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Background: Proximal renal tubular dysfunction occurs during diabetic ketoacidosis (DKA) in type 1 diabetes. However, only a few studies have reported on the multiple proximal renal tubular functions simultaneously. Moreover, to the best of our knowledge, distal renal tubular function has not yet been investigated. Methods: Patients with newly diagnosed type 1 diabetes mellitus were classified into those with DKA and those without DKA, and their proximal and distal renal tubular functions were investigated. The diagnostic criteria for DKA were blood glucose > 200 mg/dL, blood pH < 7.3 or HCO3– < 15 mEq/L, and urine ketone body positivity. Results: Six patients with DKA and five patients without DKA were included. In patients with DKA, urinary β2-microglobulin levels were significantly higher, while blood pH, HCO3–, and tubular reabsorption of phosphorus were significantly lower than in those without DKA. There were no significant differences in blood glucose, HbA1c, serum phosphorus, urinary N-acetyl-beta-glucosaminidase, and urinary amino acid excretion between patients with and without DKA. Elevated NH3 levels and impaired urinary acidification were not observed in patients with and without DKA. Conclusions: In patients with newly diagnosed type 1 diabetes mellitus complicated with DKA, multiple proximal renal tubular dysfunctions occur simultaneously, suggesting transient Fanconi syndrome. Distal renal tubular acidosis was unlikely. The diagnostic criteria for DKA are appropriate also in the view of proximal renal tubular dysfunction and are considered suggestive of pathophysiological factors that may cause proximal renal tubular dysfunction. [ABSTRACT FROM AUTHOR]

Background: Distal renal tubular acidosis (dRTA) is a condition characterized by the impaired ability to secrete hydrogen ions from the distal tubule. In pediatric patients, common clinical features of dRTA include excessive urine production (polyuria), frequent nighttime urination (nocturia), poor growth and weight gain (failure to thrive), difficulty with bowel movements (constipation), abnormal breathing, and the presence of kidney stones (nephrolithiasis). While urinary tract infections (UTIs) are frequently associated with dRTA, renal failure is uncommon and seldom reported in children. Case Presentation: A 10-year-old girl was referred for the evaluation due to a progressive loss of gross motor milestones over a period of 3 years. She also experienced an acute episode of paralysis and was found to have bilateral medullary nephrocalcinosis (right staghorn calculus) accompanied by moderate renal failure and a UTI. Her development in other areas was appropriate for her age. Importantly, there was a history suggestive of excessive urine production (polyuria), increased thirst (polydipsia), and frequent nighttime urination (nocturia). Physical examination revealed proximal myopathy, characterized by a waddling gait and a positive Gower's sign, as well as diminished reflexes and muscle tone in the lower limbs. Laboratory tests indicated the presence of sepsis (total leukocyte count – 26,660, CRP-174.29) and elevated renal parameters (serum creatinine – 4.27) along with active urinary abnormalities. Urine culture and sensitivity testing showed significant growth of Escherichia coli (>100,000 CFU). A computed tomography scan of the kidneys, ureters, and bladder revealed a staghorn calculus on the right side, as well as bilateral medullary nephrocalcinosis and swollen kidneys. The patient was diagnosed with dRTA based on several factors, including hypokalemic hyperchloremic metabolic acidosis with a normal anion gap, high urine pH, borderline hypercalciuria, presence of medullary nephrocalcinosis, and after ruling out other potential differential diagnoses. Following treatment for the UTI and sepsis, as well as standard treatment for dRTA, the child exhibited symptomatic improvement. Her creatinine levels returned to 0.8 mg/dL, and the septic markers declined to normal levels. To further investigate the cause of the initial decline in renal function in addition to the UTI, a renal biopsy was performed. Conclusion: This case report emphasizes the significance of including medullary nephrocalcinosis and renal tubular acidosis in the list of potential diagnoses for patients presenting with progressive gross motor developmental regression, acute flaccid paralysis, and proximal myopathy. Timely identification of these conditions can help avoid unnecessary and expensive investigations, while also facilitating prompt clinical recovery in affected children. Early diagnosis plays a crucial role in guiding appropriate management strategies and improving patient outcomes. [ABSTRACT FROM AUTHOR]

Introduction: Hypoxic respiratory failure occurs when the respiratory system cannot adequately provide oxygen to the body, leading to hypoxemia. High-flow nasal cannula (HFNC) improved the survival rate among patients with acute hypoxic respiratory failure. Due to physiological alterations, pregnancy can exacerbate distal renal tubular acidosis (dRTA). Pregnancy complicated by hypokalemic periodic paralysis (HPP) poses significant risks due to the potential cardiac and respiratory failure related to low potassium levels. Case description: A woman, 21 years old, pregnant with her first child at 33-34 weeks gestation came with complaints of shortness of breath one day before admission. Complaints accompanied by cramps in both legs. On the second day, the respiratory rate (RR) suddenly increased to 35x/min, and oxygen saturation (SpO2) was 95% on a non-rebreathing mask (NRM) at 15 l/min. The patient was transferred to the Intensive Care Unit (ICU) with a diagnosis of primigravida at 33-34 weeks, respiratory failure, HPP, suspected dRTA, severe metabolic acidosis, sepsis, and urinary tract infection (UTI). She was given O2 via HFNC at flow 40 l/min and a fraction of inspired oxygen (FiO2) 66%. Improvement was seen on the 4th day; the patient's shortness of breath was reduced with HFNC, and the patient's motor strength improved. Conclusion: The use of HFNC showed a positive outcome and was proven to have been successful in treating hypoxic respiratory failure in pregnant women. Respiratory muscle weakness and severe metabolic acidosis caused by dRTA and HPP cannot be cleared due to the limited settings in rural areas. Furthermore, the assessment and management of HPP and dRTA are still limited in many hospitals in remote areas of Indonesia. [ABSTRACT FROM AUTHOR]

Abstract Background Proximal renal tubular dysfunction occurs during diabetic ketoacidosis (DKA) in type 1 diabetes. However, only a few studies have reported on the multiple proximal renal tubular functions simultaneously. Moreover, to the best of our knowledge, distal renal tubular function has not yet been investigated. Methods Patients with newly diagnosed type 1 diabetes mellitus were classified into those with DKA and those without DKA, and their proximal and distal renal tubular functions were investigated. The diagnostic criteria for DKA were blood glucose > 200 mg/dL, blood pH

Background: Adults who have incomplete distal renal tubular acidosis (dRTA) may present with recurrent urolithiasis due to metabolic acidosis, leading to bone resorption, which in turn causes hypercalciuria and urine alkalinization (pH > 6.0). Oral potassium citrate is the most commonly used treatment for dRTA, but some patients cannot tolerate this treatment. The objective of this single-arm study was to evaluate the effect of phytate, an inhibitor of bone resorption, on calciuria of patients with incomplete dRTA. Methods: The calciuria levels of 16 patients who had incomplete dRTA with urolithiasis and could not tolerate potassium citrate treatment were recorded before (baseline) and after 6 months of treatment with oral calcium magnesium phytate (380 mg every 12 h). There were no dietary modifications or other treatments. Results: The baseline calciuria was 317 ± 81 mg/24 h and the level after 6 months was 221 ± 38 mg/24 h (p < 0.005). Conclusions: Our results suggest that calcium magnesium phytate should be considered as an alternative or adjunctive treatment for hypercalciuria in patients with incomplete dRTA. [ABSTRACT FROM AUTHOR]

Distal renal tubular acidosis (RTA1) is a rare disease. It confirms the lab’s data and rules out other differential diagnoses. Late evaluation can interfere with healthy development. We explain a 38-year-old patient with a late and accidental RTA1 diagnosis. Correct treatment with alkali consumption and potassium citrate improves her general condition and eliminates further weakness attacks. Early diagnosis is crucial for patient development and morbidity avoidance with accurate treatments.

Abstract Introduction Sjögren’s disease (SD) is an immune-mediated chronic inflammatory disease that affects epithelial tissues, mainly salivary and lacrimal glands. It also presents extraglandular manifestations. The main renal manifestation is tubulointerstitial nephritis (TIN), which can manifest as renal tubular acidosis (RTA). Urinary citrate may be a biomarker of RTA in these patients. The objective of this study was to evaluate whether hypocitraturia is a predictive biomarker of RTA in a sample of patients with SD in a tertiary hospital in southern Brazil. Methods All patients with SD who met the inclusion criteria and who participated in the rheumatology outpatient clinic of the Irmandade Santa Casa de Misericórdia de Porto Alegre were included. Demographic, SD, serological and urinary data were obtained. RTA was considered in those patients who persistently presented urinary pH above 5.5 and serum pH below 7.35. Patients who persistently had urinary pH above 5.5 underwent a urinary acidification test with furosemide and fludrocortisone. These patients received 1 mg of fludrocortisone and 40 mg of furosemide and had their urine samples tested 2, 4 and 6 h after taking the medications. The test was stopped at any urine sample with pH 5.5 or less. The variables were expressed as mean and standard deviation or interquartile range. The association between hypocitraturia and RTA was assessed using the chi-square. Results Forty-two patients were included, 95.2% female with a median age of 61.73 years. The prevalence of complete distal RTA was 4.88%. Twenty-eight patients underwent urine acidification testing. Five patients had hypocitraturia, and two of them had complete distal RTA. The association between hypocitraturia and RTA was statistically significant (p

Primary hypokalaemic periodic paralysis during pregnancy has been rarely reported. Four pregnant women with the acute onset of flaccid paralysis presented between January 2018 and December 2021. Focussed history and physical examination helped an appropriate radiological and laboratory investigation plan to be made. All women recovered within 4–7 days of potassium supplementation. Supplemental potassium continued until delivery. A pain management plan with continuous epidural infusion helped in avoiding stress-induced hypokalaemia. None of the women developed an episode of muscle weakness during the intervening period. In conclusion, a focussed history and targeted laboratory investigation are needed to diagnose primary hypokalaemic periodic paralysis. Early administration of oral or intravenous potassium is crucial in improving fetomaternal outcomes. [ABSTRACT FROM AUTHOR]

5-Amino salicylic acid (5-ASA) is a known culprit for the development of tubulointerstitial nephritis. Together with impaired kidney function, tubulointerstitial nephritis can lead to specific tubular malfunctions including distal renal tubular acidosis. Distal renal tubular acidosis is an acid-base disorder in which acid secretion in the distal part of the renal tubular system is decreased. Patients with distal renal tubular acidosis are predisposed to recurrently form calcium phosphate kidney stones. This results from the inability to acidify the urine properly as well as from a decreased citrate concentration in the urine, which is another pathognomonic feature of distal renal tubular acidosis. We present the case of a man in his late 40s with Crohn’s disease who developed tubulointerstitial nephritis associated with 5-ASA leading to the development of distal renal tubular acidosis and recurrent calcium phosphate nephrolithiasis. After steroid therapy and partial recovery of kidney function, we observed an increase of citraturia in response to treatment with dapagliflozin, potentially indicating beneficial effects of sodium/glucose cotransporter 2 inhibition on the recurrence of calcium phosphate stone disease in interstitial nephritis-induced distal tubular acidosis.

Introduction: This study was designed to determine the mineral composition of calculi in nephrocalcinosis with nephrolithiasis, diagnose the underlying disease, and monitor the course of renal function in patients with nephrocalcinosis-nephrolithiasis. Methods: Renal calculi extruded in a series of 8 patients with nephrocalcinosis were analysed using Fourier transmission infrared spectrometry. In 4 patients, next-generation sequencing using a nephrocalcinosis-nephrolithiasis panel was performed to determine the nature of the underlying disease. In addition, longitudinal analysis of renal function was performed in all patients. Results: Seven patients revealed carbonate apatite as the sole constituent of renal calculi. One patient showed a mixed composition of dicalcium phosphate dihydrate/carbonate apatite at first analysis yet in subsequent episodes also had calculi composed of pure carbonate apatite. Further molecular analysis displayed distal renal tubular acidosis in 2 of 4 patients who consented to sequencing. No known genetic defect could be found in the other two cases. In line with prior reports, decline of renal function was dependent on underlying disease. Distal renal tubular acidosis revealed a progressive course of renal failure, whereas other causes showed stable renal function in long term analysis. Conclusion: Nephrocalcinosis with nephrolithiasis is a rare condition with heterogeneous aetiology. Yet mineral composition of renal calculi predominantly consisted of pure carbonate apatite. This uniform finding is similar to subcutaneous calcifications of various origins and might propose a general principle of tissue calcification. Progressive decline of renal function was found in distal renal tubular acidosis, whereas other conditions remained stable over time.

Introduction: This study was designed to determine the mineral composition of calculi in nephrocalcinosis with nephrolithiasis, diagnose the underlying disease, and monitor the course of renal function in patients with nephrocalcinosis-nephrolithiasis. Methods: Renal calculi extruded in a series of 8 patients with nephrocalcinosis were analysed using Fourier transmission infrared spectrometry. In 4 patients, next-generation sequencing using a nephrocalcinosis-nephrolithiasis panel was performed to determine the nature of the underlying disease. In addition, longitudinal analysis of renal function was performed in all patients. Results: Seven patients revealed carbonate apatite as the sole constituent of renal calculi. One patient showed a mixed composition of dicalcium phosphate dihydrate/carbonate apatite at first analysis yet in subsequent episodes also had calculi composed of pure carbonate apatite. Further molecular analysis displayed distal renal tubular acidosis in 2 of 4 patients who consented to sequencing. No known genetic defect could be found in the other two cases. In line with prior reports, decline of renal function was dependent on underlying disease. Distal renal tubular acidosis revealed a progressive course of renal failure, whereas other causes showed stable renal function in long term analysis. Conclusion: Nephrocalcinosis with nephrolithiasis is a rare condition with heterogeneous aetiology. Yet mineral composition of renal calculi predominantly consisted of pure carbonate apatite. This uniform finding is similar to subcutaneous calcifications of various origins and might propose a general principle of tissue calcification. Progressive decline of renal function was found in distal renal tubular acidosis, whereas other conditions remained stable over time. Plain Language Summary: Renal stones may occur in conditions that involve calcification of the kidney itself. In this case series, we chemically analysed these stones. In some cases, we also performed genetic tests. Interestingly, we found a similar composition in most stones, irrespective of the underlying disorder. This suggests a common mechanism of calcification. [ABSTRACT FROM AUTHOR]

We report an infant case of transient distal renal tubular acidosis and Fanconi syndrome caused by rotavirus gastroenteritis. A 10-month-old boy was admitted to the hospital because of frequent vomiting, lack of vitality, and dehydration. He was diagnosed with rotavirus gastroenteritis on account of his positive stool rotavirus antigen test. Although he presented with acidemia and severe mixed metabolic acidosis, he also had a urine pH of 6.0, indicating impaired urinary acidification. Therefore, he was diagnosed with distal renal tubular acidosis. On the third day of hospitalization, a relatively low %tubular reabsorption of phosphate level with hypophosphatemia, increased fractional excretion of uric acid with hypouricemia, and high urinary β2-microglobulin levels were observed. Moreover, he was diagnosed with Fanconi syndrome on account of multiple proximal tubular dysfunctions. After remission of rotavirus gastroenteritis, the signs of renal tubular dysfunction improved. This was a case of rotavirus gastroenteritis-caused transient distal renal tubular acidosis and Fanconi syndrome. Severe metabolic acidosis resulted from anion-gap metabolic acidosis due to acute kidney injury by rotavirus gastroenteritis and normal anion-gap acidosis due to renal tubular acidosis. When renal tubular acidosis is associated with a disease that causes anion-gap metabolic acidosis, mixed metabolic acidosis occurs and becomes exacerbated. Furthermore, it is important to consider the complications of renal tubular acidosis in the case of severe metabolic acidosis. [ABSTRACT FROM AUTHOR]

Hypokalemia due to loss of potassium through the kidneys can be caused by distal Renal Tubular Acidosis (dRTA). The etiology of dRTA can be primary due to genetic defects or secondary to autoimmune diseases, especially Sjogren’s syndrome (SS). The occurrence of dRTA in SS patients is low, at only 5% of cases. This case was interesting because dRTA was the initial clinical manifestation that led to the diagnosis of SS in the patient. A 48-year-old woman came with complaints of recurrent weakness. The patient was routinely hospitalized with severe hypokalemia and received potassium supplementation. The diagnosis of dRTA was based on repeated weakness, normal blood pressure, severe and recurrent hypokalemia, high urinary potassium, alkaline urine, low plasma bicarbonate, and standard anion gap metabolic acidosis. The diagnosis of SS in this patient was confirmed based on dry eyes, dry mouth, positive Schirmer’s test, and positive autoantibodies to SS-A and Ro-52. There was a delay in the diagnosis of SS for two years in this patient because the complaints were initially subtle and non-specific. The hypokalemia in this patient was secondary to dRTA associated with primary SS. The possibility of an underlying autoimmune disorder should be considered in a patient presenting with recurrent severe hypokalemia. dRTA, as the etiology of hypokalemia, can be a gateway to the diagnosis of SS. In this patient, complaints related to dRTA appeared before the onset of sicca symptoms, and the diagnosis of SS was established.

Introduction: Distal renal tubular acidosis (dRTA) is a disease that may develop either primarily or secondarily, resulting from urinary acidification defects in distal tubules. Hearing loss may accompany primary forms of dRTA. This study aims to determine the characteristics of hearing loss due to different gene mutations in patients with dRTA. Methods: Behavioral and electrophysiological audiological evaluations were performed after otolaryngology examination in 21 patients with clinically diagnosed dRTA. Radiological imaging of the inner ear (n = 9) was conducted and results of genetic analyses using next-generation sequencing method (n = 16) were included. Results: Twenty-one patients with dRTA from 20 unrelated families, aged between 8 months and 33 years (median = 12, interquartile range = 20), participated. All patients with ATP6V1B1 mutations (n = 9) had different degrees of hearing loss. There was one patient with hearing loss in patients with ATP6V0A4 mutations (n = 6). One patient with the WDR72 mutation had normal hearing. Large vestibular aqueduct syndrome (LVAS) was detected in 6 (67%) of 9 patients whose radiological evaluation results were available. Conclusions: LVAS is common in patients with dRTA and may influence the type and severity of hearing loss in these patients. The possibility of both congenital and late-onset and progressive hearing loss should be considered in dRTA patients. A regular audiological follow-up is essential for the early detection of a possible late-onset or progressive hearing loss in these patients. [ABSTRACT FROM AUTHOR]

Distal renal tubular acidosis (RTA) is a rare adverse reaction to immune checkpoint inhibitors, which only occurs in a small number of cases. To the best of our knowledge, distal RTA caused by sintilimab, a programmed cell death protein 1 (PD-1) inhibitor, has not been previously reported. In the present study, the case of a 62-year-old man with metastatic cardiac carcinoma treated with sintilimab anti-PD-1 therapy was reported. After the fourth administration of sintilimab, the treatment course was interrupted by metabolic hyperchloraemic acidosis with hypokalaemia. Following urine and blood tests, immunotherapy-induced distal RTA was suspected. Treatment with sintilimab and chemotherapy was stopped, and treatment with sodium bicarbonate and potassium citrate was started, which resulted in an adequate response. The present study provides the first case of distal RTA secondary to sintilimab treatment. [ABSTRACT FROM AUTHOR]

Background: Distal renal tubular acidosis (dRTA) can be acquired or inherited. Hereditary types of dRTA are mostly seen in the pediatric population, whereas acquired forms predominate in adults. The diagnosis of hereditary dRTA can be confirmed by genetic testing. Five genes are known to cause the disease: ATP6V1B1, ATP6V0A4, FOXI1, SLC4A1, and WDR72. Most of the children with autosomal dominant forms carry mutations in the SLC4A1 gene, whereas the most common mutation in autosomal recessive type is ATP6V0A4 and ATP6V1B1 genes. Objective: In this systematic review of case reports, we discuss the clinical features and mutation variants of hereditary dRTA due to homozygous pathogenic variations in the WDR72 gene, which has been recently identified. Methods: The PubMed and Google Scholar databases were searched with defined search terms and eligibility criteria independently by different authors. Results: Of five full-text articles retrieved, four were finally included which provided data of 14 individuals, all of which had specific mutations in WDR72 gene. The majority of cases were attributed to individuals of Asian descent (71%) with equal distribution of males and females. The mean age of onset was 4.42 years. Amelogenesis imperfecta (AI) was described in 90% of patients, nephrocalcinosis in 62.5%, polyuria in 55.5%, proximal muscle weakness in 55.5%, and rickets in two patients. Conclusion: In patients exhibiting features such as metabolic acidosis, hypokalemia, AI, polyuria, nephrocalcinosis, and growth retardation, genetic analysis for WDR72 mutation should be considered.

Distal renal tubular acidosis (RTA) is a common cause of renal stones and nephrocalcinosis in children. Distal RTA can be either acquired or congenital because of a genetic defect. Tuberous sclerosis complex is an autosomal dominant inherited neurocutaneous syndrome with variable renal involvement. We describe a case of a six-year-old boy with tuberous sclerosis complex who developed distal RTA and renal stones.

Introduction: Primary Sjogren's syndrome (pSS) a systemic autoimmune disease also known as sicca syndrome, primarily affects exocrine glands, particularly the salivary and lacrimal glands, and causes xerostomia and xerophthalmia. Renal involvement in cases of pSS is a rare occurrence. Patients with Sjogren's syndrome presenting with severe hypokalemia or paralysis are uncommon. Methods: We present a case of a 45-year-old female presenting in our emergency department with hypokalemia-induced quadriparesis resulting from distal renal tubular acidosis due to Sjogren's syndrome. It was revealed that symptoms of arthralgia and dry mouth had frequently been present for the past few years, with a persistent need for water intake. Results: The patient was given symptomatic treatment during hospitalization and recovered successfully. The report emphasizes that although Sjogren's syndrome is most often associated with chronic sicca symptoms, it may present for the first time with extraglandular manifestations, which may be life-threatening. Conclusion: Extraglandular forms of Sjogren's disease can result in severe hypokalemia and paralysis of the limbs and respiratory muscles, which, if ignored, can be deadly for the patient. The course of action for such situations should be early identification and timely treatment because they are treatable and can give patients an asymptomatic and decent quality of life. [ABSTRACT FROM AUTHOR]

The clinical manifestations of primary distal renal tubular acidosis usually begin in childhood, but the disease is caused by a genetic defect that persists throughout life. This review focuses on the complications of distal tubular acidosis that occur or remain long-term such as nephrocalcinosis and urolithiasis, growth impairment, bone mineralization, severe hypokalemia, kidney cysts, and progressive kidney failure, as well as other persistent manifestations that occur independent of acidosis but are associated with some inherited forms of the disease. The pathogenic factors responsible for kidney failure are discussed in particular because it is a complication to which different publications have recently drawn attention and which affects a high percentage of adults with primary distal renal tubular acidosis. The need to maintain optimal metabolic control of the disease and scheduled clinical follow-up throughout life and the importance of organizing protocols for the transition of patients to adult nephrology services are emphasized. [ABSTRACT FROM AUTHOR]

Introduction: Zoledronic acid (ZA) is a widely used bisphosphonate compound for the prevention of skeletal metastasis-associated osteolysis and treatment of post-menopause osteoporosis. Acute kidney injury is one of the commonly described renal complications. Electrolyte disorder has also been reported relevant to ZA exposure and nephrotoxicity. Syndrome of persistent hypophosphatemia, hypokalemia, and metabolic acidosis is regarded as the initial signs of acute kidney injury. Case Presentation: We reported a 64-year-old female with bone metastasis from lung adenocarcinoma who received a 5-year history of 4-week cycle of ZA infusion. She initially presented with symptomatic severe hypophosphatemia and was finally identified with ZA-induced generalized tubular dysfunction as Fanconi's syndrome and distal renal tubular acidosis. Renal pathological findings revealed toxic renal tubular necrosis. The ZA infusion was thus extended to an 8-week cycle with oral phosphate supplementation and alfacalcidol. Although periodic changes pre- and post-ZA infusion existed yet, hypophosphatemia was effectively improved, and the rapid decline of eGFR was partially delayed. We reviewed the literature and mainly summarized the characteristics of bisphosphonate-associated hypophosphatemia. Moderate hypophosphatemia was more frequently mentioned in contrast to severe cases being predisposed to be reported. Progressive hypophosphatemia serves as an early sign of kidney injury. Conclusion: Progressive electrolyte disorders and CKD were the long-term renal outcomes of the current patient. We would like to arouse more attention to electrolyte imbalance related to early ZA-induced kidney injury and emphasize the significance of close monitoring. [ABSTRACT FROM AUTHOR]

Distal renal tubular acidosis (dRTA), a disease characterized by the failure of the distal nephron to secrete acid into the urine, can be caused by mutations in SLC4A1 gene encoding erythroid and kidney anion exchanger 1 (AE1). Here, an induced pluripotent stem cell (iPSC) line was generated from a patient with dRTA and hemolytic anemia carrying compound heterozygous SLC4A1 mutations containing c.1199_1225del (p.Ala400_Ala408del), resulting in Southeast Asian ovalocytosis (SAO), and c.1331C>A (p.Thr444Asn). Peripheral blood mononuclear cells (PBMCs) were reprogrammed using Sendai viral reprogramming. The established iPSC line, MUSIi019-A, exhibited pluripotent property and retained the same mutations observed in the patients.

Background and AimsThe genetic and clinical characteristics of patients with distal renal tubular acidosis (dRTA) caused by SLC4A1 mutations have not been systematically recorded before. Here, we summarized the SLC4A1 mutations and clinical characteristics associated with dRTA.MethodsDatabase was searched, and the mutations and clinical manifestations of patients were summarized from the relevant articles.ResultsFifty-three eligible articles involving 169 patients were included and 41 mutations were identified totally. Fifteen mutations involving 100 patients were autosomal dominant inheritance, 21 mutations involving 61 patients were autosomal recessive inheritance. Nephrocalcinosis or kidney stones were found in 72.27%, impairment in renal function in 14.29%, developmental disorders in 61.16%, hematological abnormalities in 33.88%, and muscle weakness in 13.45% of patients. The age of onset was younger (P

The article presents the discussion on workup and clinical course being consistent with the diagnosis of failure to thrive due to distal renal tubular acidosis (dRTA). Topics include Distal renal tubular acidosis (dRTA) is characterized by impaired urinary acid secretion in the distal nephron with resultant hyperchloremic hypokalemic metabolic acidosis with a normal anion gap; and associated with dental amelogenesis imperfecta and acidosis.

Acute hypokalemic paralysis (AHP) is a life-threatening emergency. It is exceptionally unusual for hypothyroidism to present with AHP. This association can be either primary or secondary through distal renal tubular acidosis. We report two cases who presented with acute quadriplegia. The succeeding investigations revealed severe hypokalemia and autoimmune hypothyroidism. The second case was found to have Sjogren’s syndrome additionally. The underlying aetiology of hypokalemia in both cases was found to be dRTA. The combination of such conditions is reported sporadically. Here we also discuss the potential association of AHP with autoimmune conditions by proxy through dRTA. [ABSTRACT FROM AUTHOR]

Sjogren's syndrome (SS) is an autoimmune disease affecting multiple exocrine glands such as salivary and lacrimal glands, with focal lymphocytic infiltration. The disease predominantly affects women. The classic presentation is xerostomia and keratoconjunctivitis. In adult populations, tubulointerstitial nephritis, which can manifest as renal tubular acidosis (RTA), is the most prevalent renal manifestation of SS. However, in pediatric populations, RTA only occurs in 7.1-19.2% of cases with renal potassium wasting or hypokalemic paralysis. Here, we describe a case of SS manifesting with hypokalemic paralysis with underlying distal renal tubular acidosis (dRTA)., Competing Interests: Human subjects: Consent for treatment and open access publication was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Ravisankar et al.)

We report the case of a Filipino girl with autosomal‐recessive‐type distal renal tubular acidosis and Glanzmann thrombasthenia caused by homozygous variants in the genes SLC4A1 and ITGA2B within the long homozygous DNA region on chromosome 17q21.31. This haplotype may be retained among individuals of Filipino descent. We report the case of a Filipino girl with autosomal‐recessive‐type distal renal tubular acidosis and Glanzmann thrombasthenia owing to runs of homozygosity. Association of the two diseases could be life‐threatening. This haplotype may be retained among Filipinos. [ABSTRACT FROM AUTHOR]

Resumen: La acidosis tubular renal distal (ATRD) es una enfermedad rara que se debe al fallo del proceso normal de acidificación de la orina a nivel tubular distal y colector. Se caracteriza por una acidosis metabólica hiperclorémica persistente, con anión gap normal en plasma, en presencia de un pH urinario elevado y baja excreción urinaria de amonio.Se han descrito hasta el momento 5 genes cuyas mutaciones dan lugar a ATRD primaria. Las alteraciones de los genes ATP6V1B1 y ATP6V0A4 se heredan de forma recesiva y están asociadas a formas de inicio más precoces y con sordera neurosensorial en muchos casos. Las variantes patogénicas en el gen SLC4A1 se heredan habitualmente de forma dominante y dan lugar a cuadros más leves, con un diagnóstico más tardío y alteraciones electrolíticas menores. Sin embargo, la evolución a nefrocalcinosis y litiasis, y el desarrollo de enfermedad renal crónica a medio-largo plazo se ha descrito de forma similar en estos 3 grupos. Por último, se han descrito también formas recesivas de ATRD asociadas a mutaciones en los genes FOXI1 y WDR72.El manejo clínico de la ATRD se basa en sales de bicarbonato o citrato, que no logran corregir en todos los casos las alteraciones metabólicas descritas y, por lo tanto, las consecuencias asociadas a ellas. Recientemente, un nuevo tratamiento basado en sales de bicarbonato y citrato de liberación prolongada ha recibido la denominación de medicamento huérfano en Europa para el tratamiento de la ATRD. Abstract: Distal renal tubular acidosis (DRTA) is a rare disease resulting from a failure in the normal urine acidification process at the distal tubule and collecting duct level. It is characterised by persistent hyperchloremic metabolic acidosis, with a normal anion gap in plasma, in the presence of high urinary pH and low urinary excretion of ammonium.To date, 5 genes whose mutations give rise to primary DRTA have been described. Alterations in the ATP6V1B1 and ATP6V0A4 genes are inherited recessively and are associated with forms of early onset and, in many cases, with neurosensorial deafness. Pathogenic variants in the SLC4A1 gene are habitually inherited dominantly and give rise to milder symptoms, with a later diagnosis and milder electrolytic alterations. Nonetheless, evolution to nephrocalcinosis and lithiasis, and the development of chronic kidney disease in the medium to long term has been described in a similar manner in all 3 groups. Lastly, recessive forms of DTRA associated to mutations in the FOXI1 and WDR72 genes have also been described.The clinical management of DTRA is based on bicarbonate or citrate salts, which do not succeed in correcting all cases of the metabolic alterations described and, thus, the consequences associated with them. Recently, a new treatment based on slow-release bicarbonate and citrate salts has received the designation of orphan drug in Europe for the treatment of DTRA.

Distal renal tubular acidosis (dRTA) may rarely occur in the course of autoimmune diseases. We present a patient who was followed up with Graves' disease and vitiligo and who was diagnosed with dRTA upon detection of hypopotasemia. A 9.2-year-old girl presented with complaints of sweating, palpitations, and hand tremors. The patient had vitiligo on examination and was diagnosed with Graves' disease per clinical and laboratory findings. The patient, who received methimazole and was followed up as a euthyroid, was found to have hypokalemia in biochemical examinations performed at the age of 13 years. While investigating the etiology of hypokalemia, the patient was diagnosed with dRTA. Since she had two autoimmune pathologies, it was thought that the dRTA might be of autoimmune origin. Checking serum potassium levels in the follow-up of patients with Graves' disease may allow early diagnosis and treatment of accompanying dRTA. [ABSTRACT FROM AUTHOR]

Abstract We report the case of a Filipino girl with autosomal‐recessive‐type distal renal tubular acidosis and Glanzmann thrombasthenia caused by homozygous variants in the genes SLC4A1 and ITGA2B within the long homozygous DNA region on chromosome 17q21.31. This haplotype may be retained among individuals of Filipino descent.

Background: Distal renal tubular acidosis (dRTA) is characterized by an impairment of urinary acidification resulting in metabolic acidosis, hypokalemia, and inappropriately elevated urine pH. If not treated, this chronic condition eventually leads to nephrocalcinosis, nephrolithiasis, impaired renal function, and bone demineralization. dRTA is a well-defined entity that can be diagnosed by genetic testing of 5 genes known to be disease-causative. Incomplete dRTA (idRTA) is defined as impaired urinary acidification that does not lead to overt metabolic acidosis and therefore can be diagnosed if patients fail to adequately acidify urine after an ammonium chloride (NH4Cl) challenge or furosemide and fludrocortisone test. It is still uncertain whether idRTA represents a distinct entity or is part of the dRTA spectrum and whether it is caused by mutations in the same genes of overt dRTA. Methods: In this cross-sectional study, we investigated a group of 22 stone formers whose clinical features were suspicious of idRTA. They underwent an NH4Cl challenge and were found to have impaired urinary acidification ability. These patients were then analyzed by genetic testing with sequencing of 5 genes: SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72. Results: Two unrelated individuals were found to have two different variants in SLC4A1 that had never been described before. Conclusions: Our results suggest the involvement of other genes or nongenetic tubular dysfunction in the pathogenesis of idRTA in stone formers. However, genetic testing may represent a cost-effective tool to recognize, treat, and prevent complications in these patients.

Resumen: Antecedentes y objetivos: La acidosis tubular renal distal (ATRd) es una enfermedad minoritaria, de origen genético o adquirido, caracterizada por una incapacidad de excreción urinaria de hidrogeniones (H+), hipobicarbonatemia, hipercloremia, hipocitraturia y habitualmente hipokaliemia e hipercalciuria. Las formas genéticas suelen diagnosticarse en los primeros meses de vida y su tratamiento consiste en suplementos de álcali encaminados a evitar las consecuencias clínicas a largo plazo, sobre todo la enfermedad renal crónica (presente en algunas series hasta en el 82% de los pacientes) y la enfermedad ósea asociada. Se desarrolló una encuesta multirrespuesta cerrada de 10 preguntas encaminada a conocer aspectos epidemiológicos, diagnósticos, del manejo clínico y terapéutico, dentro del colectivo de nefrólogos españoles. Materiales y métodos: Encuesta distribuida a los asistentes a un foro científico sobre ATRd durante el congreso de 2019 de la Sociedad Española de Nefrología (SEN); las respuestas se recogieron a la salida del mismo. Los resultados se analizaron con un test estadístico paramétrico estableciéndose el porcentaje de cada respuesta a las 10 preguntas. Resultados: De entre los que respondieron a la encuesta, el 44,4 y el 37,7% no atendieron a ningún paciente con ATRd en el último año ni en los tres anteriores, respectivamente. Cuando se sospecha la patología, el diagnóstico genético confirmatorio se realiza solo en el 13,3% de los casos y el estudio familiar solo en el 11,1%. Solo el 26,6% afirman que el control metabólico es excelente, bueno o muy bueno, y el 69% piensan que el cumplimiento terapéutico es regular, malo o muy malo. Conclusiones: La encuesta ha puesto de manifiesto el relativo desconocimiento de esta patología, así como la baja satisfacción con el control metabólico y el pobre cumplimiento terapéutico, lo cual puede conllevar una mayor severidad en la enfermedad renal y ósea asociadas a la ATRd. Abstract: Background and objectives: dRTA is a genetic or acquired rare disease, characterized by an unability to excrete hydrogens (H+) into urine, hypobicarbonatemia, hyperchloremia, and frequently hypercalciuria and hypokalaemia. Genetic forms are usually diagnosed during the first months of life and its treatment is based on providing alkali supplements in order to prevent long term clinical consequences, particularly chronic kidney disease (described in some cohorts up to 82% of dRTA patients) and the associated bone disease. A 10 queries multi choice closed response survey was designed to know more about epidemiological, diagnostics, clinical management and therapeutical issues of this disease among Spanish nephrologists. Materials and methods: This survey was delivered to the attendees to a scientific meeting on dRTA at the Spanish Nephrology Society congress in 2019. Surveys were collected at the end of this dRTA event. Results were analyzed by using a parametric statistical test, obtaining the percentage of each response for the 10 questions. Results: Among the survey responders, 44.4% and 37.7% did not visit any dRTA patient during the 1st and 3rd last year respectively. When having a suspicious diagnose, confirming genetic diagnostic test is only performed on the 13.3% of cases and pedigree studies only on 11.1%. Only a 26.6% confirms that metabolic control is excellent, good or very good, and 69% of the responders believe that treatment compliance is not bad, bad or very bad. Conclusions: This survey enhances the fact that dRTA is not a well known entity, satisfaction with metabolic control is poor and compliance is low. All these factors can lead to a higher severity of renal and bone diseases associated to dRTA.

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Distal renal tubular acidosis (dRTA) is a rare renal tubular disorder characterized by normal anion gap metabolic acidosis, hypokalemia, and high urine pH. It can be inherited or acquired. In untreated pediatric patients with dRTA, rickets and growth retardation are common. We report the case of a 12-year-old Lao girl who presented with typical clinical features of dRTA with severe bone deformities that developed after a bed-ridden state due to a bicycle accident at the age of 8 years. Initial laboratory tests revealed metabolic acidosis with a normal anion gap, hypokalemia, and alkali urine. Renal ultrasonography revealed bilateral medullary nephrocalcinosis. Whole exome sequencing revealed no pathogenic mutations. After treatment with oral alkali, potassium, and vitamin D, she could walk and run. Later, she underwent corrective orthopedic surgeries for bony deformities. Thus, in pediatric dRTA patients, despite severe symptoms remaining untreated, accurate diagnosis and proper management can improve quality of life.

Abstract Background Familial distal renal tubular acidosis (dRTA) associated with mutations of solute carrier family 4 membrane − 1 (SLC4A1) gene could co-exist with red cell membrane abnormality, Southeast Asian ovalocytosis (SAO). Although this association is well described in Southeast Asian countries, it is less frequently found in Sri Lanka. Case presentation We describe six patients who had dRTA co-existing with SAO. All of them initially presented with severe hypokalemia and paralysis. They presented within a period of six months to the Teaching Hospital Anuradhapura, Sri Lanka. All had metabolic acidosis indicated by low serum bicarbonate. Three of them were having underlying chronic kidney disease as well. Those three patients had mixed high and normal anion gap metabolic acidosis indicated by low delta ratio. In all dRTA was confirmed by presence of normal anion gap, hyperchloraemia, high urine pH and positive urine anion gap. Examination of blood films of all of them revealed presence of stomatocytes and macro-ovalocytosis compatible with SAO. In relation to complications of dRTA, two patients had medullary nephrocalcinosis. Three patients had biochemical evidence of osteomalacia, with two of them having radiological evidence of diffuse osteosclerosis. One patient had secondary hyperparathyroidism and a pathological fracture. Conclusions Erythrocyte in SAO is exceptionally rigid and this abnormality is said to be evolved as it protects against Plasmodium vivax malaria and cerebral malaria cause by Plasmodium falciparum. Although two families of SAO was described earlier, SAO and dRTA combination was reported only once in a patient from Anuradhapura district. Distal renal tubular acidosis, SAO combination and its related complications including nephrocalcinosis, chronic kidney disease and metabolic bone disease was not described in Sri-Lankan literature. This case series emphasize the importance of investigating recurrent/ chronic hypokalemia to diagnose dRTA and its associations, as early correction of acidosis could prevent development of chronic kidney disease and metabolic bone disease.

A 42-year-old woman presented with muscle weakness and hypokalemic distal renal tubular acidosis (dRTA). Investigations revealed concurrent Sjögren's syndrome (SS) and Hashimoto's thyroiditis contributing to hypokalemic dRTA. A renal biopsy revealed focal tubulointerstitial nephritis (TIN) suggestive of SS-related renal involvement, along with distinctive ischemic glomerular changes and tubular alterations consistent with hypokalemic nephropathy. Rapid improvement in tubular injury markers and hypobicarbonemia followed potassium supplementation, suggesting that hypokalemia contributed to proximal tubular injury. This case underscores the diagnostic challenge posed by the simultaneous presence of TIN and hypokalemic nephropathy, potentially masking hypokalemic nephropathy in patients with hypokalemic dRTA secondary to SS-TIN.

The article provides answers to the possible diagnosis and treatments of a 12-year-old female with hypokalemic paralysis and discolored teeth, including her diagnosis of normal anion gap metabolic acidosis (NAGMA) with hypokalemia and possible treatments like oral potassium supplements.

Nephrocalcinosis (NC) is the augmented calcium content within the renal parenchyma. Its pathogenesis mainly involves hypercalciuria. The presence of medullary NC provides a window to the clinician for the diagnosis of many important diseases. In this case series, we highlight three diseases that could be diagnosed with a high index of suspicion and detailed evaluation after their presentation as medullary NC. [ABSTRACT FROM AUTHOR]

Background: Primary distal renal tubular acidosis (dRTA) is a rare genetic disorder caused by impaired distal mechanisms of urinary acidification. Most cases are secondary to pathogenic variants in ATP6V0A4, ATP6V1B1, and SLC4A1 genes, which encode transporters regulating acid-base balance in the collecting duct. Methods: Retrospective study of molecular and clinical data from diagnosis and long-term follow-up (10, 20, and 40±10 years) of 16 patients with primary dRTA diagnosed in childhood. Results: Molecular analyses revealed nine patients had ATP6V0A4 pathogenic variants, five in ATP6V1B1, and two in SLC4A1. A novel intragenic deletion and a common ATP6V0A4 gene variant (c.1691 + 2dupT) in ATP6V0A4 occurred in two-thirds of these patients, suggesting a founder effect. Median age at diagnosis was 3.25 months (IQR 1, 13.5), which was higher in the SLC4A1 group. Median SDS height at diagnosis was −1.02 (IQR −1.79, 0.14). Delayed clinical diagnosis was significantly related to growth failure (P = 0.01). Median SDS height at 20 years follow-up was −1.23 (IQR −1.71, −0.48), and did not significantly improve from diagnosis (P = 0.76). Kidney function declined over time: at last follow-up, 43% had moderate to severe chronic kidney disease (CKD). Adequate metabolic control was not related to CKD development. Incidence of sensorineural hearing loss (SNHL) was high in ATP6V1B1 patients, though not universal. Patients harboring ATP6V0A4 variants also developed SNHL at a high rate (80%) over time. Conclusions: Patients with dRTA can develop moderate to severe CKD over time with a high frequency despite adequate metabolic control. Early diagnosis ameliorates long-term height prognosis. [ABSTRACT FROM AUTHOR]

The discovery of rare genetic variation through different gene sequencing methods is a very challenging subject in the field of human genetics. A case of a 1-year-old boy with metabolic acidosis and hypokalemia, a small penis, growth retardation, and G-6PD deficiency was reported. Since the clinical symptoms are complex and seem uncorrelated, the authors hypothesized that the child had chromosome or gene problems, and exome sequencing (ES) was applied to samples from him and his parents. Three main locus mutations in three genes were found in the proband, including SLC4A1, FGFR1, and G6PD genes. A missense mutation (c.1766G>T, p.R589 L) was found in exon 14 of SLC4A1 gene, which was a de novo mutation. Another missense mutation (c.1028 A>G, p.H343R) was found in exon 9 of FGFR1 gene, which was also a de novo mutation. These findings further demonstrate the utility of ES in the diagnosis of rare diseases.

Distal renal tubular acidosis (dRTA) is characterized by an impaired ability of the distal tubule to excrete acid, leading to metabolic acidosis. Associated complications include bone disease, growth failure, urolithiasis and hypokalaemia. Due to its rarity, there is limited evidence to guide diagnosis and management; however, available data strongly suggest that metabolic control of the acidosis by alkali supplementation can halt or revert almost all complications. Despite this, cohort studies show that adequate metabolic control is present in only about half of patients, highlighting problems with treatment provision or adherence. With these clinical practice points the authors, part of the working groups tubulopathies in the European Rare Kidney Disease Reference network and inherited kidney diseases of the European Society for Paediatric Nephrology, aim to provide guidance for the management of patients with dRTA to facilitate adequate treatment and establish an initial best practice standard against which treatment of patients can be audited. [ABSTRACT FROM AUTHOR]

Evolution moves in mysterious ways. Excretion of waste products by glomerular filtration made perfect sense when life evolved in the ocean. Yet, the associated loss of water and solutes became a problem when life moved onto land: a serious design change was needed and this occurred in the form of ever more powerful tubules that attached to the glomerulus. By reabsorbing typically more than 99% of the glomerular filtrate, the tubules not only minimise urinary losses, but, crucially, also maintain homeostasis: tubular reabsorption and secretion are adjusted so as to maintain an overall balance, in which urine volume and composition matches intake and environmental stressors. A whole orchestra of highly specialised tubular transport proteins is involved in this process and dysfunction of one or more of these results in the so-called kidney tubulopathies, characterised by specific patterns of clinical and biochemical abnormalities. In turn, recognition of these patterns helps establish a specific diagnosis and pinpoints the defective transport pathway. In this review, we will discuss these clinical and biochemical "fingerprints" of tubular disorders of salt-handling and how sodium handling affects volume homeostasis but also handling of other solutes. [ABSTRACT FROM AUTHOR]

Background: Recent reports indicate that chronic reduction of glomerular filtration rate (GFR) is common in patients with distal renal tubular acidosis (DRTA). Factors responsible for decreased GFR need clarification. Methods: We reviewed records of 25 patients with genetically confirmed DRTA included in the RenalTube database. Patients < 18 years at diagnosis and having at least one annual follow-up were selected and classified in two groups according to GFR ≥ 90 (normal GFR) or < 90 mL/min/1.73 m2 (low GFR) after median follow-up of 8.8 years. Results: Eighteen and seven patients had normal and low GFR (X ± SEM, 121.16 ± 28.87 and 71.80 ± 10.60 mL/min/1.73 m2, respectively, p < 0.01). At diagnosis, these 2 subgroups did not differ in sex, age, underlying mutated gene, GFR, height SDS, or percentage of ultrasound nephrocalcinosis. Serum creatinine (SCr) was different but likely due to median ages of presentation being 0.6 and 4.0 in normal and low GFR patients, respectively. On the last recorded visit, no differences between both groups were found in serum bicarbonate, serum potassium, or alkali dosage. Height SDS of patients with normal GFR was − 0.15 ± 0.47 whereas it was − 1.06 ± 0.60 in the low GFR group (p = 0.27). Interestingly, 23% of the whole group had low birth weight (LBW; < 2500 g), equating to 20% and 29% in the normal and low GFR patients, respectively (p = 0.65). Conclusions: Our findings confirm the risk of kidney function reduction in patients with DRTA of pediatric age onset, suggesting that low GFR is related with less favorable growth outcome and discloses the high frequency of LBW in primary DRTA, a hitherto unrecognized feature. [ABSTRACT FROM AUTHOR]

Background: Distal renal tubular acidosis (dRTA) is characterized by an impairment of urinary acidification resulting in metabolic acidosis, hypokalemia, and inappropriately elevated urine pH. If not treated, this chronic condition eventually leads to nephrocalcinosis, nephrolithiasis, impaired renal function, and bone demineralization. dRTA is a well-defined entity that can be diagnosed by genetic testing of 5 genes known to be disease-causative. Incomplete dRTA (idRTA) is defined as impaired urinary acidification that does not lead to overt metabolic acidosis and therefore can be diagnosed if patients fail to adequately acidify urine after an ammonium chloride (NH4Cl) challenge or furosemide and fludrocortisone test. It is still uncertain whether idRTA represents a distinct entity or is part of the dRTA spectrum and whether it is caused by mutations in the same genes of overt dRTA. Methods: In this cross-sectional study, we investigated a group of 22 stone formers whose clinical features were suspicious of idRTA. They underwent an NH4Cl challenge and were found to have impaired urinary acidification ability. These patients were then analyzed by genetic testing with sequencing of 5 genes: SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72. Results: Two unrelated individuals were found to have two different variants in SLC4A1 that had never been described before. Conclusions: Our results suggest the involvement of other genes or nongenetic tubular dysfunction in the pathogenesis of idRTA in stone formers. However, genetic testing may represent a cost-effective tool to recognize, treat, and prevent complications in these patients. [ABSTRACT FROM AUTHOR]

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Abstract Distal renal tubular acidosis is a risk factor for refeeding syndrome. Frequent measurement of serum phosphorus levels at the initiation of nutrition and rapid administration of phosphate preparations are required to prevent organ failure.