Research progress of cystic fibrosis associated Pseudo-Bartter syndrome / 中华实用儿科临床杂志

Cystic fibrosis (CF) is an autosomal recessive inherited disease affecting multiple body systems.Pseudo-Bartter syndrome (PBS) is a common manifestation of CF, with such clinical features as hypochloremia, hyponatremia, hypokalemia and metabolic alkalosis.However, PBS patients do not have renal tubulopathy.Children with CF are prone to develop electrolyte abnormalities due to fluid and electrolyte loss.In this article, the pathogenesis, clinical manifestations, diagnosis, and treatment of CF associated PBS were reviewed in order to enhance clinical understan-ding of this disease.

Hipokalemia de gradiente transtubular alto: una propuesta práctica para su enfoque / High transtubular gradient hypokalemia: a practical proposal for its focus

Resumen El potasio es un ion de predominio intracelular involucrado en múltiples funciones esenciales para mantener la homeostasis celular. Por lo anterior, sus concentraciones a nivel plasmático se encuentran estrechamente reguladas mediante el sistema renal y endocrino, además de estar afectado ante situaciones como la acidosis, cambios en la osmolaridad plasmática y concentración de otros electrolitos. La hipokalemia es un trastorno electrolítico común en la práctica clínica causado por el aporte inadecuado o pérdidas excesivas. Su enfoque diagnóstico requiere de una apropiada historia clínica que incluya antecedentes personales patológicos, farmacológicos, y un examen físico detallado con determinación del estado de volemia e hidratación del paciente, así como la medición de otros electrolitos a nivel plasmático y ocasionalmente en orina. El gradiente transtubular de potasio es una herramienta útil para direccionar posibles causas. Dentro de las causas de hipokalemia de gradiente transtubular elevado se encuentra el síndrome de Bartter.

Abstract Potassium is a predominantly intracellular ion involved in multiple essential functions to maintain cellular homeostasis. Therefore, its variations at the plasma level are tightly regulated by the renal and the endocrine systems; in addition to being affected by situations such as acidosis, changes in plasma osmolality and concentration of another electrolytes. Hypokalemia is a common electrolyte disorder in clinical practice affected by reporting excessive damage or loss. Its diagnostic approach requires a complete medical record that includes personal pathological and pharmacological information, a specific physical examination with certain conditions like patient's blood volume and hydration status, as well as the measurement of other electrolytes at the plasma level and occasionally in urine. The transtubular potassium gradient is a useful tool to address possible causes. Bartter syndrome is one of the causes of elevated transtubular gradient hypokalemia.

Severe polyhydramnios as neonatal presentation of Bartter's syndrome type IV / Polihidrâmnios grave como manifestação neonatal da síndrome de Bartter tipo IV

Abstract Introduction: Bartter's syndrome comprises a heterogeneous group of inherited salt-losing tubulopathies. There are two forms of clinical presentation: classical and neonatal, the most severe type. Types I and II account for most of the neonatal cases. Types III and V are usually less severe. Characteristically Bartter's syndrome type IV is a saltlosing nephropathy with mild to severe neonatal symptoms, with a specific feature - sensorineural deafness. Bartter's syndrome type IV is the least common of all recessive types of the disease. Description: the first reported case of a Portuguese child with neurosensorial deafness, polyuria, polydipsia and failure to thrive, born prematurely due to severe polyhydramnios, with the G47R mutation in the BSND gene that causes Bartter's syndrome type IV. Discussion: there are few published cases of BS type IV due to this mutation and those reported mostly have moderate clinical manifestations which begin later in life. The poor phenotype-genotype relationship combined with the rarity of this syndrome usually precludes an antenatal diagnosis. In the presence of a severe polyhydramnios case, with no fetal malformation detected, normal karyotype and after maternal disease exclusion, autosomal recessive diseases, including tubulopathies, should always be suspected.

Resumo Introdução: a síndrome de Bartter inclui um grupo heterogéneo de tubulopatias hereditárias perdedoras de sal. Existem duas formas de apresentação clínica: clássica e neonatal, a forma mais grave. Os tipo I e II representam a maioria dos casos neonatais. Os tipos III e V são geralmente menos graves. Caracteristicamente, a síndrome de Bartter tipo IV é uma nefropatia perdedora de sal com sintomas neonatais ligeiros a graves, com um aspeto especí- fico - surdez neurossensorial. A síndrome de Bartter tipo IV é o tipo menos comum das formas recessivas da doença. Descrição: relatamos o primeiro caso de uma criança portuguesa, com surdez neurossensorial, poliúria, polidipsia e restrição de crescimento, nascida prematuramente devido a polihidrâmnios grave, homozigótica para a mutação G47R do gene BSND, responsável pela síndrome de Bartter tipo IV. Discussão: são raros os casos publicados sobre síndrome de Bartter tipo IV atribuída a esta mutação, e a maioria referem-se a diagnósticos mais tardios, com manifestações clínicas ligeiras. A fraca correlação fenótipo-genótipo combinada com a raridade desta síndrome tornam o diagnóstico pré-natal desafiante. Perante um caso de polihidrâmnios grave em um feto sem malformações aparentes, cariótipo normal e após exclusão de patologia materna, as doenças autossómicas recessivas, incluindo as tubulopatias, devem ser sempre consideradas.

Mutation analysis of KCNJ1 gene and investigation of phenotype in 5 Chinese patients with Bartter syndrome type 2 / 中华肾脏病杂志

Objective@#To identify and analyze the variants of the KCNJ1 gene in five Chinese patients with Bartter syndrome type 2 (BS2), and to describe their clinical features as well as treatment results.@*Methods@#Data and blood samples of five BS2 patients and their relatives confirmed by Qingdao Municipal Hospital from June 2012 to January 2019 were collected. Whole-exome-sequencing (WES) based on the second generation high throughput sequencing was performed to detect variants. The 2015 American College of Medical Genetics and Genomics Standards and Guidelines were applied to analyze the pathogenicity of the variants. The clinical features and laboratory results were retrospectively studied. The response to treatment and follow-up data were reviewed.@*Results@#Ten variants including six novel ones of KCNJ1 gene were identified through WES and verified by Sanger dideoxy sequencing. Missense variants accounted for the highest proportion. The common symptoms and signs of five BS2 patients from high to low incidence were polydipsia and polyuria (5/5), one of them (1/5) presented with diabetes insipidus; maternal polyhydramnios and premature delivery (4/5); growth retardation (3/5). Initially, two patients presented with hypochloremic metabolic alkalosis and hypokalemia, whereas the acid-base disturbance was absent in the others. One patient experienced hyperkalemia. In terms of calcium-phosphorus metabolism, one patient had evident parathyroid hormone (PTH) resistance (hypocalcemia, hyperphosphatemia and markedly elevated serum intact PTH levels), three presented with PTH overacting (hypercalcemia, hypophosphatemia and mild elevated serum intact PTH levels), and one showed normal blood calcium and phosphorus concentrations with high-normal serum intact PTH levels. All patients had nephrocalcinosis or hypercalciuria, and one of them complicated with nephrolithiasis. Indomethacin helped to correct the growth retardation, halt polydipsia polyuria, decrease the elevated urinary calcium excretion, and normalize electrolyte disturbance as well as PTH parameters in some patients.@*Conclusions@#This investigation identifies ten variants of KCNJ1 gene, including six ones that have not been previously reported, which will enrich the human gene mutation database (HGMD). These patients in our study have atypical BS phenotype, so that careful differentiation from other parathyroid diseases will be required for clinicians.

A Unusal Presentation Of Bartter Syndrome

Bartter Syndrome is a rare congenital disease that manifests as hypokalemia, hyponatremia and hypotension. The disease occurs due to defective genes that are responsible for the reabsorption of certain electrolytes in the renal tubules. Hence it results in salt-wasting dyselectrolytemia. By its inheritable nature, the usual presentation of the disease is in the infants and children. But this case report presents an adult with symptoms of Bartter Syndrome which was discovered by chance while the patient was being treated for Acute gastroenteritis. Adult onset of Bartter Syndrome is incredibly rare and has been reported only in few other cases.

Síndrome de Bartter: una tubulopatía infrecuente de inicio antenatal / Bartter syndrome: an infrequent tubulopathy of prenatal onset

INTRODUCCIÓN: Síndrome de Bartter (SB) es una tubulopatía hereditaria, poco frecuente que tiene dos formas de presentación, forma grave de inicio antenatal (Bartter neonatal) y forma de aparición más tardía (Bartter clásico). En su forma antenatal se manifiesta con poliuria fetal, polihidroamnios de inicio precoz y severo, parto prematuro secundario y restricción de crecimiento intrauterino. La etapa postnatal presenta episodios recurrentes de deshidratación y desbalance electrolítico que pue den comprometer la sobrevida del paciente. OBJETIVO: Comunicar un caso de SB neonatal y presentar una revisión de la literatura en esta patología. CASO CLÍNICO: Prematuro 35 semanas, con antecedente de severo polihidroamnios diagnosticado a las 27 semanas de gestación, sin causa aparente. Desde su nacimiento evolucionó con poliuria y alcalosis metabólica hipokalémica haciendo plantear, en primera semana de vida, diagnóstico de Síndrome de Bartter neonatal. El laboratorio confirmó per didas urinarias de electrólitos. Fue manejado con balance hídrico estricto y suplementación de sodio y potasio, logrando estabilizar peso y desbalance electrolítico. Se mantiene en control nefrológico, con suplementación de gluconato de potasio y cloruro de sodio. Se agregó ibuprofeno al cuarto mes como parte del tratamiento. Al séptimo mes de vida, ecografía renal demostró nefrocalcinosis. Al año de vida se evidenció hipoacusia sensorioneural profunda requiriendo implante coclear. CONCLUSIÓN: Presencia de polihidroamnios severo de aparición temprana sin causa identificada debe hacer sospechar SB, que aun siendo infrecuente determina graves alteraciones hidroelectrolíticas y debe ser iniciado su tratamiento precozmente.

INTRODUCTION: Bartter syndrome (BS) is a rare inherited tubulopathy that has two presentation forms, the first one is a severe form of antenatal onset (neonatal Bartter) and the second one is a later on set form during the first years of life (classic Bartter). In the antenatal form, it manifests with fetal polyuria, polyhydramnios of early and severe onset, premature delivery, and intrauterine growth restriction. In the postnatal stage, it presents recurrent episodes of dehydration and electrolyte im balance that can compromise the survival of the patient. OBJECTIVE: To report a clinical case of neo natal BS and a review of the literature. CLINICAL CASE: Premature newborn of 35 weeks of gestation with history of severe polyhydramnios diagnosed at 27 weeks of gestation, without apparent cause. From birth, the patient presented polyuria and hypokalemic metabolic alkalosis making a diagnosis of Neonatal Bartter Syndrome in the first week of life. Laboratory tests confirmed urinary electrolyte losses. The patient was treated with strict water balance and sodium and potassium supplementa tion, achieving weight and electrolyte imbalance stabilization. The patient remains in control in the nephrology unit, with potassium gluconate and sodium chloride supplementation. At the fourth month, ibuprofen was added as part of treatment. At the seventh month of life, renal ultrasound showed nephrocalcinosis. At one year of life, profound sensorineural hearing loss was observed re quiring a cochlear implant. CONCLUSION: The presence of severe polyhydramnios of early onset with no identified cause should lead to suspicion of neonatal BS which even when infrequent determines severe hydroelectrolytic alterations and should be treated early.

Variant analysis and genotype/phenotype association study in 42 Chinese patients with Bartter syndrome type 3 / 中华肾脏病杂志

Objective To analyze the variants of 42 Chinese patients with Bartter syndrome type 3 (BS3) and explore the characteristics of genotype and phenotype. Methods Forty-two genetically diagnosed patients from 40 Han and one Hui families were collected in the Affiliated Hospital of Qingdao University and the Affiliated Qingdao Municipal Hospital of Qingdao University during the period of June 2012 to October 2018. The second-generation sequencing and multiplex ligase probe-dependent amplification (MLPA) technique were used to analyze the CLCNKB gene variation and its characteristics in children with BS3. The clinical data were collected, and the therapeutic effect and growth improvement were observed and followed up. Thirty eight patients were divided into severe (n=26) and light (n=12) groups according to the severity of genetic variation. The clinical phenotypic characteristics of the two groups were compared. Results Thirty-six variants including 16 novel ones of CLCNKB gene were found. The whole gene deletion of CLCNKB gene was the most frequent mutation (40％), and the rate of large deletions was up to 55％. The most common symptoms included development retardation (38/42), polydipsia and polyuria (35/42), constipation (31/42) and vomiting (27/42). All patients presented with hypokalemia, hypochloremia and metabolic alkalosis. After the medicine treatment that based on indomethacin and potassium chloride, most patients could achieve obvious recovery of growth rate and restoration of hypokalemia. The severe group showed more severe metabolic alkalosis than the light group. Conclusions Thirty-six variants of CLCNKB gene have been found in this study, including 16 novel ones, which enrich the human gene mutation database (HGMD) and provide valuable references to diagnosis, treatment and the genetic counseling of Chinese population.

Síndrome pseudo Bartter asociado a la infusión endovenosa de colistina

RESUMEN El Síndrome Pseudo Bartter (PB) es una patología rara que consiste en una tubulopatía perdedora de sal debida a una alteración en la función de la rama ascendente del asa de Henle. Puede estar asociada con el uso de fármacos como la colistina. Conduce a una disminución sérica de electrolitos en sangre con hiperreninemia, hiperaldosteronemia y alcalosis metabólica, con repercusión en el área neuromotora y cardiovascular principalmente. Presentamos una serie de 3 pacientes que recibieron tratamiento con colistina, con edad media 66,6±20,4 años, predomino del sexo femenino. El Síndrome PB apareció a los 13,6±4,7 días del uso de colistina. Tras la instauración terapéutica presentaron disminución sérica de calcio, potasio y magnesio, acompañados de alcalosis metabólica y normotensión, resolviendo el cuadro a los 5,6±3,2 días. La aparición del Síndrome PB tras el uso de la colistina es rara, las alteraciones producidas por la tubulopatía no responden a la corrección insistente de los déficits solamente, requieren de tratamiento adicional para su resolución. La falta de conocimiento de esta complicación puede presentar desenlaces fatales para los pacientes y una intervención oportuna produce soluciones aparentemente alentadoras.

ABSTRACT Pseudo Bartter Syndrome (PB) is a rare pathology that consists of a salt-losing tubulopathy due to an alteration in the function of the ascending limp of the loop of Henle. It may be associated with the use of drugs such as colistin. It leads to a serum decrease of blood electrolytes with hyperreninism, hyperaldosteronism and metabolic alkalosis, with repercussion in the neuromotor and cardiovascular areas mainly. We present a series of 3 patients who received treatment with colistin, with a mean age of 66,6±20,4 years, predominantly female. PB Syndrome appeared at 13,6±4,7 days after the use of colistin. After the therapeutic initiation they presented serum decrease of calcium, potassium and magnesium, accompanied by metabolic alkalosis and normal blood pressure, all of them have shown resolution of the metabolic disturbances at 5,6±3,2 days. The appearance of PB Syndrome after the use of colistin is rare. The alterations produced by the tubulopathy do not respond to the insistent correction of the deficits only and require additional treatment for their resolution. The lack of knowledge of this complication could lead to fatal outcomes for patients and a timely intervention produces apparently encouraging solutions.

Clinical characterization and diagnosis of cystic fibrosis through exome sequencing in Chinese infants with Bartter-syndrome-like hypokalemia alkalosis / 医学前沿

Cystic fibrosis (CF) is a fatal autosomal-recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by recurrent pulmonary infection with obstructive pulmonary disease. CF is common in the Caucasian population but is rare in the Chinese population. The symptoms of early-stage CF are often untypical and may sometimes manifest as Bartter syndrome (BS)-like hypokalemic alkalosis. Therefore, the ability of doctors to differentiate CF from BS-like hypokalemic alkalosis in Chinese infants is a great challenge in the timely and accurate diagnosis of CF. In China, sporadic CF has not been diagnosed in children younger than three years of age to date. Three infants, who were initially admitted to our hospital over the period of June 2013 to September 2014 with BS-like hypokalemic alkalosis, were diagnosed with CF through exome sequencing and sweat chloride measurement. The compound heterozygous mutations of the CFTR gene were detected in two infants, and a homozygous missense mutation was found in one infant. Among the six identified mutations, two are novel point mutations (c.1526G > C and c.3062C > T) that are possibly pathogenic. The three infants are the youngest Chinese patients to have been diagnosed with sporadic CF at a very early stage. Follow-up examination showed that all of the cases remained symptom-free after early intervention, indicating the potential benefit of very early diagnosis and timely intervention in children with CF. Our results demonstrate the necessity of distinguishing CF from BS in Chinese infants with hypokalemic alkalosis and the significant diagnostic value of powerful exome sequencing for rare genetic diseases. Furthermore, our findings expand the CFTR mutation spectrum associated with CF.

Bartter syndrome and Liddle syndrome / 中华实用儿科临床杂志

Bartter syndrome and Liddie syndrome are genetic renal tubular disorders characterized by hypokalemic alkalosis.Bartter syndrome is mainly an autosomal recessive disease,caused by mutations of one of the five ion channel genes in renal tubular epithelial cells.Plasma renin and aldosterone levels are increased but blood pressure is normal,the main treatment is to correct hypokalemia,to prevent and cure complications.Liddle syndrome is an autosomal dominant disease,caused by epithelial Na-channel gene mutation,and presented with increased blood pressure but decreased plasma levels of renin and aldosterone.Patients with Liddle syndrome should limit the intake of sodium and supplement potassium,take Triamterene or Amiloride to control hypertension.

Mutation analysis of SLC12A1 gene in nine Chinese patients with Bartter syndrome type Ⅰ / 中华肾脏病杂志

Objective To analyze the mutations of SLC12A1 gene in nine Chinese families with Bartter syndrome type I (BS1),and analyze the relationship between genotype and phenotype.Methods The next generation sequencing was used to detect mutations in nine BS1 patients including eight with antenatal BS (aBS) and one with classical BS (cBS).Clinical characteristics and biochemical findings at the first admission as well as follow-up were reviewed.Results 15 different mutations of SLC12A1 gene were identified,including 11 novel ones.Among nine probands,seven were compound heterozygotes,two were homozygotes.All patients presented with polydipsia and polyuria,and eight with growth retardation.All patients had lower than-normal serum chloride concentration,metabolic alkalosis,and elevated basal renin activity and aldosterone,and seven had hypokalemia.Through treatment of indomethacin and/or potassium chloride,biochemical indicators could roughly restored normal.Conclusion These findings will enrich the human gene mutation database (HGMD) and provide valuable references to the genetic counseling and diagnosis for Chinese population.

Research advances in hypokalemic salt-losing tubulopathies / 上海交通大学学报（医学版）

Hereditary tubular disorders play an important role in the ion transport mechanism of kidney. Hypokalemic salt-losing tubulopathies (SLTs) are a set of rare hereditary diseases, which accompany with hypokalaemic metabolic alkalosis, normo or hypotension, and are associated with high plasma renin activity and hyperaldosteronemia. Bartter syndrome and Gitelman syndrome, characterized by the disability of the thick ascending limb of Henle's loop and/or the distal convoluted tubule, respectively, are two common types of SLTs. Some types of SLTs share similar clinical manifestations, making them difficult to diagnose. Besides, with the development of molecular genetics, new disease-causing genes have been discovered. It's inconvenient for clinicians to refer to the old classification of SLTs. The review mainly covered the newly discovered pathogenic genes of SLTs and the corresponding pathogenic mechanisms. In addition, a new system for classification of SLTs based on physiology and pharmacology was introduced.

Síndrome de pseudo-Bartter como presentación inicial de fibrosis quística

Las manifestaciones clínicas de la fibrosis quística comprometen diferentes órganos; siendo los sistemas respiratorio y gastrointestinal los más frecuentemente afectados. Puede presentarse como un desequilibrio ácido-base y electrolítico conocido como síndrome de pseudo-Bartter que se define como un episodio de deshidratación con alcalosis metabólica hipoclorémica hiponatrémica e hipocalémica en ausencia de alteración tubular renal. Se presenta el caso clínico de un lactante menor masculino de cuatro meses con dos hospitalizaciones previas por deshidratación moderada y desequilibrio hidroelectrolítico con hiponatremia. La tercera hospitalización fue el 27 de enero de 2017 por 20 días. En esta ocasión fue admitido por gastroenteritis aguda, con deshidratación moderada, desequilibrio hidroelectrolítico, y observación por un trastorno metabólico. Por presentar deshidratación con alcalosis metabólica hipoclorémica hiponatrémica e hipocalémica sin tubulopatía renal se diagnosticó síndrome de pseudo Bartter y se sospechó fibrosis quística que se corroboró con medición de electrolitos en sudor y análisis molecular de las mutaciones . Conclusión: Debe considerarse el diagnóstico de fibrosis quística en un niño, sobre todo menor de dos años, con deshidratación, alcalosis metabólica hiponatrémica hipoclorémica aunque no haya presentado síntomas respiratorios o gastrointestinales típicos de la enfermedad. El diagnóstico temprano es fundamental para mejorar el pronóstico y la sobrevida a largo plazo

The clinical manifestations of cystic fibrosis may involve multiple organs. Although the respiratory and gastrointestinal are the most commonly affected systems, it can present as an acid- base and electrolyte imbalance called pseudo -Bartter syndrome which is defined as an episode of dehidration with metbolic alkalosis with hypochloremia, hyponatremia and hypokalemia in the absence of renal tubular pathology. We report a case of a 4-month-old male infant with 2 previous episodes of moderate dehydration and hydroelectrolyte imbalance with hyponatremia. He was admitted on January 27 th 2017 for 20-days hospital stay. On his 3th hospitalization, he was admitted with acute gastroenteritis, moderate dehydration, hydroelectrolyte imbalance, and probable metabolic disorder. Due to the presence of metabolic hypochloremic alkalosis with hyponatremia and hypokalemia without renal tubulopathy, Pseudo Bartter Syndrome was diagnosed and cystic fibrosis was suspected and corroborated later with the measurement of sweat electrolytes and molecular analysis of mutations. Conclusion: The diagnosis of cystic fibrosis must be suspected in a child, especially those under 2 years old, with hyponatremic hypochloremic,hypokalemic metabolic alkalosis dehydration should be considered even in the absence of respiratory or gastrointestinal symptoms, which are typically present in this disease. An early diagnosis is essential to improve the prognosis and long term survivor

A clinical and hereditary analysis of novel complex heterozygous KCNJ1 mutation in a Bartter syndrome type Ⅱ patient / 中华内科杂志

Bartter syndrome (BS) is a hereditary condition transmitted as an autosomal recessive (Bartter type 1 to 4) or dominant trait (Bartter type 5).The disease associates hypokalemic alkalosis with varying degrees of hypercalciuria.Here we presented a case (BS type Ⅱ) of a 17 years old female presented with polyhydramnios,polyuria,nephrocalcinosis and hypokalemia,which was alleviated after treatment with celecoxib and vitamin D3.DNA sequencing identified compound heterozygous KCNJ1 gene mutations,c.931 C ＞ T (p.R311 W) and c.445-446insCCTGAACAC (p.V149Afs,150X),with the latter a novel mutation.Her father and mother were heterozygous carriers of c.931C ＞ T (p.R311W) and c.445-446insCCTGAACAC (p.V149Afs,150X),respectively.In conclusion,this case of BS type 1 is caused by a novel compound heterozygous KCNJ1 mutation.Further studies are needed to verify the effect of celecoxib in BS patients.

A clinical and hereditary analysis of novel complex heterozygous KCNJ1 mutation in a Bartter syndrome type Ⅱ patient / 中华内科杂志

Bartter syndrome (BS) is a hereditary condition transmitted as an autosomal recessive (Bartter type 1 to 4) or dominant trait (Bartter type 5).The disease associates hypokalemic alkalosis with varying degrees of hypercalciuria.Here we presented a case (BS type Ⅱ) of a 17 years old female presented with polyhydramnios,polyuria,nephrocalcinosis and hypokalemia,which was alleviated after treatment with celecoxib and vitamin D3.DNA sequencing identified compound heterozygous KCNJ1 gene mutations,c.931 C ＞ T (p.R311 W) and c.445-446insCCTGAACAC (p.V149Afs,150X),with the latter a novel mutation.Her father and mother were heterozygous carriers of c.931C ＞ T (p.R311W) and c.445-446insCCTGAACAC (p.V149Afs,150X),respectively.In conclusion,this case of BS type 1 is caused by a novel compound heterozygous KCNJ1 mutation.Further studies are needed to verify the effect of celecoxib in BS patients.

Gene analysis, treatment, and follow-up of sixteen Chinese patients with Bartter syndrome / 中华肾脏病杂志

Objective To analyze the mutations of causal genes in sixteen Chinese patients with suspicious Bartter syndrome,and follow up their treatment results.Methods Mutations were identified by the next generation sequencing and the multiplex ligation-dependent probe amplification (MLPA).Clinical and biochemical features at the first presentation as well as follow-up results were reviewed.Results 15 different CLCNKB gene mutations were identified in sixteen patients with BS,including 11 novel ones.A novel missense mutation and a novel small deletion were found from SLC12A1 gene.A novel gross deletion was found in CLCNKA gene.A recurrent missense mutation was identified from BSND gene.The whole gene deletion mutation of CLCNKB gene was the most frequent mutation (32％),and the rate of gross deletion was up to 50 percent in this group of Chinese patients.The most common clinical manifestations were development retardation (15/16),polydipsia and polyuria (15/16).All of the patients were detected with hypokalemia,hypochloremia and metabolic alkalosis.Indomethacin treatment had significant improvement to the stature and weight restoration.Conclusion The present study has found 19 mutations,including 14 novel ones,which enriches the human gene mutation database (HGMD) and provides valuable references to the genetic counseling and diagnosis of Chinese population.

Síndrome de pseudo-Bartter como presentación de fibrosis quística con mutación DF508 / Pseudo-Bartter syndrome as manifestation of cystic fibrosis with DF508 mutation

Resumen: Introducción: El síndrome de pseudo-Bartter (SPB) se define como una alcalosis metabólica hipoclorémica con hipocaliemia en ausencia de tubulopatía. Los pacientes con fibrosis quística (FQ), al presentar alteraciones hidrolectrolíticas, pueden llegar a presentarlo. Caso clínico: Lactante femenino con antecedente de 2 eventos de deshidratación. Se presenta a los 5 meses de vida con vómito, rechazo al alimento, tos crónica, poliuria, desnutrición, alcalosis metabólica, hipocaliemia, hiponatremia, hipocloremia y falla renal aguda. Se realizó estudio de tos crónica, con lo que se descartó tuberculosis pulmonar, enfermedad por reflujo gastroesofágico y alteración en la mecánica de la deglución. Ante la alcalosis metabólica sin tubulopatía se diagnosticó SPB; por la historia de desnutrición y tos crónica se sospechó de FQ, la cual se corroboró con medición de electrolitos en sudor y mediante análisis molecular de la mutación delta F508. Este es uno de los pocos casos reportados con SPB y esta mutación. Conclusiones: En pacientes con cuadros repetitivos de deshidratación hiponatrémica con alcalosis metabólica hipoclorémica o SPB debe considerarse como diagnóstico diferencial FQ. La FQ pude presentarse como SPB, principalmente en pacientes menores de 2 años.

Abstract: Background: Pseudo Bartter syndrome (PBS) is defined as hypokalaemic hypochloraemic metabolic alkalosis in the absence of renal tubular pathology. Children with cystic fibrosis (CF) are at risk of developing electrolyte abnormalities and even PBS may occur. Case report: 5 months old female infant with a history of two events of dehydration with vomit, refusal to eat, chronic cough, polyuria, malnutrition, metabolic alkalosis, hypokalemia, hyponatremia, hypochloremia and acute renal failure. Chronic cough study was performed, discarding pulmonary tuberculosis, gastroesophageal reflux disease and impaired swallowing. PBS was diagnosed due to hypokalaemic hypochloraemic metabolic alkalosis in the absence of renal tubular pathology. CF was corroborated by electrolytes in sweat and through molecular analysis of the delta F508 mutation. This is one of the few reported cases linking PBS and this mutation. Conclusions: In patients with hyponatremic dehydration episodes with hypokalaemic hypochloraemic metabolic alkalosis, PBS should be considered as differential diagnosis. CF could be presented as PBS, mainly in patients younger than 2 years.

Utilization of furosemide/hydrochlorothiazide load test in differential diagnosis of Bartter syndrome from Gitelman syndrome in children / 临床儿科杂志

Objective To explore the application of furosemide/hydrochlorothiazide load test in clinical classification of Bartter syndrome and Gitelman syndrome and the significance of selecting target genes. Method The clinical features, biomarkers, the furosemide/hydrochlorothiazide load test, and gene detection in 5 patients with Bartter syndrome and Gitelman syndrome were retrospectively analyzed during 2012 to 2014. Results All of those 5 patients were manifested low potassium and metabolic acidosis; basis of renin, angiotensin II, and aldosterone were elevated. The blood pressures were normal. Most of the patients suffered from polydipsia, diuresis, and different degrees of growth retardation. The gene analysis of these 5 patients made the same diagnoses as furosemide/hydrochlorothiazide load test did. Conclusions Furosemide/hydrochlorothiazide load test can make a differentiation of Bartter syndrome from Gitelman syndrome and thus it can guide the selection of targeted gene detection.

Clinical analysis on 18 children with neonatal bartter syndrome / 中国医师杂志

Objective To analyze the clinical characteristics of Neonatal Bartter syndrome in order to enhance understanding of the disease.Methods Eighteen children with Neonatal Bartter syndrome who were admitted into our hospital from November 2006 to July 2013 were selected as research subjects.A ret-rospective study was done on the clinical data and the outcome of treatment.Results ⑴Clinical character-istics This group included 13 males and 5 females.The onset age ranged from birth to 1 years 3 months (4.01 ±4.49years).Six cases got the disease after birth.Amniotic fluid which lead to premature birth and low birth weight may happened in cases.The most common clinical symptom was malnutrition (89%).⑵Laboratory tests and Renal ultrasound All of the children showed hypokalemia and metabolic alkalosis in some degree,renin and angiotensin increased.In some cases urinary calcium /creatinine ratio were in-creased and urinary specific gravity,showed a low proportion of urine.Some cases'renal ultrasound exami-nation revealed nephrocalcinosis.⑶ Therapy:All of the patients in this group were given intravenous and /or oral potassium chloride treatment.For drug treatment,10 cases were given single application of indom-ethacin [1 ~3mg/(kg·d),points 3 times per day oral]treatment.Conclusions The incidence of Neo-natal Bartter syndrome was early in infant onset as early as after birth,even the fetal period.Some patients may appear premature birth and /or low birth weigh because of amniotic fluid.The main clinical manifesta-tions include malnutrition,no weight increasing,retardation,serious dehydration and even life-threatening. The characteristic appearance such as the forehead,small jaw,eyes are the important characteristics of neo-natal Bartter syndrome.Patients often appears Hypokalemia,hyponatremia and Hypochloremia.Urinary po-tassium of this type increased.Most children's urinary sodium and chloride increased significantly.

Chloride channels and kidney diseases / 临床儿科杂志

Chloride ion is an important anion in organisms, managing various physiological events. A particular gene mu-tation leads to involved channel deifciency and to develop channelopathy. In kidney, different chloride channels distribute along certain fractions of the renal tubule, located at apical and basolateral membranes of tubular epithelial cells. Previous studies dis-covered that voltage-sensitive chloride channels in kidney are associated with Bartter syndrome and Dent’s disease. In addition, the kidney can be involved by cystic ifbrosis resulting from dysfunction of cystic ifbrosis transmembrane conductance regulator. In this review, the function and mechanism of chloride channels in maintenance of normal renal function, and the renal diseases caused by related gene defects were discussed.