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ABCD syndrome (ABnormal Calcium, Calcinosis, and Creatinine in Down syndrome) is characterized by an association of hypercalcemia, hypercalciuria, nephrocalcinosis, and impaired kidney function in patients with Down syndrome. Only 7 cases have been published worldwide, although it is believed to be underdiagnosed. This report describes 2 new patients with ABCD syndrome and compares them with the cases reported to date. Although it is a rare cause of pediatric hypercalcemia, it should be considered in children with Down syndrome once other more common etiologies have been ruled out. Once this diagnosis is confirmed, the recommended treatment is to reduce dietary calcium intake and work with an interdisciplinary team to maintain an adequate calorie and protein intake., (Sociedad Argentina de Pediatría.)

Background: Microscopic nephrocalcinosis is a common pathological feature of chronic kidney disease (CKD) in cats. Detection of macroscopic nephrocalcinosis using ultrasonography and its implications remain unexplored., Objectives: Identify risk factors associated with ultrasound-diagnosed nephrocalcinosis and evaluate the influence of nephrocalcinosis on CKD progression., Animals: Thirty-six euthyroid client-owned cats with CKD., Methods: Prospective cohort study. Cats with CKD with and without ionized hypercalcemia were enrolled for renal ultrasonography. Cats were categorized according to the presence or absence of ultrasound-diagnosed nephrocalcinosis. Binary logistic regression was performed to identify nephrocalcinosis risk factors. The influence of nephrocalcinosis on CKD progression was assessed using linear mixed models., Results: Ultrasound-diagnosed nephrocalcinosis was evident in 61% of CKD cats overall, with increased prevalence (81%) in those with hypercalcemia. At enrollment, higher blood ionized calcium concentration (odds ratio [OR], 1.27 per 0.1 mg/dL; P = .01), plasma phosphate concentration (OR, 1.16 per 0.1 mg/dL; P = .05), plasma creatinine concentration (OR, 1.29 per 0.1 mg/dL; P = .02) and alanine aminotransferase activity (OR, 2.08 per 10 U/L; P = .04) were independent nephrocalcinosis risk factors. The rate of change in log-transformed fibroblast growth factor-23 differed significantly between groups (P = .04). Cats with CKD and nephrocalcinosis had increasing plasma creatinine concentrations (.03 ± .01 mg/dL/month; P = .04) and phosphate concentrations (.06 ± .02 mg/dL/month; P < .001) and decreasing body weight (.02 ± .01 kg/month; P < .001) over time., Conclusions and Clinical Importance: Nephrocalcinosis is prevalent in cats with CKD, especially in those with hypercalcemia. This pathological feature appears to be associated with CKD progression in cats., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

X-linked hypophosphatemia (XLH) is the most common monogenetic cause of chronic hypophosphatemia, characterized by rickets and osteomalacia. Disease manifestations and treatment of XLH patients in the Netherlands are currently unknown. Characteristics of XLH patients participating in the Dutch observational registry for genetic hypophosphatemia and acquired renal phosphate wasting were analyzed. Eighty XLH patients, including 29 children, were included. Genetic testing, performed in 78.8% of patients, showed a PHEX mutation in 96.8%. Median (range) Z-score for height was - 2.5 (- 5.5; 1.0) in adults and - 1.4 (- 3.7; 1.0) in children. Many patients were overweight or obese: 64.3% of adults and 37.0% of children. All children received XLH-related medication e.g., active vitamin D, phosphate supplementation or burosumab, while 8 adults used no medication. Lower age at start of XLH-related treatment was associated with higher height at inclusion. Hearing loss was reported in 6.9% of children and 31.4% of adults. Knee deformities were observed in 75.0% of all patients and osteoarthritis in 51.0% of adult patients. Nephrocalcinosis was observed in 62.1% of children and 33.3% of adults. Earlier start of XLH-related treatment was associated with higher risk of nephrocalcinosis and detection at younger age. Hyperparathyroidism longer than six months was reported in 37.9% of children and 35.3% of adults. This nationwide study confirms the high prevalence of adiposity, hearing loss, bone deformities, osteoarthritis, nephrocalcinosis and hyperparathyroidism in Dutch XLH patients. Early start of XLH-related treatment appears to be beneficial for longitudinal growth but may increase development of nephrocalcinosis., (© 2024. The Author(s).)

Objective: The present study compared the clinical features of patients with primary Sjögren's syndrome (pSS) with and without nephrolithiasis and/or nephrocalcinosis to determine factors related to renal dysfunction., Methods: The clinical features of 68 patients with anti-Sjogren's syndrome antigen A (SSA)/Ro-antibody-positive pSS with and without nephrolithiasis and/or nephrocalcinosis who underwent abdominal computed tomography and/or ultrasonography were retrospectively analysed., Results: Of the 68 patients with anti-SSA-antibody-positive pSS, 23 (33%) had renal nephrolithiasis and/or nephrocalcinosis, whereas 45 (67%) did not. Fourteen (20%) patients had renal dysfunction at diagnostic imaging. Among five patients who underwent renal biopsy, four patients with renal nephrolithiasis and/or nephrocalcinosis were diagnosed with tubulointerstitial nephritis, and one without nephrolithiasis and/or nephrocalcinosis was diagnosed with minimal change nephrotic syndrome. Estimated glomerular filtration rate at diagnostic imaging was significantly lower in patients with than without nephrolithiasis and/or nephrocalcinosis group (P = 0.010). In addition to nephrolithiasis and/or nephrocalcinosis (odds ratio [OR], 3.467; P = 0.045), the gap between serum sodium and chloride concentrations (OR, 10.400; P = 0.012) and increased urinary β2-microglobulin (OR, 5.444; P = 0.033) were associated with renal dysfunction at the time of diagnostic imaging., Conclusion: Nephrolithiasis and/or nephrocalcinosis, normal anion gap metabolic acidosis, and tubulointerstitial damage are associated with renal dysfunction in patients with pSS., (© Japan College of Rheumatology 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHNNC) is a rare autosomal recessive renal tubulopathy disorder characterized by excessive urinary loss of calcium and magnesium, polyuria, polydipsia, bilateral nephrocalcinosis, progressive chronic kidney disease, and renal failure. Also, sometimes amelogenesis imperfecta and severe ocular abnormalities are involved. The CLDN-16 and CLDN-19 genes encode the tight junction proteins claudin-16 and claudin-19, respectively, in the thick ascending loop of Henle in the kidney, epithelial cells of the retina, dental enamel, etc. Loss of function of the CLDN-16 and/or CLDN-19 genes leads to FHHNC. We present a case of FHHNC type 1, which was first confused with autosomal dominant hypocalcaemia (ADH) due to the presence of a very low serum parathyroid hormone (PTH) concentration and other similar clinical features before the genetic investigations. After the exome sequencing, FHHNC type 1 was confirmed by uncovering a novel homozygous missense mutation in the CLDN-16 gene (Exon 2, c.374 T > C) which causes, altered protein structure with F55S. Associated clinical, biochemical, and imaging findings also corroborate final diagnosis. Our findings expand the spectrum of the CLDN-16 mutation, which will further help in the genetic diagnosis and management of FHNNC., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Primary hyperoxaluria type 1 (PH1) is a rare, severe genetic disease causing increased hepatic oxalate production resulting in urinary stone disease, nephrocalcinosis, and often progressive chronic kidney disease. Little is known about the natural history of urine and plasma oxalate values over time in children with PH1., Methods: For this retrospective observational study, we analyzed data from genetically confirmed PH1 patients enrolled in the Rare Kidney Stone Consortium PH Registry between 2003 and 2018 who had at least 2 measurements before age 18 years of urine oxalate-to-creatinine ratio (Uox:cr), 24-h urine oxalate excretion normalized to body surface area (24-h Uox), or plasma oxalate concentration (Pox). We compared values among 3 groups: homozygous G170R, heterozygous G170R, and non-G170R AGXT variants both before and after initiating pyridoxine (B6)., Results: Of 403 patients with PH1 in the registry, 83 met the inclusion criteria. Uox:cr decreased rapidly over the first 5 years of life. Both before and after B6 initiation, patients with non-G170R had the highest Uox:cr, 24-h Uox, and Pox. Patients with heterozygous G170R had similar Uox:cr to homozygous G170R prior to B6. Patients with homozygous G170R had the lowest 24-h Uox and Uox:cr after B6. Urinary oxalate excretion and Pox tend to decrease over time during childhood. eGFR over time was not different among groups., Conclusions: Children with PH1 under 5 years old have relatively higher urinary oxalate excretion which may put them at greater risk for nephrocalcinosis and kidney failure than older PH1 patients. Those with homozygous G170R variants may have milder disease. A higher resolution version of the Graphical abstract is available as Supplementary information., (© 2023. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Our paper presents the ultrasound (US) patterns of a rare kidney disease-medullary sponge kidney (MSK)-that have not been described before in comparison with other causes of medullary hyperechogenicity and correlates them with the severity of the disease and prognosis. This is a clinical observational study of all US examinations in the Nephrology Department over a period of 6 years. The abdominal US focused on the kidneys was recorded. US characteristics of the medulla and cortex were analyzed. We found 10 patients with characteristic daisy flower (DF) kidneys. Positive diagnosis in association with other renal risk factors, prognosis, and evolution were evaluated. Two patterns of medullary hyperechogenicity were found and were correlated with disease severity and kidney function. The first pattern is a homogenous echogenicity of the medulla described as a "daisy-like" appearance. The second pattern: calcifications associated with medullar echogenicity, stone production, nephrocalcinosis, and impaired kidney function: "atypical daisy-like." Medullary hyperechogenicity can have more US patterns. In MSK, if the medullary echogenicity is homogenous the evolution is benign, whereas the second, inhomogeneous pattern, has a variable clinical presentation with nephrocalcinosis and the outcome is more severe, leading to chronic kidney disease and impairing the quality of life.

Background: Postoperative hypoparathyroidism (PO-HypoPT) is a complication usually seen after thyroid surgery. PO-HypoPT, which lasts longer than 6 months is defined permanently. The aim of this study was to evaluate how close permanent PO-HypoPT patients can approach target values., Methods: One hundred seven patients who were followed-up with permanent diagnosis of PO-HypoPT between 2016-2020 were included in the study. The study protocol includes serum albumin corrected total calcium (Alb-sCa), phosphate (P), Ca-P product, and 24 h urine calcium measurements. Laboratory measurements of the patients include the values recorded in 4-year visits and in the last visit. In addition, radiological reports of renal/abdominal ultrasound and cranial tomography examinations performed in our hospital for any reason during this period were also reviewed., Results: When looking at the total measurements in the 4-year period, the Alb-sCa level was below the target in most of the measurements (68.1%). P level was higher than normal in 296 (46.2%) measurements. Twenty-four h urine ca excretion was measured 185 times in total visits, and 81 (43.7%) of these measurements showed hypercalciuric values. The patient's latest visit measurements were evaluated on 4 targets (Alb-sCa, P, Ca-P product and 24 h urine Ca excretion). The number of patients meeting all four targets was only 21 (19.6%). Six (7.5%) patients had kidney stones or nephrocalcinosis. Three (0.09%) patients with imaging had calcification in the basal ganglia., Conclusions: Our study shows that the management of the patients with PO-HypoPT is suboptimal with active vitamin D and cholecalciferol treatment.

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., (© 2022. The Author(s), under exclusive licence to International Pediatric Nephrology Association.)

Background: Although nephrolithiasis (NL) and nephrocalcinosis (NC) are very common features of primary hyperoxaluria type 1 (PH1), the long-term prognosis of NL and NC after preemptive liver transplantation (PLT) has not been elucidated., Material and Methods: We describe the cases of two chronic kidney disease (CKD) stage three patients with different clinical courses after PLT for PH1., Results: The first patient underwent PLT at 7 years of age with an estimated glomerular filtration rate (eGFR) of 47.8 ml/min/1.73 m 2 . Two years later, she experienced several episodes of obstructive pyelonephritis due to urolithiasis, and developed septic shock in one of these episodes. At the same time as these episodes, preexisting NL and NC progressively improved, with disappearance on X-ray disappeared at 8 years after transplantation. Her renal function has been maintained with an eGFR of 58.7 ml/min/1.73 m 2 . The second patient received PLT at 10 years of age with an eGFR of 58.9 ml/min/1.73 m 2 . Her renal function has been maintained with an eGFR of 65.9 ml/min/1.73 m 2 . She had repeated urolithiasis which started to appear at 3 years after LT. The radiological findings still show bilateral NL and NC, but the stones in the renal pelvis have shown mild improvement., Conclusions: Regardless of the regression in NC seen on X-ray, long-term maintenance of the renal function in patients with PH1 with CKD stage 3 can be achieved with PLT. In patients with NL, there is a risk of serious complications due to posttransplant immunosuppressive therapy when obstructive pyelonephritis occurs after LT., (© 2022 Wiley Periodicals LLC.)

Background: Dent disease is an X-linked disorder characterized by low molecular weight proteinuria (LMWP), hypercalciuria, nephrolithiasis and chronic kidney disease (CKD). It is caused by mutations in the chloride voltage-gated channel 5 (CLCN5) gene (Dent disease-1), or in the OCRL gene (Dent disease-2). It is associated with chronic metabolic acidosis; however metabolic alkalosis has rarely been reported., Case Presentation: We present a family with Dent-2 disease and a Bartter-like phenotype. The main clinical problems observed in the proband included a) primary phosphaturia leading to osteomalacia and stunted growth; b) elevated serum calcitriol levels, leading to hypercalcemia, hypercalciuria, nephrolithiasis and nephrocalcinosis; c) severe salt wasting causing hypotension, hyperaldosteronism, hypokalemia and metabolic alkalosis; d) partial nephrogenic diabetes insipidus attributed to hypercalcemia, hypokalemia and nephrocalcinosis; e) albuminuria, LMWP. Phosphorous repletion resulted in abrupt cessation of hypercalciuria and significant improvement of hypophosphatemia, physical stamina and bone histology. Years later, he presented progressive CKD with nephrotic range proteinuria attributed to focal segmental glomerulosclerosis (FSGS). Targeted genetic analysis for several phosphaturic diseases was unsuccessful. Whole Exome Sequencing (WES) revealed a c.1893C > A variant (Asp631Glu) in the OCRL gene which was co-segregated with the disease in male family members., Conclusions: We present the clinical characteristics of the Asp631Glu mutation in the OCRL gene, presenting as Dent-2 disease with Bartter-like features. Phosphorous repletion resulted in significant improvement of all clinical features except for progressive CKD. Angiotensin blockade improved proteinuria and stabilized kidney function for several years., (© 2022. The Author(s).)

Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive disorder that is characterized by renal magnesium wasting, hypercalciuria and eventually kidney failure which mostly affects children and young aged adults. Mutation of genes of claudin-16 and claudin-19 are involved in the pathogenesis of this disorder, which leads to renal magnesium and calcium wasting. A 35-year-old man with end-stage kidney disease (ESKD) was referred to our clinic due to bilateral nephrocalcinosis, detected by ultrasonographic study, for further evaluation. Detailed investigations revealed that his siblings had also similar presentations of hypomagnesemia, hypercalciuria, nephrocalcinosis and chronic kidney disease (CKD). Sanger sequencing showed a novel mutation (c.338G > A: p.C113Y) at the second exon of the CLDN16 gene. The patient underwent kidney transplantation and his siblings received only medical treatment. In young patients with ESKD and concomitant nephrocalcinosis, especially where there is a family history of CKD/ESKD, genetic evaluation is strongly recommended.  DOI: 10.52547/ijkd.6845.

Kidney stones (also known as urinary stones or nephrolithiasis) are highly prevalent, affecting approximately 10% of adults worldwide, and the incidence of stone disease is increasing. Kidney stone formation results from an imbalance of inhibitors and promoters of crystallization, and calcium-containing calculi account for over 80% of stones. In most patients, the underlying aetiology is thought to be multifactorial, with environmental, dietary, hormonal and genetic components. The advent of high-throughput sequencing techniques has enabled a monogenic cause of kidney stones to be identified in up to 30% of children and 10% of adults who form stones, with ~35 different genes implicated. In addition, genome-wide association studies have implicated a series of genes involved in renal tubular handling of lithogenic substrates and of inhibitors of crystallization in stone disease in the general population. Such findings will likely lead to the identification of additional treatment targets involving underlying enzymatic or protein defects, including but not limited to those that alter urinary biochemistry., (© 2021. Springer Nature Limited.)

In primary hyperoxaluria, increased hepatic oxalate production sometimes leads to severe nephrocalcinosis and early end-stage kidney disease. Oral administration of Oxalobacter formigenes (O. formigenes), an oxalate-degrading bacterium, is thought to derive oxalate from systemic sources by inducing net enteric oxalate secretion. Here, the impact of O. formigenes on nephrocalcinosis was investigated in an ethylene glycol rat model mimicking hepatic oxalate overproduction in primary hyperoxaluria. Eighteen rats were administered ethylene glycol (0.75% in drinking water) for 6 weeks, of which 9 were treated by oral gavage with O. formigenes and 9 received vehicle. Five control rats did not receive ethylene glycol or O. formigenes. Plasma and urinary oxalate levels, calcium oxalate crystalluria, urinary volume, fluid intake, and serum creatinine were monitored during the study. On killing, nephrocalcinosis was quantified. Ethylene glycol intake induced pronounced hyperoxalemia, hyperoxaluria, calcium oxalate crystalluria and nephrocalcinosis. Concomitant O. formigenes treatment partially prevented the ethylene glycol-induced increase in plasma oxalate and completely prevented nephrocalcinosis. Urinary oxalate excretion was not reduced by O. formigenes treatment. Nevertheless, absence of crystals in renal tissue of O. formigenes-treated ethylene glycol animals indicates that the propensity for oxalate to crystallize in the kidneys was reduced compared to non-treated animals. This is supported by the lower plasma oxalate concentrations in O. formigenes-treated animals. This study shows a beneficial effect of O. formigenes treatment on ethylene glycol-induced hyperoxalemia and nephrocalcinosis, and thus supports a possible beneficial effect of O. formigenes in primary hyperoxaluria., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Biallelic loss of function mutations in the CLDN16 gene cause familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC), and chronic kidney disease. Here we report two cases of FHHNC with diverse clinical presentations and hypercalcemia in one as a novel finding. Pt#1 initially presented with urinary tract infection and failure to thrive at 5.5 months of age to another center. Bilateral nephrocalcinosis, hypercalcemia (Ca: 12.2 mg/dl), elevated parathyroid hormone (PTH) level, and hypercalciuria were detected. Persistently elevated PTH with high/normal Ca levels led to subtotal-parathyroidectomy at the age of 2.5. However, PTH levels remained elevated with progressive deterioration in renal function. At 9-year-old, she was referred to us for evaluation of hyperparathyroidism and, hypomagnesemia together with hypercalciuria, elevated PTH with normal Ca levels, and medullary nephrocalcinosis were detected. Compound heterozygosity of CLDN16 variants (c.715G>A, p.G239R; and novel c.360C>A, p.C120*) confirmed the diagnosis. Pt#2 was a 10-month-old boy, admitted with irritability and urinary crystals. Hypocalcemia, hypophosphatemia, elevated PTH and ALP, low 25(OH)D levels, and radiographic findings of rickets were detected. However, additional findings of hypercalciuria and bilateral nephrocalcinosis were inconsistent with the nutritional rickets. Low/normal serum Mg levels suggested the diagnosis of FHHNC which was confirmed genetically as a homozygous missense (c.602G > A; p.G201E) variant in CLDN16. Yet, hypocalcemia and hypomagnesemia persisted in spite of treatment. In conclusion, FHHNC may present with diverse clinical features with mild hypomagnesemia leading to secondary hyperparathyroidism with changing Ca levels from low to high. Early and accurate clinical and molecular genetic diagnosis is important for proper management., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Nephrocalcinosis is a pathological feature of chronic kidney disease (CKD). Its pathophysiological implications for cats with CKD are unexplored., Objectives: Identify nephrocalcinosis risk factors and evaluate its influence on CKD progression and all-cause mortality., Animals: Fifty-one euthyroid client-owned cats with International Renal Interest Society (IRIS) stages 2-3 azotemic CKD., Methods: Retrospective cohort study. Histopathological kidney sections were assessed for nephrocalcinosis (von Kossa stain). Nephrocalcinosis severity was determined by image analysis (ImageJ). Ordinal logistic regressions were performed to identify nephrocalcinosis risk factors. The influence of nephrocalcinosis on CKD progression and mortality risk were assessed using linear mixed model and Cox regression, respectively. Cats were categorized by their owner-reported time-averaged phosphate-restricted diet (PRD) intake, where PRD comprised ≥50%, 10-50%, or none of food intake., Results: Nephrocalcinosis was rated as mild-to-severe in 78.4% and absent-to-minimal in 21.6% of cases. Higher baseline plasma total calcium concentration (tCa; odds ratio [OR] = 3.07 per 1 mg/dL; P = .02) and eating a PRD (10%-50%: OR = 8.35; P = .01; ≥50%: OR = 5.47; P = .01) were independent nephrocalcinosis risk factors. Cats with absent-to-minimal nephrocalcinosis had increasing plasma creatinine (0.250 ± 0.074 mg/dL/month; P = .002), urea (5.06 ± 1.82 mg/dL/month; P = .01), and phosphate (0.233 ± 0.115 mg/dL/month; P = .05) concentrations over a 1-year period, and had shorter median survival times than cats with mild-to-severe nephrocalcinosis., Conclusion and Clinical Importance: Higher plasma tCa at CKD diagnosis and PRD intake are independently associated with nephrocalcinosis. However, nephrocalcinosis is not associated with rapid CKD progression in cats., (© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Objectives: To study childhood nephrolithiasis and nephrocalcinosis caused by metabolic disorders, distal renal tubular acidosis (dRTA), and familial hypomagnesemia, hypercalciuria, and nephrocalcinosis (FHHNC)., Methods: We retrospectively evaluated 86 children presented over 10 years (2011-2021), with nephrolithiasis (89%) and nephrocalcinosis (11%) caused by metabolic disorders (62%), FHHNC (21%), and dRTA (17%)., Results: The mean age at discovery was 72.7 months. The underlying metabolic etiologies included hyperoxaluria (38%), cystinuria (32%), hypercalciuria (24%), and hyperuricosuria (6%). Genetic testing was carried out for 23 patients. Hyperoxaluria was typically treated medically (75%). However, the majority progressed to end-stage kidney disease (ESKD). Most children with cystinuria, hypercalciuria, and hyperuricosuria required medical and surgical intervention. Patients with FHHNC typically presented with nephrocalcinosis. Genetic testing revealed Claudin-16 mutations in 7 children. Patients often progressed to stage II-IV chronic kidney disease (61%) and ESKD (6%). Patients with dRTA typically presented with nephrocalcinosis (80%), as well as poor weight gain and failure to thrive (86%), and medical treatment included sodium bicarbonate and potassium replacement. Despite nephrocalcinosis progression, most patients had normal renal function (53%), although the remaining 47% progressed to chronic kidney disease (none reached ESKD)., Conclusion: Childhood nephrolithiasis is mainly related to metabolic disorders and is associated with poor renal outcomes. Nephrocalcinosis and nephrolithiasis have poor outcomes when associated with FHHNC, while nephrocalcinosis associated with dRTA has relatively good renal outcomes., (Copyright: © Saudi Medical Journal.)

Background: Nephrocalcinosis is often asymptomatic but can manifest with renal colic or hematuria. There is no reported association between nephrocalcinosis and renal vascular malformations, which may also be a source of hematuria. We herein present a case of a patient with hematuria related to nephrocalcinosis and renal papillary varicosities. These varicosities were diagnosed and successfully treated with flexible ureteroscopy and laser fulguration., Case Presentation: A 24-year-old female with a history of epilepsy (on zonisamide), recent uncomplicated pregnancy, and new diagnosis of nephrocalcinosis presented with right flank pain and intermittent gross hematuria. Imaging revealed intermittent right sided hydronephrosis. A cystoscopy identified hematuria from the right ureteral orifice. Diagnostic flexible ureteroscopy revealed numerous intrapapillary renal stones and varicose veins of several renal papillae. A 200 μm holmium laser fiber was used to unroof these stones and fulgurate the varicosities with resolution of her symptoms for several months. She later presented with left-sided symptoms and underwent left ureteroscopy with similar findings and identical successful treatment., Conclusion: Unilateral hematuria from discrete vascular lesions of the renal collecting system may be obscured by other benign co-existing conditions, such as nephrocalcinosis and nephrolithiasis. Although a simultaneous presentation is rare, flexible ureteroscopy with laser fulguration offers an ideal diagnostic and therapeutic modality for these concurrent conditions if symptoms arise., (© 2021. The Author(s).)

The enamel renal syndrome (ERS) is a rare disorder featured by amelogenesis imperfecta , gingival fibromatosis and nephrocalcinosis. ERS is caused by bi-allelic mutations in the secretory pathway pseudokinase FAM20A. How mutations in FAM20A may modify the gingival connective tissue homeostasis and cause fibromatosis is currently unknown. We here analyzed conditioned media of gingival fibroblasts (GFs) obtained from four unrelated ERS patients carrying distinct mutations and control subjects. Secretomic analysis identified 109 dysregulated proteins whose abundance had increased (69 proteins) or decreased (40 proteins) at least 1.5-fold compared to control GFs. Proteins over-represented were mainly involved in extracellular matrix organization, collagen fibril assembly, and biomineralization whereas those under-represented were extracellular matrix-associated proteins. More specifically, transforming growth factor-beta 2, a member of the TGFβ family involved in both mineralization and fibrosis was strongly increased in samples from GFs of ERS patients and so were various known targets of the TGFβ signaling pathway including Collagens, Matrix metallopeptidase 2 and Fibronectin. For the over-expressed proteins quantitative RT-PCR analysis showed increased transcript levels, suggesting increased synthesis and this was further confirmed at the tissue level. Additional immunohistochemical and western blot analyses showed activation and nuclear localization of the classical TGFβ effector phospho-Smad3 in both ERS gingival tissue and ERS GFs. Exposure of the mutant cells to TGFB1 further upregulated the expression of TGFβ targets suggesting that this pathway could be a central player in the pathogenesis of the ERS gingival fibromatosis. In conclusion our data strongly suggest that TGFβ -induced modifications of the extracellular matrix contribute to the pathogenesis of ERS. To our knowledge this is the first proteomic-based analysis of FAM20A-associated modifications., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Simancas Escorcia, Guillou, Abbad, Derrien, Rodrigues Rezende Costa, Cannaya, Benassarou, Chatziantoniou, Berdal, Acevedo, Cases, Cosette and Kozyraki.)

Introduction: Chronic hypoparathyroidism managed with conventional treatment, comprising oral administration of calcium and active vitamin D, has been associated with renal complications, including nephrolithiasis and nephrocalcinosis. Further larger-scale studies are needed to examine these risks. This study evaluated the risk of nephrolithiasis and nephrocalcinosis in patients with chronic hypoparathyroidism., Methods: A retrospective cohort study using a managed care claims database in the United States from January 2007 to June 2017. Included patients were those with chronic hypoparathyroidism (excluding those receiving parathyroid hormone) and randomly selected patients without hypoparathyroidism over a maximum of 5-year follow-up. The main outcome measures were nephrolithiasis, identified by diagnosis codes or procedure codes for removing kidney stones, and nephrocalcinosis, identified by diagnosis codes., Results: The nephrolithiasis analyses included 8097 adult patients with hypoparathyroidism and 40,485 adult patients without hypoparathyroidism. After excluding patients with a diagnosis of nephrocalcinosis at baseline, nephrocalcinosis analyses included 8051 patients with hypoparathyroidism and 40,466 patients without hypoparathyroidism. During 5 years of follow-up, patients with chronic hypoparathyroidism had significantly increased risk of nephrolithiasis and nephrocalcinosis in Kaplan-Meier analysis compared with patients without hypoparathyroidism (both P < 0.001). In the adjusted analyses, chronic hypoparathyroidism was associated with higher risks of nephrolithiasis (hazard ratio [HR], 1.81; 95% confidence interval [CI] 1.60-2.04) and nephrocalcinosis (HR, 6.94; 95% CI 4.41-10.92). A sensitivity analysis restricted to patients with at least one kidney imaging examination showed that 2.6% of patients (n = 59) with hypoparathyroidism and 0.5% of patients (n = 20) without hypoparathyroidism (ratio, 5.5; P < 0.001) developed nephrocalcinosis., Conclusions: This large retrospective cohort study showed a statistically significant and clinically meaningful increased risk of nephrolithiasis and nephrocalcinosis in patients who have chronic hypoparathyroidism compared with those who do not have chronic hypoparathyroidism.

SHORT syndrome is a rare developmental disorder frequently associated with growth failure and insulin resistant diabetes mellitus (IRDM). Since GH has a diabetogenic effect, GH therapy has been regarded as a contraindication. We observed a Brazilian girl with SHORT syndrome who received GH therapy from 4 6/12 years of age for SGA short stature. GH dosage was increased from 0.23 to 0.36 mg/kg/week, but statural response to GH therapy remained poor. Her blood HbA1c level, though it remained 5.5-6.0% in childhood, began to elevate with puberty and increased to 9.2% at 10 6/12 years of age, despite the discontinuation of GH therapy at 9 11/12 years of age. Laboratory studies indicated antibody-negative IRDM. She was treated with metformin and canagliflozin (a sodium glucose co-transporter 2 (SGLT2) inhibitor), which ameliorated overt diurnal hyperglycemia and mild nocturnal hypoglycemia and reduced her blood HbA1c around 7%. Whole exome sequencing revealed a de novo heterozygous pathogenic variant (c.1945C>T:p.(Arg649Trp)) in PIK3R1 known as the sole causative gene for SHORT syndrome. Subsequent literature review for patients with molecularly confirmed SHORT syndrome revealed the development of IRDM in 10 of 15 GH-untreated patients aged ≥12 years but in none of three GH-treated and six GH-untreated patients aged ≤10 years. These findings imply a critical role of pubertal development and/or advanced age rather than GH therapy in the development of IRDM, and a usefulness of SGLT2 inhibitor in the treatment of IRDM.

Background: SHORT syndrome is a rare genetic disease named with the acronyms of short stature, hyper-extensibility of joints, ocular depression, Rieger anomaly and teething delay. It is inherited in an autosomal dominant manner confirmed by the identification of heterozygous mutations in PIK3R1. This study hereby presents a 15-year-old female with intrauterine growth restriction, short stature, teething delay, characteristic facial gestalts who was identified a novel de novo nonsense mutation in PIK3R1., Case Presentation: The proband was admitted to our department due to irregular menstrual cycle and hirsutism with short stature, who had a history of intrauterine growth restriction and presented with short stature, teething delay, characteristic facial gestalts, hirsutism, and thyroid disease. Whole-exome sequencing and Sanger sequencing revealed c.1960C > T, a novel de novo nonsense mutation, leading to the termination of protein translation (p. Gln654*)., Conclusions: This is the first case report of SHORT syndrome complicated with thyroid disease in China, identifying a novel de novo heterozygous nonsense mutation in PIK3R1 gene (p. Gln654*). The phenotypes are mildly different from other cases previously described in the literature, in which our patient presents with lipoatrophy, facial feature, and first reported thyroid disease. Thyroid disease may be a new clinical symptom of patients with SHORT syndrome.

Intrarenal calcium oxalate (CaOx) crystals induce renal tubular epithelial cells (TECs) injury and inflammation, which involve Toll-like receptor 4 (TLR4)/interferon regulatory factor 1 (IRF1) signaling. Additionally, infiltrating macrophages (Mϕs) might influence intrarenal CaOx crystals and CaOx-induced renal injury. Although the roles of nuclear factor erythroid 2-related factor 2 (Nrf2) in regulating inflammation and macrophage polarization are well characterized, its potential mechanisms in regulating CaOx nephrocalcinosis remain undefined. Methods: We used a Gene Expression Omnibus dataset to analyze gene-expression profiles. Luciferase reporter, western blot, quantitative polymerase chain reaction, immunofluorescence staining, fluorescence in situ hybridization, positron emission tomography computed tomography imaging, flow cytometry, and chromatin immunoprecipitation assays were employed to study the mechanism of miR-93-TLR4/IRF1 regulation by Nrf2. Anti-inflammatory activity and regulation of macrophage polarization by Nrf2 were investigated in vitro and in vivo . Results: We found that stone-mediated kidney inflammation significantly affected stone growth, and that sulforaphane attenuated CaOx nephrocalcinosis-induced kidney injury and renal CaOx crystals deposition. Additionally, Nrf2 levels significantly increased and negatively correlated with TLR4 and IRF1 levels in a mouse model of CaOx nephrocalcinosis following sulforaphane treatment. Moreover, Nrf2 suppressed TLR4 and IRF1 levels and decreased M1-macrophage polarization which induced by supernatants from COM-stimulated TECs in vitro . In terms of mechanism, transcription factor analyses, microRNA microarray, and chromatin immunoprecipitation assays showed that Nrf2 exhibited positive transcriptional activation of miR-93-5p. In addition, Luciferase reporter, qRT-PCR, and western blot validated that miR-93-5p targets TLR4 and IRF1 mRNA. Furthermore, suppressed miR-93-5p expression partially reversed Nrf2-dependent TLR4/IRF1 downregulation. Conclusions: The results suggested that sulforaphane might promote M2Mϕ polarization and inhibit CaOx nephrocalcinosis-induced inflammatory injury to renal tubular epithelial cells via the Nrf2-miR-93-TLR4/IRF1 pathway in vitro and in vivo., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Hypomagnesemia is commonly observed in heart transplant (HT) recipients receiving calcineurin inhibitors. Since low serum magnesium (s-Mg) has been implicated in the progression of atherosclerosis, potentially leading to worsening coronary heart disease, arrhythmias and sudden death, we investigated the association between s-Mg and HT outcomes. Between 2002 and 2017, 150 HT patients assessed for s-Mg were divided into high (≥1.7 mg/dL) and low s-Mg groups according to the median value of all s-Mg levels recorded during the first 3 months post-HT. Endpoints included survival, cardiac allograft vasculopathy (CAV), any-treated rejection (ATR) and NF-MACE. Kaplan-Meier analysis showed that at 15 years after HT, both survival (76 vs 33%, log-rank p = 0.007) and freedom from CAV (75 vs 48%, log-rank p = 0.01) were higher in the high versus low s-Mg group. There were no significant differences in freedom from NF-MACE or ATR. Multivariate analyses consistently demonstrated that low s-Mg was independently associated with a significant 2.6-fold increased risk of mortality and 4-fold increased risk of CAV (95%CI 1.06 to 6.4, p = 0.04; 95%CI 1.12 to 14.42, p = 0.01, respectively). In conclusion, low s-Mg is independently associated with increased mortality and CAV in HT patients. Larger multi-center prospective studies are needed to confirm these findings and to examine the effect of Mg supplementation., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Gitelman syndrome (GS) is an inherited salt-wasting tubulopathy characterized by hypocalciuria, hypokalemia, hypomagnesemia and metabolic alkalosis, due to inactivating mutations in the SLC12A3 gene. Symptoms may be systemic, neurological, cardiovascular, ophthalmological or musculoskeletal. We describe a 70 year-old patient affected by recurrent arthralgias, hypoesthesia and hyposthenia in all 4 limbs and severe hypokalemia, complicated by atrial flutter. Moreover, our patient reported eating large amounts of licorice, and was treated with medium-high dosages of furosemide, thus making diagnosis very challenging. Genetic analysis demonstrated a novel heterozygous mutation in the SLC12A3 gene; therefore, we diagnosed GS and started potassium and magnesium replacement. GS combined with chondrocalcinosis and neurological involvement is quite common, but this is the first case of an EMG-proven severe neuropathy associated with GS. Herein, we underline the close correlation between hypomagnesemia, chondrocalcinosis and neurological involvement. Moreover, we report a new heterozygous mutation in exon 23 (2738G>A), supporting evidence of a large genetic heterogeneity in this late-onset congenital tubulopathy.

Background: Dysbiosis, bacterial translocation and systemic inflammation have been found to be associated with human and experimental forms of chronic kidney disease (CKD), but the functional contribution of the intestinal microbiota to CKD-related intestinal barrier dysfunction and CKD progression is unknown, especially in CKD secondary to hyperoxaluria and nephrocalcinosis., Methods: C57BL/6N mice fed an oxalate-rich diet for either 10 or 20 days developed reversible or progressive kidney disease, respectively., Results: Oxalate-induced CKD manifested as azotaemia, renal anaemia and hyperkalaemia. CKD was associated with persistent dysbiosis and intestinal barrier dysfunction. Local as well as systemic inflammation was evident and partially persisted despite better renal function after returning to an oxalate-free diet, indicating some innate immune memory. Eradication of the microbiota with a combination of antibiotics improved intestinal barrier function but had no effect on renal function, nephrocalcinosis, kidney remodelling and atrophy compared with control mice not receiving antibiotics., Conclusions: Together, in chronic oxalate nephropathy, the intestinal microbiota contributes to the CKD-related dysfunction of the intestinal barrier but not to the progression of nephrocalcinosis itself, as well to its related kidney atrophy and excretory dysfunction., (© The Author(s) 2019. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Loss-of-function mutations of SLC34A3 represent an established cause of a distinct renal phosphate wasting disorder termed hereditary hypophosphatemic rickets with hypercalciuria (HHRH). SLC34A3 encodes the renal phosphate transporter NaPi2c expressed at the apical brush border of proximal renal tubules. Substitution of p.Ser192Leu is one of the most frequent genetic changes among HHRH patients in Europe, but has never been systematically evaluated, clinically or on a cellular level. Identification of a 32-year-old female with a homozgyous c.575C>T, p.Ser192Leu substitution enabled a more comprehensive assessment of the impact of this missense variant. Clinically, the patient showed renal phosphate wasting and nephrocalcinosis without any bone abnormalities. Heterozygous carriers of deleterious SLC34A3 variants were previously described to harbor an increased risk of kidney stone formation and renal calcification. We hence examined the frequency of p.Ser192Leu variants in our adult kidney stone cohort and compared the results to clinical findings of previously published cases of both mono- and biallelic p.Ser192Leu changes. On a cellular level, p.Ser192Leu-mutated transporters localize to the plasma membrane in different cellular systems, but lead to significantly reduced transport activity of inorganic phosphate upon overexpression in Xenopus oocytes. Despite the reduced function in ectopic cellular systems, the clinical consequences of p.Ser192Leu may appear relatively mild, at least in our index patient, and can potentially be missed in clinical practice.

Background: Reduced kidney volume (KV) following prematurity is a proxy for reduced nephron number and is associated with the development of hypertension and end-stage renal disease in adults. We investigated whether extreme prematurity affects KV, function, and blood pressure in school-aged children and if nephrocalcinosis (NC) developed during the neonatal period had additional effects., Methods: We investigated 60 children at a mean age of 7.7 years: 20 born extremely preterm (EPT < 28 weeks gestational age with NC (NC+)), 20 born EPT without NC (NC-), and 19 born as full-term infants (control). We measured KV by ultrasound, collected blood and urine samples to evaluate renal function, and measured office and 24-h ambulatory blood pressure (ABPM)., Results: Children born EPT had significantly smaller kidneys (EPT (NC+ NC-) vs control (estimated difference, 11.8 (CI - 21.51 to - 2.09 ml), p = 0.018) and lower but normal cystatin C-based glomerular filtration rate compared with control (estimated difference, - 10.11 (CI - 0.69 to - 19.5), p = 0.035). KV and function were not different between NC+ and NC- groups. Change in KV in relation to BSA (KV/BSA) from the neonatal period to school age showed significantly more EPT children with neonatal NC having a negative evolution of KV (p = 0.01). Blood pressure was normal and not different between the 3 groups. Fifty percent of EPT had a less than 10% day-to-night decline in ABPM., Conclusions: Kidney growth and volume is affected by EPT birth with NC being a potential aggravating factor. Circadian blood pressure regulation seems abnormal in EPT-born children.

Background: Primary distal renal tubular acidosis (dRTA) is a rare disorder, and we aimed to gather data on treatment and long-term outcome., Methods: We contacted paediatric and adult nephrologists through European professional organizations. Responding clinicians entered demographic, biochemical, genetic and clinical data in an online form., Results: Adequate data were collected on 340 patients (29 countries, female 52%). Mutation testing had been performed on 206 patients (61%); pathogenic mutations were identified in 170 patients (83%). The median (range) presentation age was 0.5 (0-54) years and age at last follow-up was 11.0 (0-70.0) years. Adult height was slightly below average with a mean (SD score) of -0.57 (±1.16). There was an increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (35%) and adults (82%). Nephrocalcinosis was reported in 88%. Nephrolithiasis was more common with SLC4A1 mutations (42% versus 21%). Thirty-six percent had hearing loss, particularly in ATP6V1B1 (88%). The median (interquartile range) prescribed dose of alkali (mEq/kg/day) was 1.9 (1.2-3.3). Adequate metabolic control (normal plasma bicarbonate and normocalciuria) was achieved in 158 patients (51%), more commonly in countries with higher gross domestic product (67% versus 23%), and was associated with higher height and estimated glomerular filtration rate., Conclusion: Long-term follow-up from this large dRTA cohort shows an overall favourable outcome with normal adult height for most and no patient with CKD Stage 5. However, 82% of adult patients have CKD Stages 2-4. Importance of adequate metabolic control was highlighted by better growth and renal function but was achieved in only half of patients., (© The Author(s) 2019. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.)

Rationale: Medullary sponge kidney (MSK) is a rare congenital abnormality characterized by cystic dilatation of the medullary collecting tubules. The disorder is likely to be complicated by nephrocalcinosis, urolithiasis, tubular dysfunctions, and urinary tract infections. In addition, it may be rarely associated with extrarenal anomalies., Patient Concern: We present a case of 17-year old girl who was referred for metabolic evaluation of bilateral nephrocalcinosis. Physical examination showed signs of mild, left-sided hemihypertrophy involving the lower limb, buttock, trunk, face, and tongue. The imaging studies of kidneys including intravenous urography and contrast computed tomography showed numerous medullary calcification and a typical picture of MSK-"paint brush"/"bouquet of flowers" appearance of the dilated tubules within the renal medulla. Laboratory evaluation revealed sterile pyuria, hypercalciuria, and hypocitraturia., Intervention: The patient was subsequently treated with potassium citrate, hydrochlorothiazide, low sodium and low oxalate diet accompanied by high fluid intake., Outcomes: After a 1-year therapy the normalization of calciuria and citraturia occurred and no progression of nephrocalcinosis was observed., Lessons: We conclude that MSK should always be considered as a cause of nephrocalcinosis. Since the final diagnosis requires specific imaging techniques, the concomitant extrarenal abnormalities such as hemihypertrophy may facilitate diagnostic decisions.

The mechanisms that drive T cell aging are not understood. We report that children and adult telomerase mutation carriers with short telomere length (TL) develop a T cell immunodeficiency that can manifest in the absence of bone marrow failure and causes life-threatening opportunistic infections. Mutation carriers shared T cell-aging phenotypes seen in adults 5 decades older, including depleted naive T cells, increased apoptosis, and restricted T cell repertoire. T cell receptor excision circles (TRECs) were also undetectable or low, suggesting that newborn screening may identify individuals with germline telomere maintenance defects. Telomerase-null mice with short TL showed defects throughout T cell development, including increased apoptosis of stimulated thymocytes, their intrathymic precursors, in addition to depleted hematopoietic reserves. When we examined the transcriptional programs of T cells from telomerase mutation carriers, we found they diverged from older adults with normal TL. Short telomere T cells upregulated DNA damage and intrinsic apoptosis pathways, while older adult T cells upregulated extrinsic apoptosis pathways and programmed cell death 1 (PD-1) expression. T cells from mice with short TL also showed an active DNA-damage response, in contrast with old WT mice, despite their shared propensity to apoptosis. Our data suggest there are TL-dependent and TL-independent mechanisms that differentially contribute to distinct molecular programs of T cell apoptosis with aging.

30% of the patients suffering from hyperoxaluria type 1 are diagnosed only when they already had reached end-stage renal disease. We report the case of a 57-year-old woman with history of chronic kidney failure presenting with paraplegia due to spinal cord compression by thoracic mass-like lesions. Bone biopsy specimen obtained by decompressive laminectomy revealed calcium oxalate deposits. Once diagnosis of primary hyperoxaluria was confirmed, she underwent haemodialysis with incomplete improvement of her neurological disorders and was registered on the waiting list for transplantation.

Background: Sixty mutations of claudin 16 coding gene have been reported in familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) patients. Recent investigations revealed that a highly conserved glycine-leucine-tryptophan ( 115 G-L-W 117 ) motif in the first extracellular segment (ESC1) of claudin 16 might be essential for stabilization of the appropriately folded ECS1 structure and conservation of normal claudin 16 function. However, neither missense nor nonsense mutation has ever been described in this motif. Our study aimed at identifying mutations in a Chinese patient with FHHNC and exploring the association between genotype and phenotype., Case Presentation: A 33-year-old female presented with 4 years history of recurrent acute pyelonephritis without other notable past medical history. Her healthy parents, who aged 56 and 53 respectively, were second cousins, and her only sibling died from renal failure without definite cause at age 25. Renal ultrasound imaging demonstrated atrophic kidneys and bilateral nephrocalcinosis. The laboratory workup revealed impaired renal function (Stage CKD IV), hypocalcemia and mild hypomagnesemia, accompanied with marked renal loss of magnesium and hypercalciuria. During the follow-up, treatment with calcitriol and calcium but not with magnesium was difficult to achieve normal serum calcium levels, whereas her serum magnesium concentration fluctuated within normal ranges. In the end, the patient unavoidably reached ESRD at 36 years old. The clinical features and family history suggested the diagnosis of FHHNC. To make a definite diagnosis, we use whole-exome sequencing to identify the disease-causing mutations and Sanger sequencing to confirm the mutation co-segregation in the family. As a result, a novel homozygous mutation (c.346C > G, p.Leu116Val) in 115 G-L-W 117 motif of claudin 16 was identified. Her parents, grandmother and one of her cousins carried heterozygous p.Leu116Val, whereas 200 unrelated controls did not carry this mutation., Conclusions: We described a delayed diagnosis patient with FHHNC in the Chinese population and identified a novel missense mutation in the highly conserved 115 G-L-W 117 motif of claudin 16 for the first time. According to the reported data and the information deduced from 3D modeling, we speculate that this mutation probably reserve partial residual function which might be related to the slight phenotype of the patient.

Primary Sjögren's syndrome is a systemic and chronic autoimmune disease. Renal involvement may occur in up to 30% of patients. The incidence of tubulopathies ranges from 2.6 to 33%. They are manifested by defects in the urine concentration and hydroelectrolyte alterations, mainly distal tubular acidosis and exceptionally proximal tubular acidosis. These disorders can be associated with nephrocalcinosis and renal lithiasis. We report the case of a patient with primary Sjögren who presented proximal renal tubular acidosis associated with recurrent renal colic due to renal lithiasis and nephrocalcinosis. We highlight the importance of diagnosing renal tubular acidosis in patients with Sjögren's syndrome that present alterations in urinary sediment and electrolyte disorders to avoid nephrocalcinosis and nephrolithiasis. Acidosis correction treatment aims to prevent the progression of the disorder and preserve renal function.

Primary hyperoxaluria (PH) is a metabolic liver disease with an autosomal recessive inheritance that results in oxalate overproduction that cannot be metabolized by the liver. Urinary excretion of oxalate results in lithiasis and nephrocalcinosis leading to a progressive loss of renal function that often requires renal replacement therapy despite medical treatment. Type 1 PH is the most common form and is due to a deficiency in the alanine-glycolate aminotransferase enzyme found in hepatic peroxisomes. Therefore, a liver-kidney simultaneous transplant (LKST) is the definitive treatment for end-stage renal disease (ESRD) patients. However, some studies suggest that the morbidity and mortality rates are greater when this procedure is performed instead of only a kidney transplant (IKT). Herein, we report five patients with PH and a mean glomerular filtration rate of 20.2 ± 1.3 ml/min/1.73 m2 who received a LKST between 1999 and 2015 at the Hospital Universitario 12 de Octubre. Recurrence and liver or kidney graft loss was not observed during the postoperative period and only one case of late acute rejection without graft loss was diagnosed. The recipient survival rate was 100% with a median follow up of 84 months. As LKST is a curative and safe procedure with a low mortality and high survival rate, it must be considered as the treatment of choice in adults with HP and ESRD.

Baştuğ F, Nalçacıoğlu H, Baş VN, Tekatlı-Çelik B, Çetinkaya H, Yel S. Acute renal failure due to severe hypercalcemia and nephrocalcinosis treated with two doses of pamidronate in an infant with Williams-Beuren syndrome. Turk J Pediatr 2018; 60: 210-215. Infantile hypercalcemia has been reported in 15% of infants and children with Williams-Beuren syndrome (WBS) and has generally mild clinical symptoms. However, the need for pamidronate treatment in a few infants with severe hypercalcemia associated with WBS has been reported in literature. Many disorders, such as primary hyperoxaluria, associated with nephrocalcinosis can lead to renal failure, but there are only a few reports in infants with WBS who have decreased renal function and nephrocalsinosis. We present a 23-month-old girl with WBS (confirmed with fluorescent in situ hybridization probes) who presented with acute renal failure with severe symptomatic hypercalcemia and nephrocalcinosis, which responded to two infusions of pamidronate.

Background: Short stature is one of the common disorders referred for investigation of an endocrine disorder. The etiologies of short stature vary and are commonly grouped into pathological and non-pathological disorders. The objective of the study was to determine the etiologies and describe the characteristics of short stature patients who attended the Pediatric Endocrinology Clinic and to compare factors between normal variant short stature (NVSS) and growth hormone deficiency (GHD)., Methods: This was a retrospective review of 572 patients referred for evaluation of short stature between January 2004 and December 2015. Short stature was defined as height below -2 standard deviation score (SDS) by gender and age based on population data of Thai children., Results: In total, 521 patients were identified as having short stature. NVSS was the most common etiology (44.9%) and pathological short stature was found in 35.3% of the cases, of which 21.2% had GHD. The median age at presentation of NVSS patients was 8.6 years while that of pathological short stature patients was 2.1 years (p<0.001). Patients with NVSS had significantly higher median height SDS (HSDS) than patients with pathological diseases. The common etiologies in severe short patients, defined by HSDS ≤-3, were syndromic short stature (16.2%) and GHD (14.1%). In the moderate short stature group (HSDS between -2 and -3), constitutional delay of growth and puberty (CDGP) was the most common etiology (34.1%)., Conclusions: NVSS was the most common etiology of short stature, followed by syndromic short stature and GHD. Physical examination is crucial to identify GHD from syndromic short patients.

Objective: Although ED patients presenting with supraventricular tachycardia (SVT) are commonly investigated, the value of these investigations has been questioned. We aimed to determine the frequency and utility of investigations in patients with SVT., Methods: We undertook an explicit retrospective medical record audit of patients with SVT who presented to a single ED (January 2004 to June 2014). Data on demographics, presenting complaints, investigations and outcomes were extracted. The outcomes were nature and utility of investigations., Results: A total of 633 patients were enrolled (mean [SD] age 55.4 [17.7] years, 62% female). Laboratory investigations were common: electrolytes (83.7% of patients), full blood count (81.2%), magnesium (57.5%), calcium (39.3%) and thyroid function (30.3%). These investigations revealed many mildly abnormal results but resulted in electrolyte supplementation in only 19 patients: eight with mild hypokalaemia (potassium 3.0-3.5 mmol/L) and 11 with mild hypomagnesia (magnesium 0.49-1.1 mmol/L). Troponin was ordered for 302 (47.7%) patients, many of whom had no history or risk factors for cardiac disease, or ischaemic symptoms associated with their SVT. The troponin was normal, mildly and moderately elevated in 65.2, 24.5 and 10.2% of cases, respectively. Only seven (1.1%) patients were diagnosed with acute myocardial ischemia. Although 190 (30.0%) patients had a chest X-ray (CXR), it was normal in 78.4% of cases. All CXR abnormalities were incidental and not relevant to the immediate ED management., Conclusion: Patients with uncomplicated SVT are over-investigated. Guidelines for ED SVT investigation are recommended. Further research is recommended to determine the indications for each investigation in the setting of SVT., (© 2017 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.)

Prior to 1971, type Ia glycogen storage disease was marked by life-threatening hypoglycemia, lactic acidosis, severe failure to thrive, and developmental delay. With the introduction of continuous feeds in the 1970s and cornstarch in the 1980s, the prognosis improved, but complications almost universally developed. Changes in the management of type Ia glycogen storage disease have resulted in improved metabolic control, and this manuscript reviews the increasing evidence that complications can be delayed or prevented with optimal metabolic control as previously was seen in diabetes., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Magnesium is essential to the proper functioning of numerous cellular processes. Magnesium ion (Mg 2+ ) deficits, as reflected in hypomagnesemia, can cause neuromuscular irritability, seizures and cardiac arrhythmias. With normal Mg 2+ intake, homeostasis is maintained primarily through the regulated reabsorption of Mg 2+ by the thick ascending limb of Henle's loop and distal convoluted tubule of the kidney. Inadequate reabsorption results in renal Mg 2+ wasting, as evidenced by an inappropriately high fractional Mg 2+ excretion. Familial renal Mg 2+ wasting is suggestive of a genetic cause, and subsequent studies in these hypomagnesemic families have revealed over a dozen genes directly or indirectly involved in Mg 2+ transport. Those can be classified into four groups: hypercalciuric hypomagnesemias (encompassing mutations in CLDN16, CLDN19, CASR, CLCNKB), Gitelman-like hypomagnesemias (CLCNKB, SLC12A3, BSND, KCNJ10, FYXD2, HNF1B, PCBD1), mitochondrial hypomagnesemias (SARS2, MT-TI, Kearns-Sayre syndrome) and other hypomagnesemias (TRPM6, CNMM2, EGF, EGFR, KCNA1, FAM111A). Although identification of these genes has not yet changed treatment, which remains Mg 2+ supplementation, it has contributed enormously to our understanding of Mg 2+ transport and renal function. In this review, we discuss general mechanisms and symptoms of genetic causes of hypomagnesemia as well as the specific molecular mechanisms and clinical phenotypes associated with each syndrome.

Introduction: Renal dysfunction associated with primary hyperparathyroidism was studied mostly in patients with mildly asymptomatic or asymptomatic parathyroid disorders. Clinical and biochemical profile of asymptomatic and symptomatic disease vary grossly. The present study analyzed renal function in patients with primary hyperparathyroidism and the relation with clinical features, biochemical features and sonologic changes of kidneys in a cohort of primary symptomatic hyperparathyroidism., Study Design: Cross-sectional study was done in a cohort of surgically proven patients of primary symptomatic hyperparathyroidism. Urinary tract was evaluated with high definition Ultrasonography and renal function was estimated using Modification of Diet in Renal disease (MDRD) Study equation before and after parathyroidectomy., Result: Case records 145 patients were studied and there were 44 patients (30.4%) with estimated Glomerular Filtration Rate (eGFR) less than 60 mL/min/1.73 m 2 . Associated renal complications, coincident hypertension and high serum level of calcium were strongly associated with renal dysfunction. Renal dysfunction marginally improved after 1 year following surgical cure of hyperparathyroidism in 25% of patients with renal dysfunction. There was no detectable change in renal function during the follow up period., Conclusion: There was high prevalence of renal dysfunction among symptomatic hyperparathyroidism. Patients with primary hyperparathyroidism should undergo complete sonological assessment of kidneys which may include presence of nephrocalcinosis and cortical echogenicity. Successful parathyroidectomy prevented deterioration of renal function in most of patients and a significant subset with renal dysfunction showed improvement of functional status., (Copyright © 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Objectives: To identify a clinical profile and laboratory findings of a cohort of hypoparathyroidism patients and determine the prevalence and predictors for renal abnormalities., Materials and Methods: Data from medical records of five different visits were obtained, focusing on therapeutic doses of calcium and vitamin D, on laboratory tests and renal ultrasonography (USG)., Results: Fifty-five patients were identified, 42 females and 13 males; mean age of 44.5 and average time of the disease of 11.2 years. The most frequent etiology was post-surgical. Levels of serum calcium and creatinine increased between the first and last visits (p < 0.001 and p < 0.05, respectively); and serum levels of phosphate decreased during the same period (p < 0.001). Out of the 55 patients, 40 had USG, and 10 (25%) presented with kidney calcifications. There was no significant difference in the amount of calcium and vitamin D doses among patients with kidney calcifications and others. No correlation between serum and urinary levels of calcium and the presence of calcification was found. Urinary calcium excretion in 24h was significantly higher in patients with kidney calcification (3.3 mg/kg/d) than in those without calcification (1.8 mg/kg/d) (p < 0.05)., Conclusions: The reduction of hypocalcemia and hyperphosphatemia suggest an effectiveness of the treatment, and the increase in serum creatinine demonstrates an impairment of renal function during follow-up. Kidney calcifications were prevalent in this cohort, and higher urinary calcium excretion, even if still within the normal range, was associated with development of calcification. These findings suggest that lower rates of urinary calcium excretion should be aimed for in the management of hypoparathyroidism.

Competing Interests: Compliance with Ethical Standards Funders We have no funding sources to declare. Prior Presentations This Clinical Image has never been presented at a conference or accepted for publication by another journal or institution. Conflict of Interest The authors declare that they do not have a conflict of interest.

Background: The aim of our study is to measure total Magnesium in pregnant women screened for GDM and to compare total magnesium between whom were diagnosed having GDM and those having normal pregnancy., Methods: Our study is a prospective study involved 99 pregnant women referred to Maternity and Child Hospital Al Ahsa (Kingdom of Saudi Arabia) for 100g Oral Glucose Tolerance test. All included pregnant women were in their 24-28 weeks of gestation with free past medical history and were free for any medicine. A 100-g Oral Glucose Tolerance (OGTT) with total plasma magnesium measurement were done to all included women. All patient were followed tell delivery., Results: Among 99 patients enrolled in our study, GDM was diagnosed in 19 patients (19.2%). Fifteen patients have normal fasting glycaemia and were diagnosed having GDM on 100-g OGTT. Four patients have fasting glycaemia more than 126mg/dl (7mmol/l) confirming the diagnosis of GDM. Hypomagnesemia was confirmed in eight patients (8.08%). no one of them had GDM. The serum magnesium concentration in GDM women was lower that of normal pregnant women but the difference was not significant. (0.89±0.1 vs 0.92±0.2mmol/l, p=0.51). BMI, systolic and diastolic blood pressure were not significantly different between the pregnant women who developed or not gestational diabetes., Conclusion: In our study, the development of GDM cannot be explained by low total serum magnesium. The low total serum magnesium in patient diagnosed having GDM compared to whom free of GDM and the importance of magnesium in the genesis of insulin resistance should encourage more large trial to explain the exact role of magnesium in the pathophysiology of GDM., (Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.)