Pattern of hereditary renal tubular disorders in Egyptian children.

BACKGROUND: Hereditary renal tubular disorders (HRTD) represent a group of genetic diseases characterized by disturbances in fluid, electrolyte, and acid-base homeostasis. There is a paucity of studies on pediatric HRTD in Egypt. In this study, we aimed to study the pattern, characteristics, and growth outcome of HRTD at an Egyptian medical center. METHODS: This study included children from one month to < 18-years of age with HRTD who were diagnosed and followed up at the Pediatric Nephrology Unit of Sohag University Hospital from January 2015 to December 2021. Data on patients` demographics, clinical features, growth profiles, and laboratory characteristics were collected. RESULTS: Fifty-eight children (57% males; 72% parental consanguinity; 60% positive family history) were diagnosed with seven HRTD types. The most commonly encountered disorders were distal renal tubular acidosis (distal renal tubular acidosis [RTA] 27 cases, 46.6%) and Bartter syndrome (16 cases 27.6%). Other identified disorders were Fanconi syndrome (6 cases with cystinosis), isolated proximal RTA (4 cases), nephrogenic diabetes insipidus (3 cases), and one case for each RTA type IV and Gitelman syndrome. The median age at diagnosis was 17 months with a variable diagnostic delay. The most common presenting features were failure to thrive (91.4%), developmental delay (79.3%), and dehydration episodes (72.4%). Most children showed marked improvement in growth parameters in response to appropriate management, except for cases with Fanconi syndrome. Last, only one case (with cystinosis) developed end-stage kidney disease. CONCLUSIONS: HRTD (most commonly distal RTA and Bartter syndrome) could be relatively common among Egyptian children, and the diagnosis seems challenging and often delayed.

Characteristics of electrolyte imbalance and pseudo-bartter syndrome in hospitalized cystic fibrosis children and adolescents.

INTRODUCTION: Pseudo-Bartter syndrome (PBS) is a rare manifestation of Cystic fibrosis (CF) and can often be the initial presentation in these patients, however, due to significantly overlapping symptoms it is often misdiagnosed as simple dehydration or Bartter syndrome. The objective of our study was to highlight the key features of PBS and electrolyte imbalance in CF patients helping in early and prompt diagnosis. METHOD: We performed a retrospective study from January 2015 to December 2019 at the Aga Khan University Hospital (AKUH), Pakistan. CF patients aged from 1-18 years, admitted at AKUH were enrolled and their laboratory data and individual charts were reviewed. Patients were categorized into three groups based on their serum electrolyte profile and their clinical findings were compared. RESULT: We enrolled 72 CF patients, out of which 42 (58%) were categorized into the Normal Electrolyte (NE) group, 19 (26%) into the Electrolyte Imbalance (EI) group and 11 (15%) in the PBS group. Out of 11 cases, 6 (54.54%) patients in PBS group presented with features consistent with PBS leading to CF diagnosis labeled as "early presenters". Mean age of patients in the PBS group was 3.81± 0.86 years and their age at diagnosis were significantly lower as compared to other groups. Gastrointestinal disturbances including diarrhea, vomiting and constipation were more common in the EI and PBS groups. Polyuria was most common in the PBS (72%) group. Length of hospital stay showed no significant difference. CONCLUSION: Pseudo-Bartter syndrome can be a presenting feature of cystic fibrosis. Electrolyte imbalance should be anticipated in hospitalized CF children and adolescent.

Growth hormone deficiency in children with antenatal Bartter syndrome.

Background Bartter syndrome is a group of rare autosomal-recessive renal disorders characterized by hypokalemic hypochloremic metabolic alkalosis associated with severe growth failure; the exact causes for growth retardation are unclear. GH deficiency (GHD) has been reported in a few cases of Bartter syndrome. The aim of our study was to determine the prevalence of GHD in children with antenatal Bartter syndrome and to assess their response to GH therapy. Methods Ten patients aged 1.5-14.5 years and diagnosed with antenatal Bartter syndrome were enrolled. Seven children with short stature underwent GH stimulation tests. Results Common presenting symptoms were failure to thrive and polyuria. The mean patient height at study entry was -2.7 standard deviation (SD) (range 0.89 to -5.95) and mean weight (SD) was -1.7 (range 1.89 to -4.11). A decline in height and weight (SD) was observed over the years. GHD was diagnosed in four children and GH therapy was started in all of them. Two patients responded very well and gained >1 SD in height, one patient stopped therapy due to non-adherence and one had a poor response. Conclusions In addition to other important causes for poor growth in antenatal Bartter syndrome, our findings suggest that GHD should also be considered as a cause of growth retardation and therefore, clinical assessment of the GH axis is recommended. GH therapy has a role in the treatment of growth failure in some individuals with Bartter syndrome.

Mimicry and well known genetic friends: molecular diagnosis in an Iranian cohort of suspected Bartter syndrome and proposition of an algorithm for clinical differential diagnosis.

BACKGROUND: Bartter Syndrome is a rare, genetically heterogeneous, mainly autosomal recessively inherited condition characterized by hypochloremic hypokalemic metabolic alkalosis. Mutations in several genes encoding for ion channels localizing to the renal tubules including SLC12A1, KCNJ1, BSND, CLCNKA, CLCNKB, MAGED2 and CASR have been identified as underlying molecular cause. No genetically defined cases have been described in the Iranian population to date. Like for other rare genetic disorders, implementation of Next Generation Sequencing (NGS) technologies has greatly facilitated genetic diagnostics and counseling over the last years. In this study, we describe the clinical, biochemical and genetic characteristics of patients from 15 Iranian families with a clinical diagnosis of Bartter Syndrome. RESULTS: Age range of patients included in this study was 3 months to 6 years and all patients showed hypokalemic metabolic alkalosis. 3 patients additionally displayed hypercalciuria, with evidence of nephrocalcinosis in one case. Screening by Whole Exome Sequencing (WES) and long range PCR revealed that 12/17 patients (70%) had a deletion of the entire CLCNKB gene that was previously identified as the most common cause of Bartter Syndrome in other populations. 4/17 individuals (approximately 25% of cases) were found to suffer in fact from pseudo-Bartter syndrome resulting from congenital chloride diarrhea due to a novel homozygous mutation in the SLC26A3 gene, Pendred syndrome due to a known homozygous mutation in SLC26A4, Cystic Fibrosis (CF) due to a novel mutation in CFTR and apparent mineralocorticoid excess syndrome due to a novel homozygous loss of function mutation in HSD11B2 gene. 1 case (5%) remained unsolved. CONCLUSIONS: Our findings demonstrate deletion of CLCNKB is the most common cause of Bartter syndrome in Iranian patients and we show that age of onset of clinical symptoms as well as clinical features amongst those patients are variable. Further, using WES we were able to prove that nearly 1/4 patients in fact suffered from Pseudo-Bartter Syndrome, reversing the initial clinical diagnosis with important impact on the subsequent treatment and clinical follow up pathway. Finally, we propose an algorithm for clinical differential diagnosis of Bartter Syndrome.

[Bartter syndrome, severe rare orphan kidney disease: a step towards therapy through pharmacogenetic and epidemiological studies].

Bartter syndromes (BS) types 1-5 are rare salt-losing tubulopathies presenting with overlapping clinical phenotypes including marked salt wasting and hypokalemia leading to polyuria, polydipsia, volume contraction, muscle weakness and growth retardation. These diseases are due to an impairment of sodium, potassium, chloride reabsorption caused by mutations in genes encoding for ion channel or transporters expressed in specific nephron tubule segments. Particularly, BS type 3 is a clinically heterogeneous form caused by mutations in CLCNKB gene which encodes the ClC-Kb chloride channel involved in NaCl reabsorption in the renal tubule. Specific therapy for BS is lacking and the only pharmacotherapy up today available is purely symptomatic and characterized by limiting side effects. The improvement of our understanding of the phenotype/genotype correlation and of the precise pathogenic mechanisms associated with BS type 3 as well as the pharmacological characterization of ClC-K chloride channels are fundamental to design therapies tailored upon patients' mutation. This mini review focused on recent studies representing relevant forward steps in the field as well as noteworthy examples of how basic and clinical research can cooperate to gain insight into the pathophysiology of this renal channelopathy, paving the way for a personalized therapy.

Molecular pathophysiology of Bartter's and Gitelman's syndromes.

BACKGROUND: In the last two decades, progress in cytogenetic and genome research has enabled investigators to unravel the underlying molecular mechanisms of inherited tubulopathies such as Bartter's and Gitelman's syndromes and helped physicians to better understand not only these two pathologic entities but also renal pathophysiology and salt sensitive hypertension. DATA SOURCES: Articles collected from PubMed and open access journals included original articles, research articles, and comprehensive reviews. They were evaluated by the authors with an special emphasis on originality and up to date information about molecular pathophysiology. RESULTS: Bartter's and Gitelman's syndromes are two different inherited salt loosing tubulopathies. They are characterized by various inability of distal nephron to reabsorb sodium chloride with resultant extarcellular volume contraction and increased activity of the renin angiotensin aldosterone system. Hypokalemic metabolic alkalosis is a common feature of these two forms of tubulopathies. Hypercalciuria characterizes the majority of Bartter's syndrome, and hypomagnesemia with hypocalciuria characterizes Gitelman's syndrome. Low blood pressure is a common feature among patients who suffered from these tubulopathies. Bartter's syndromes encompass a heterogeneous group of ion channels defects localized at the thick ascending limp of Henle's loop with resultant loss of function of sodium-potassium-2 chloride cotransporter. These defects result in the impairment of the countercurrent multiplication system of the kidney as well as calcium, potassium and acid base disturbances which in the majority of cases are proved lethal especially in the antenatal and/or immediate postnatal life period. The underlying pathology in Gitelman's syndrome is defined to the distal convoluted tubule and is related to loss of function of the sodium-chloride cotransporter. The results of this defect encompass the inability of extracellular volume homeostasis, magnesium and potassium conservation, and acid base disturbances which are generally mild and in the majority of cases are not life-threatening. CONCLUSIONS: Recent advances in molecular pathophysiology of Bartter's and Gitelman's syndromes have helped physicians to better understand the underlying mechanisms of these pathologic entities which remain obscure. Data collected from experiments among genetically manipulated animals enable us to better understand the pathophysiology of mammalian kidney and the underlying mechanisms of salt sensitive hypertension and to lay a foundation for the future development of new drugs, especially diuretics and antihypertensive drugs.

Pseudo-bartter syndrome, pattern and correlation with other cystic fibrosis features.

Pseudo-Bartter Syndrome (PBS), although quite common in patients with cystic fibrosis (CF), is often missed as simple dehydration or Bartter syndrome. This study was performed in patients with PBS to compare the pattern and course of the disease with those with CF not manifesting with this syndrome. All patients with CF who attended the respiratory clinic at Queen Rania Al-Abdallah Hospital from January 2000 to April 2010 were included in this retrospective case-control study. A specially formulated data sheet was used and those with PBS and those not having the syndrome were identified. A total of 110 patients (51% female) with CF with a median age of seven years were followed-up. Eighteen (16.3%) of them had one or more episodes of PBS. The median follow-up period was 6.2 years. All the episodes occurred during summer and in infancy. Median age of the initial episode of PBS was three months. One-third of them were initially followed at the nephrology clinic. Three patterns of PBS were identified: single episode in three (16.6%) patients, recurrent in 12 (66.6%) patients and chronic in three (16.6%) patients. Early colonization of Pseudomonas spp before 1 st birthday was seen in 44% patients with PBS compared with 12% in other CF patients (P-value = 0.0075). The total number of colonized patients and other CF features at the time of the study did not differ significantly among patients, although the mean Shwachman-Kulczycki score is significantly lower in those with recurrent PBS (69 compared with 85 in other CF patients). Gene mutation was identified in only 30% of the entire cohort. PBS is common in patients with CF, and it should be kept in mind in any patient with hypotonic dehydration and metabolic alkalosis. Recurrent pattern is associated with earlier Pseudomonas colonization.

Síndrome de Bartter: reporte de un caso y revisión de la literatura / Bartter syndrome: a case report and literature review / Síndrome de Bartter: relatório de um caso e revisão da literatura

Se presenta el caso de un lactante masculino de 14 meses de edad que consulta por vómito, astenia, adinamia y palidez generalizada. Ingresa con un peso de 5.4 kg y una talla de 69 cm, marcada disminución del panículo adiposo y de la masa muscular, sin edemas. Los análisis reportaron potasio sérico 2,02 mEq/L, cloro 89,4 mEq/L, sodio 134,5 mEq/L, magnesio 2,39 mg/dl, albumina 4,52 gr/dl, creatinina sérica 0,17 mg/dl, uroanálisis con proteinuria 75 mg/dl y ecografía renal normal. Se sospecha síndrome de Bartter, por lo que se solicitan gases venosos que muestran pH 7,519, pO2 60 mmHg, pCO2 32,5 mmHg, HCO3 25,8 mmol/l, BE 3,3 mmol/L, relación calcio/creatinina en orina: 0,056, aldosterona 11,9 ngr/dl y renina total 459 pg/ml. Con estos resultados se hace el diagnóstico de SB, siendo compatible con el tipo III. Se iniciaron suplementos de potasio y diuréticos ahorradores de potasio sin lograr un adecuado aumento del potasio sérico y solo hasta iniciar indometacina este se logra corregir,al igual que la adecuada ganancia pondoestatural. A continuación se hace una revisión de la literatura sobre el síndrome de Bartter...

A case of 14-month male infant presenting with vomit, asthenia, adynamia, and generalized paleness is presented. At admission, his weight is 5.4 kg and height 69 cm, with marked reduction of his adipose pannus and muscular mass, with no edema. The tests reported serum potassium 2.02 mEq/L, chlorine 89.4 mEq/L, sodium 134.5 mEq/L, magnesium 2.39 mg/ dl, albumin 4.52 gr/dl, serum creatinine 0.17 mg/dl, urinalysis with proteinuria 75 mg/dl, and a normal renal echography. Bartter syndrome was suspected reason why venous gases were ordered which showed pH 7.519, pO2 60 mmHg, pCO2 32,5 mmHg, HCO3 25.8 mmol/l, BE 3.3 mmol/L, urine calcium/creatinine ratio 0.056, aldosterone 11.9 ngr/dl and total renin 459 pg/ml. With these results, the patient was diagnosed with BS, being compatible with type III. Potassium supplements and potassium sparing diuretics were started without achieving a proper serum potassium increase and only after starting indomethacine it could be corrected as well as the appropriate pondostatural increase. Below, there is a literature review about the Bartter syndrome Bartter, tubulopathy, hypokalemia...

Apresenta-se o caso de um lactante masculino de 14 meses de idade que consulta por vômito, astenia, adinamia e palidez generalizada. Dá entrada com um peso de 5.4 kg e uma estatura de 69 cm, marcada diminuição do panículo adiposo e da massa muscular, sem edemas. Os exames mostraram potássio sérico 2,02 mEq/L, cloro 89,4 mEq/L, sódio 134,5 mEq/L, magnésio 2,39 mg/dl, albumina 4,52 gr/dl, creatina sérica 0,17 mg/dl, uroanálise com proteinúria 75 mg/dl e ecografia renal normal. Suspeita-se de síndrome de Bartter, por isso são solicitados gases venosos que mostram pH 7,519, pO2 60 mmHg, pCO2 32,5 mmHg, HCO3 25,8 mmol/l, BE 3,3 mmol/L, relação cálcio/ creatina na urina: 0,056, aldosterona 11,9 ngr/dl e renina total 459 pg/ml. Com estes resultados é feito o diagnóstico de SB, sendo compatível com o tipo III. Iniciaram-se suplementos de potássio e diuréticos economizadores de potássio sem obter-se um aumento adequado do potássio sérico, somente ao iniciar indometacina o mesmo é corrigido, da mesma forma que o adequado desenvolvimento pondoestatural. A seguir é feita uma revisão da literatura sobre a síndrome de Bartter...

[Childhood genetic renal diseases in southern Israel].

Genetic kidney diseases (GKDs) are an important and well-known entity in pediatric nephrology. Advances in genetic and molecular approaches in the last 15 years have enabled elucidation of the underlying molecular defects in many of these disorders. Herein, the authors summarize the progress that has been made over this period in disclosing the molecular basis of several novel GKDs which were characterized in this area and include Bartter syndrome type IV, type II Bartter syndrome and transient neonatal hyperkalemia, cystinuria and mental retardation, familial hypomagnesemia with secondary hypocalcemia, infantile nephronophthisis and familial hemolytic uremic syndrome with factor H deficiency. Retrospective analysis of the authors' data reveals that GKDs are over-represented among the pediatric population in southern Israel. GKD are seen 4 times more often than end-stage renal disease (ESRD) and comprise 38% of all cases of ESRD in our area. This high rate of GKD is mainly due to the high frequency of consanguineous marriages that prevails in this area. Understanding of the genetic and molecular background of these diseases is a result of a fruitful collaboration between the pediatric nephrologists and scientists, and has a direct implication on the diagnosis and treatment of the affected families.

Etiology of nephrocalcinosis in northern Indian children.

This retrospective survey examines the etiology of nephrocalcinosis (NC) in 40 patients (26 boys), over an 8-year period. The median age at onset of symptoms and presentation was 36 months and 72 months, respectively. Clinical features included marked failure to thrive (82.5%), polyuria (60%) and bony deformities (52.5%). The etiology of NC included distal renal tubular acidosis (RTA) in 50% patients and idiopathic hypercalciuria and hyperoxaluria in 7.5% each. Other causes were Bartter syndrome, primary hypomagnesemia with hypercalciuria, severe hypothyroidism and vitamin D excess. No cause for NC was found in 12.5% patients. Specific therapy, where possible, ameliorated the biochemical aberrations, although the extent of NC remained unchanged. At a median (range) follow up of 35 (14-240) months, glomerular filtration rate (GFR) had declined from 82.0 (42-114) ml/min per 1.73 m2 body surface area to 70.8 (21.3-126.5) ml/min per 1.73 m2 body surface area (P = 0.001). Our findings confirm that, even with limited diagnostic facilities, protocol-based evaluation permits determination of the etiology of NC in most patients.

Gitelman's syndrome with mental retardation.

A 56-year-old mentally retarded Japanese woman (intelligence quotient: 49) was admitted to our hospital with the chief complaints of headache, dizziness, vomiting, and lower limb paralysis. Laboratory tests showed severe hypokalemia, metabolic alkalosis, hypomagnesemia, and hypocalciuria. These findings suggested a diagnosis of Gitelman's syndrome (GS). We examined the thiazide-sensitive Na-Cl cotransporter (TSC) gene for the mutations that can be responsible for Gitelman's syndrome, and confirmed the diagnosis. After potassium and magnesium supplementation, her paralysis improved dramatically. The marriage of her parents was consanguineous. She had nine siblings (all with mental retardation), among whom five had died of unknown causes during childhood. Familial mental retardation has never been detected before in Gitelman's syndrome. Here we report a rare case of Gitelman's syndrome with familial mental retardation.

Bartter's syndrome in Arabic children: review of 13 cases.

BACKGROUND: Bartter's syndrome (BS) is an inherited disease of renal potassium wasting characterized by hypokalemic alkalosis, normal blood pressure, vascular insensitivity to pressor agents and elevated plasma concentrations of renin and aldosterone. It is caused by generalized hyperplasia of the juxtaglomerular apparatus at the site of renin production caused by mutations in the Na-K-2Cl cotransporter gene, NKCC2. The objective of our study is to establish the prevalence and incidence of BS in Kuwait and to assess treatment modalities for it. METHODS AND RESULTS: Bartter's syndrome was diagnosed in 13 Kuwaiti children over a 14 year period (1981-1995) with the estimated incidence of 1.7/100,000 live births. The mean age at diagnosis was 9.3 months (range 2-32 months). There were five males and eight females (ratio 1:1.6). The mean duration of follow up was 5.6 years (1-14 years). Both consanguinity and familial history among our patients were high (69 and 54%, respectively). All patients had hypokalemia, hypochloremia with metabolic alkalosis, hyperreninemia and were normotensive. Clinical presentation was essentially similar to that in other series. Eleven patients (85%) had growth failure, two had nephrocalcinosis (15%) and one had renal failure. All patients were treated with supplemental potassium, an aldosterone antagonist (spironolactone) and a prostaglandin synthetase inhibitor (indomethacin or aspirin) sequentially. Significant catch-up of growth (four patients) and increases in serum potassium (eight patients) were recorded after administration of indomethacin therapy. One patient died of severe pneumonia with respiratory failure from hypokalemic myopathy. Clinical presentation, inheritance, complications and therapy of BS are briefly discussed. CONCLUSION: Bartter's syndrome is a rare disease, but should be considered in the differential diagnosis of other disorders with growth failure and/or hypokalemia. Early diagnosis, close follow up and compliance with treatment may lead to appropriate growth and development.

Bartter syndrome in Costa Rica: a description of 20 cases.

Bartter syndrome involves an overlapping set of closely related renal tubular disorders which can be subdivided into at least three clinical phenotypes: (1) classic Bartter syndrome (2) Gitelman syndrome, and (3) a neonatal variant of Bartter syndrome. In contrast to classic Bartter syndrome and Gitelman syndrome, the neonatal variant of Bartter syndrome has both the features of renal tubular hypokalemic alkalosis as well as profound systemic manifestations. Specifically, neonatal Bartter syndrome is characterized by intrauterine polyhydramnios, premature delivery, and life-threatening episodes of fever and dehydration. Most of these infants also have severe hypercalciuria with associated nephrocalcinosis and osteopenia. Over a 22-year period, 20 Costa Rican patients with a congenital syndrome that resembles neonatal Bartter syndrome have been identified and characterized. While these patients exhibit some of the clinical characteristics previously described for neonatal Bartter syndrome, this cohort also has a set of distinct features. They are predominantly female, have a later age of diagnosis, manifest a relatively unique set of physical traits, and appear to have milder clinical disease. Given these differences, it will be important to apply the emerging molecular tools to determine whether the phenotypic variability indicates genetic heterogeneity in neonatal-onset Bartter syndrome.

A case of adult-onset Bartter's syndrome.

Bartter's Syndrome is characterized by renal potassium wasting with hypokalemia, metabolic alkalosis, increased renin-angiotensin-aldosterone system, normal blood pressure, resistance to the pressor effects of angiotensin II and juxtaglomerular cell hyperplasia. Most of the cases have been noted in the pediatric age group and adult-onset cases are very rare. We report a case of adult-onset Bartter's syndrome.

Long-term evolution and growth patterns in a family with Bartter's syndrome.

The five-year evolution of three siblings of a sibship affected by a combined potassium and magnesium wasting abnormality associated with hypocalciuria is presented. Fractional distal chloride reabsorption was low. A number of therapeutic measures were attempted with partial or no success. Consequently, patients were kept on oral potassium and magnesium supplementation only. Special attention was paid to nutritional status. Although the three girls maintained a plasma potassium range of 2.6 to 3 meq/l, sexual and mental maturation were not delayed. Growth remained within the lower limits of normality. Considering the poor results obtained from treatment and the side-effects, we conclude that this long-term approach is sound, at least, in less severe cases of Bartter's syndrome.

Bartter's syndrome. A review of 28 patients followed for 10 years.

Twenty-eight patients with Bartter's syndrome diagnosed during the years 1964-86 and followed for an average of 9.9 years have been reviewed. Their mean age at the time of diagnosis was 32.9 years. As a group they were shorter than normal subjects. In 19 patients hypokalaemia was detected incidentally. Neuromuscular symptoms, usually minor, had occurred in 19 subjects. Pregnancies and deliveries were unremarkable. One patient has died from malignant lymphoma, the others are alive. Of these, one patient has developed renal failure and received a renal transplant. The other patients have preserved a normal renal function and the majority have been healthy and working full time. Treatment rarely resulted in normokalaemia. The annual incidence of the syndrome has been estimated at 1.2 per million people.

["Hormone receptor diseases" in Japan: A nation-wide survey for testicular feminization syndrome, pseudohypoparathyroidism, nephrogenic diabetes insipidus, Bartter's syndrome and congenital adrenocortical unresponsiveness to ACTH (author's transl)].

A nation-wide survey for five "hormone receptor diseases" was carried out. For the first survey, an inquiry was sent to all hospitals in Japan having more than 200 beds, in order to determine how many patients there were between 1968-1977. A further detailed survey was carried out on patients who were reported in the first survey. The approximate numbers of patients in Japan estimated from these surveys are the following: testicular feminization syndrome (TFS), 390; pseudohypoparathyroidism (PHP), 220, nephrogenic diabetes insipidus (NDI), 280; Bartter's syndrome, 90; congenital adrenocortical unresponsiveness to ACTH (CAUA), 18. In 73 cases of TFS, partial virilization was observed in 23% (the incomplete form). Testes were found in all cases and the epididymis in 84%, whereas none of the patients had seminal vesicles. PHP consisted of 38 Type-I cases, 6 Type-II cases and 25 unclassified cases. There were 27 males and 42 females. Skeletal anomalies were found in two-thirds of the patients. Grades of hypocalcemia and soft tissue calcification were more prominent in Type I. After treatment, none of the Type-I patients showed normal urinary cyclic AMP response to parathormone, although urinary phosphate response was normalized in one and markedly improved in 4. In 78 patients with NDI, there were 67 males and 11 females. The age of the onset of NDI ranged from 0 to over 50, but 22 out of 29 cases of hereditary NDI had the onset at age 0. There seemed to be at least two subtypes; one beginning in the neonatal period or early childhood, and the other having the onset in late childhood or adult. The important initial symptoms were fever and anorexia in the early onset type. Growth retardation was remarkable in early childhood. Diuretics were effective in most of the cases. There were 22 male and 12 female patients with Bartter's syndrome. Indomethacin was effective in 9 out of 10 patients studied.