ1 gene were found, the most common type was missense variant. The common symptoms and signs from high to low incidence were: polydipsia and polyuria (5/5), one of them (1/5) presented with diabetes insipidus; maternal polyhydramnios and premature delivery (4/5); growth retardation (3/5). Two patients presented with hypochloremic metabolic alkalosis and hypokalemia; whereas the acid-base disturbance was absent in the others. One patient had evident parathyroid hormone (PTH) resistance (hypocalcemia, hyperphosphatemia and markedly elevated PTH levels), three presented with PTH overacting (hypercalcemia, hypophosphatemia and mild elevated PTH levels), and one showed normal blood calcium and phosphorus concentrations with high-normal PTH levels. All patients had nephrocalcinosis and/or hypercalciuria, and one of them complicated with nephrolithiasis. Indomethacin has significant therapeutic effect on the growth retardation, polydipsia and polyuria and treatment was associated with a decrease in urine calcium excretion, normalization of electrolyte disturbance and PTH parameters. CONCLUSIONS Ten variants of KCNJ1 gene were identified in five Chinese probands. These patients had atypical BS phenotype lacking evident metabolic alkalosis and/or manifesting with PTH overaction/resistance, which reminds clinicians to carefully differentiate BS2 with other parathyroid disorders. This is the first report of BS2 from Chinese populations.
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Affiliation(s)
- Jianxin Zuo
- Department of Obstetrics, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China
| | - Wencong Guo
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Shujuan Wang
- Department of Nursing, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Yanhua Lang
- Department of Nursing, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Sai Wang
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Xiaomeng Shi
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Ruixiao Zhang
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Xiangzhong Zhao
- Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China
| | - Yue Han
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China.
| | - Leping Shao
- Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Qingdao University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Department of Nephrology, the Affiliated Qingdao Municipal Hospital of Shandong University, No.5 Donghai Middle Road, Qingdao 266071, People's Republic of China; Central Laboratory, the Affiliated Hospital of Qingdao University, Qingdao 266003, People's Republic of China.
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11
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Elfert KA, Geller DS, Nelson-Williams C, Lifton RP, Al-Malki H, Nauman A. Late-Onset Bartter Syndrome Type II Due to a Homozygous Mutation in KCNJ1 Gene: A Case Report and Literature Review. AMERICAN JOURNAL OF CASE REPORTS 2020; 21:e924527. [PMID: 32997650 PMCID: PMC7534490 DOI: 10.12659/ajcr.924527] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Bartter syndrome is a rare genetic disease characterized by hypokalemia, metabolic alkalosis, and hyperreninemic hyperaldosteronism. Five different subtypes have been described based on the genetic defect identified. Bartter syndrome type II is caused by homozygous or compound heterozygous loss-of-function mutations in the KCNJ1 gene encoding ROMK. This subtype is typically described as a severe antenatal form of the disease, often presenting with polyhydramnios before childbirth. CASE REPORT Here, we describe the case of a 26-year-old man who presented with generalized body weakness and hypokalemia and was ultimately diagnosed with Bartter syndrome type II based on his clinical features coupled with the identification of a homozygous missense mutation in KCNJ1. CONCLUSIONS To the best of our knowledge, this is the fifth case of late-onset Bartter syndrome type II. Interestingly, the mutation identified in our patient has been previously described in patients with antenatal Bartter's Syndrome. The late presentation in our patient suggests a surprising degree of phenotypic variability, even in patients carrying the identical disease-causing mutation.
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Affiliation(s)
- Khaled A Elfert
- Department of Internal Medicine, Hamad Medical Corporation, Doha, Qatar
| | - David S Geller
- Department of Nephrology, Yale University School of Medicine, New Haven, CT, USA.,Department of Nephrology, West Haven VA Hospital, West Haven, CT, USA
| | | | - Richard P Lifton
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Hassan Al-Malki
- Department of Nephrology, Hamad Medical Corporation, Doha, Qatar
| | - Awais Nauman
- Department of Nephrology, Hamad Medical Corporation, Doha, Qatar
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12
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Nozu K, Yamamura T, Horinouchi T, Nagano C, Sakakibara N, Ishikura K, Hamada R, Morisada N, Iijima K. Inherited salt-losing tubulopathy: An old condition but a new category of tubulopathy. Pediatr Int 2020; 62:428-437. [PMID: 31830341 DOI: 10.1111/ped.14089] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/11/2019] [Accepted: 10/21/2019] [Indexed: 12/16/2022]
Abstract
Bartter syndrome (BS) and Gitelman syndrome (GS) are syndromes associated with congenital tubular dysfunction, characterized by hypokalemia and metabolic alkalosis. Clinically, BS is classified into two types: the severe antenatal/neonatal type, which develops during the fetal period with polyhydramnios and preterm delivery; and the relatively mild classic type, which is usually found during infancy with failure to thrive. GS can be clinically differentiated from BS by its age at onset, usually after school age, or laboratory findings of hypomagnesemia and hypocalciuria. Recent advances in molecular biology have shown that these diseases can be genetically classified into type 1 to 5 BS and GS. As a result, it has become clear that the clinical classification of antenatal/neonatal BS, classic BS, and GS does not always correspond to the clinical symptoms associated with the genotypes in a one-to-one manner; and there is clinically no clear differential border between type 3 BS and GS. This has caused confusion among clinicians in the diagnosis of these diseases. It has been proposed that the disease name "inherited salt-losing tubulopathy" can be used for cases of tubulopathies accompanied by hypokalemia and metabolic alkalosis. It is reasonable to use this term prior to genetic typing into type 1-5 BS or GS, to avoid confusion in a clinical setting. In this article, we review causative genes and phenotypic correlations, diagnosis, and treatment strategies for salt-losing tubulopathy as well as the clinical characteristics of pseudo-BS/GS, which can also be called a "salt-losing disorder".
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Affiliation(s)
- Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomohiko Yamamura
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Tomoko Horinouchi
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - China Nagano
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Nana Sakakibara
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kenji Ishikura
- Kitasato University School of Medicine, Sagamihara, Japan
| | - Riku Hamada
- Department of Nephrology, Tokyo Metropolitan Children's Medical Center, Fuchu, Japan
| | - Naoya Morisada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
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13
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Khandelwal P, Sabanadesan J, Sinha A, Hari P, Bagga A. Isolated nephrocalcinosis due to compound heterozygous mutations in renal outer medullary potassium channel. CEN Case Rep 2020; 9:232-236. [PMID: 32185747 DOI: 10.1007/s13730-020-00464-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 03/03/2020] [Indexed: 02/06/2023] Open
Abstract
Identification of a monogenic etiology is possible in a proportion of patients with childhood-onset nephrolithiasis or nephrocalcinosis. Bartter syndrome (BS), a hereditary tubulopathy characterized by polyuria, hypokalemic alkalosis and growth retardation that rarely presents with isolated nephrocalcinosis. Patients with defect in renal outer medullary potassium channel, encoded by the KCNJ1 gene causing BS type 2, typically present during the neonatal period. We describe a 14-year-old girl with mild late-onset BS type 2 with reported pathogenic compound heterozygous variations in exon 2 of KCNJ1 (c.146G > A and c.657C > G). This patient presented with isolated medullary nephrocalcinosis due to hypercalciuria; absence of hypokalemia and metabolic alkalosis was unique. This case highlights the importance of screening the KCNJ1 gene in patients with hypercalciuria and nephrocalcinosis, even in older children.
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Affiliation(s)
- Priyanka Khandelwal
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Jasintha Sabanadesan
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Aditi Sinha
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Pankaj Hari
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India
| | - Arvind Bagga
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, 110029, India.
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14
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Duodenal web masquerading as pseudohypoaldosteronism of infancy. JOURNAL OF CLINICAL AND TRANSLATIONAL ENDOCRINOLOGY CASE REPORTS 2020. [DOI: 10.1016/j.jecr.2020.100056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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15
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Recent insights into sodium and potassium handling by the aldosterone-sensitive distal nephron: implications on pathophysiology and drug discovery. J Nephrol 2020; 33:447-466. [DOI: 10.1007/s40620-020-00700-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 01/02/2020] [Indexed: 12/31/2022]
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16
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Cohen E, Sawyer JK, Peterson NG, Dow JAT, Fox DT. Physiology, Development, and Disease Modeling in the Drosophila Excretory System. Genetics 2020; 214:235-264. [PMID: 32029579 PMCID: PMC7017010 DOI: 10.1534/genetics.119.302289] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 11/04/2019] [Indexed: 02/06/2023] Open
Abstract
The insect excretory system contains two organ systems acting in concert: the Malpighian tubules and the hindgut perform essential roles in excretion and ionic and osmotic homeostasis. For over 350 years, these two organs have fascinated biologists as a model of organ structure and function. As part of a recent surge in interest, research on the Malpighian tubules and hindgut of Drosophila have uncovered important paradigms of organ physiology and development. Further, many human disease processes can be modeled in these organs. Here, focusing on discoveries in the past 10 years, we provide an overview of the anatomy and physiology of the Drosophila excretory system. We describe the major developmental events that build these organs during embryogenesis, remodel them during metamorphosis, and repair them following injury. Finally, we highlight the use of the Malpighian tubules and hindgut as accessible models of human disease biology. The Malpighian tubule is a particularly excellent model to study rapid fluid transport, neuroendocrine control of renal function, and modeling of numerous human renal conditions such as kidney stones, while the hindgut provides an outstanding model for processes such as the role of cell chirality in development, nonstem cell-based injury repair, cancer-promoting processes, and communication between the intestine and nervous system.
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Affiliation(s)
| | - Jessica K Sawyer
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, and
| | | | - Julian A T Dow
- Institute of Molecular, Cell, and Systems Biology, University of Glasgow, G12 8QQ, United Kingdom
| | - Donald T Fox
- Department of Cell Biology and
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, and
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17
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van der Wijst J, Belge H, Bindels RJM, Devuyst O. Learning Physiology From Inherited Kidney Disorders. Physiol Rev 2019; 99:1575-1653. [PMID: 31215303 DOI: 10.1152/physrev.00008.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The identification of genes causing inherited kidney diseases yielded crucial insights in the molecular basis of disease and improved our understanding of physiological processes that operate in the kidney. Monogenic kidney disorders are caused by mutations in genes coding for a large variety of proteins including receptors, channels and transporters, enzymes, transcription factors, and structural components, operating in specialized cell types that perform highly regulated homeostatic functions. Common variants in some of these genes are also associated with complex traits, as evidenced by genome-wide association studies in the general population. In this review, we discuss how the molecular genetics of inherited disorders affecting different tubular segments of the nephron improved our understanding of various transport processes and of their involvement in homeostasis, while providing novel therapeutic targets. These include inherited disorders causing a dysfunction of the proximal tubule (renal Fanconi syndrome), with emphasis on epithelial differentiation and receptor-mediated endocytosis, or affecting the reabsorption of glucose, the handling of uric acid, and the reabsorption of sodium, calcium, and magnesium along the kidney tubule.
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Affiliation(s)
- Jenny van der Wijst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Hendrica Belge
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
| | - Olivier Devuyst
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen , The Netherlands ; Institute of Physiology, University of Zurich , Zurich , Switzerland ; and Division of Nephrology, Institute of Experimental and Clinical Research (IREC), Medical School, Université catholique de Louvain, Brussels, Belgium
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18
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Halperin D, Dolgin V, Geylis M, Drabkin M, Yogev Y, Wormser O, Schreiber R, Shalev H, Landau D, Birk OS. A novel SLC12A1 mutation in Bedouin kindred with antenatal Bartter syndrome type I. Ann Hum Genet 2019; 83:361-366. [PMID: 30977917 DOI: 10.1111/ahg.12317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/18/2019] [Accepted: 03/26/2019] [Indexed: 12/01/2022]
Abstract
Four affected individuals of consanguineous kindred presented at infancy with an apparently autosomal recessive syndrome of polyuria and hypokalemic metabolic alkalosis, following maternal polyhydramnios and premature delivery, culminating in severe failure to thrive. Hypercalciuria, nephrocalcinosis, and hyperaldosteronism were further apparent as well as an unusual finding of intermittent hypernatremia. Additionally, all patients demonstrated variable micrognathia with upper respiratory airway abnormalities. As neither postnatal hyperkalemia nor permanent hearing deficits were shown, clinical assessment was consistent with antenatal Bartter syndrome (ABS) type I, which was never described before in the Israeli Bedouin population. Through genome-wide linkage analysis, we identified a single ∼3.3 Mbp disease-associated locus on chromosome 15q21.1, segregating within the pedigree. Whole-exome sequencing revealed a single novel homozygous missense mutation within this locus, in SLC12A1, encoding the Na-K-Cl cotransporter, NKCC2, in accordance with the clinical diagnosis. In this concise study, we report a novel missense mutation within the SLC12A1 gene, causing a severe form of ABS type I, the first to be described in Israeli Bedouins, with unusual clinical features of hypernatremia caused by nephrogenic diabetes insipidus and putatively related micrognathia with upper airway abnormalities .
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Affiliation(s)
- Daniel Halperin
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Vadim Dolgin
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Michael Geylis
- Pediatric Nephrology Clinic, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Max Drabkin
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Yuval Yogev
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ohad Wormser
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ruth Schreiber
- Pediatric Nephrology Clinic, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Hanna Shalev
- Pediatric Nephrology Clinic, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Daniel Landau
- Pediatrics Department A, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.,Pediatrics Department B, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Ohad S Birk
- The Morris Kahn Laboratory of Human Genetics, National Institute for Biotechnology in the Negev and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel.,Genetics Institute, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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19
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Abstract
Bartter and Gitelman syndromes are conditions characterized by renal salt-wasting. Clinical presentations range from severe antenatal disease to asymptomatic with incidental diagnosis. Hypokalemic hypochloremic metabolic alkalosis is the common feature. Bartter variants may be associated with polyuria and weakness. Gitelman syndrome is often subtle, and typically diagnosed later life with incidental hypokalemia and hypomagnesemia. Treatment may involve fluid and electrolyte replenishment, prostaglandin inhibition, and renin-angiotensin-aldosterone system axis disruption. Investigators have identified causative mutations but genotypic-phenotypic correlations are still being characterized. Collaborative registries will allow improved classification schema and development of effective treatments.
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Affiliation(s)
- Rosanna Fulchiero
- Department of Pediatrics, Inova Children's Hospital, 3300 Gallows Road, Falls Church, VA 22042, USA
| | - Patricia Seo-Mayer
- Department of Pediatrics, Inova Children's Hospital, 3300 Gallows Road, Falls Church, VA 22042, USA; Division of Nephrology and Hypertension, Pediatric Specialists of Virginia, 3023 Hamaker Court, Suite 600, Fairfax, VA 22031, USA; Virginia Commonwealth School of Medicine, Richmond, VA, USA.
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20
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Abstract
PURPOSE OF REVIEW Antenatal Bartter's syndrome (aBS) is the most severe form of Bartter's syndrome, requiring close follow-up, in particular during the neonatal period, primarily because of prematurity. The recent identification of a novel and very severe form of aBS merits an update on this topic. RECENT FINDING Despite the identification of several genes involved in Bartter's syndrome, about 20% of patients clinically diagnosed with aBS remained without genetic explanation for decades. We recently identified mutations in MAGED2 as a cause of an X-linked form of aBS characterized by a very early onset of severe polyhydramnios and extreme prematurity leading to high mortality. Remarkably, all symptoms in surviving patients with MAGE-D2 mutations resolve spontaneously, within weeks after preterm birth. Interestingly, MAGE-D2 affects the expression of the sodium chloride cotransporters NKCC2 and NCC, explaining thereby the severity of the disease. Importantly, a more recent analysis of MAGED2 in a large French cohort of patients with aBS confirmed our data and showed that females can also be affected. SUMMARY MAGE-D2 is critical for renal salt reabsorption in the fetus, amniotic fluid volume regulation, and maintenance of pregnancy. Most importantly, MAGED2 must be included in the genetic screening of every form of aBS.
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21
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Future considerations based on the information from Barrter's and Gitelman's syndromes. Curr Opin Nephrol Hypertens 2018; 26:9-13. [PMID: 27798456 DOI: 10.1097/mnh.0000000000000285] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Bartter and Gitelman syndromes are typical normotensive salt losing hypokalaemic tubulopathies. Their pathogenesis was gradually deciphered in the past 5 decades, first by typical salt balance studies and histopathology, followed by genetic characterization and discovery of the affected different ion channels. Although the different genotypic subtypes were originally thought to show a similar phenotype, important clinical and biochemical differences can now be found. New findings on the regulation of these channels, as well as the recent discovery of newly affected genes, merit an update on this topic. RECENT FINDINGS Na-K-2CL cotransporter and NaCl cotransporter, the two main luminal channels in the thick ascending limb and distal convoluted tubule were found to be regulated by Ste 20-related proline alanine-rich kinase and oxidative stress response kinase. Knockout mice to these channels express a Bartter-like phenotype. MAGE-D2 is new gene found to cause severe polyhydramnios and transient postnatal Bartter-like syndrome. Variants in the different channels causing Bartter syndromes/Gitelman syndromes may also confer susceptibility for hypertension or protect against it. SUMMARY It remains to be determined if polymorphism or epigenetic changes in these genes and proteins may affect salt handling, explaining, apart from Bartter syndromes and Gitelman syndromes, also hypertension or stroke tendency, or both.
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22
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Abstract
Bartter syndrome (BS) type 1 (OMIM #601678) is a hereditary salt-losing renal tubular disorder characterized by hypokalemic metabolic alkalosis, hypercalciuria, nephrocalcinosis, polyuria, recurrent vomiting, and growth retardation. It is caused by loss-of-function mutations of the SLC12A1 gene, encoding the furosemide-sensitive Na-K-Cl cotransporter. Recently, a phenotypic variability has been observed in patients with genetically determined BS, including absence of nephrocalcinosis, hypokalemia, and/or metabolic alkalosis in the first year of life as well as persistent metabolic acidosis mimicking distal renal tubular acidosis. We report the case of a child with a genetically determined diagnosis of Bartter syndrome type 1 who presented with a phenotype of nephrogenic diabetes insipidus, with severe hypernatremia and urinary concentrating defect. In these atypical cases, molecular analysis is mandatory to define the diagnosis, in order to establish the correct clinical and therapeutic management.
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23
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Li H, Sun S, Chen J, Xu G, Wang H, Qian Q. Genetics of Magnesium Disorders. KIDNEY DISEASES 2017; 3:85-97. [PMID: 29344503 DOI: 10.1159/000477730] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 05/23/2017] [Indexed: 12/30/2022]
Abstract
Background Magnesium (Mg2+), the second most abundant cation in the cell, is woven into a multitude of cellular functions. Dysmagnesemia is associated with multiple diseases and, when severe, can be life-threatening. Summary This review discusses Mg2+ homeostasis and function with specific focus on renal Mg2+ handling. Intrarenal channels and transporters related to Mg2+ absorption are discussed. Unraveling the rare genetic diseases with manifestations of dysmagnesemia has greatly increased our understanding of the complex and intricate regulatory network in the kidney, specifically, functions of tight junction proteins including claudin-14, -16, -19, and -10; apical ion channels including: TRPM6, Kv1.1, and ROMK; small regulatory proteins including AC3 and ANK3; and basolateral proteins including EGF receptor, γ-subunit (FXYD2) of Na-K-ATPase, Kir4.1, CaSR, CNNM2, and SLC41A. Although our understanding of Mg2+ handling of the kidney has expanded considerably in the last two decades, many questions remain. Future studies are needed to elucidate a multitude of unknown aspects of Mg2+ handling in the kidney. Key Message Understanding rare and genetic diseases of Mg2+ dysregulation has expanded our knowledge and furthers the development of strategies for preventing and managing dysmagnesemia.
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Affiliation(s)
- Heng Li
- Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.,Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Shiren Sun
- Department of Nephrology, Xijing Hospital, The Fourth Military Medical University, Xian, China
| | - Jianghua Chen
- Kidney Disease Center, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Goushuang Xu
- Department of Nephrology, Xijing Hospital, The Fourth Military Medical University, Xian, China
| | - Hanmin Wang
- Department of Nephrology, Xijing Hospital, The Fourth Military Medical University, Xian, China
| | - Qi Qian
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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24
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Breinbjerg A, Siggaard Rittig C, Gregersen N, Rittig S, Hvarregaard Christensen J. A novel variant in the SLC12A1 gene in two families with antenatal Bartter syndrome. Acta Paediatr 2017; 106:161-167. [PMID: 27748541 DOI: 10.1111/apa.13635] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 09/20/2016] [Accepted: 10/13/2016] [Indexed: 12/27/2022]
Abstract
AIM Bartter syndrome is an autosomal-recessive inherited disease in which patients present with hypokalaemia and metabolic alkalosis. We present two apparently nonrelated cases with antenatal Bartter syndrome type I, due to a novel variant in the SLC12A1 gene encoding the bumetanide-sensitive sodium-(potassium)-chloride cotransporter 2 in the thick ascending limb of the loop of Henle. METHODS Blood samples were received from the two cases and 19 of their relatives, and deoxyribonucleic acid was extracted. The coding regions of the SLC12A1 gene were amplified using polymerase chain reaction, followed by bidirectional direct deoxyribonucleic acid sequencing. RESULTS Each affected child in the two families was homozygous for a novel inherited variant in the SLC12A1gene, c.1614T>A. The variant predicts a change from a tyrosine codon to a stop codon (p.Tyr538Ter). The two cases presented antenatally and at six months of age, respectively. CONCLUSION The two cases were homozygous for the same variant in the SLC12A1 gene, but presented clinically at different ages. This could eventually be explained by the presence of other gene variants or environmental factors modifying the phenotypes. The phenotypes of the patients were similar to other patients with antenatal Bartter syndrome.
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Affiliation(s)
- Anders Breinbjerg
- Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
| | | | - Niels Gregersen
- Research Unit for Molecular Medicine; Aarhus University Hospital; Aarhus Denmark
| | - Søren Rittig
- Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
| | - Jane Hvarregaard Christensen
- Department of Pediatrics; Aarhus University Hospital; Aarhus Denmark
- Department of Biomedicine; Aarhus University; Aarhus Denmark
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Accentuated hyperparathyroidism in type II Bartter syndrome. Pediatr Nephrol 2016; 31:1085-90. [PMID: 26857709 DOI: 10.1007/s00467-016-3337-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/11/2016] [Accepted: 01/12/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND Bartter syndrome (BS) may be associated with different degrees of hypercalciuria, but marked parathyroid hormone (PTH) abnormalities have not been described. METHODS We compared clinical and laboratory data of patients with either ROMK-deficient type II BS (n = 14) or Barttin-deficient type IV BS (n = 20). RESULTS Only BS-IV patients remained mildly hypokalemic in spite of a higher need for potassium supplementation. Estimated glomerular filtration rate (eGFR) was mildly decreased in only four BS-IV patients. Average PTH values were significantly higher in BS-II (160.6 ± 85.8 vs. 92.5 ± 48 pg/ml in BS-IV, p = 0.006). In both groups, there was a positive correlation between age and log(PTH). Levels of 25(OH) vitamin D were not different. Total serum calcium was lower (within normal limits) and age-related serum phosphate (Pi)-SDS was increased in BS-II (1.19 ± 0.71 vs. 0.01 ± 1.04 in BS-IV, p < 0.001). The GFR threshold for Pi reabsorption was higher in BS-II (5.63 ± 1.25 vs. 4.36 ± 0.98, p = 0.002). Spot urine calcium/creatinine ratio and nephrocalcinosis rate (100 vs. 16 %) were higher in the BS-II group. CONCLUSIONS PTH, serum Pi levels, and urinary threshold for Pi reabsorption are significantly elevated in type II vs. type IV BS, suggesting a PTH resistance state. This may be a response to more severe long-standing hypercalciuria, leading to a higher rate of nephrocalcinosis in BS-II.
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Zieg J, Gonsorcikova L, Landau D. Current views on the diagnosis and management of hypokalaemia in children. Acta Paediatr 2016; 105:762-72. [PMID: 26972906 DOI: 10.1111/apa.13398] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 02/13/2016] [Accepted: 03/08/2016] [Indexed: 12/20/2022]
Abstract
UNLABELLED Hypokalaemia is a common electrolyte disorder in children, caused by decreased potassium intake, increased gastrointestinal and urinary losses or transcellular shift. Patients with severe hypokalaemia may suffer from symptoms such as life-threatening cardiac arrhythmias. The aim of our study was to review the aetiology of hypokalaemia, suggest a diagnostic algorithm and discuss the management of patients with various aetiologies of hypokalaemia. CONCLUSION Understanding the pathophysiology of hypokalaemic states, along with a detailed medical history, physical examination and specific laboratory tests are required for proper diagnosis and appropriate treatment.
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Affiliation(s)
- Jakub Zieg
- Department of Paediatrics; 2 Faculty of Medicine; Motol University Hospital; Charles University in Prague; Praha Czech Republic
| | - Lucie Gonsorcikova
- Department of Paediatrics; 2 Faculty of Medicine; Motol University Hospital; Charles University in Prague; Praha Czech Republic
| | - Daniel Landau
- Paediatrics Department B; Faculty of Health Sciences; Schneider Children's Medical Center of Israel; Ben-Gurion University; Beer Sheva Israel
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Affiliation(s)
- Nine V A M Knoers
- From the Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht (N.V.A.M.K.), and the Department of Physiology and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen (R.J.B.) - both in the Netherlands
| | - René J Bindels
- From the Department of Genetics and Center for Molecular Medicine, University Medical Center Utrecht, Utrecht (N.V.A.M.K.), and the Department of Physiology and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen (R.J.B.) - both in the Netherlands
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Carrisoza-Gaytan R, Carattino MD, Kleyman TR, Satlin LM. An unexpected journey: conceptual evolution of mechanoregulated potassium transport in the distal nephron. Am J Physiol Cell Physiol 2015; 310:C243-59. [PMID: 26632600 DOI: 10.1152/ajpcell.00328.2015] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Flow-induced K secretion (FIKS) in the aldosterone-sensitive distal nephron (ASDN) is mediated by large-conductance, Ca(2+)/stretch-activated BK channels composed of pore-forming α-subunits (BKα) and accessory β-subunits. This channel also plays a critical role in the renal adaptation to dietary K loading. Within the ASDN, the cortical collecting duct (CCD) is a major site for the final renal regulation of K homeostasis. Principal cells in the ASDN possess a single apical cilium whereas the surfaces of adjacent intercalated cells, devoid of cilia, are decorated with abundant microvilli and microplicae. Increases in tubular (urinary) flow rate, induced by volume expansion, diuretics, or a high K diet, subject CCD cells to hydrodynamic forces (fluid shear stress, circumferential stretch, and drag/torque on apical cilia and presumably microvilli/microplicae) that are transduced into increases in principal (PC) and intercalated (IC) cell cytoplasmic Ca(2+) concentration that activate apical voltage-, stretch- and Ca(2+)-activated BK channels, which mediate FIKS. This review summarizes studies by ourselves and others that have led to the evolving picture that the BK channel is localized in a macromolecular complex at the apical membrane, composed of mechanosensitive apical Ca(2+) channels and a variety of kinases/phosphatases as well as other signaling molecules anchored to the cytoskeleton, and that an increase in tubular fluid flow rate leads to IC- and PC-specific responses determined, in large part, by the cell-specific composition of the BK channels.
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Affiliation(s)
| | - Marcelo D Carattino
- Renal-Electrolyte Division, Department of Medicine, Pittsburgh, Pennsylvania
| | - Thomas R Kleyman
- Renal-Electrolyte Division, Department of Medicine, Pittsburgh, Pennsylvania
| | - Lisa M Satlin
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, New York; and
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Azzi A, Chehade H, Deschênes G. Neonates with Bartter syndrome have enormous fluid and sodium requirements. Acta Paediatr 2015; 104:e294-9. [PMID: 25703573 DOI: 10.1111/apa.12981] [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: 10/14/2014] [Revised: 12/07/2014] [Accepted: 02/19/2015] [Indexed: 11/30/2022]
Abstract
AIM Managing neonatal Bartter syndrome by achieving adequate weight gain is challenging. We assessed the correlation between weight gain in neonatal Bartter syndrome and the introduction of fluid and sodium supplementations and indomethacin during the first 4 weeks of life. METHODS Daily fluid and electrolytes requirements were analysed using linear regression and Spearman correlation coefficients. The weight gain coefficient was calculated as daily weight gain after physiological neonatal weight loss. RESULTS We studied seven infants. The highest weight gain coefficients occurred between weeks two and four in the five neonates who either received prompt amounts of fluid (maximum 810 mL/kg/day) and sodium (maximum 70 mmol/kg/day) or were treated with indomethacin. For the two patients with the highest weight gain coefficient, water and sodium supplementations were decreased in weeks two to four leading to a significant negative Spearman correlation between weight gain and fluid supplements (r = -0.55 and -0.68) and weight gain and sodium supplementations (r = -0.96 and -0.72). The two patients with the lowest weight gain coefficient had positive Spearman correlation coefficients between weight gain and fluid and sodium supplementations. CONCLUSION Infants with neonatal Bartter syndrome required rapid and enormous fluid and sodium supplementations or the early introduction of indomethacin treatment to achieve adequate weight gain during the early postnatal period.
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Affiliation(s)
- Antonio Azzi
- Department of Pediatrics; Division of Pediatric Nephrology; Lausanne University Hospital; Lausanne Switzerland
| | - Hassib Chehade
- Department of Pediatrics; Division of Pediatric Nephrology; Lausanne University Hospital; Lausanne Switzerland
| | - Georges Deschênes
- Department of Pediatrics; Division of Pediatric Nephrology; Robert Debré University Hospital; Paris France
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Marcucci G, Cianferotti L, Beck-Peccoz P, Capezzone M, Cetani F, Colao A, Davì MV, degli Uberti E, Del Prato S, Elisei R, Faggiano A, Ferone D, Foresta C, Fugazzola L, Ghigo E, Giacchetti G, Giorgino F, Lenzi A, Malandrino P, Mannelli M, Marcocci C, Masi L, Pacini F, Opocher G, Radicioni A, Tonacchera M, Vigneri R, Zatelli MC, Brandi ML. Rare diseases in clinical endocrinology: a taxonomic classification system. J Endocrinol Invest 2015; 38:193-259. [PMID: 25376364 DOI: 10.1007/s40618-014-0202-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 10/17/2014] [Indexed: 02/05/2023]
Abstract
PURPOSE Rare endocrine-metabolic diseases (REMD) represent an important area in the field of medicine and pharmacology. The rare diseases of interest to endocrinologists involve all fields of endocrinology, including rare diseases of the pituitary, thyroid and adrenal glands, paraganglia, ovary and testis, disorders of bone and mineral metabolism, energy and lipid metabolism, water metabolism, and syndromes with possible involvement of multiple endocrine glands, and neuroendocrine tumors. Taking advantage of the constitution of a study group on REMD within the Italian Society of Endocrinology, consisting of basic and clinical scientists, a document on the taxonomy of REMD has been produced. METHODS AND RESULTS This document has been designed to include mainly REMD manifesting or persisting into adulthood. The taxonomy of REMD of the adult comprises a total of 166 main disorders, 338 including all variants and subtypes, described into 11 tables. CONCLUSIONS This report provides a complete taxonomy to classify REMD of the adult. In the future, the creation of registries of rare endocrine diseases to collect data on cohorts of patients and the development of common and standardized diagnostic and therapeutic pathways for each rare endocrine disease is advisable. This will help planning and performing intervention studies in larger groups of patients to prove the efficacy, effectiveness, and safety of a specific treatment.
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Affiliation(s)
- G Marcucci
- Head, Bone Metablic Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Viale Pieraccini 6, 50139, Florence, Italy.
| | - L Cianferotti
- Head, Bone Metablic Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Viale Pieraccini 6, 50139, Florence, Italy
| | - P Beck-Peccoz
- Department of Clinical Sciences and Community Health, University of Milan and Endocrine Unit, Fondazione IRCCS Ca' Granda, Milan, Italy
| | - M Capezzone
- Section of Endocrinology and Metabolism, Department of Internal Medicine, Endocrinology and Metabolism and Biochemistry, University of Siena, Policlinico Santa Maria alle Scotte, Siena, Italy
| | - F Cetani
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - A Colao
- Dipartimento di Medicina Clinica e Chirurgia, Università Federico II di Napoli, Naples, Italy
| | - M V Davì
- Section D, Department of Medicine, Clinic of Internal Medicine, University of Verona, Verona, Italy
| | - E degli Uberti
- Section of Endocrinology, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - S Del Prato
- Section of Metabolic Diseases and Diabetes, Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - R Elisei
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - A Faggiano
- Dipartimento di Medicina Clinica e Chirurgia, Università Federico II di Napoli, Naples, Italy
| | - D Ferone
- Endocrinology, Department of Internal Medicine and Medical Specialties and Center of Excellence for Biomedical Research, IRCCS AOU San Martino-IST, University of Genoa, Genoa, Italy
| | - C Foresta
- Department of Medicine and Centre for Human Reproduction Pathology, University of Padova, Padua, Italy
| | - L Fugazzola
- Department of Clinical Sciences and Community Health, University of Milan and Endocrine Unit, Fondazione IRCCS Ca' Granda, Milan, Italy
| | - E Ghigo
- Division of Endocrinology, Diabetology and Metabolism Department of Medical Sciences, University Hospital Città Salute e Scienza, Turin, Italy
| | - G Giacchetti
- Division of Endocrinology, Azienda Ospedaliero-Universitaria, Ospedali Riuniti Umberto I-GM Lancisi-G Salesi, Università Politecnica delle Marche, Ancona, Italy
| | - F Giorgino
- Section of Internal Medicine, Endocrinology, Andrology and Metabolic Diseases, Department of Emergency and Organ Transplantation, University of Bari Aldo Moro, Bari, Italy
| | - A Lenzi
- Chair of Endocrinology, Section Medical Pathophysiology, Food Science and Endocrinology, Department Exp. Medicine, Sapienza University of Rome, Policlinico Umberto I, Rome, Italy
| | - P Malandrino
- Endocrinology, Department of Clinical and Molecular Biomedicine, Garibaldi-Nesima Medical Center, University of Catania, Catania, Italy
| | - M Mannelli
- Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences, University of Florence, Florence, Italy
| | - C Marcocci
- Department of Endocrinology and Metabolism, University of Pisa, Pisa, Italy
| | - L Masi
- Department of Orthopedic, Metabolic Bone Diseases Unit AOUC-Careggi Hospital, Largo Palagi, 1, Florence, Italy
| | - F Pacini
- Section of Endocrinology and Metabolism, University of Siena, Siena, Italy
| | - G Opocher
- Familial Cancer Clinic and Oncoendocrinology, Veneto Institute of Oncology, IRCCS, Padua, Italy
- Department of Medicine DIMED, University of Padova, Padova, Italy
| | - A Radicioni
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - M Tonacchera
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - R Vigneri
- Department of Clinical and Molecular Biomedicine, University of Catania, and Humanitas Catania Center of Oncology, Catania, Italy
| | - M C Zatelli
- Section of Endocrinology, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - M L Brandi
- Head, Bone Metablic Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Viale Pieraccini 6, 50139, Florence, Italy.
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Nascimento CLP, Garcia CL, Schvartsman BGS, Vaisbich MH. Treatment of Bartter syndrome. Unsolved issue. J Pediatr (Rio J) 2014; 90:512-7. [PMID: 24878005 DOI: 10.1016/j.jped.2014.01.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 01/25/2014] [Accepted: 01/28/2014] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE To describe the results of a long-term follow-up of Bartter syndrome patients treated with different drugs. METHOD Patients were diagnosed according to clinical and laboratory data. Treatment protocol was potassium supplementation, sodium, spironolactone, and non-steroidal anti-inflammatory drug. Patients who developed proteinuria were converted to angiotensin conversion enzyme inhibitor. The variables evaluated for each drug were Z-score for weight and stature, proteinuria, creatinine clearance, gastrointestinal complaints, amount of potassium supplementation, serum potassium and bicarbonate levels, and findings of upper digestive endoscopy. RESULTS 20 patients were included. Follow-up was 10.1 ± 5.2 years. 17 patients received indomethacin for 5.9 ± 5.3 years; 19 received celecoxib, median of 35 months; and five received enalapril, median of 23 months. During indomethacin, a statistically significant increase was observed in the Z-score for stature and weight, without a change in the creatinine clearance. Seven of 17 patients had gastrointestinal symptoms, and upper digestive endoscopy evidenced gastritis in three patients and gastric ulcer in four patients. During celecoxib use, a significant increase was detected in the Z-score for stature and weight and a reduction of hyperfiltration; seven patients presented gastrointestinal symptoms, and upper digestive endoscopy evidenced mild gastritis in three. During enalapril use, no significant changes were observed in the Z-score for stature, weight and creatinine clearance. The conversion to enalapril resulted in a significant reduction in proteinuria. CONCLUSION The authors suggest starting the treatment with celecoxib, and replacing by ACEi if necessary, monitoring the renal function. The safety and efficacy of celecoxib need to be assessed in larger controlled studies.
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Affiliation(s)
- Carla Lessa Pena Nascimento
- Unidade de Nefrologia, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Cecilia Lopes Garcia
- Unidade de Nefrologia, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Benita Galassi Soares Schvartsman
- Unidade de Nefrologia, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil
| | - Maria Helena Vaisbich
- Unidade de Nefrologia, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil; Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
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Nascimento CLP, Garcia CL, Schvartsman BGS, Vaisbich MH. Treatment of Bartter syndrome. Unsolved issue. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2014. [DOI: 10.1016/j.jpedp.2014.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Abstract
Electrolyte disorders can result in life-threatening complications. The kidneys are tasked with maintaining electrolyte homoeostasis, yet the low glomerular filtration rate of neonatal kidneys, tubular immaturity, and high extrarenal fluid losses contribute to increased occurrence of electrolyte disorders in neonates. Understanding the physiologic basis of renal electrolyte handling is crucial in identifying underlying causes and initiation of proper treatment. This article reviews key aspects of renal physiology, the diagnostic workup of disorders of plasma sodium and potassium, and the appropriate treatment, in addition to inherited disorders associated with neonatal electrolyte disturbances that illuminate the physiology of renal electrolyte handling.
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Affiliation(s)
- Detlef Bockenhauer
- UCL Institute of Child Health, Great Ormond Street Hospital for Children NHS Foundation Trust, Nephrology Unit, 30 Guilford Street, London WC1 3EH, UK.
| | - Jakub Zieg
- Department of Pediatrics, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital, V Úvalu 84, 15006 Praha 5, Czech Republic
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Markus B, Alshafee I, Birk OS. Deciphering the fine-structure of tribal admixture in the Bedouin population using genomic data. Heredity (Edinb) 2014; 112:182-9. [PMID: 24084643 PMCID: PMC3907104 DOI: 10.1038/hdy.2013.90] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 07/03/2013] [Accepted: 08/22/2013] [Indexed: 02/04/2023] Open
Abstract
The Bedouin Israeli population is highly inbred and structured with a very high prevalence of recessive diseases. Many studies in the past two decades focused on linkage analysis in large, multiple consanguineous pedigrees of this population. The advent of high-throughput technologies motivated researchers to search for rare variants shared between smaller pedigrees, integrating data from clinically similar yet seemingly non-related sporadic cases. However, such analyses are challenging because, without pedigree data, there is no prior knowledge regarding possible relatedness between the sporadic cases. Here, we describe models and techniques for the study of relationships between pedigrees and use them for the inference of tribal co-ancestry, delineating the complex social interactions between different tribes in the Negev Bedouins of southern Israel. Through our analysis, we differentiate between tribes that share many yet small genomic segments because of co-ancestry versus tribes that share larger segments because of recent admixture. The emergent pattern is well correlated with the prevalence of rare mutations in the different tribes. Tribes that do not intermarry, mostly because of social restrictions, hold private mutations, whereas tribes that do intermarry demonstrate a genetic flow of mutations between them. Thus, social structure within an inbred community can be delineated through genomic data, with implications to genetic counseling and genetic mapping.
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Affiliation(s)
- B Markus
- The Morris Kahn Laboratory of Human Genetics
at the National Institute for Biotechnology in the Negev (NIBN) and Faculty of Health
Sciences, Ben Gurion University, Beer-Sheva, Israel
| | - I Alshafee
- Soroka Medical Center, The Genetics
Institute, Beer-sheva, Israel
| | - O S Birk
- The Morris Kahn Laboratory of Human Genetics
at the National Institute for Biotechnology in the Negev (NIBN) and Faculty of Health
Sciences, Ben Gurion University, Beer-Sheva, Israel
- Soroka Medical Center, The Genetics
Institute, Beer-sheva, Israel
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35
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Kleyman TR, Satlin LM, Hallows KR. Opening lines of communication in the distal nephron. J Clin Invest 2013; 123:4139-41. [PMID: 24051382 DOI: 10.1172/jci71944] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The distal nephron is composed of two main cell types: principal cells and intercalated cells. These cells have distinct morphologic features that allow them to be readily distinguished by light microscopy, as well as distinct suites of proteins that facilitate cell-specific transport properties. In this issue of the JCI, Gueutin and colleagues describe a new mechanism by which β-intercalated cells, via release of ATP and prostaglandin E2 (PGE2), influence the activity of transporters in principal cells.
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Zhou X, Zhang Z, Shin MK, Horwitz SB, Levorse JM, Zhu L, Sharif-Rodriguez W, Streltsov DY, Dajee M, Hernandez M, Pan Y, Urosevic-Price O, Wang L, Forrest G, Szeto D, Zhu Y, Cui Y, Michael B, Balogh LA, Welling PA, Wade JB, Roy S, Sullivan KA. Heterozygous disruption of renal outer medullary potassium channel in rats is associated with reduced blood pressure. Hypertension 2013; 62:288-94. [PMID: 23753405 DOI: 10.1161/hypertensionaha.111.01051] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The renal outer medullary potassium channel (ROMK, KCNJ1) mediates potassium recycling and facilitates sodium reabsorption through the Na(+)/K(+)/2Cl(-) cotransporter in the loop of Henle and potassium secretion at the cortical collecting duct. Human genetic studies indicate that ROMK homozygous loss-of-function mutations cause type II Bartter syndrome, featuring polyuria, renal salt wasting, and hypotension; humans heterozygous for ROMK mutations identified in the Framingham Heart Study have reduced blood pressure. ROMK null mice recapitulate many of the features of type II Bartter syndrome. We have generated an ROMK knockout rat model in Dahl salt-sensitive background by using zinc finger nuclease technology and investigated the effects of knocking out ROMK on systemic and renal hemodynamics and kidney histology in the Dahl salt-sensitive rats. The ROMK(-/-) pups recapitulated features identified in the ROMK null mice. The ROMK(+/-) rats, when challenged with a 4% salt diet, exhibited a reduced blood pressure compared with their ROMK(+/+) littermates. More importantly, when challenged with an 8% salt diet, the Dahl salt-sensitive rats with 50% less ROMK expression showed increased protection from salt-induced blood pressure elevation and signs of protection from renal injury. Our findings in ROMK knockout Dahl salt-sensitive rats, together with the previous reports in humans and mice, underscore a critical role of ROMK in blood pressure regulation.
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Affiliation(s)
- Xiaoyan Zhou
- Department of Cardiovascular Diseases, Merck Research Laboratories, 126 E Lincoln Ave, Rahway, NJ 07065, USA.
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Fretzayas A, Gole E, Attilakos A, Daskalaki A, Nicolaidou P, Papadopoulou A. Expanding the spectrum of genetic mutations in antenatal Bartter syndrome type II. Pediatr Int 2013; 55:371-3. [PMID: 23782368 DOI: 10.1111/j.1442-200x.2012.03716.x] [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: 12/02/2011] [Revised: 05/01/2012] [Accepted: 07/17/2012] [Indexed: 12/01/2022]
Abstract
Bartter syndrome (BS) is a group of genetic disorders characterized by hypokalemic metabolic alkalosis, hyponatremia and elevated renin and aldosterone plasma concentrations. BS type II is caused by mutations in the KCNJ1 gene and usually presents with transient hyperkalemia. We report here a novel KCNJ1 mutation in a male neonate, prematurely born after a pregnancy complicated by polyhydramnios. The infant presented with typical clinical and laboratory findings of BS type II, such as hyponatremia, hypochloremic metabolic alkalosis, severe weight loss, elevated renin and aldosterone levels and transient hyperkalemia in the early postnatal period, which were later normalized. Molecular analysis revealed a compound heterozygous mutation in the KCNJ1 gene, consisting of a novel K76E and an already described V315G mutation, both affecting functional domains of the channel protein. Typical manifestations of antenatal BS in combination with hyperkalemia should prompt the clinician to search for mutations in the KCNJ1 gene first.
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Affiliation(s)
- Andreas Fretzayas
- Third Department of Pediatrics, Medical School, University General Hospital Attikon, University of Athens, Athens, Greece.
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Zennaro MC, Hubert EL, Fernandes-Rosa FL. Aldosterone resistance: structural and functional considerations and new perspectives. Mol Cell Endocrinol 2012; 350:206-15. [PMID: 21664233 DOI: 10.1016/j.mce.2011.04.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 04/20/2011] [Accepted: 04/24/2011] [Indexed: 11/30/2022]
Abstract
Aldosterone plays an essential role in the maintenance of fluid and electrolyte homeostasis in the distal nephron. Loss-of-function mutations in two key components of the aldosterone response, the mineralocorticoid receptor and the epithelial sodium channel ENaC, lead to type 1 pseudohypoaldosteronism (PHA1), a rare genetic disease of aldosterone resistance characterized by salt wasting, dehydration, failure to thrive, hyperkalemia and metabolic acidosis. This review describes the clinical, biological and genetic characteristics of the different forms of PHA1 and highlights recent advances in the understanding of the pathogenesis of the disease. We will also discuss genotype-phenotype correlations and new clinical and genetic entities that may prove relevant for patient's care in neonates with renal salt losing syndromes and/or failure to thrive.
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Seyberth HW, Schlingmann KP. Bartter- and Gitelman-like syndromes: salt-losing tubulopathies with loop or DCT defects. Pediatr Nephrol 2011; 26:1789-802. [PMID: 21503667 PMCID: PMC3163795 DOI: 10.1007/s00467-011-1871-4] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 03/09/2011] [Accepted: 03/09/2011] [Indexed: 12/11/2022]
Abstract
Salt-losing tubulopathies with secondary hyperaldosteronism (SLT) comprise a set of well-defined inherited tubular disorders. Two segments along the distal nephron are primarily involved in the pathogenesis of SLTs: the thick ascending limb of Henle's loop, and the distal convoluted tubule (DCT). The functions of these pre- and postmacula densa segments are quite distinct, and this has a major impact on the clinical presentation of loop and DCT disorders - the Bartter- and Gitelman-like syndromes. Defects in the water-impermeable thick ascending limb, with its greater salt reabsorption capacity, lead to major salt and water losses similar to the effect of loop diuretics. In contrast, defects in the DCT, with its minor capacity of salt reabsorption and its crucial role in fine-tuning of urinary calcium and magnesium excretion, provoke more chronic solute imbalances similar to the effects of chronic treatment with thiazides. The most severe disorder is a combination of a loop and DCT disorder similar to the enhanced diuretic effect of a co-medication of loop diuretics with thiazides. Besides salt and water supplementation, prostaglandin E2-synthase inhibition is the most effective therapeutic option in polyuric loop disorders (e.g., pure furosemide and mixed furosemide-amiloride type), especially in preterm infants with severe volume depletion. In DCT disorders (e.g., pure thiazide and mixed thiazide-furosemide type), renin-angiotensin-aldosterone system (RAAS) blockers might be indicated after salt, potassium, and magnesium supplementation are deemed insufficient. It appears that in most patients with SLT, a combination of solute supplementation with some drug treatment (e.g., indomethacin) is needed for a lifetime.
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Affiliation(s)
- Hannsjörg W. Seyberth
- Department of Pediatrics and Adolescent Medicine, Philipps University, Marburg, Germany ,Lazarettgarten 23, 76829 Landau, Germany
| | - Karl P. Schlingmann
- Department of General Pediatrics, University Children’s Hospital, Münster, Germany
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Deschênes G, Fila M. Primary molecular disorders and secondary biological adaptations in bartter syndrome. Int J Nephrol 2011; 2011:396209. [PMID: 21941653 PMCID: PMC3177086 DOI: 10.4061/2011/396209] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 06/01/2011] [Indexed: 12/17/2022] Open
Abstract
Bartter syndrome is a hereditary disorder that has been characterized by the association of hypokalemia, alkalosis, and the hypertrophy of the juxtaglomerular complex with secondary hyperaldosteronism and normal blood pressure. By contrast, the genetic causes of Bartter syndrome primarily affect molecular structures directly involved in the sodium reabsorption at the level of the Henle loop. The ensuing urinary sodium wasting and chronic sodium depletion are responsible for the contraction of the extracellular volume, the activation of the renin-aldosterone axis, the secretion of prostaglandins, and the biological adaptations of downstream tubular segments, meaning the distal convoluted tubule and the collecting duct. These secondary biological adaptations lead to hypokalemia and alkalosis, illustrating a close integration of the solutes regulation in the tubular structures.
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Affiliation(s)
- Georges Deschênes
- Pediatric Nephrology Unit, Hôpital Robert-Debré, 48 Bd Sérurier, 75019 Paris, France
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Lee BH, Cho HY, Lee H, Han KH, Kang HG, Ha IS, Lee JH, Park YS, Shin JI, Lee DY, Kim SY, Choi Y, Cheong HI. Genetic basis of Bartter syndrome in Korea. Nephrol Dial Transplant 2011; 27:1516-21. [PMID: 21865213 DOI: 10.1093/ndt/gfr475] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Bartter syndrome (BS) is clinically classified into antenatal or neonatal BS (aBS) and classic BS (cBS) as well as five subtypes based on the underlying mutant gene; SLC12A1 (BS I), KCNJ1 (BS II), CLCNKB (BS III), BSND (BS IV) and CASR (BS V). METHODS Clinico-genetic features of a nationwide cohort of 26 Korean children with BS were investigated. RESULTS The clinical diagnosis was aBS in 8 (30.8%), cBS in 15 (57.7%) and mixed Bartter-Gitelman phenotype in 3 cases (11.5%). Five of eight patients with aBS and all 18 patients with either cBS or mixed Bartter-Gitelman phenotype had CLCNKB mutations. Among the 23 patients (46 alleles) with CLCNKB mutations, p.W610X and large deletions were detected in 25 (54.3%) and 10 (21.7%) alleles, respectively. There was no genotype-phenotype correlation in patients with CLCNKB mutations. CONCLUSIONS Twenty-three (88.5%) of the 26 BS patients involved in this study had CLCNKB mutations. The p.W610X mutation and large deletion were two common types of mutations in CLCNKB. The clinical manifestations of BS III were heterogeneous without a genotype-phenotype correlation, typically manifesting cBS phenotype but also aBS or mixed Bartter-Gitelman phenotypes. The molecular diagnostic steps for patients with BS in our population should be designed taking these peculiar genotype distributions into consideration, and a new more clinically relevant classification including BS and Gitelman syndrome is required.
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Affiliation(s)
- Beom Hee Lee
- Department of Pediatrics, Seoul National University Children's Hospital, and Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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A novel compound heterozygous ROMK mutation presenting as late onset Bartter syndrome associated with nephrocalcinosis and elevated 1,25(OH)(2) vitamin D levels. Clin Exp Nephrol 2011; 15:572-6. [PMID: 21431899 DOI: 10.1007/s10157-011-0431-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Accepted: 02/24/2011] [Indexed: 10/18/2022]
Abstract
Bartter syndrome (BS) is a rare renal tubular disorder presenting with hypokalemic metabolic alkalosis, which is classified into five types. KCNJ1 mutations usually cause the neonatal form of BS, type II BS (OMIM 241200). However, this report concerns a female patient with a novel, compound heterozygous KCNJ1 mutation that causes late-onset BS. The unique clinical findings of this case include persistently elevated 1,25(OH)(2) vitamin D levels, possibly due to increase prostaglandin E(2) levels, and medullary nephrocalcinosis. Treatment with COX-2 inhibitors resolved her hypercalciuria and improved her height and weight; renal function remains stable and there is no progression of nephrocalcinosis.
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Recurrent urinary tract infections in an infant with antenatal Bartter syndrome. World J Pediatr 2011; 7:86-8. [PMID: 20127218 DOI: 10.1007/s12519-010-0021-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2009] [Accepted: 05/25/2009] [Indexed: 10/19/2022]
Abstract
BACKGROUND antenatal variant of Bartter syndrome is characterized by a history of polyhydramnios, premature birth, metabolic alkalosis, hypokalemia, polyuria and renal salt wasting. In this report we present a premature female baby with antenatal Barter syndrome who had three episodes of urinary tract infection (UTI), without evidence for congenital anomaly of the kidneys or urinary tract. METHODS antenatal Bartter syndrome was diagnosed according to the standard criteria. Ultrasound scan and voiding cystourethrography were performed to exclude congenital anomaly of the kidneys and urinary tract. RESULTS the baby presented with early hyperkalemia and acidosis. The typical biochemical features of the Bartter syndrome were observed in the second month. Despite appropriate treatment she had persistent hypercalciuria. The clinical course was complicated with recurrent episodes of febrile UTIs. Urinary tract system imaging did not demonstrate congenital anomalies. She finally died of severe dehydration, acidosis and renal failure. CONCLUSION since no congenital anomaly of the kidneys or urinary tract was demonstrated in our patient, we believe that severe, persistent hypercalciuria is the most important risk factor for development of recurrent UTIs.
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Farfel A, Mayan H, Melnikov S, Holtzman EJ, Pinhas-Hamiel O, Farfel Z. Effect of age and affection status on blood pressure, serum potassium and stature in familial hyperkalaemia and hypertension. Nephrol Dial Transplant 2010; 26:1547-53. [PMID: 20956807 DOI: 10.1093/ndt/gfq612] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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Puricelli E, Bettinelli A, Borsa N, Sironi F, Mattiello C, Tammaro F, Tedeschi S, Bianchetti MG. Long-term follow-up of patients with Bartter syndrome type I and II. Nephrol Dial Transplant 2010; 25:2976-81. [PMID: 20219833 DOI: 10.1093/ndt/gfq119] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Little information is available on a long-term follow-up in Bartter syndrome type I and II. METHODS Clinical presentation, treatment and long-term follow-up (5.0-21, median 11 years) were evaluated in 15 Italian patients with homozygous (n = 7) or compound heterozygous (n = 8) mutations in the SLC12A1 (n = 10) or KCNJ1 (n = 5) genes. RESULTS Thirteen new mutations were identified. The 15 children were born pre-term with a normal for gestational age body weight. Medical treatment at the last follow-up control included supplementation with potassium in 13, non-steroidal anti-inflammatory agents in 12 and gastroprotective drugs in five patients. At last follow-up, body weight and height were within normal ranges in the patients. Glomerular filtration rate was <90 mL/min/1.73 m(2) in four patients (one of them with a pathologically increased urinary protein excretion). In three patients, abdominal ultrasound detected gallstones. The group of patients with antenatal Bartter syndrome had a lower renin ratio (P < 0.05) and a higher standard deviation score (SDS) for height (P < 0.05) than a previously studied group of patients with classical Bartter syndrome. CONCLUSIONS Patients with Bartter syndrome type I and II tend to present a satisfactory prognosis after a median follow-up of more than 10 years. Gallstones might represent a new complication of antenatal Bartter syndrome.
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Affiliation(s)
- Elena Puricelli
- Department of Pediatrics, San Leopoldo Mandic Hospital, Largo Mandic 1, Merate, Lecco, Italy
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Hibino H, Inanobe A, Furutani K, Murakami S, Findlay I, Kurachi Y. Inwardly rectifying potassium channels: their structure, function, and physiological roles. Physiol Rev 2010; 90:291-366. [PMID: 20086079 DOI: 10.1152/physrev.00021.2009] [Citation(s) in RCA: 1082] [Impact Index Per Article: 77.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inwardly rectifying K(+) (Kir) channels allow K(+) to move more easily into rather than out of the cell. They have diverse physiological functions depending on their type and their location. There are seven Kir channel subfamilies that can be classified into four functional groups: classical Kir channels (Kir2.x) are constitutively active, G protein-gated Kir channels (Kir3.x) are regulated by G protein-coupled receptors, ATP-sensitive K(+) channels (Kir6.x) are tightly linked to cellular metabolism, and K(+) transport channels (Kir1.x, Kir4.x, Kir5.x, and Kir7.x). Inward rectification results from pore block by intracellular substances such as Mg(2+) and polyamines. Kir channel activity can be modulated by ions, phospholipids, and binding proteins. The basic building block of a Kir channel is made up of two transmembrane helices with cytoplasmic NH(2) and COOH termini and an extracellular loop which folds back to form the pore-lining ion selectivity filter. In vivo, functional Kir channels are composed of four such subunits which are either homo- or heterotetramers. Gene targeting and genetic analysis have linked Kir channel dysfunction to diverse pathologies. The crystal structure of different Kir channels is opening the way to understanding the structure-function relationships of this simple but diverse ion channel family.
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Affiliation(s)
- Hiroshi Hibino
- Department of Pharmacology, Graduate School of Medicine and The Center for Advanced Medical Engineering and Informatics, Osaka University, Osaka 565-0871, Japan
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Distal potassium handling based on flow modulation of maxi-K channel activity. Curr Opin Nephrol Hypertens 2009; 18:350-5. [PMID: 19448535 DOI: 10.1097/mnh.0b013e32832c75d8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE OF REVIEW Studies on the mechanisms of distal K+ secretion have highlighted the importance of the renal outer-medullary K+ (ROMK) and maxi-K channels. This review considers several human disorders characterized by hypokalemia and hyperkalemia, as well as mouse models of these disorders, and the mechanisms by which ROMK and maxi-K may be dysregulated. RECENT FINDINGS Analysis of knockout mice lacking ROMK, a model for type II Bartter's syndrome, has shown a role for maxi-K in distal K+ secretion. Knockout mice lacking either the alpha or beta1 subunits of maxi-K also show deficits in flow-dependent K+ secretion. Analysis of transgenic and knock-in mouse models of pseudohypoaldosteronism type II, in which mutant forms of with-no-lysine kinase 4 are expressed, suggests ways in which ROMK and maxi-K may be dysregulated to result in hyperkalemia. Modeling studies also provide insights into the role of Na+ delivery vs. flow in K+ secretion. SUMMARY The importance of both ROMK and maxi-K to distal K+ secretion is now well established, but the relative role that each of these two channels plays in normal and diseased states has not been definitively established. Analysis of human and animal model data can generate hypotheses for future experiments.
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Welling PA, Ho K. A comprehensive guide to the ROMK potassium channel: form and function in health and disease. Am J Physiol Renal Physiol 2009; 297:F849-63. [PMID: 19458126 DOI: 10.1152/ajprenal.00181.2009] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The discovery of the renal outer medullary K+ channel (ROMK, K(ir)1.1), the founding member of the inward-rectifying K+ channel (K(ir)) family, by Ho and Hebert in 1993 revolutionized our understanding of potassium channel biology and renal potassium handling. Because of the central role that ROMK plays in the regulation of salt and potassium homeostasis, considerable efforts have been invested in understanding the underlying molecular mechanisms. Here we provide a comprehensive guide to ROMK, spanning from the physiology in the kidney to the organization and regulation by intracellular factors to the structural basis of its function at the atomic level.
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Affiliation(s)
- Paul A Welling
- Dept. of Physiology, Univ. of Maryland School of Medicine, 655 W. Baltimore St., Baltimore, MD 21201, USA.
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Vieux R, Hamon I, Feldmann M, André JL, Hascoët JM. Particularités diagnostiques du syndrome de Bartter néonatal chez le nouveau-né grand prématuré. Arch Pediatr 2009; 16:23-6. [DOI: 10.1016/j.arcped.2008.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2007] [Revised: 08/18/2008] [Accepted: 10/04/2008] [Indexed: 10/21/2022]
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