Renal AND Renal tubular acidosis [keywords]
- Autosomal dominant osteopetrosis associated with renal tubular acidosis is due to a CLCN7 mutation. [JOURNAL ARTICLE]
- Am J Med Genet A 2016 Aug 19.
The aim of this study was to identify the causative mutation in a family with an unusual presentation of autosomal dominant osteopetrosis (OPT), proximal renal tubular acidosis (RTA), renal stones, epilepsy, and blindness, a combination of features not previously reported. We undertook exome sequencing of one affected and one unaffected family member, followed by targeted analysis of known candidate genes to identify the causative mutation. This identified a missense mutation (c.643G>A; p.Gly215Arg) in the gene encoding the chloride/proton antiporter 7 (gene CLCN7, protein CLC-7), which was confirmed by amplification refractory mutation system (ARMS)-PCR, and to be present in the three available patients. CLC-7 mutations are known to cause autosomal dominant OPT type 2, also called Albers-Schonberg disease, which is characterized by osteosclerosis, predominantly of the spine, pelvis and skull base, resulting in bone fragility and fractures. Albers-Schonberg disease is not reported to be associated with RTA, but autosomal recessive OPT type 3 (OPTB3) with RTA is associated with carbonic anhydrase type 2 (CA2) mutations. No mutations were detected in CA2 or any other genes known to cause proximal RTA. Neither CLCN7 nor CA2 mutations have previously been reported to be associated with renal stones or epilepsy. Thus, we identified a CLCN7 mutation in a family with autosomal dominant osteopetrosis, RTA, renal stones, epilepsy, and blindness. © 2016 Wiley Periodicals, Inc.
- Spectrum of Renal and Urinary Tract Diseases in Kashmiri Children. [Journal Article]
- J Clin Diagn Res 2016 Jun; 10(6):SM01-2.
Definite paucity of data pertaining to spectrum of renal and urinary tract diseases in our state and in various parts of India forms the basis of this study. Available data has emphasized more on specific clinical syndromes and chronic renal diseases rather than over all spectrums of renal and urinary tract diseases, that too in adult population.The present study a retrospective analysis, forms one of the basic data of paediatric nephrology and urology related disorders in our state.Retrospective analysis of the case records of all the hospitalized patients with renal and urinary tract diseases between 2012 and 2013 were performed. Case records were analysed and categorized into various groups like; Urinary Tract Infections (UTI), Acute Kidney Injury (AKI), Acute Glomerulonephritis (AGN), Nephrotic Syndrome (NS), haematuria, Polycystic Kidney Disease (PCKD), Posterior Urethral Valve (PUV), Vesicoureteric Reflux (VUR), Chronic Kidney Disease (CKD), Congenital Anomalies of Kidney and Urinary Iract (CAKUT) and others. These groups were divided into subgroups to get more insight about the pattern of these diseases.Out of 28114 patients hospitalized between 2012 and 2013 years, 447 (232 males and 215 females) patients were diagnosed of renal and urinary tract diseases which forms 1.58% the total admitted patients. Among these patients 32.9% (147/447) were diagnosed Acute Kidney Injury (AKI); 24.1% (108/447): Urinary Tract Infection (UTI); 9.6% (43/447): Acute Glomerulonephritis (AGN); 5.6% (25/447): bilateral hydronephrosis with UTI; 4.47% (20/447): nephrotic syndrome (NS); 3.5% (16/447): haematuria; and 4% (18/447) were having CAKUT (Congenital Anomalies Of Kidney And Urinary Tract). In addition to this there were 17 cases of Renal Tubular Acidosis (RTA), 3 cases of Barter syndrome and one case of Liddle syndrome.A substantial number of children are hospitalized with renal and urinary tract diseases with delayed ages of presentation, which at times have suffered irreversible renal damage that could have been prevented or treated if diagnosed earlier. Our study indicates that majority of these renal and urinary tract diseases are preventable and treatable. Henceforth, there is a need to develop a comprehensive service for the children with renal and urinary tract diseases in Jammu & Kashmir (J&K) India.
- The need for genetic study to diagnose some cases of distal renal tubular acidosis. [JOURNAL ARTICLE]
- Nefrologia 2016 Aug 1.
We describe the case of a young woman who was diagnosed with advanced kidney disease, with an incidental finding of nephrocalcinosis of unknown aetiology, having been found asymptomatic throughout her life. The genetic study by panels of known genes associated with tubulointerstitial disease allowed us to discover autosomal dominant distal renal tubular acidosis associated with a de novo mutation in exon 14 of the SLC4A1 gene, which would have been impossible to diagnose clinically due to the advanced nature of the kidney disease when it was discovered.
- Fanconi-Bickel syndrome in two Palestinian children: marked phenotypic variability with identical mutation. [Journal Article]
- BMC Res Notes 2016.:387.
Fanconi-Bickel syndrome (FBS, OMIM 227810) is a rare autosomal recessive disease caused by a deficiency of glucose transporter 2 (GLUT2), a member of the facilitative glucose transporter family (Santer et al. J Inherit Metab Dis 21:191-194, 1998). The typical clinical picture is characterized by hepatorenal glycogen accumulation resulting in hepato- and nephromegaly, impaired utilization of glucose and galactose, proximal renal tubular dysfunction, rickets and severe short stature.We report 2 Palestinian patients from 2 families who were homozygous for the mutation p.R301X (C>T) in exon 7of GLUT2 gene. Patient 1 showed clinical and laboratory improvement with age characterized by normal growth and resolution of rickets. Patient 2 had severe phenotype characterized by progressive weight loss, persistent metabolic acidosis, marked polyuria and clinical and laboratory findings of rickets progressing to death at age 10 months.This report further expands the clinical spectrum of FBS even with identical mutations. Other yet unknown genetic, environmental or stochastic factors may be responsible for phenotypic variability.
- Acidosis and Urinary Calcium Excretion: Insights from Genetic Disorders. [JOURNAL ARTICLE]
- J Am Soc Nephrol 2016 Jul 28.
Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibition of calcium transport processes within the renal tubule. The mechanisms whereby acid alters the integrity and stability of bone have been examined extensively in the published literature. Here, after briefly reviewing this literature, we consider the effects of acid on calcium transport in the renal tubule and then discuss why not all gene defects that cause renal tubular acidosis are associated with hypercalciuria and nephrocalcinosis.
- Metabolic diagnosis and medical prevention of calcium nephrolithiasis and its systemic manifestations: a consensus statement. [JOURNAL ARTICLE]
- J Nephrol 2016 Jul 25.
Recently published guidelines on the medical management of renal stone disease did not address relevant topics in the field of idiopathic calcium nephrolithiasis, which are important also for clinical research.A steering committee identified 27 questions, which were proposed to a faculty of 44 experts in nephrolithiasis and allied fields. A systematic review of the literature was conducted and 5216 potentially relevant articles were selected; from these, 407 articles were deemed to provide useful scientific information. The Faculty, divided into working groups, analysed the relevant literature. Preliminary statements developed by each group were exhaustively discussed in plenary sessions and approved.Statements were developed to inform clinicians on the identification of secondary forms of calcium nephrolithiasis and systemic complications; on the definition of idiopathic calcium nephrolithiasis; on the use of urinary tests of crystallization and of surgical observations during stone treatment in the management of these patients; on the identification of patients warranting preventive measures; on the role of fluid and nutritional measures and of drugs to prevent recurrent episodes of stones; and finally, on the cooperation between the urologist and nephrologist in the renal stone patients.This document has addressed idiopathic calcium nephrolithiasis from the perspective of a disease that can associate with systemic disorders, emphasizing the interplay needed between urologists and nephrologists. It is complementary to the American Urological Association and European Association of Urology guidelines. Future areas for research are identified.
- Advanced ureteroscopy for stone disease: characteristics of renal papillae in kidney stone formers. [JOURNAL ARTICLE]
- Minerva Urol Nefrol 2016 Jul 21.
The mechanism of kidney stone formation is not well understood. To better understand the pathophysiology for specific kidney stone compositions and systemic diseases associated with kidney stones, endoscopic papillary mapping studies with concurrent biopsies have been conducted. This review will summarize the findings of these studies and proposed mechanisms for thirteen disease processes associated with kidney stones.A review of the literature was performed identifying thirteen studies that endoscopically mapped and biopsied renal papillae of different stone formers. These studies characterized renal papillae based on amount of Randall's plaque, Bellini duct pathology, papillary contour changes, presence of attached stones, pitting, and frequently papillary and cortical biopsies. The groups studied and reviewed here are kidney stone formers who have a history of idiopathic calcium oxalate stone formation, cystinuria, brushite stones, gastric bypass, ileostomy, small bowel resection, primary hyperparathyroidism, distal renal tubular acidosis (dRTA), primary hyperoxaluria, idiopathic calcium phosphate stone formation, medullary sponge kidney (MSK), uric acid stones, and struvite stones. A proposed standardized scoring system for papillary pathology was also reviewed.The series showed various degrees and types of changes to the renal papillae and corresponding histopathologic changes for each type of stone former reviewed. Those with predominantly alone Randall's plaque pathology had less tissue damage versus those with extensive Bellini duct lesions who had more interstitial fibrosis and cortical pathology. Randall's plaques are associated with stone formers who have low urinary volume, high urinary calcium, and acidic urine and thus are frequently seen in those with brushite stones, primary hyperparathyroidism, small bowel resection, and idiopathic calcium phosphate stone formers. Bellini duct plugging and pathology is theorized to occur via free solution crystallization, ductal obstruction, inflammation, cellular injury, fibrosis, and acidification defects.Ureteroscopic manifestations of stone disease can vary from normal appearing papillae to significantly diseased appearing papillae. Some diseases have very characteristic papillary changes.Further studies are necessary to fully elucidate the mechanisms of stone formation in patients with nephrolithiasis.
- Successful treatment of proximal renal tubular acidosis and Fanconi syndrome with vitamin D replacement. [Case Reports]
- Saudi J Kidney Dis Transpl 2016 Jul-Aug; 27(4):812-5.
Proximal renal tubular acidosis (RTA), also known as Type II RTA, is characterized by a defect in the ability to reabsorb bicarbonate (HCO 3 ) in the proximal tubule. It is usually associated with generalized dysfunction of the proximal tubule as part of Fanconi syndrome. Very few case reports in the literature support Vitamin D deficiency as a cause of proximal RTA. We present a case of a young female who presented with proximal RTA and Fanconi syndrome and excellently responded to Vitamin D replacement. Thus, work-up for the etiology of proximal RTA should include Vitamin D levels since replacement of this vitamin in those who are deficient can lead to cure of such patients.
- Abnormal distal renal tubular acidification in patients with low bone mass: prevalence and impact of alkali treatment. [JOURNAL ARTICLE]
- Urolithiasis 2016 Jul 13.
Chronic acid retention is known to promote bone dissolution. In this study, 23 % of patients with osteopenia/osteoporosis were diagnosed with abnormal distal renal tubular acidification (dRTA), a kidney dysfunction leading to chronic acid retention. Treating those patients with alkali-therapy shows improvement in bone density. To evaluate the prevalence of abnormal distal renal tubular acidification in patients with low bone mass (LBM) and the impact of additional alkali treatment on bone density in patients with concomitant LBM and dRTA,183 patients referred for metabolic evaluation of densitometrically proven low bone mass were screened for abnormal distal renal tubular acidification between 2006 and 2013. In all LBM urine pH (U-pH) was measured in the 2nd morning urines after 12 h of fasting. If U-pH was ≥5.80, LBM underwent a 1-day ammonium chloride loading, and U-pH was remeasured the next morning. If U-pH after acid loading did not drop below 5.45, patients were diagnosed with abnormal distal renal tubular acidification. Normal values were obtained from 21 healthy controls. All LBM with dRTA were recommended alkali citrate in addition to conventional therapy of LBM, and follow-up DXAs were obtained until 2014. 85 LBM underwent NH4Cl loading. 42 LBM patients were diagnosed with incomplete dRTA (idRTA; prevalence 23.0 %). During follow-up (1.6-8 years) of idRTA-LBM patients, subjects adhering to alkali treatment tended to improve BMD at all sites measured, whereas BMD of non-adherent idRTA patients worsened/remained unchanged. (1) About one out of four patients with osteopenia/osteoporosis has idRTA. (2) Upon NH4Cl loading, idRTA patients do not lower urine pH normally, but show signs of increased acid-buffering by bone dissolution. (3) In idRTA patients with low bone mass on conventional therapy, additional long-term alkali treatment improves bone mass at lumbar spine and potentially at other bone sites. (4) All patients with low bone mass undergoing metabolic evaluation should be screened for idRTA.
- Recurrent Attacks of Hypokalemic Quadriparesis: An Unusual Presentation of Primary Sjögren Syndrome. [Journal Article]
- Intern Med 2016; 55(13):1797-800.
We herein report the case of a 64-year old woman with recurrent attacks of hypokalemic quadriparesis which resulted from distal renal tubular acidosis (dRTA) secondary to Sjögren syndrome. The patient presented with sudden onset quadriparesis. A physical examination showed symmetric weakness of all four limbs. Severe hypokalemia (1.8 mEq/L), accompanied by normal anion gap metabolic acidosis, a positive urine anion gap and an inappropriately high urine pH pointed toward the diagnosis of dRTA. Further investigations disclosed primary Sjögren syndrome, which had not previously been recognized. On the basis of the current report and a review of the literature we suggest investigating the possibility of Sjögren syndrome in all patients with clinically unexplained dRTA.