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Ying Q, Ye Z, Zhang W, Pan Y, Dai L, Lin K, Feng X, Dong X, He F. Novel SLC12A3 gene mutations and clinical characteristics in two pedigrees with Gitelman syndrome. Clin Endocrinol (Oxf) 2023; 99:474-480. [PMID: 36562655 DOI: 10.1111/cen.14870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/20/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Gitelman syndrome (GS) is an autosomal recessive tubulopathy resulting from inactivating mutations in the SLC12A3 gene that encodes the thiazide-sensitive sodium-chloride cotransporter (NCC). To date, more than 500 mutations have been identified in the SLC12A3 gene. In this study, we identified two new mutations in the SLC12A3 gene in two Chinese GS pedigrees. DESIGN, PATIENTS AND MEASUREMENTS The clinical characteristics and laboratory examination of two suspected GS patients in our hospital were analyzed. In addition, two pedigrees including 11 members and 2 patients underwent SLC12A3 gene analysis. RESULTS Both patients were middle-aged women with characteristics of hypokalemic metabolic alkalosis, hypomagnesemia, low level of urinary calcium and the elevated levels of renin-angiotensin-aldosterone system. So, they were clinically diagnosed as GS. Patient 2 also had type 2 diabetes and Graves' disease. Both patients were found to carry two mutations of SLC12A3 gene by Sanger direct sequencing, which were all compound heterozygous mutations. We identified three mutations in these two Chinese GS pedigrees, one of which was c.179C>T (Thr60Met). The novel c.2159G>T (p. Gly720Val) and c.2675T>C (p. Leu892Pro) mutations were strongly predicted to be pathogenic using four network programs-Polyphen-2, SIFT, Mutation Taster and LRT. CONCLUSIONS We identified two novel SLC12A3 genetic variant [c.2159G>T (p.Gly720Val) and c.2675T>C (p.Leu892Pro)] in two Chinese GS pedigrees. The discovery of new mutations has enriched the spectrum of SLC12A3 genotypes.
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Affiliation(s)
- Qiao Ying
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Zhinan Ye
- Department of Neurology, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Wei Zhang
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Yingying Pan
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Linxiong Dai
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Kaisang Lin
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
| | - Xiaocheng Feng
- Department of Endocrinology and Metabolism, School of Medicine, Zhejiang University Affiliated Sir Run Shaw Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Xuehong Dong
- Department of Endocrinology and Metabolism, School of Medicine, Zhejiang University Affiliated Sir Run Shaw Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Fei He
- Department of Endocrinology and Metabolism, Taizhou Municipal Hospital, Taizhou, Zhejiang, People's Republic of China
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Li N, Gu HF. Genetic and Biological Effects of SLC12A3, a Sodium-Chloride Cotransporter, in Gitelman Syndrome and Diabetic Kidney Disease. Front Genet 2022; 13:799224. [PMID: 35591852 PMCID: PMC9111839 DOI: 10.3389/fgene.2022.799224] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Accepted: 01/12/2022] [Indexed: 11/13/2022] Open
Abstract
The SLC12A3 (Solute carrier family 12 member 3) gene encodes a sodium-chloride cotransporter and mediates Na+ and Cl− reabsorption in the distal convoluted tubule of kidneys. An experimental study has previously showed that with knockdown of zebrafish ortholog, slc12a3 led to structural abnormality of kidney pronephric distal duct at 1-cell stage, suggesting that SLC12A3 may have genetic effects in renal disorders. Many clinical reports have demonstrated that the function-loss mutations in the SLC12A3 gene, mainly including Thr60Met, Asp486Asn, Gly741Arg, Leu859Pro, Arg861Cys, Arg913Gln, Arg928Cys and Cys994Tyr, play the pathogenic effects in Gitelman syndrome. This kidney disease is inherited as an autosomal recessive trait. In addition, several population genetic association studies have indicated that the single nucleotide variant Arg913Gln in the SLC12A3 gene is associated with diabetic kidney disease in type 2 diabetes subjects. In this review, we first summarized bioinformatics of the SLC12A3 gene and its genetic variation. We then described the different genetic and biological effects of SLC12A3 in Gitelman syndrome and diabetic kidney disease. We also discussed about further genetic and biological analyses of SLC12A3 as pharmacokinetic targets of diuretics.
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Affiliation(s)
- Nan Li
- Department of Endocrinology, Jiangsu Province Hospital of Traditional Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Harvest F. Gu
- Laboratory of Molecular Medicine, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
- *Correspondence: Harvest F. Gu,
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Jiang L, Peng X, Zhao B, Zhang L, Xu L, Li X, Nie M, Chen L. Frequent SLC12A3 mutations in Chinese Gitelman syndrome patients: structure and function disorder. Endocr Connect 2022; 11:EC-21-0262.R2. [PMID: 34860177 PMCID: PMC8859957 DOI: 10.1530/ec-21-0262] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/03/2021] [Indexed: 11/08/2022]
Abstract
PURPOSES This study was conducted to identify the frequent mutations from reported Chinese Gitelman syndrome (GS) patients, to predict the three-dimensional structure change of human Na-Cl co-transporter (hNCC), and to test the activity of these mutations and some novel mutations in vitro and in vivo. METHODS SLC12A3 gene mutations in Chinese GS patients previously reported in the PubMed, China National Knowledge Infrastructure, and Wanfang database were summarized. Predicted configurations of wild type (WT) and mutant proteins were achieved using the I-TASSER workplace. Six missense mutations (T60M, L215F, D486N, N534K, Q617R, and R928C) were generated by site-directed mutagenesis. 22Na+ uptake experiment was carried out in the Xenopus laevisoocyte expression system. In the study, 35 GS patients and 20 healthy volunteers underwent the thiazide test. RESULTS T60M, T163M, D486N, R913Q, R928C, and R959frameshift were frequent SLC12A3 gene mutations (mutated frequency >3%) in 310 Chinese GS families. The protein's three-dimensional structure was predicted to be altered in all mutations. Compared with WT hNCC, the thiazide-sensitive 22Na+ uptake was significantly diminished for all six mutations: T60M 22 ± 9.2%, R928C 29 ± 12%, L215F 38 ± 14%, N534K 41 ± 15.5%, Q617R 63 ± 22.1%, and D486N 77 ± 20.4%. In thiazide test, the net increase in chloride fractional excretion in 20 healthy controls was significantly higher than GS patients with or without T60M or D486N mutations. CONCLUSIONS Frequent mutations (T60M, D486N, and R928C) and novel mutations (L215F, N534K, and Q617R) lead to protein structure alternation and protein dysfunction verified by 22Na+ uptake experiment in vitro and thiazide test on the patients.
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Affiliation(s)
- Lanping Jiang
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Department of Nephrology & Key Laboratory of Nephrology, National Health Commission and Guangdong Province, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyan Peng
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Renal Division, Children’s Hospital Affiliated to Capital Institute of Pediatrics, Beijing, China
| | - Bingbin Zhao
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lei Zhang
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lubin Xu
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xuemei Li
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Min Nie
- Department of Endocrinology & Key Laboratory of Endocrinology, National Health and Family Planning Commission, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Correspondence should be addressed to L Chen or M Nie: or
| | - Limeng Chen
- Department of Nephrology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Correspondence should be addressed to L Chen or M Nie: or
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Ko K, Kim JW. The First Korean Case of SLC12A3 Aberrant Skipping of Two Exons Detected by RNA Splicing Analysis. Case Rep Nephrol Dial 2021; 11:210-213. [PMID: 34414213 PMCID: PMC8339508 DOI: 10.1159/000517139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 05/07/2021] [Indexed: 11/21/2022] Open
Abstract
Gitelman syndrome is a salt-losing tubular disorder that is transmitted as an autosomal recessive trait. Variants in the SLC12A3 gene are found in the majority of Gitelman syndrome patients. A 26-year-old woman visited the genetic counseling clinic. Her fiancé was a known Gitelman syndrome patient who was previously diagnosed with 2 pathogenic variants in SLC12A3. In advance of marriage and future family planning, she wanted to perform genetic testing of SLC12A3. A silent exonic variant c.1050G>A was found, and multiple splice site in silico algorithms predicted this variant to have potential alteration of splicing. This variant was classified as “variant of uncertain significance,” and RNA splicing analysis was additionally performed. RNA splicing analysis showed aberrant splicing of exon 7–8 skipping. The result points out the potential pathogenicity of this variant, which should be considered a candidate of variant reclassification in the future. We highly recommend the performance of additional RNA splicing analysis, especially for silent variants predicted to have potential alteration of splicing.
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Affiliation(s)
- Kiwoong Ko
- Department of Laboratory Medicine, Samkwang Medical Lab, Seoul, Republic of Korea
| | - Jong-Won Kim
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
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Zhang L, Huang K, Wang S, Fu H, Wang J, Shen H, Lu Z, Chen J, Bao Y, Feng C, Dong G, Mao J. Clinical and Genetic Features in 31 Serial Chinese Children With Gitelman Syndrome. Front Pediatr 2021; 9:544925. [PMID: 33996672 PMCID: PMC8116576 DOI: 10.3389/fped.2021.544925] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 03/19/2021] [Indexed: 11/13/2022] Open
Abstract
Gitelman syndrome (GS, OMIM 263800) is a genetic congenital tubulopathy associated with salt loss, which is characterized by hypokalemic metabolic toxicity, hypocalciuria, and hypomagnesemia. GS, which is typically detected in adolescence or adulthood, has long been considered a benign tubular lesion; however, the disease is associated with a significant decrease in the quality of life. In this study, we assessed the genotype-phenotype correlations based on the medical histories, clinical symptoms, laboratory test results, and whole-exome sequencing profiles from pediatric patients with GS. Between January 2014 and December 2020, all 31 consecutively enrolled patients complained of fatigue, salt craving, and muscle weakness. Sixteen patients demonstrated growth retardation, and five patients presented with nocturia and constipation. All patients presented with hypokalemic metabolic alkalosis, normal blood pressure, hyperaldosteronism, and a preserved glomerular filtration rate, and 24 of the 31 (77.4%) patients had hypomagnesemia. Homozygous, compound heterozygous, and heterozygous mutations in SLC12A3 were detected in 4, 24, and 3 patients, respectively. GS patients often present with muscle weakness and fatigue caused by hypokalemia and hypomagnesemia. Therefore, early diagnosis of GS is important in young children to reduce the possibility of growth retardation, tetany, and seizures. Next-generation sequencing such as whole-exome or whole-genome sequencing provides a practical tool for the early diagnosis and improvement of GS prognosis. Further whole-genome sequencing is expected to reveal more variants in SLC123A among GS patients with single heterozygous mutations.
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Affiliation(s)
- Lingxia Zhang
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Ke Huang
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Shugang Wang
- Chigene (Beijing) Translational Medical Research Center, Yizhuang, China
| | - Haidong Fu
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Jingjing Wang
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Huijun Shen
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Zhihong Lu
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Junyi Chen
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yu Bao
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Chunyue Feng
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Guanping Dong
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Jianhua Mao
- Department of Nephrology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, China
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Clinical Characteristics and Gene Mutation Analysis of the Chinese Han Population with Gitelman Syndrome: 3 Case Reports and a Literature Review. Case Rep Med 2020; 2020:6263721. [PMID: 33163079 PMCID: PMC7604593 DOI: 10.1155/2020/6263721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/22/2020] [Accepted: 10/13/2020] [Indexed: 01/19/2023] Open
Abstract
The present study reported clinical characteristics and the results of gene mutation analysis of 3 Chinese patients with Gitelman syndrome (GS). Three patients manifested with normal blood pressure, recurrent hypokalemia, and metabolic alkalosis. Only case 2 had obvious hypomagnesemia. Gene sequencing showed a compound heterozygous mutation in SCL12A3 in case 1 and a homozygous mutation in SCL12A3 in case 2. Heterozygous mutations in SCL12A3 and CLCNKB were found in case 3. Then, the literature was reviewed. The keyword “Gitelman syndrome” was inputted into the PubMed, Wanfang Database, and CNK to search all Chinese patients with GS diagnosed by gene mutations and to extract complete clinical data from December 1998 to 2018. Finally, a total of 124 cases of GS were included. No significant differences in the levels of serum potassium and magnesium were observed among the different gene mutations, and the serum magnesium levels in adults were lower than those of the juvenile. GS with reduced blood magnesium had a serious clinical phenotype. Therefore, GS had a diverse phenotype, and its final diagnosis required genetic profiling. The relationship of gene mutation and clinical phenotype needed further study.
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Ishikawa M, Tada Y, Tanaka H, Morii W, Inaba M, Takada H, Mori T, Noguchi E. A Family with Gitelman Syndrome with Asymptomatic Phenotypes while Carrying Reported SLC12A3 Mutations. Case Rep Nephrol Dial 2020; 10:71-78. [PMID: 32884933 PMCID: PMC7443650 DOI: 10.1159/000507845] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 04/13/2020] [Indexed: 12/13/2022] Open
Abstract
Gitelman syndrome (GS) is an autosomal recessive disorder characterized by alkalosis, hypokalemia, and hypomagnesemia. Although hundreds of genetic variants associated with GS have been reported, many of them are categorized as of uncertain significance in ClinVar. Here, we describe a pediatric GS patient from a three-generation family whose mother and maternal grandmother were asymptomatic. The proband was a 16-year-old Japanese girl with muscle weakness and continuous hypokalemic metabolic alkalosis. The patient, her mother, and her maternal grandmother were compound heterozygous for, and each expressing a different combination of, previously reported SLC12A3variants in GS patients. The mother and the maternal grandmother had no symptoms related to GS, and blood gas tests showed that the blood potassium levels and venous pH were within normal limits; however, the venous blood HCO<sub>3</sub>- levels were slightly elevated. The phenotypic effect of missense mutations is difficult to evaluate, and accumulation of genotypic data with accurate phenotyping, including those of “healthy” and “asymptomatic” individuals in various ethnic populations, will improve the genetic diagnosis of GS.
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Affiliation(s)
- Moena Ishikawa
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Yumi Tada
- Department of Pediatrics, Tsukuba Gakuen Hospital, Tsukuba, Japan
| | - Hiromu Tanaka
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Wataru Morii
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Masako Inaba
- Department of Child Health, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Hidetoshi Takada
- Department of Child Health, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
| | - Emiko Noguchi
- Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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Oba T, Kobayashi S, Nakamura Y, Nagao M, Nozu K, Fukuda I, Iijima K, Sugihara H. A Case of Gitelman Syndrome that Was Difficult to Distinguish from Hypokalemic Periodic Paralysis Caused by Graves' Disease. J NIPPON MED SCH 2019; 86:301-306. [PMID: 31105122 DOI: 10.1272/jnms.jnms.2019_86-505] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A 21-year-old man presented with hyperthyroidism and hypokalemia and was treated for thyrotoxic hypokalemic periodic paralysis caused by Graves' disease. Thyroid function soon normalized but hypokalemia persisted. Laboratory data revealed hyperreninemic hyperaldosteronism and metabolic alkalosis consistent with Gitelman Syndrome. The patient was found to have a previously unreported compound heterozygous mutation of T180K and L858H in the SLC12A3 gene, and Gitelman Syndrome was diagnosed. He was started on eplerenone to control serum potassium level. Alternative diagnoses should be considered when electrolyte imbalances persist after disease resolution.
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Affiliation(s)
- Takeshi Oba
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
| | - Shunsuke Kobayashi
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
| | - Yuko Nakamura
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
| | - Mototsugu Nagao
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine
| | - Izumi Fukuda
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
| | - Kazumoto Iijima
- Department of Pediatrics, Kobe University Graduate School of Medicine
| | - Hitoshi Sugihara
- Department of Endocrinology, Diabetes and Metabolism, Graduate School of Medicine, Nippon Medical School
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Gug C, Mihaescu A, Mozos I. Two mutations in the thiazide-sensitive NaCl co-transporter gene in a Romanian Gitelman syndrome patient: case report. Ther Clin Risk Manag 2018; 14:149-155. [PMID: 29403282 PMCID: PMC5784745 DOI: 10.2147/tcrm.s150483] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Background Gitelman syndrome (GS) is considered as the most common renal tubular disorder, and we report the first Romanian patient with GS confirmed at molecular level and diagnosed according to genetic testing. Patient and methods This paper describes the case of a 27-year-old woman admitted with severe hypokalemia, slight hypomagnesemia, hypocalcemia, hypocalciuria, metabolic alkalosis, hyperreninemia, low blood pressure, limb muscle weakness, marked fatigue and palpitations. Family history revealed a consanguineous family with autosomal-recessive transmission of GS with two cases over five generations. Results Next-generation sequencing technology detected two different homozygous mutations c.1805_1806delAT and c.2660+1G>A in the SLC12A3 gene, which encodes the thiazide-sensitive NaCl co-transporter, confirmed by the Sanger method. Conclusion Clinicians should be aware of the existence of GS, manage the condition properly and consider the risk of disease recurrence to the next generations.
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Affiliation(s)
| | | | - Ioana Mozos
- Department of Functional Sciences.,Center for Translational Research and Systems Medicine, "Victor Babes" University of Medicine and Pharmacy, Timisoara, Romania
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Zhao H, Yang Y, Lu Y, Mort M, Cooper DN, Zuo Z, Zhou Y. Quantitative mapping of genetic similarity in human heritable diseases by shared mutations. Hum Mutat 2017; 39:292-301. [PMID: 29044887 DOI: 10.1002/humu.23358] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Revised: 09/22/2017] [Accepted: 09/27/2017] [Indexed: 01/12/2023]
Abstract
Many genetic diseases exhibit considerable epidemiological comorbidity and common symptoms, which provokes debate about the extent of their etiological overlap. The rapid growth in the number of known disease-causing mutations in the Human Gene Mutation Database (HGMD) has allowed us to characterize genetic similarities between diseases by ascertaining the extent to which identical genetic mutations are shared between diseases. Using this approach, we show that 41.6% of disease pairs in all possible pairs (42, 083) exhibit a significant sharing of mutations (P value < 0.05). These mutation-related disease pairs are in agreement with heritability-based disease-disease relations in 48 neurological and psychiatric disease pairs (Spearman's correlation coefficient = 0.50; P value = 3.4 × 10-5 ), and share over-expressed genes significantly more often than unrelated disease pairs (1.5-1.8-fold higher; P value ≤ 1.6 × 10-4 ). The usefulness of mutation-related disease pairs was further demonstrated for predicting novel mutations and identifying individuals susceptible to Crohn disease. Moreover, the mutation-based disease network concurs closely with that based on phenotypes.
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Affiliation(s)
- Huiying Zhao
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China.,Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Yuedong Yang
- School of Data and Computer Science, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Yutong Lu
- School of Data and Computer Science, Sun Yat-sen University, Guangzhou, People's Republic of China
| | - Matthew Mort
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - David N Cooper
- Institute of Medical Genetics, Cardiff University, Heath Park, Cardiff, UK
| | - Zhiyi Zuo
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China.,Department of Anesthesiology, University of Virginia, Charlottesville, Virginia
| | - Yaoqi Zhou
- Institute for Glycomics and School of Information and Communication Technology, Griffith University, Gold Coast, Queensland, Australia
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Luo JW, Meng XR, Yang X, Liang JX, Hong FY, Zheng XY, Li WH. Analysis of mutations of two Gitelman syndrome family SLC12A3 genes and proposed treatments using Chinese medicine. Chin J Integr Med 2016; 23:461-468. [PMID: 26825084 DOI: 10.1007/s11655-016-2461-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To determine the gene location of two Gitelman syndrome (GS) family SLC12A3 genes and explore treatments using Chinese medicine (CM) prescriptions. METHODS In order to locate the two GS mutations, samples were collected from 11 people from two different pedigrees for direct genetic sequencing and comparison of the 26 exons of SLC12A3. Furthermore, the change of serum potassium was monitored throughout the therapy and those two probands undertook a sequential superposition of Western medicine (including potassium, Panangin and potassium-sparing diuretics) with CM prescription based on Buyang Huanwu Decoction () and Sijunzi Decoction (). The treatment included three stages, oral potassium chloride for the first 2 weeks (stage 1), potassium-sparing diuretic and Panangin with potassium chloride for the next 2 weeks (stage 2), CM along with the medicine in stage 2 for the final 2 weeks (stage 3). RESULTS The three mutations occurring in proband 1 from pedigree I were Thr60Met, 965-1_976del13ins12 (small indels mutation) and Ala122Ala (homozygous silent mutation). Likewise, three mutations, Asn359Lys, Thr382Met and Arg913Gln, appeared in the proband 2 from pedigree II. The serum potassium levels increasing from baseline to sequential stages were 1.63 mmol/L (baseline), 2.5 mmol/L (stage 1), 3.1 mmol/L (stage 2) and 3.9 mmol/L (stage 3) in the proband 1, and 2.8 mmol/L (baseline), 3.1 mmol/L (stage 1), 3.5 mmol/L (stage 2) and 4.3 mmol/L (stage 3) in the proband 2, respectively. The symptoms (numbness of limbs, weakness, palpitations, etc.) of both probands were all alleviated. CONCLUSIONS The mutations of both GS pedigrees can be defined as compound heterozygous mutations, most of which are known as missense mutations. Applying CM could be an appropriate choice for future intervention of GS.
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Affiliation(s)
- Jie-Wei Luo
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, 350001, China
| | - Xiao-Rong Meng
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, 350001, China
| | - Xiao Yang
- Fujian University of Traditional Chinese Medicine, Fuzhou, 350108, China
| | - Ji-Xing Liang
- Department of Endocrine and Kidney, Fujian Provincial Hospital, Fuzhou, 350001, China
| | - Fu-Yuan Hong
- Department of Endocrine and Kidney, Fujian Provincial Hospital, Fuzhou, 350001, China
| | - Xing-Yu Zheng
- Department of Traditional Chinese Medicine, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, 350001, China
| | - Wei-Hua Li
- Department of Surgical Oncology, Fujian Provincial Hospital, Fujian Medical University, Fuzhou, 350001, China.
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Kim Y, Kang SS, Park WY, Jin K, Kim DK, Han S. A Pedigree with c.179 Cytosine to Threonine Missense Mutation of SLC12A3 Gene Presenting Gitelman's Syndrome. Electrolyte Blood Press 2016; 14:16-9. [PMID: 27453715 PMCID: PMC4949203 DOI: 10.5049/ebp.2016.14.1.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 06/02/2016] [Indexed: 11/23/2022] Open
Abstract
A 42-year-old man came to the hospital presenting chest discomfort and general weakness. He had come to the hospital with the same symptoms 3 months ago and 12 years prior. His laboratory test showed hypokalemia, hypomagnesemia and hypocalciuria. The arterial blood gas analysis showed hypochloremic metabolic alkalosis. He had an ultrasonography guided renal biopsy, the result was normal at light microscopy and immunofluorescence microscopy. However, a special stain for Na-Cl cotransporter was weakly expressed compared with the control. The patient and his family underwent genetic sequencing about the SLC12A3 gene. He had a homozygous mutation in the 179th nucleotide of Exon 1 on the SLC12A3 gene (p.Thr60Met) and his parents and sisters were diagnosed as carrier state of Gitelman's syndrome (GS). GS is an inherited tubular disorder which presents mild hypokalemia, hypomagnesemia and hypocalciuria. Since the symptoms and laboratory results are not severe, it can go unnoticed by physicians. Herein we present a family with GS, diagnosed by genetic sequencing.
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Affiliation(s)
- Yaerim Kim
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
| | - Seong Sik Kang
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
| | - Woo Yeong Park
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
| | - Kyubok Jin
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
| | - Dae-Kwang Kim
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
| | - Seungyeup Han
- Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea
- Keimyung University Kidney Institute, Daegu, Korea
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Lee JW, Lee J, Heo NJ, Cheong HI, Han JS. Mutations in SLC12A3 and CLCNKB and Their Correlation with Clinical Phenotype in Patients with Gitelman and Gitelman-like Syndrome. J Korean Med Sci 2016; 31:47-54. [PMID: 26770037 PMCID: PMC4712579 DOI: 10.3346/jkms.2016.31.1.47] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 09/24/2015] [Indexed: 12/17/2022] Open
Abstract
Gitelman's syndrome (GS) is caused by loss-of-function mutations in SLC12A3 and characterized by hypokalemic metabolic alkalosis, hypocalciuria, and hypomagnesemia. Long-term prognosis and the role of gene diagnosis in GS are still unclear. To investigate genotype-phenotype correlation in GS and Gitelman-like syndrome, we enrolled 34 patients who showed hypokalemic metabolic alkalosis without secondary causes. Mutation analysis of SLC12A3 and CLCNKB was performed. Thirty-one patients had mutations in SLC12A3, 5 patients in CLCNKB, and 2 patients in both genes. There was no significant difference between male and female in clinical manifestations at the time of presentation, except for early onset of symptoms in males and more profound hypokalemia in females. We identified 10 novel mutations in SLC12A3 and 4 in CLCNKB. Compared with those with CLCNKB mutations, patients with SLC12A3 mutations were characterized by more consistent hypocalciuria and hypomagnesemia. Patients with 2 mutant SLC12A3 alleles, compared with those with 1 mutant allele, did not have more severe clinical and laboratory findings except for lower plasma magnesium concentrations. Male and female patients did not differ in their requirement for electrolyte replacements. Two patients with concomitant SLC12A3 and CLCNKB mutations had early-onset severe symptoms and showed different response to treatment. Hypocalciuria and hypomagnesemia are useful markers in differentiation of GS and classical Bartter's syndrome. Gender, genotypes or the number of SLC12A3 mutant alleles cannot predict the severity of disease or response to treatment.
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Affiliation(s)
- Jae Wook Lee
- Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea
| | - Jeonghwan Lee
- Department of Internal Medicine, Hallym University Hangang Sacred Heart Hospital, Seoul, Korea
| | - Nam Ju Heo
- Department of Internal Medicine, Seoul National University Hospital Healthcare System Gangnam Center, Seoul, Korea
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea
- Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul, Korea
- Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea
| | - Jin Suk Han
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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Li C, Zhou X, Han W, Jiang X, Liu J, Fang L, Wang H, Guan Q, Gao L, Zhao J, Xu J, Xu C. Identification of two novel mutations in SLC12A3 gene in two Chinese pedigrees with Gitelman syndrome and review of literature. Clin Endocrinol (Oxf) 2015; 83:985-93. [PMID: 25990047 DOI: 10.1111/cen.12820] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/19/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022]
Abstract
OBJECTIVE Gitelman syndrome (GS) is one of the most common causes of inherited hypokalaemia. As it was caused by mutations in the SLC12A3 gene, GS is a highly heterogeneous disease. Here, we aimed to investigate the clinical and genetic characteristics of two Chinese pedigrees and summarize the advance in GS genetics, diagnosis and management. SUBJECTS AND METHODS Two three-generation families with GS were identified and screened for mutations in the SLC12A3 gene. Genotype-phenotype correlations were analysed. RESULTS The two probands (A and B) were characterized by hypokalaemia, hypomagnesaemia and hypocalciuria without hypertension. Complete DNA sequencing of the SLC12A3 gene revealed two novel compound heterozygous mutations (c.179C>T and c.234delG; c.486-490delTACGGinsA and c.1925G>A), which are predicted to drastically affect normal protein structure. The female members of the pedigrees showed mild-to-no phenotype, although they carried the same mutations as the probands. Moreover, proband B presented with more severe symptoms than did proband A, which might be related to a lower serum magnesium level. During the 1-year follow-up, both probands showed satisfactory symptom improvement following the use of potassium and magnesium supplements. CONCLUSION Our findings strongly suggested that the two novel mutations in the SLC12A3 gene are the causative agents of GS, which may provide further insights into the function of this gene and help clinicians better understand this disorder.
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Affiliation(s)
- Congcong Li
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Xinli Zhou
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Wenxia Han
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Xiuyun Jiang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Jia Liu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Li Fang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Hai Wang
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Qingbo Guan
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Ling Gao
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
- Scientific Center, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Jin Xu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
| | - Chao Xu
- Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University, Jinan, Shandong, China
- Institute of Endocrinology and Metabolism, Shandong Academy of Clinical Medicine, Jinan, Shandong, China
- Shandong Clinical Medical Center of Endocrinology and Metabolism, Jinan, Shandong, China
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Kortenoeven MLA, Pedersen NB, Rosenbaek LL, Fenton RA. Vasopressin regulation of sodium transport in the distal nephron and collecting duct. Am J Physiol Renal Physiol 2015; 309:F280-99. [DOI: 10.1152/ajprenal.00093.2015] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 05/27/2015] [Indexed: 12/22/2022] Open
Abstract
Arginine vasopressin (AVP) is released from the posterior pituitary gland during states of hyperosmolality or hypovolemia. AVP is a peptide hormone, with antidiuretic and antinatriuretic properties. It allows the kidneys to increase body water retention predominantly by increasing the cell surface expression of aquaporin water channels in the collecting duct alongside increasing the osmotic driving forces for water reabsorption. The antinatriuretic effects of AVP are mediated by the regulation of sodium transport throughout the distal nephron, from the thick ascending limb through to the collecting duct, which in turn partially facilitates osmotic movement of water. In this review, we will discuss the regulatory role of AVP in sodium transport and summarize the effects of AVP on various molecular targets, including the sodium-potassium-chloride cotransporter NKCC2, the thiazide-sensitive sodium-chloride cotransporter NCC, and the epithelial sodium channel ENaC.
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Affiliation(s)
- M. L. A. Kortenoeven
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark
| | - N. B. Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark; and
| | - L. L. Rosenbaek
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - R. A. Fenton
- Department of Biomedicine and Center for Interactions of Proteins in Epithelial Transport (InterPrET), Aarhus University, Aarhus, Denmark
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Wang L, Dong C, Xi YG, Su X. Thiazide-sensitive Na+-Cl- cotransporter: genetic polymorphisms and human diseases. Acta Biochim Biophys Sin (Shanghai) 2015; 47:325-34. [PMID: 25841442 DOI: 10.1093/abbs/gmv020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/26/2015] [Indexed: 12/16/2022] Open
Abstract
The thiazide-sensitive Na(+)-Cl(-) cotransporter (TSC) is responsible for the major sodium chloride reabsorption pathway, which is located in the apical membrane of the epithelial cells of the distal convoluted tubule. TSC is involved in several physiological activities including transepithelial ion absorption and secretion, cell volume regulation, and setting intracellular Cl(-) concentration below or above its electrochemical potential equilibrium. In addition, TSC serves as the target of thiazide-type diuretics that are the first line of therapy for the treatment of hypertension in the clinic, and its mutants are also reported to be associated with the hereditary disease, Gitelman's syndrome. This review aims to summarize the publications with regard to the TSC by focusing on the association between TSC mutants and human hypertension as well as Gitelman's syndrome.
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Affiliation(s)
- Linghong Wang
- Clinical Medical Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot 010050, China
| | - Chao Dong
- Clinical Medical Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot 010050, China
| | - Ya-Guang Xi
- Clinical Medical Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot 010050, China
| | - Xiulan Su
- Clinical Medical Research Center of the Affiliated Hospital, Inner Mongolia Medical University, Hohhot 010050, China
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Abstract
The distal convoluted tubule (DCT) is a short nephron segment, interposed between the macula densa and collecting duct. Even though it is short, it plays a key role in regulating extracellular fluid volume and electrolyte homeostasis. DCT cells are rich in mitochondria, and possess the highest density of Na+/K+-ATPase along the nephron, where it is expressed on the highly amplified basolateral membranes. DCT cells are largely water impermeable, and reabsorb sodium and chloride across the apical membrane via electroneurtral pathways. Prominent among this is the thiazide-sensitive sodium chloride cotransporter, target of widely used diuretic drugs. These cells also play a key role in magnesium reabsorption, which occurs predominantly, via a transient receptor potential channel (TRPM6). Human genetic diseases in which DCT function is perturbed have provided critical insights into the physiological role of the DCT, and how transport is regulated. These include Familial Hyperkalemic Hypertension, the salt-wasting diseases Gitelman syndrome and EAST syndrome, and hereditary hypomagnesemias. The DCT is also established as an important target for the hormones angiotensin II and aldosterone; it also appears to respond to sympathetic-nerve stimulation and changes in plasma potassium. Here, we discuss what is currently known about DCT physiology. Early studies that determined transport rates of ions by the DCT are described, as are the channels and transporters expressed along the DCT with the advent of molecular cloning. Regulation of expression and activity of these channels and transporters is also described; particular emphasis is placed on the contribution of genetic forms of DCT dysregulation to our understanding.
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Affiliation(s)
- James A McCormick
- Division of Nephrology & Hypertension, Oregon Health & Science University, & VA Medical Center, Portland, Oregon, United States
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Jiang L, Chen C, Yuan T, Qin Y, Hu M, Li X, Xing X, Lee X, Nie M, Chen L. Clinical severity of Gitelman syndrome determined by serum magnesium. Am J Nephrol 2014; 39:357-66. [PMID: 24776766 DOI: 10.1159/000360773] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/17/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND/AIMS Normomagnesemia is considered atypical in Gitelman syndrome (GS). Here, we describe clinical, pathological and genetic characteristics in Chinese GS patients with or without hypomagnesemia in order to determine whether serum magnesium concentration indicates the severity of the disease. METHODS 7 normomagnesemic and 25 hypomagnesemic GS patients who were confirmed by direct sequencing of SLC12A3 gene were included. Clinical manifestation and laboratory tests were documented. Supine and upright plasma renin activity, angiotensin II and aldosterone were determined by radioimmunoassay. Transient receptor potential channel melastatin subtype 6 (TRPM6) was detected by immunohistochemistry in paraffin-embedded renal biopsy sections of 12 GS patients. 14 patients with glomerular minor lesion served as controls. The distribution of the mutations on the predicted NCC protein was analyzed and compared between two subgroups. RESULTS Clinical manifestations, electrolyte abnormalities, metabolic alkalosis and renin-angiotensin-aldosterone system activation were found to be milder in normomagnesemic compared with the hypomagnesemic group. Compared with glomerular minor lesion controls, the TRPM6-positive area was significantly decreased in hypomagnesemic patients (4.96 ± 1.88 vs. 8.63 ± 2.67%) while it was near normal (7.82 ± 5.23%) in 2 normomagnesemic GS patients. A higher percentage of intracellular mutations was observed in normomagnesemic patients than hypomagnesemic patients (92.31 vs. 56.52%, p = 0.02). CONCLUSIONS Normomagnesemia is not rare in GS. Serum magnesium may indicate the severity of GS.
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Affiliation(s)
- Lanping Jiang
- Department of Nephrology, Ministry of Health, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
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Yang SS, Fang YW, Tseng MH, Chu PY, Yu IS, Wu HC, Lin SW, Chau T, Uchida S, Sasaki S, Lin YF, Sytwu HK, Lin SH. Phosphorylation regulates NCC stability and transporter activity in vivo. J Am Soc Nephrol 2013; 24:1587-97. [PMID: 23833262 DOI: 10.1681/asn.2012070742] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A T60M mutation in the thiazide-sensitive sodium chloride cotransporter (NCC) is common in patients with Gitelman's syndrome (GS). This mutation prevents Ste20-related proline and alanine-rich kinase (SPAK)/oxidative stress responsive kinase-1 (OSR1)-mediated phosphorylation of NCC and alters NCC transporter activity in vitro. Here, we examined the physiologic effects of NCC phosphorylation in vivo using a novel Ncc T58M (human T60M) knock-in mouse model. Ncc(T58M/T58M) mice exhibited typical features of GS with a blunted response to thiazide diuretics. Despite expressing normal levels of Ncc mRNA, these mice had lower levels of total Ncc and p-Ncc protein that did not change with a low-salt diet that increased p-Spak. In contrast to wild-type Ncc, which localized to the apical membrane of distal convoluted tubule cells, T58M Ncc localized primarily to the cytosolic region and caused an increase in late distal convoluted tubule volume. In MDCK cells, exogenous expression of phosphorylation-defective NCC mutants reduced total protein expression levels and membrane stability. Furthermore, our analysis found diminished total urine NCC excretion in a cohort of GS patients with homozygous NCC T60M mutations. When Wnk4(D561A/+) mice, a model of pseudohypoaldosteronism type II expressing an activated Spak/Osr1-Ncc, were crossed with Ncc(T58M/T58M) mice, total Ncc and p-Ncc protein levels decreased and the GS phenotype persisted over the hypertensive phenotype. Overall, these data suggest that SPAK-mediated phosphorylation of NCC at T60 regulates NCC stability and function, and defective phosphorylation at this residue corrects the phenotype of pseudohypoaldosteronism type II.
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Affiliation(s)
- Sung-Sen Yang
- Division of Nephrology, Department of Medicine, Tri-Service General Hospital, Taipei, Taiwan
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Zhang C, Zhu Y, Huang F, Jiang G, Chang J, Li R. Novel missense mutations of WNK1 in patients with hypokalemic salt-losing tubulopathies. Clin Genet 2012; 83:545-52. [PMID: 22934535 DOI: 10.1111/cge.12008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 08/28/2012] [Accepted: 08/28/2012] [Indexed: 12/16/2022]
Affiliation(s)
| | - Y Zhu
- Department of Nephrology, Xinhua Hospital, School of Medicine; Shanghai Jiao Tong University; Shanghai; China
| | - F Huang
- Department of Nephrology, Xinhua Hospital, School of Medicine; Shanghai Jiao Tong University; Shanghai; China
| | - G Jiang
- Department of Nephrology, Xinhua Hospital, School of Medicine; Shanghai Jiao Tong University; Shanghai; China
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Abstract
PURPOSE OF REVIEW Sodium and chloride transport play a fundamental role in many physiological processes. In the kidney, sodium secretion and reabsorption are essential to maintain the extracellular volume and, thus, blood pressure (BP). In vascular smooth muscle, it is important for contractility and in the nervous system for the functioning of GABAergic neurons. Hence, the emergence of a WNK/SPAK/OSR1 kinase cascade that activates NaCl cotransporters has widespread physiological implications. This review gives an overview of the actions of SPAK and OSR1 kinases on NaCl cotransporters and highlights their possible therapeutic potential. RECENT FINDINGS Evidence has emerged from in-vitro phosphorylation assays that WNK kinases can activate SPAK and OSR1 kinases by phosphorylation of a key Thr residue in their catalytic domains. Once activated, SPAK and OSR1 in turn activate members of the SCL12A family of solute carriers by phosphorylation of conserved Ser/Thr residues in the N-terminal domain of these carrier proteins. The importance of this pathway has recently emerged from studies on mice that lack a catalytically active SPAK enzyme. These models are strikingly hypotensive with marked reduction in the phosphorylation of Na⁺/Cl⁻ cotransporter (NCC) in the kidney, and reduced Na⁺/K⁺/2Cl⁻ cotransporter (NKCC1) phosphorylation in the vessel wall. SUMMARY SPAK and OSR1 kinases regulate SCL12A transporters with important physiological effects for sodium homeostasis by the kidney, aortic contractility and neuronal excitability. In vivo, SPAK plays a major role in the regulation of blood pressure and represents a potential target for the development of novel diuretics.
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de La Faille R, Vallet M, Venisse A, Nau V, Collet-Gaudillat C, Houillier P, Jeunemaitre X, Vargas-Poussou R. A pseudo-dominant form of Gitelman's syndrome. NDT Plus 2011; 4:386-9. [PMID: 25984200 PMCID: PMC4421668 DOI: 10.1093/ndtplus/sfr094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 06/30/2011] [Indexed: 11/14/2022] Open
Abstract
Gitelman’s syndrome is an autosomal recessive salt losing nephropathy caused by inactivated mutations of the SLC12A3 gene, encoding the NaCl cotransporter of the distal convoluted tubule. We report a French family with five affected members over two generations suggesting a dominant transmission. After SLC12A3 sequencing of seven individuals, four mutations were detected. Pseudo-dominant transmission was explained by the union of a compound heterozygous woman (two mutations on one allele and one mutation on the other) with a heterozygous healthy man. This study shows the importance of complete genetic analysis of families with unusual presentation.
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Affiliation(s)
- Renaud de La Faille
- Assistance Publique-Hôpitaux de Paris, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France ; University Paris Descartes, Faculty of Medicine, Paris, France
| | - Marion Vallet
- Assistance Publique-Hôpitaux de Paris, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France ; University Paris Descartes, Faculty of Medicine, Paris, France
| | - Annabelle Venisse
- Assistance Publique-Hôpitaux de Paris, Department of Genetics, Hôpital Européen Georges Pompidou, Paris, France
| | - Valérie Nau
- Assistance Publique-Hôpitaux de Paris, Department of Genetics, Hôpital Européen Georges Pompidou, Paris, France
| | | | - Pascal Houillier
- Assistance Publique-Hôpitaux de Paris, Department of Physiology, Hôpital Européen Georges Pompidou, Paris, France ; University Paris Descartes, Faculty of Medicine, Paris, France
| | - Xavier Jeunemaitre
- University Paris Descartes, Faculty of Medicine, Paris, France ; Assistance Publique-Hôpitaux de Paris, Department of Genetics, Hôpital Européen Georges Pompidou, Paris, France ; INSERM, UMRS-970, Paris Cardiovascular Research Center, Paris, France
| | - Rosa Vargas-Poussou
- Assistance Publique-Hôpitaux de Paris, Department of Genetics, Hôpital Européen Georges Pompidou, Paris, France ; INSERM, UMRS-970, Paris Cardiovascular Research Center, Paris, France
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Richardson C, Sakamoto K, de los Heros P, Deak M, Campbell DG, Prescott AR, Alessi DR. Regulation of the NKCC2 ion cotransporter by SPAK-OSR1-dependent and -independent pathways. J Cell Sci 2011; 124:789-800. [PMID: 21321328 DOI: 10.1242/jcs.077230] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ion cotransporters, such as the Na(+)/Cl(-) cotransporter (NCC), control renal salt re-absorption and are regulated by the WNK-signalling pathway, which is over-stimulated in patients suffering from Gordon's hypertension syndrome. Here, we study the regulation of the NKCC2 (SLC12A1) ion cotransporter that contributes towards ~25% of renal salt re-absorption and is inhibited by loop-diuretic hypertensive drugs. We demonstrate that hypotonic low-chloride conditions that activate the WNK1-SPAK and OSR1 pathway promote phosphorylation of NKCC2 isoforms (A, B and F) at five residues (Ser91, Thr95, Thr100, Thr105 and Ser130). We establish that the SPAK and OSR1 kinases activated by WNK interact with an RFQV motif on NKCC2 and directly phosphorylate Thr95, Thr100, Thr105 and, possibly, Ser91. Our data indicate that a SPAK-OSR1-independent kinase, perhaps AMP-activated protein kinase (AMPK), phosphorylates Ser130 and that phosphorylation of Thr105 and Ser130 plays the most important roles in stimulating NKCC2 activity. In contrast with NCC, whose membrane translocation is triggered by SPAK-OSR1 phosphorylation, NKCC2 appears to be constitutively at the membrane. Our findings provide new insights into how NKCC2 is regulated and suggest that inhibitors of SPAK and/or OSR1 for the treatment of hypertension would be therapeutically distinct from thiazide or loop diuretics, as they would suppress the activity of both NCC and NKCC2.
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Affiliation(s)
- Ciaran Richardson
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
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Yagi H, Yahata K, Usui T, Hasegawa C, Seta K, Sugawara A. Inheritance of an autosomal recessive disorder, Gitelman's syndrome, across two generations in one family. Intern Med 2011; 50:1211-4. [PMID: 21628937 DOI: 10.2169/internalmedicine.50.4354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gitelman's syndrome (GS) is an autosomal recessive disorder; it is rarely inherited over several generations. A 16-year-old boy showed hypokalemia and hypocalciuria. Clinically, he was diagnosed as GS because of diuretic responsiveness to furosemide but not thiazide. Genetic testing disclosed he was a compound heterozygote (T180K/V677M) for the SLC12A3 gene. Unexpectedly, the patient's father also showed hypokalemia and hypocalciuria. The genetic analysis showed he had an L849H mutation in addition to T180K. The present pedigree showed an extremely rare case. Diuretic tests are useful diagnostic methods, and genetic testing is necessary for precise evaluation of complicated cases as in this family.
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Affiliation(s)
- Hiroki Yagi
- Department of Nephrology, National Hospital Organization Kyoto Medical Center, Japan
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Lo YF, Nozu K, Iijima K, Morishita T, Huang CC, Yang SS, Sytwu HK, Fang YW, Tseng MH, Lin SH. Recurrent deep intronic mutations in the SLC12A3 gene responsible for Gitelman's syndrome. Clin J Am Soc Nephrol 2010; 6:630-9. [PMID: 21051746 DOI: 10.2215/cjn.06730810] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND OBJECTIVES Gitelman's syndrome (GS) is an autosomal recessive renal tubular disorder caused by mutations in the SLC12A3 gene encoding the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC). Despite meticulous sequencing of genomic DNA, approximately one-third of GS patients are negative or heterozygotes for the known mutations. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Because blood leukocytes express NCC mRNA, we evaluate whether deep intronic mutations contribute to GS patients with uniallelic or undetectable SLC12A3 mutations. Twenty-nine patients with GS (men/women = 16/13), including eight negative and 21 uniallelic SLC12A3 mutations from 19 unrelated families, and normal controls were enrolled in an academic medical center. Analysis of cDNA from blood leukocytes, sequencing of the corresponding introns of genomic DNA for abnormal transcript, and analysis of NCC protein expression from renal biopsy were performed. RESULTS We identified nine Taiwan aboriginal patients carrying c.1670-191C→T mutations in intron 13 and 10 nonaboriginal patients carrying c.2548+253C→T mutations in intron 21 from 14 families (14/19). These two mutations undetected in 100 healthy subjects created pseudoexons containing new premature termination codons. Haplotype analysis with markers flanking SLC12A3 revealed that both mutations did not have founder effects. Apical NCC expression in the DCT of renal tissue was markedly diminished in two patients carrying deep intronic mutations. CONCLUSIONS Deep intronic mutations in SLC12A3 causing defective NCC expression can be identified with the RNA-based approach in patients with GS. c.1670-191C→T and c.2548+253C→T are hot spot mutations that can be screened in GS patients with uniallelic or negative SLC12A3 mutations.
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Affiliation(s)
- Yi-Fen Lo
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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Syrén ML, Borsa Ghiringhelli N, Bettinelli A, Colussi G, Vargas-Poussou R, Tammaro F, Coviello DA, Tedeschi S. The mutation c.1196_1202dup7bp (p.Ser402X) in the SLC12A3 gene clusters in Italian Gitelman syndrome patients and reflects the presence of a common ancestor. Nephrol Dial Transplant 2010; 26:557-61. [DOI: 10.1093/ndt/gfq458] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Marie-Louise Syrén
- Dipartimento di Scienze Materno-Infantili, Università degli Studi di Milano, Milan, Italy
- Laboratorio di Genetica Medica, Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Nicolò Borsa Ghiringhelli
- Laboratorio di Genetica Medica, Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | | | - Giacomo Colussi
- SC di Nefrologia, A.O. Ospedale Niguarda-Ca’ Granda, Milan, Italy
| | - Rosa Vargas-Poussou
- Département de Génétique, Hôpital Européen Georges Pompidou, AP-HP, Paris, France
- Faculté de Médecine, Université Paris-Descartes, Paris, F75006, France
| | - Fabiana Tammaro
- SC di Pediatria, Ospedale S. Leopoldo Mandic, Merate, Lecco, Italy
| | - Domenico A. Coviello
- Laboratorio di Genetica Medica, Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Milan, Italy
| | - Silvana Tedeschi
- Laboratorio di Genetica Medica, Fondazione IRCCS Ca’ Granda-Ospedale Maggiore Policlinico, Milan, Italy
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Nakamura A, Shimizu C, Nagai S, Yoshida M, Aoki K, Kondo T, Miyoshi H, Wada N, Tajima T, Terauchi Y, Yoshioka N, Koike T. Problems in diagnosing atypical Gitelman's syndrome presenting with normomagnesaemia. Clin Endocrinol (Oxf) 2010; 72:272-6. [PMID: 19508680 DOI: 10.1111/j.1365-2265.2009.03649.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Gitelman's syndrome, recognized as a variant of Bartter's syndrome, is characterized by hypokalaemic metabolic alkalosis in combination with hypomagnesaemia and hypocalciuria. Overlapping biochemical features in Gitelman's syndrome and Bartter's syndrome has been observed. Here, we investigated the clinical, biochemical, and genetic characteristics of five, chronic, nonhypertensive and hypokalaemic Japanese patients. METHODS Serum and urinary electrolytes, plasma renin activity and plasma aldosterone concentration were measured in five patients (four males and one female) with hypokalaemia. Renal clearance tests were performed and distal fractional chloride reabsorption calculated. Finally, mutational analysis of the thiazide-sensitive Na-Cl co-transporter gene was performed. RESULTS Symptoms in patients varied from mild (muscle weakness and numbness) to severe (tetany and foot paralysis). All patients were normotensive or hypotensive, and all had hypokalaemia, hypocalciuria, and hyperreninaemic hyperaldosteronism. However, two male patients had normomagnesaemia, while the remainder was hypomagnesaemic. Renal clearance tests showed that the administration of furosemide decreased distal fractional chloride reabsorption, while thiazide ingestion failed to decrease it. Genetic analysis identified six thiazide-sensitive Na-Cl co-transporter gene mutations, including two novel ones. Therefore, on the basis of the confirmatory renal clearance tests and mutational analysis, a diagnosis of Gitelman's syndrome was made in these patients. CONCLUSIONS Two of the five patients diagnosed with Gitelman's syndrome were normomagnesaemic, which is uncommon in this syndrome. Our study indicates that renal clearance tests and mutation analysis can play an important role in diagnosing Gitelman's syndrome more precisely.
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Affiliation(s)
- Akinobu Nakamura
- Department of Medicine II, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Molecular physiology of the thiazide-sensitive sodium-chloride cotransporter. Curr Opin Nephrol Hypertens 2009; 18:421-7. [PMID: 19636250 DOI: 10.1097/mnh.0b013e32832f2fcb] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review summarizes recent advances in the understanding of the molecular physiology and regulation of the thiazide-sensitive sodium-chloride cotransporter (NCC). RECENT FINDINGS Mutations of with-no-lysine (WNK) kinases 1 and 4 result in hyperactivity of NCC and familial hyperkalemic hypertension, a genetic syndrome of hypertension. Recent studies have shown that WNK1 and WNK4 activate the STE20 family protein kinases Ste20-related proline/alanine-rich kinase and odd-skipped-related 1, resulting in phosphorylation and activation of NCC. Additionally, a mouse knock-in model for a WNK4 familial hyperkalemic hypertension mutant demonstrated increased Ste20-related proline/alanine-rich kinase/odd-skipped-related 1 and NCC phosphorylation. It is unclear how these studies fit with the data indicating that WNK4 inhibits NCC, and the familial hyperkalemic hypertension mutations of WNK4 are loss-of-function mutations. Another WNK kinase, WNK3, also regulates NCC, activating NCC and antagonizing the effect of WNK4. Extracellular signal-related kinase 1/2 mitogen-activated protein kinase activation by Ras guanyl nucleotide-releasing protein 1 is another kinase pathway that appears to be a potent regulator of NCC. Other studies have described a role for angiotensin II in pressure natriuresis via actions on NCC. Recent studies examining the hormonal regulation of NCC have implicated angiotensin II and aldosterone in regulation of the WNK4-Ste20-related proline/alanine-rich kinase-NCC pathway. SUMMARY NCC is subject to a complex regulatory network of kinases, which appear quite sensitive to alterations of the hormonal and physiologic milieu.
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Fava C, Montagnana M, Rosberg L, Burri P, Jönsson A, Wanby P, Wahrenberg H, Hulthén UL, Aurell M, Guidi GC, Melander O. Novel mutations in theSLC12A3gene causing Gitelman's syndrome in Swedes. ACTA ACUST UNITED AC 2009; 18:395-9. [PMID: 17654016 DOI: 10.1080/10425170701400456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE Gitelman's syndrome (GS) is an inherited autosomal recessive disorder due to loss of function mutations in the SLC12A3 gene encoding the Na-Cl co-transporter (NCCT), the target of thiazide diuretics. The defective function of the NCCT, which normally is expressed in the apical membrane of the distal convolute tubule in the kidney, leads to mild hypotension, hypokalemia, hyperreninemic hyperaldosteronism, mild metabolic alkalosis, hypomagnesemia and hypocalciuria. Up to now, more than 100 mutations of the SLC12A3 gene have been described in GS patients. METHODS We have collected 30 patients from Sweden with a clinical diagnosis of GS and undertaken a mutation screening by SSCP and successive sequencing of the 26 exons and intronic boundaries. Both mutations were identified in most (n = 28, 93%) and at least one mutation was identified in all patients. RESULTS We found 22 different mutations evenly distributed throughout the gene, 11 of which have not been described previously. The new variants include 8 missense mutations (Glu68Lys, His69Asn, Argl45His, Vall53Met, Gly230Asp, Gly342Ala, Val677Leu and Gly867Ser), 1 insertion (c.834_835insG on exon 6) and 2 splice-site mutations (c.2667 + lT>G substitution in splicing donor site after exon 22, c.1569-1G>A substitution in the splicing acceptor site before exon 13). CONCLUSION In Swedish patients with the clinical features of GS, disease-causing mutations in the SLC12A3 gene were identified in most patients. The spectrum of GS mutations is wide making full mutation screening of the SLC12A3 gene necessary to confirm the diagnosis.
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Affiliation(s)
- Cristiano Fava
- Division of Endocrinology, Department of Clinical Sciences, University of Malmö, Malmo, Sweden.
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Qin L, Shao L, Ren H, Wang W, Pan X, Zhang W, Wang Z, Shen P, Chen N. Identification of five novel variants in the thiazide-sensitive NaCl co-transporter gene in Chinese patients with Gitelman syndrome. Nephrology (Carlton) 2009; 14:52-8. [PMID: 19207868 DOI: 10.1111/j.1440-1797.2008.01042.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
AIM Gitelman syndrome (GS) is an autosomal recessive renal tubulopathy characterized by hypokalaemic metabolic alkalosis, significant hypomagnesemia, low urinary calcium, secondary aldosteronism and normal blood pressure. GS is caused by inactivating variants in the SLC12A3 gene, which encodes the thiazide-sensitive NaCl co-transporter. So far, more than 100 variants have been described in the SLC12A3 gene in Gitelman syndrome. METHODS Biochemical parameters in blood and urine were measured and documented. Genomic DNA was extracted from peripheral blood of all patients. Variants were screened for the SLC12A3 and CLCNKB gene by sequencing directly. Reverse-transcription polymerase chain reaction and complementary DNA sequence analysis were performed to confirm deletion or splicing variants. RESULTS We identified 13 variants in the SLC12A3 gene in 13 Chinese patients, including 10 missense substitutions, two splicing variants, and one deletion/insertion variant. Five novel variants were identified for the first time in patients with Gitelman syndrome. We did not find any variants in the CLCNKB gene. A homozygous Thr60Met carrier suffered from hypothyroidism and received thyroxine replacement therapy. CONCLUSION We have identified 13 variants, including five novel variants in the SLC12A3 gene in 13 patients with Gitelman syndrome. T60M is the most frequent variant in our patients. There was no significant correlation between genotype and phenotype in our patients.
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Affiliation(s)
- Ling Qin
- Department of Nephrology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, China
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Richardson C, Alessi DR. The regulation of salt transport and blood pressure by the WNK-SPAK/OSR1 signalling pathway. J Cell Sci 2008; 121:3293-304. [DOI: 10.1242/jcs.029223] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has recently been shown that the WNK [with-no-K(Lys)] kinases (WNK1, WNK2, WNK3 and WNK4) have vital roles in the control of salt homeostasis and blood pressure. This Commentary focuses on recent findings that have uncovered the backbone of a novel signal-transduction network that is controlled by WNK kinases. Under hyperosmotic or hypotonic low-Cl– conditions, WNK isoforms are activated, and subsequently phosphorylate and activate the related protein kinases SPAK and OSR1. SPAK and OSR1 phosphorylate and activate ion co-transporters that include NCC, NKCC1 and NKCC2, which are targets for the commonly used blood-pressure-lowering thiazide-diuretic and loop-diuretic drugs. The finding that mutations in WNK1, WNK4, NCC and NKCC2 cause inherited blood-pressure syndromes in humans highlights the importance of these enzymes. We argue that these new findings indicate that SPAK and OSR1 are promising drug targets for the treatment of hypertension, because inhibiting these enzymes would reduce NCC and NKCC2 activity and thereby suppress renal salt re-absorption. We also discuss unresolved and controversial questions in this field of research.
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Affiliation(s)
- Ciaran Richardson
- MRC Protein Phosphorylation Unit, Sir James Black Centre, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
| | - Dario R. Alessi
- MRC Protein Phosphorylation Unit, Sir James Black Centre, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK
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Aoi N, Nakayama T, Sato N, Kosuge K, Haketa A, Sato M, Soma M. Case-control study of the role of the Gitelman's syndrome gene in essential hypertension. Endocr J 2008; 55:305-10. [PMID: 18362449 DOI: 10.1507/endocrj.k07e-021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Gitelman's syndrome is an inherited tubular disorder characterized by sodium wasting, low blood pressure, secondary hyperaldosteronism, metabolic alkalosis, hypokalemia, hypomagnesemia of renal origin, and hypocalciuria. The majority of patients with this syndrome carry inactivating mutations in the SLC12A3 gene encoding the thiazide-sensitive Na (+)-Cl (-) cotransporter (NCC) located in the distal convoluted tubule, which is involved in renal sodium reabsorption. This suggests that the SLC12A3 gene is involved in mediation of blood pressure levels. The aim of the present study was to investigate relationships between single nucleotide polymorphisms (SNPs) in the human SLC12A3 gene and essential hypertension (EH) in Japanese. METHOD We selected 3 SNPs in the human SLC12A3 gene (T180K, A569V, L849H), and performed a case-control study of 315 EH patients and 305 normotensive (NT) individuals. RESULTS There was no significant difference in overall distribution of genotypes or alleles of any of the SNPs between the EH and NT groups. CONCLUSION We conclude that the causal gene of Gitelman's syndrome is not involved in determining blood pressure levels.
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Affiliation(s)
- Noriko Aoi
- Division of Molecular Diagnostics, Department of Advanced Medical Science, Nihon University School of Medicine, Tokyo, Japan
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Shao L, Ren H, Wang W, Zhang W, Feng X, Li X, Chen N. Novel SLC12A3 mutations in Chinese patients with Gitelman's syndrome. Nephron Clin Pract 2008; 108:p29-36. [PMID: 18287808 DOI: 10.1159/000117815] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Accepted: 12/19/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Inactivating mutations of the SLC12A3 gene are the most common cause of Gitelman's syndrome (GS), a disorder inherited as an autosomal recessive trait. In a minority of cases, GS-like phenotypes are caused by mutations in the CLCNKB gene. METHODS We searched for SLC12A3 and CLCNKB gene mutations in 13 Chinese patients (9 males and 4 females, age 35 +/- 14 years) from 8 unrelated families with the clinical and biochemical features of GS. All coding regions, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. RESULTS We identified 10 mutations distributed throughout the SLC12A3 gene. Seven are novel variants, including 4 missense mutations (Gly196Val, Cys430Gly, Gly439Val and Leu571Pro), 2 deletions (1384delG and 346-353delACTGATGG) and 1 in-frame insertion (997insCys). Three mutations were recurrent, including 2 missense mutations (Thr60Met and Asp486Asn) and 1 deletion (2883-2884delAG). The homozygous or heterozygous mutation Thr60Met was found in 8 of 13 patients. There were no mutations detected in the CLCNKB gene. CONCLUSIONS Thr60Met may be the most common mutation in Chinese patients with GS. Possible specific genotype-phenotype correlations were difficult to identify.
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Affiliation(s)
- Leping Shao
- Department of Nephrology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Aoi N, Nakayama T, Tahira Y, Haketa A, Yabuki M, Sekiyama T, Nakane C, Mano H, Kawachi H, Sato N, Soma M, Matsumoto K. Two novel genotypes of the thiazide-sensitive Na-Cl cotransporter (SLC12A3) gene in patients with Gitelman's syndrome. Endocrine 2007; 31:149-53. [PMID: 17873326 DOI: 10.1007/s12020-007-0024-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 05/07/2007] [Accepted: 05/14/2007] [Indexed: 02/08/2023]
Abstract
Gitelman's syndrome is an autosomal recessive disorder marked by salt wasting and hypokalaemia resulting from loss-of-function mutations in the SLC12A3 gene that codes for the thiazide-sensitive Na-Cl cotransporter. Gitelman's syndrome is usually distinguished from Bartter's syndrome by the presence of both hypomagnesaemia and hypocalciuria. Although recent advances in molecular genetics may make it possible to both diagnose and differentiate these diseases, the phenotypes sometimes overlap. Here we report two sporadic cases of Gitelman's syndrome and two novel genotypes of SLC12A3. Patient 1 was a compound heterozygote with a known missense mutation, L849H, and a novel mutation, R852H in exon 22. Patient 2 was homozygous for the missense mutation L849H. To our knowledge, this is the first report of a patient homozygous for 849H. Interestingly, both patients were affected with autoimmune thyroid disease. Patient 1 was affected with Hashimoto's disease, and Patient 2 was affected with Graves' disease. The symptoms of Patient 2 were more serious than those of Patient 1. Although the patients both carried the 849H allele (Patient 1 as a heterozygote and Patient 2 as a homozygous), their clinical symptoms differed. The difference in the clinical features may have been due both to phenotypic differences and the fact that Gitelman's syndrome is a complicated disorder.
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Affiliation(s)
- Noriko Aoi
- Division of Nephrology and Endocrinology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan
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Hashida T, Yamada M, Hashimoto K, Satoh T, Okada S, Shibusawa N, Ishizuka T, Mori M. Loss of consciousness and hypokalemia in an elderly man with a mutation of the thiazide-sensitive Na-Cl cotransporter gene. Endocr J 2006; 53:859-63. [PMID: 16966826 DOI: 10.1507/endocrj.k06-076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
An 80-year-old man was referred to our department for evaluation of repetitive loss of consciousness and faintness with hypokalemia. He had relatively low blood pressure, hypomagnesemia, hypocalciuria and chondrocalcinosis in the knee, clinically suggesting Gitelman's syndrome. A renal clearance study could not be carried out due to the patient's age and complications of the heart. Sequence analysis of the gene of thiazide-sensitive Na-Cl cotransporter (TSC) showed a heterozygous missense mutation from C to T at 1712 base pairs from the translation start site, with resultant changes in codon 569 from alanine to valine (A569V). Treatment with oral administration of potassium chloride improved all the symptoms. Although Gitelman's syndrome has been considered to be autosomal recessive, cases of only heterozygous mutation detected have recently been reported. Therefore, the mutation found in this patient may be responsible for Gitelman's syndrome.
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Affiliation(s)
- Tetsu Hashida
- Department of Medicine and Molecular Science, Gunma University Graduate School of Medicine, Maebashi, Japan
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Komatsuda A, Iwamoto K, Wakui H, Sawada KI, Yamaguchi A. Analysis of mutations in the urate transporter 1 (URAT1) gene of Japanese patients with hypouricemia in northern Japan and review of the literature. Ren Fail 2006; 28:223-7. [PMID: 16703794 DOI: 10.1080/08860220600580365] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Renal hypouricemia is an autosomal recessive disorder resulting from inactivating mutations in the urate transporter 1 (URAT1) encoded by SLC22A12. To date, 10 mutations have been identified and W258X in the URAT1 gene is the predominant cause in middle to southwestern Japan. However, it is still unclear whether there is a regional specific distribution of mutations in northern Japan. In this study, we analyzed mutations in the URAT1 gene of five Japanese patients with renal hypouricemia in northern Japan. METHODS Peripheral blood mononuclear cells were isolated from patients with hypouricemia and healthy control subjects. A mutation analysis of the URAT1 gene was performed completely by direct automated sequencing of polymerase chain reaction-amplified DNA products. RESULTS We identified two mutations. These mutations [c.269G>A (R90H) and c.774G>A (W258X)] have been reported in Japanese patients. Two of five patients were homozygotes (W258X), two carried single heterozygous mutations (W258X), and the remaining one was a compound heterozygote (R90H and W258X). CONCLUSIONS Our study suggests that there is no regional different distribution of the URAT1 genetic mutations in Japanese with renal hypouricemia.
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Affiliation(s)
- Atsushi Komatsuda
- Third Department of Internal Medicine, Akita University School of Medicine, Japan.
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Naraba H, Kokubo Y, Tomoike H, Iwai N. Functional confirmation of Gitelman's syndrome mutations in Japanese. Hypertens Res 2006; 28:805-9. [PMID: 16471174 DOI: 10.1291/hypres.28.805] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gitelman's syndrome is an autosomal recessive inherited renal tubular disorder resulting from loss-of-function mutations in the thiazide-sensitive sodium chloride cotransporter gene (SLC12A3). We have previously reported that the combined allele frequency for the reported Gitelman's syndrome mutations is 0.0321. However, almost all of the reported Gitelman's syndrome mutations were from case reports without functional confirmation. In the present study, we assessed the functionality of the two most prevalent mutations in Japanese, T180K and L849H, using a mammalian cell expression system. Human SLC12A3 cDNA was transiently expressed in Chinese hamster ovary (CHO) cells under the control of a cytomegalo virus (CMV) promoter. The T180K and L849H mutations were introduced by site-directed mutagenesis. The activity of the Na+-Cl- cotransporter was assessed by measuring tracer 22Na+ uptake. While the T180K variation was just a polymorphism, the L849H mutation was confirmed to be a loss-of-function mutation and appears to be responsible for the Gitelman's syndrome. This observation may have very important clinical implications, since the allele frequency of this variation is 0.0126.
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Riancho JA, Saro G, Sañudo C, Izquierdo MJ, Zarrabeitia MT. Gitelman syndrome: genetic and expression analysis of the thiazide-sensitive sodium-chloride transporter in blood cells. Nephrol Dial Transplant 2005; 21:217-20. [PMID: 16221718 DOI: 10.1093/ndt/gfi093] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Gitelman syndrome is caused by mutations of the SLC12A3 gene, which encodes the thiazide-sensitive NaCl transporter NCCT. Although several mutations causing Gitelman syndrome have been described, their molecular consequences have been rarely studied. We report a patient with Gitelman syndrome due to a mutation in the GT donor splicing site of intron 9. The analysis of RNA from peripheral blood cells showed a complete deletion of exon 9. This case report confirms the feasibility of using readily accessible blood cells to study the expression of the SLC12A3 gene, a procedure that may facilitate further studies of the functional genomics of Gitelman syndrome.
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Affiliation(s)
- Jose A Riancho
- Department Internal Medicine, Hospital U.M. Valdecilla, 39008 Santander, Spain.
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