Nephrocalcinosis

OBJECTIVE: To assess sperm retrieval rates in adolescents and young adults with Klinefelter syndrome, with the ultimate goal of improving fertility in this population. Secondary aims were to evaluate other clinical characteristics of the cohort and identify predictors of sperm retrieval. STUDY DESIGN: Patients 12-25 years of age with Klinefelter syndrome (47,XXY) were recruited at the Boston Children's Hospital. Physical examination, biochemical evaluation, scrotal ultrasonography, and semen analysis were performed...

We present two unrelated cases of young adults with hypercalcemia, hypercalciuria, and nephrocalcinosis. Both had suppressed intact parathyroid hormone levels and high 1,25 vitamin D levels after only brief, low-dose, over-the-counter vitamin supplementation. Neither had evidence of a granulomatous disorder. Their presentation mimicked that of 1,25 hydroxy vitamin D intoxication. In both patients, the diagnosis of idiopathic infantile hypercalcemia was confirmed with immeasurably low 24,25 vitamin D levels...

BACKGROUND: Partial duplication of 2p is a rare condition that causes facial anomalies, psychomotor delay, and growth failure. Hypercalcaemia is rare in children. So far, duplication of 2p has never been associated with hypercalcaemia. METHODS: Here, we report a girl with a partial duplication of 2p presenting with moderate to severe hypercalcaemia at the age of 2 years. She also had hypercalciuria, nephrocalcinosis, decreased renal function, and secondary hyperparathyroidism at presentation...

INTRODUCTION: Renal injury due to sarcoidosis develops in less than a quarter of patients with this systemic disease. In most cases, granulomatous tissue alters the production of vitamin D, which leads to hypercalciuria, nephrocalcinosis, and nephrolithiasis. Granulomatous interstitial nephritis is another well-recognized pathological process associated with sarcoidosis. However, a glomerular pathology is very rarely noted, and only a few cases are reported to have cellular crescentic glomerulonephritis...

BACKGROUND: Bisphosphonates are used in the treatment of vitamin D intoxication (VDI) after failure of conventional therapy including prednisolone. Safety concerns restrict the use of bisphosphonates from being used as first-line therapy for VDI in children. The aim of this study was to evaluate the efficacy and safety of pamidronate in comparison with prednisolone in children with VDI. METHODS: We reviewed the hospital records of children consecutively diagnosed with VDI at two medical centers in a 15 year period...

Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is an autosomal-recessive renal tubular disorder characterized by excessive urinary losses of magnesium and calcium, bilateral nephrocalcinosis and progressive chronic renal failure. Presentation with FHHNC symptoms generally occurs early in childhood or before adolescence. At present, the only therapeutic option is supportive and consists of oral magnesium supplementation and thiazide diuretics. However, neither treatment seems to have a significant effect on the levels of serum magnesium or urine calcium or on the decline of renal function...

OBJECTIVE: Hereditary hypophosphatemias (HH) are rare monogenic conditions characterized by decreased renal tubular phosphate reabsorption. The aim of this study was to explore the prevalence, genotypes, phenotypic spectrum, treatment response, and complications of treatment in the Norwegian population of children with HH. DESIGN: Retrospective national cohort study. METHODS: Sanger sequencing and multiplex ligand-dependent probe amplification analysis of PHEX and Sanger sequencing of FGF23, DMP1, ENPP1KL, and FAM20C were performed to assess genotype in patients with HH with or without rickets in all pediatric hospital departments across Norway...

Diagnosis and management of pediatric nephrolithiasis/nephrocalcinosis is a very complex and challenging task for every pediatrician. It is based on correct. disease history taking, which may guide to the mode of inheritance (dominant, recessive, x-linked). Ethnicity and consanguinity should also be investigated since they predispose to high prevalence of certain disorders. One should always begin with cheap and available screening tests. Herein we will review clinical, biochemical, metabolic and genetic characteristics of the inherited diseases which lead to nephrolithiasis/nephrocalcinosis, such as: idiopathic hypercalciuria, renal hypophosphatemia, renal tubular acidosis, idiopathic infantile hypercalcemia, Dent disease, familial hypomagnesemia with hypercalciuria and nephrocalcinosis, hypocitraturia, cystinuria, primary hyperoxaluria and renal hypouricemia...

This review of the original autopsy report of Beethoven's remains indicates Paget's disease within the skull, which was dense and twice normal thickness, with dilated vessels at the petrous bone. The facial nerves were enlarged and the eighth nerves atrophied despite their sharing a common meatus at the internal auditory canal. Nephrolithiasis and pyelonephritis with cortical and perinephric abscesses were also reported. The hypercalcaemia was probably caused by hyperparathyroidism, which may be associated with Paget's disease, and both may have played a role in his psychiatric symptoms as well as in his abdominal pain and gastrointestinal complaints...

The recognition of fabricated illness (FI) in a child represents a diagnostic challenge. The suspicion of FI often arises from the discrepancy between laboratory tests and clinical history. For instance, (unnecessary) insulin injections by caregivers has been widely described as a common cause of factitious hypoglycemia that may be inferred from discrepancies between plasma insulin and c-peptide. However, contemporary administration of insulin with an insulin secretagogue (glyburide), and of additional drugs, can make the diagnostic pathway problematic...

We present a middle-aged woman with a prior history of central nervous system (CNS) demyelinating disorder who presented with an acute onset quadriparesis and respiratory failure. The evaluation revealed distal renal tubular acidosis with hypokalemia and medullary nephrocalcinosis. Weakness persisted despite potassium correction, and ongoing evaluation confirmed recurrent CNS and long-segment spinal cord demyelination with anti-aquaporin-4 antibodies. There was no history of dry eyes or dry mouth. Anti-Sjogren's syndrome A antigen antibodies were elevated, and there was reduced salivary flow on scintigraphy...

Claudin-16 protein (CLDN16) is a component of tight junctions (TJ) with a restrictive distribution so far demonstrated mainly in the kidney. Here, we demonstrate the expression of CLDN16 also in the tooth germ and show that claudin-16 gene (CLDN16) mutations result in amelogenesis imperfecta (AI) in the 5 studied patients with familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC). To investigate the role of CLDN16 in tooth formation, we studied a murine model of FHHNC and showed that CLDN16 deficiency led to altered secretory ameloblast TJ structure, lowering of extracellular pH in the forming enamel matrix, and abnormal enamel matrix protein processing, resulting in an enamel phenotype closely resembling human AI...

BACKGROUND: An association between chronic hyperaldosteronism and medullary nephrocalcinosis has rarely been made, with only a handful of cases described in literature. CASE REPORT: We describe five cases of hyperaldosteronism with a long- standing history in whom associated medullary nephrocalcinosis was established. CONCLUSIONS: We infer that a chronic hyperaldosteronic status, whether primary or secondary, is a causal factor in the etiopathogenesis of medullary nephrocalcinosis...

Numerous cases of enamel renal syndrome have been previously reported. Various terms, such as enamel renal syndrome, amelogenesis imperfecta and gingival fibromatosis syndrome, and enamel-renal-gingival syndrome, have been used for patients presenting with the dental phenotype characteristic of this condition, nephrocalcinosis or nephrolithiasis, and gingival findings. This report describes a case of amelogenesis imperfecta of the enamel agenesis variety with nephrolithiasis in a 21-year-old male patient who complained of small teeth...

Dent disease (DD) is a rare X-linked recessive renal tubulopathy characterised by low-molecular-weight proteinuria (LMWP), hypercalciuria, nephrocalcinosis and/or nephrolithiasis. DD is caused by mutations in both the CLCN5 and OCRL genes. CLCN5 encodes the electrogenic chloride/proton exchanger ClC-5 which is involved in the tubular reabsorption of albumin and LMW proteins, OCRL encodes the inositol polyphosphate 5-phosphatase, and was initially associated with Lowe syndrome. In approximately 25 % of patients, no CLCN5 and OCRL mutations were detected...

CONTEXT: Hypoparathyroidism is characterized by hypocalcaemia, hyperphosphataemia, and low or inappropriately normal parathyroid hormone (PTH) levels. Idiopathic or genetic drivers are the predominant causes of hypoparathyroidism in paediatric-age patients. OBJECTIVE: This study investigated the aetiology and clinical course of primary hypoparathyroidism in infancy and childhood. SUBJECTS AND MEASUREMENTS: This study included 37 patients (23 males, 14 females) with primary hypoparathyroidism diagnosed prior to 18 years of age...

CONTEXT: Adults with hypoparathyroidism have significant rates of nephrocalcinosis and impaired renal function. Little is known about the impact of hypoparathyroidism treatment on renal function in children. OBJECTIVES: To determine the prevalence and predictors for renal abnormalities (nephrocalcinosis and decreased estimated glomerular filtration rate [eGFR]) in children with treated hypoparathyroidism. DESIGN AND SETTING: A retrospective chart review of patients with permanent hypoparathyroidism at the Hospital for Sick Children, Toronto, between 1996 and 2013...

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BACKGROUND: Chronic hypokalemia is known to induce renal structural and functional abnormality. The former includes induction of renal cyst formation and interstitial fibrosis while the latter entails urine-concentrating defect. However, these hypokalemia-mediated changes occur in a handful of conditions including primary aldosteronism, distal renal tubular acidosis, Liddle's disease, apparent mineralocorticoid excess syndrome and Bartter's type 3 syndrome. Such a finding has never been described in an 11 beta-hydroxylase deficient individual...

BACKGROUND: Dent disease (DD) is a rare X-linked tubulopathy characterized by a proximal tubular dysfunction leading to nephrocalcinosis/nephrolithiasis and progressive renal failure. The disease is associated with a mutation either in CLCN5 or OCRL genes. We aim to define clinical and genetic disease characteristics and summarize treatments of Polish patients with DD. METHODS: The study cohort consists of 10 boys (aged 5 - 16.5 years) whose data were collected through POLtube Registry...