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Abstract
Mutations in approximately 80 genes have been implicated as the cause of various genetic kidney diseases. However, gene delivery to kidney cells from the blood is inefficient because of the natural filtering functions of the glomerulus, and research into and development of gene therapy directed toward kidney disease has lagged behind as compared with hepatic, neuromuscular, and ocular gene therapy. This lack of progress is in spite of numerous genetic mouse models of human disease available to the research community and many vectors in existence that can theoretically deliver genes to kidney cells with high efficiency. In the past decade, several groups have begun to develop novel injection techniques in mice, such as retrograde ureter, renal vein, and direct subcapsular injections to help resolve the issue of gene delivery to the kidney through the blood. In addition, the ability to retarget vectors specifically toward kidney cells has been underutilized but shows promise. This review discusses how recent advances in gene delivery to the kidney and the field of gene therapy can leverage the wealth of knowledge of kidney genetics to work toward developing gene therapy products for patients with kidney disease.
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Affiliation(s)
- Jeffrey D Rubin
- Virology and Gene Therapy Graduate Program, Mayo Clinic, Rochester, MN, USA
| | - Michael A Barry
- Division of Infectious Diseases, Department of Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.
- Department of Immunology, Mayo Clinic, Rochester, MN, USA.
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN, USA.
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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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Abstract
Bartter syndrome is an inherited renal tubular disorder caused by a defective salt reabsorption in the thick ascending limb of loop of Henle, resulting in salt wasting, hypokalemia, and metabolic alkalosis. Mutations of several genes encoding the transporters and channels involved in salt reabsorption in the thick ascending limb cause different types of Bartter syndrome. A poor phenotype-genotype relationship due to the interaction with other cotransporters and different degrees of compensation through alternative pathways is currently reported. However, phenotypic identification still remains the first step to guide the suspicion of Bartter syndrome. Given the rarity of the syndrome, and the lack of genetic characterization in most cases, limited clinical evidence for treatment is available and the therapy is based mainly on the comprehension of renal physiology and relies on the physician's personal experiences. A better understanding of the mutated channels and transporters could possibly generate targets for specific treatment in the future, also encompassing drugs aiming to correct deficiencies in folding or plasma membrane expression of the mutated proteins.
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Affiliation(s)
- Tamara da Silva Cunha
- Nephrology Division, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina, São Paulo, Brazil,
| | - Ita Pfeferman Heilberg
- Nephrology Division, Universidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina, São Paulo, Brazil,
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Heilberg IP, Tótoli C, Calado JT. Adult presentation of Bartter syndrome type IV with erythrocytosis. ACTA ACUST UNITED AC 2015; 13:604-6. [PMID: 26537508 PMCID: PMC4878638 DOI: 10.1590/s1679-45082015rc3013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 08/29/2014] [Indexed: 11/22/2022]
Abstract
Bartter syndrome comprises a group of rare autosomal-recessive salt-losing disorders with distinct phenotypes, but one unifying pathophysiology consisting of severe reductions of sodium reabsorption caused by mutations in five genes expressed in the thick ascending limb of Henle, coupled with increased urinary excretion of potassium and hydrogen, which leads to hypokalemic alkalosis. Bartter syndrome type IV, caused by loss-of-function mutations in barttin, a subunit of chloride channel CLC-Kb expressed in the kidney and inner ear, usually occurs in the antenatal-neonatal period. We report an unusual case of late onset presentation of Bartter syndrome IV and mild phenotype in a 20 years-old man who had hypokalemia, deafness, secondary hyperparathyroidism and erythrocytosis.
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Affiliation(s)
| | - Cláudia Tótoli
- Universidade Federal de São Paulo, São Paulo, SP, Brazil
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Watanabe T, Abe Y. Bartter-like syndrome in patients with molecular defects of the insulin receptor gene. Acta Diabetol 2014; 51:891-2. [PMID: 24913309 DOI: 10.1007/s00592-014-0606-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Accepted: 05/23/2014] [Indexed: 10/25/2022]
Affiliation(s)
- Toru Watanabe
- Department of Pediatrics, Niigata City General Hospital, 463-7 Shumoku, Chuo-ku, Niigata City, 950-1197, Japan,
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Chan WKY, To KF, Tong JHM, Law CW. Paradoxical hypertension and salt wasting in Type II Bartter syndrome. Clin Kidney J 2012; 5:217-20. [PMID: 26069767 PMCID: PMC4400504 DOI: 10.1093/ckj/sfs026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 02/21/2012] [Indexed: 11/12/2022] Open
Abstract
Ante/neonatal Bartter syndrome (BS) is a rare hereditary disorder. It is characterized by renal salt wasting, hypokalaemic metabolic alkalosis, high renin and aldosterone but normal blood pressure. We report a low birth weight newborn baby who presented with repeated apnoea shortly after birth as well as hyponatraemia, hypochloraemia, hyperkalaemia and metabolic acidosis. Her biochemical features mimicked pseudohypoaldosteronism but with initial hypertension, which had not been described in BS. Her subsequent genetic study confirmed two novel heterozygous mutations in the Exon 5 of KCNJ1 compatible with Type II BS.
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Affiliation(s)
| | - Ka Fai To
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China
| | - Joanna H. M. Tong
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SAR, China
| | - Chi Wai Law
- Department of Paediatrics, Queen Elizabeth Hospital, Hong Kong SAR, China
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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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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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Seyberth HW. An improved terminology and classification of Bartter-like syndromes. ACTA ACUST UNITED AC 2008; 4:560-7. [PMID: 18695706 DOI: 10.1038/ncpneph0912] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2008] [Accepted: 07/04/2008] [Indexed: 12/15/2022]
Abstract
This Review outlines a terminology and classification of Bartter-like syndromes that is based on the underlying causes of these inherited salt-losing tubulopathies and is, therefore, more clinically relevant than the classical definition. Three major types of salt-losing tubulopathy can be defined: distal convoluted tubule dysfunction leading to hypokalemia (currently known as Gitelman or Bartter syndrome), the more-severe condition of polyuric loop dysfunction (often referred to as antenatal Bartter or hyperprostaglandin E syndrome), and the most-severe condition of combined loop and distal convoluted tubule dysfunction (antenatal Bartter or hyperprostaglandin E syndrome with sensorineural deafness). These three subtypes can each be further subdivided according to the identity of the defective ion transporter or channel: the sodium-chloride cotransporter NCCT or the chloride channel ClC-Kb in distal convoluted tubule dysfunction; the sodium-potassium-chloride cotransporter NKCC2 or the renal outer medullary potassium channel in loop dysfunction; and the chloride channels ClC-Ka and ClC-Kb or their beta-subunit Barttin in combined distal convoluted tubule and loop dysfunction. This new classification should help clinicians to better understand the pathophysiology of these syndromes and choose the most appropriate treatment for affected patients, while avoiding potentially harmful diagnostic and therapeutic approaches.
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Affiliation(s)
- Hannsjörg W Seyberth
- Center for Pediatric and Adolescent Medicine, Philipps University, Marburg, Germany.
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