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Coenzyme Q10; Mitochondria; Steroid-resistant nephrotic syndrome Coenzima Q10; Mitocondrias; Síndrome nefrótico resistente a los esteroides Coenzim Q10; Mitocondris; Síndrome nefròtic resistent als esteroides Primary Coenzyme Q10 deficiency is a rare mitochondriopathy with a wide spectrum of organ involvement, including steroid-resistant nephrotic syndrome mainly associated with disease-causing variants in the genes COQ2, COQ6 or COQ8B. We performed a systematic literature review, PodoNet, mitoNET, and CCGKDD registries queries and an online survey, collecting comprehensive clinical and genetic data of 251 patients spanning 173 published (47 updated) and 78 new cases. Kidney disease was first diagnosed at median age 1.0, 1.2 and 9.8 years in individuals with disease-causing variants in COQ2, COQ6 and COQ8B, respectively. Isolated kidney involvement at diagnosis occurred in 34% of COQ2, 10.8% of COQ6 and 70.7% of COQ8B variant individuals. Classic infantile multiorgan involvement comprised 22% of the COQ2 variant cohort while 47% of them developed neurological symptoms at median age 2.7 years. The association of steroid-resistant nephrotic syndrome and sensorineural hearing loss was confirmed as the distinctive phenotype of COQ6 variants, with hearing impairment manifesting at average age three years. None of the patients with COQ8B variants, but 50% of patients with COQ2 and COQ6 variants progressed to kidney failure by age five. At adult age, kidney survival was equally poor (20-25%) across all disorders. A number of sequence variants, including putative local founder mutations, had divergent clinical presentations, in terms of onset age, kidney and non-kidney manifestations and kidney survival. Milder kidney phenotype was present in those with biallelic truncating variants within the COQ8B variant cohort. Thus, significant intra- and inter-familial phenotype variability was observed, suggesting both genetic and non-genetic modifiers of disease severity. In addition, this project has been supported by the European Reference Network for Rare Kidney Diseases (ERKNet), the PodoNet Network for Podocyte Disorders, and the German (mitoNET) and European Networks for Mitochondrial Disorders (GENOMIT). ERKNet is co-funded by the European Union within the framework of the Third Health Programme “ERN-2016 - Framework Partnership Agreement 2017-2021.” PodoNet and mitoNET/GENOMIT have received funding from the German Ministry of Education and Research, and PodoNet from the EU 7th Framework Programme (EURenOmics; grant 2012-305608) and the German Research Foundation (Scha 477/11-1). Founder effect analyses were supported by the Polish Ministry of Science and Education (2017/25/B/NZ2/00519). We would also like to thank Drs. Kei Murayama and Masaru Shimura from Chiba Children’s Hospital, Chiba, Japan, for their contribution to the clinical assessment and follow-up of 2 families. Last but not least, we gratefully acknowledge the help of Elena Levtchenko in rolling out the survey.

Contains fulltext : 283144.pdf (Publisher’s version ) (Open Access) Primary Coenzyme Q10 (CoQ(10)) deficiency is an ultra-rare disorder caused by defects in genes involved in CoQ(10) biosynthesis leading to multidrug-resistant nephrotic syndrome as the hallmark kidney manifestation. Promising early results have been reported anecdotally with oral CoQ(10) supplementation. However, the long-term efficacy and optimal prescription remain to be established. In a global effort, we collected and analyzed information from 116 patients who received CoQ(10) supplements for primary CoQ(10) deficiency due to biallelic pathogenic variants in either the COQ2, COQ6 or COQ8B genes. Median duration of follow up on treatment was two years. The effect of treatment on proteinuria was assessed, and kidney survival was analyzed in 41 patients younger than 18 years with chronic kidney disease stage 1-4 at the start of treatment compared with that of an untreated cohort matched by genotype, age, kidney function, and proteinuria. CoQ(10) supplementation was associated with a substantial and significant sustained reduction of proteinuria by 88% at 12 months. Complete remission of proteinuria was more frequently observed in COQ6 disease. CoQ(10) supplementation led to significantly better preservation of kidney function (5-year kidney failure-free survival 62% vs. 19%) with an improvement in general condition and neurological manifestations. Side effects of treatment were uncommon and mild. Thus, our findings indicate that all patients diagnosed with primary CoQ(10) deficiency should receive early and life-long CoQ(10) supplementation to decelerate the progression of kidney disease and prevent further damage to other organs.

INTRODUCTION: Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease (~45%) that manifests before 30 years of age. The genetic locus containing COL4A1 (13q33–34) has been implicated in vesicoureteral reflux (VUR), but mutations in COL4A1 have not been reported in CAKUT. We hypothesized that COL4A1 mutations cause CAKUT in humans. METHODS: We performed whole exome sequencing (WES) in 550 families with CAKUT. As negative control cohorts we used WES sequencing data from patients with nephronophthisis (NPHP) with no genetic cause identified (n=257) and with nephrotic syndrome (NS) due to monogenic causes (n=100). RESULTS: We identified a not previously reported heterozygous missense variant in COL4A1 in three siblings with isolated VUR. When examining 549 families with CAKUT, we identified nine additional different heterozygous missense mutations in COL4A1 in 11 individuals from 11 unrelated families with CAKUT, while no COL4A1 mutations were identified in a control cohort with NPHP and only one in the cohort with NS. Most individuals (12/14) had isolated CAKUT with no extrarenal features. The predominant phenotype was VUR (9/14). There were no clinical features of the COL4A1-related disorders (e.g., HANAC syndrome, porencephaly, tortuosity of retinal arteries). Whereas COL4A1-related disorders are typically caused by glycine substitutions in the collagenous domain (84.4% of variants), only one variant in our cohort is a glycine substitution within the collagenous domain (1/10). CONCLUSION: We identified heterozygous COL4A1 mutations as a potential novel autosomal dominant cause of CAKUT that is allelic to the established COL4A1-related disorders and predominantly caused by non-glycine substitutions.

Aim Aim of the study was to determine if carotid intima media thickness in children with idiopathic nephrotic syndrome is greater than in healthy subjects, and to assess whether carotid intima media thickness in children with nephrotic syndrome is associated with clinical (including disease duration, cumulative dose of steroids, number of relapses) and biochemical parameters. Methods A cross-sectional study included 40 patients with nephrotic syndrome (mean age 11.7 ± 4.7 years). Steroid dependent nephrotic syndrome was established in 32 patients (80%), while 8 (20%) had steroid resistant nephrotic syndrome. Control group consisted of 20 age and gender matched healthy children. Blood pressure based on 24-h ambulatory blood pressure monitoring (ABPM), carotid intima media thickness, fasting glucose, insulin, HbA1c, lipid concentrations were measured in all children. Results A significant difference was detected in carotid intima media thickness values (P = 0.036). Children with nephrotic syndrome had significantly greater carotid intima media thickness compared with healthy children (0.42 ± 0.06 and 0.38 ± 0.03 mm). Carotid intima-media thickness was positively associated with duration of nephrotic syndrome (r = 0.45; P = 0.004), body mass index (r = 0.48; P = 0.002), daytime systolic blood pressure (r = 0.46; P = 0.003) and night-time systolic blood pressure (r = 0.52; P = 0.001). Multiple linear regression showed that duration of nephrotic syndrome was the only independent predictor of carotid intima media thickness in children with nephrotic syndrome (R2 = 0.244; β=0.327; P = 0.037). Conclusion The findings of the present study suggest subclinical vascular damage in patients with nephrotic syndrome. Duration of nephrotic syndrome was the only independent predictor of carotid intima media thickness.

Item does not contain fulltext BACKGROUND: Congenital anomalies of the kidney and urinary tract (CAKUT) are the most prevalent cause of kidney disease in the first three decades of life. Previous gene panel studies showed monogenic causation in up to 12% of patients with CAKUT. METHODS: We applied whole-exome sequencing to analyze the genotypes of individuals from 232 families with CAKUT, evaluating for mutations in single genes known to cause human CAKUT and genes known to cause CAKUT in mice. In consanguineous or multiplex families, we additionally performed a search for novel monogenic causes of CAKUT. RESULTS: In 29 families (13%), we detected a causative mutation in a known gene for isolated or syndromic CAKUT that sufficiently explained the patient's CAKUT phenotype. In three families (1%), we detected a mutation in a gene reported to cause a phenocopy of CAKUT. In 15 of 155 families with isolated CAKUT, we detected deleterious mutations in syndromic CAKUT genes. Our additional search for novel monogenic causes of CAKUT in consanguineous and multiplex families revealed a potential single, novel monogenic CAKUT gene in 19 of 232 families (8%). CONCLUSIONS: We identified monogenic mutations in a known human CAKUT gene or CAKUT phenocopy gene as the cause of disease in 14% of the CAKUT families in this study. Whole-exome sequencing provides an etiologic diagnosis in a high fraction of patients with CAKUT and will provide a new basis for the mechanistic understanding of CAKUT. 01 september 2018

Background and objectives Steroid-resistant nephrotic syndrome overwhelmingly progresses to ESRD. More than 30 monogenic genes have been identified to cause steroid-resistant nephrotic syndrome. We previously detected causative mutations using targeted panel sequencing in 30% of patients with steroid-resistant nephrotic syndrome. Panel sequencing has a number of limitations when compared with whole exome sequencing. We employed whole exome sequencing to detect monogenic causes of steroid-resistant nephrotic syndrome in an international cohort of 300 families. Design, setting, participants, & measurements Three hundred thirty-five individuals with steroid-resistant nephrotic syndrome from 300 families were recruited from April of 1998 to June of 2016. Age of onset was restricted to Results In 74 of 300 families (25%), we identified a causative mutation in one of 20 genes known to cause steroid-resistant nephrotic syndrome. In 11 families (3.7%), we detected a mutation in a gene that causes a phenocopy of steroid-resistant nephrotic syndrome. This is consistent with our previously published identification of mutations using a panel approach. We detected a causative mutation in a known steroid-resistant nephrotic syndrome gene in 38% of consanguineous families and in 13% of nonconsanguineous families, and 48% of children with congenital nephrotic syndrome. A total of 68 different mutations were detected in 20 of 33 steroid-resistant nephrotic syndrome genes. Fifteen of these mutations were novel. NPHS1, PLCE1, NPHS2, and SMARCAL1 were the most common genes in which we detected a mutation. In another 28% of families, we detected mutations in one or more candidate genes for steroid-resistant nephrotic syndrome. Conclusions Whole exome sequencing is a sensitive approach toward diagnosis of monogenic causes of steroid-resistant nephrotic syndrome. A molecular genetic diagnosis of steroid-resistant nephrotic syndrome may have important consequences for the management of treatment and kidney transplantation in steroid-resistant nephrotic syndrome.

WOS: 000412042200025, PubMed ID: 28566477, We investigated the value of genetic, histopathologic, and early treatment response information in prognosing long-term renal outcome in children with primary steroid-resistant nephrotic syndrome. From the PodoNet Registry, we obtained longitudinal clinical information for 1354 patients (disease onset at >3 months and, E-Rare (German Ministry of Education and Research); Polish Ministry of Science and Education grant [N402631840]; German Research FoundationGerman Research Foundation (DFG) [Scha 477/11-1]; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108S417]; European Union (EU) Seventh Framework Programme (EURenOmics) grant [2012-305608], The PodoNet project has been made possible by support received from E-Rare (German Ministry of Education and Research), European Union (EU) Seventh Framework Programme (EURenOmics) grant 2012-305608, Polish Ministry of Science and Education grant N402631840, German Research Foundation grant Scha 477/11-1, and Scientific and Technological Research Council of Turkey grant 108S417.

No efficient treatment exists for nephrotic syndrome (NS), a frequent cause of chronic kidney disease. Here we show mutations in six different genes (MAGI2, TNS2, DLC1, CDK20, ITSN1, ITSN2) as causing NS in 17 families with partially treatment-sensitive NS (pTSNS). These proteins interact and we delineate their roles in Rho-like small GTPase (RLSG) activity, and demonstrate deficiency for mutants of pTSNS patients. We find that CDK20 regulates DLC1. Knockdown of MAGI2, DLC1, or CDK20 in cultured podocytes reduces migration rate. Treatment with dexamethasone abolishes RhoA activation by knockdown of DLC1 or CDK20 indicating that steroid treatment in patients with pTSNS and mutations in these genes is mediated by this RLSG module. Furthermore, we discover ITSN1 and ITSN2 as podocytic guanine nucleotide exchange factors for Cdc42. We generate Itsn2-L knockout mice that recapitulate the mild NS phenotype. We, thus, define a functional network of RhoA regulation, thereby revealing potential therapeutic targets., Nephrotic syndrome is the second most common chronic kidney disease but there are no targeted treatment strategies available. Here the authors identify mutations of six genes codifying for proteins involved in cytoskeleton remodelling and modulation of small GTPases in 17 families with nephrotic syndrome.

Aim This studied reviewed renovascular hypertension (RVH) due to renal artery stenosis (RAS) in two Serbian paediatric centres from 2001 to 2013. Methods The patients' demographic data, underlying syndromes, blood pressure (BP), antihypertensive treatments and outcomes were reviewed. Results The incidence of RVH was 1.9 per million children per year during the study period, and there were 25 patients with RAS, aged 10.4 ± 5.2 years. At presentation, their mean blood pressure (BP) standard deviation scores were 6.9 ± 3.4 systolic and 5.2 ± 2.6 diastolic. BP loads on 24-hour ambulatory BP were 88 ± 14% systolic and 80 ± 29% diastolic. We found that 72% had fibromuscular dysplasia and 28% had underlying syndromes. RAS was unilateral in 64% and bilateral in 28%, and 8% had RAS of a single kidney. Antihypertensive treatment included antihypertensive drugs (100%), percutaneous transluminal angioplasty (92%), renal auto-transplantation (16%), surgical revascularisation (12%) and nephrectomy (12%). After 4.4 ± 3.6 years of follow-up, high BP was cured in 40% of the patients and 39.4% of the kidneys and improved in 48% (75.7%), with BP decreases of 20.3 ± 3.7% systolic and 16.3 ± 6.2% diastolic. Conclusion Fibromuscular dysplasia was the most common cause of RVH in this study, and hypertension was cured or improved in 88% of the patients.

Congenital anomalies of the kidney and urinary tract (CAKUT) account for 40–50 % of chronic kidney disease that manifests in the first two decades of life. Thus far, 31 monogenic causes of isolated CAKUT have been described, explaining ~12 % of cases. To identify additional CAKUT-causing genes, we performed whole-exome sequencing followed by a genetic burden analysis in 26 genetically unsolved families with CAKUT. We identified two heterozygous mutations in SRGAP1 in 2 unrelated families. SRGAP1 is a small GTPase-activating protein in the SLIT2–ROBO2 signaling pathway, which is essential for development of the metanephric kidney. We then examined the pathway-derived candidate gene SLIT2 for mutations in cohort of 749 individuals with CAKUT and we identified 3 unrelated individuals with heterozygous mutations. The clinical phenotypes of individuals with mutations in SLIT2 or SRGAP1 were cystic dysplastic kidneys, unilateral renal agenesis, and duplicated collecting system. We show that SRGAP1 is expressed in early mouse nephrogenic mesenchyme and that it is coexpressed with ROBO2 in SIX2-positive nephron progenitor cells of the cap mesenchyme in developing rat kidney. We demonstrate that the newly identified mutations in SRGAP1 lead to an augmented inhibition of RAC1 in cultured human embryonic kidney cells and that the SLIT2 mutations compromise the ability of the SLIT2 ligand to inhibit cell migration. Thus, we report on two novel candidate genes for causing monogenic isolated CAKUT in humans.

Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive, fatal childhood disorder associated with skeletal dysplasia, renal dysfunction, and T-cell immunodeficiency. This disease is linked to biallelic loss-of-function mutations of the SMARCAL1 gene. Although recurrent infection, due to T-cell deficiency, is a leading cause of morbidity and mortality, the etiology of the T-cell immunodeficiency is unclear. Here, we demonstrate that the T cells of SIOD patients have undetectable levels of protein and mRNA for the IL-7 receptor alpha chain (IL7R alpha) and are unresponsive to stimulation with IL-7, indicating a loss of functional receptor. No pathogenic mutations were detected in the exons of IL7R in these patients; however, CpG sites in the IL7R promoter were hypermethylated in SIOD T cells. We propose therefore that the lack of IL7R alpha expression, associated with hypermethylation of the IL7R promoter, in T cells and possibly their earlier progenitors, restricts T-cell development in SIOD patients. (C) 2015 Elsevier Inc. All rights reserved.

Congenital anomalies of the kidney and urinary tract (CAKUT) account for approximately 40% of children with ESRD in the United States. Hitherto, mutations in 23 genes have been described as causing autosomal dominant isolated CAKUT in humans. However, >90% of cases of isolated CAKUT still remain without a molecular diagnosis. Here, we hypothesized that genes mutated in recessive mouse models with the specific CAKUT phenotype of unilateral renal agenesis may also be mutated in humans with isolated CAKUT. We applied next-generation sequencing technology for targeted exon sequencing of 12 recessive murine candidate genes in 574 individuals with isolated CAKUT from 590 families. In 15 of 590 families, we identified recessive mutations in the genes FRAS1, FREM2, GRIP1, FREM1, ITGA8, and GREM1, all of which function in the interaction of the ureteric bud and the metanephric mesenchyme. We show that isolated CAKUT may be caused partially by mutations in recessive genes. Our results also indicate that biallelic missense mutations in the Fraser/MOTA/BNAR spectrum genes cause isolated CAKUT, whereas truncating mutations are found in the multiorgan form of Fraser syndrome. The newly identified recessive biallelic mutations in these six genes represent the molecular cause of isolated CAKUT in 2.5% of the 590 affected families in this study.

Background Growth retardation is one of the most visible comorbid conditions of chronic kidney disease (CKD) in children. To our knowledge, published data on longitudinal follow-up of growth in pediatric patients with CKD is lacking from the region of South-East Europe. Herein we report the results from the Serbian Pediatric Registry of Chronic Kidney Disease. Methods The data reported in the present prospective analysis were collected between 2000 and 2012. A total of 324 children with CKD were enrolled in the registry. Results Prevalence of growth failure at registry entry was 29.3 %. Mean height standard deviation scores (HtSDS) in children with stunting and those with normal stature were -3.00 [95 % confidence interval (CI) -3.21 to -2.79] and -0.08 (95 % CI -0.22 to 0.05) (p \ 0.001), respectively. Children with hereditary nephropathy had worse growth at registration (-1.51; 95 % CI -1.97 to -1.04, p = 0.008). Those with CKD stages 4 and 5 before registration had more chance to have short stature at registration than those with CKD stages 2 and 3 [odds ratio (OR) = 0.458, CI 0.268‐0.782, p = 0.004]. Dialysis was an independent negative predictor for maintaining optimal stature during the follow-up period (OR = 0.324, CI = 0.199‐0.529, p \ 0.001), while transplantation was an independent positive predictor for improvement of small stature during follow-up (OR = 3.706, CI = 1.785‐7.696, p \ 0.001). Conclusion Growth failure remains a significant problem in children with CKD, being worst in patients with hereditary renal disease. Growth is not improved by standard dialysis, but transplantation has a positive impact on growth in children.

Congenital anomalies of the kidney and urinary tract (CAKUT) account for approximately half of children with chronic kidney disease. CAKUT can be caused by monogenic mutations; however, data are lacking on their frequency. Genetic diagnosis has been hampered by genetic heterogeneity and lack of genotype–phenotype correlation. To determine the percentage of cases with CAKUT that can be explained by mutations in known CAKUT genes, we analyzed the coding exons of the 17 known dominant CAKUT-causing genes in a cohort of 749 individuals from 650 families with CAKUT. The most common phenotypes in this CAKUT cohort were vesicoureteral reflux in 288 patients, renal hypodysplasia in 120 patients, and unilateral renal agenesis in 90 patients. We identified 37 different heterozygous mutations (33 novel) in 12 of the 17 known genes in 47 patients from 41 of the 650 families (6.3%). These mutations include (number of families): BMP7 (1), CDC5L (1), CHD1L (5), EYA1 (3), GATA3 (2), HNF1B (6), PAX2 (5), RET (3), ROBO2 (4), SALL1 (9), SIX2 (1), and SIX5 (1). Furthermore, several mutations previously reported to be disease-causing are most likely benign variants. Thus, in a large cohort over 6% of families with isolated CAKUT are caused by a mutation in 12 of 17 dominant CAKUT genes. Our report represents one of the most in-depth diagnostic studies of monogenic causes of isolated CAKUT in children.

Introduction. The group of autosomal dominant disorders - Epstein syndrome, Sebastian syndrome, Fechthner syndrome and May-Hegglin anomaly - are characterised by thrombocytopenia with giant platelets, inclusion bodies in granulocytes and variable levels of deafness, disturbances of vision and renal function impairment. A common genetic background of these disorders are mutations in MYH9 gene, coding for the nonmuscle myosin heavy chain IIA. Differential diagnosis is important for the adequate treatment strategy. The aim of this case report was to present a patient with MYH9 disorder in Serbia. Case report. A 16-year-old boy was referred to our hospital with the diagnosis of resistant immune thrombocytopenia for splenectomy. Thrombocytopenia was incidentally discovered at the age of five. The treatment with corticosteroids on several occasions was unsuccessful. Although the platelet count was below 10 × 109/L, there were no bleeding symptoms. Besides thrombocytopenia with giant platelets, on admission the patient also suffered sensorineuronal hearing loss and proteinuria. The diagnosis was confirmed with immunofluorescence and genetic analyses. Conclusion. Early recognition of MYH9-related diseases is essential to avoid unnecessary and potentially harmful treatments for misdiagnosed immune thrombocytopenia, and also for timely and proper therapy in attempt to delay end-stage renal failure and improve quality of life. [Projekat Ministartsva nauke Republike Srbije, br. 175056 i br. 15079]

Ciliopathies are genetically heterogeneous disorders characterized by variable expressivity and overlaps between different disease entities. This is exemplified by the short rib-polydactyly syndromes, Jeune, Sensenbrenner, and Mainzer-Saldino chondrodysplasia syndromes. These three syndromes are frequently caused by mutations in intraflagellar transport (IFT) genes affecting the primary cilia, which play a crucial role in skeletal and chondral development. Here, we identified mutations in IFT140, an IFT complex A gene, in five Jeune asphyxiating thoracic dystrophy (JATD) and two Mainzer-Saldino syndrome (MSS) families, by screening a cohort of 66 JATD/MSS patients using whole exome sequencing and targeted resequencing of a customized ciliopathy gene panel. We also found an enrichment of rare IFT140 alleles in JATD compared with nonciliopathy diseases, implying putative modifier effects for certain alleles. IFT140 patients presented with mild chest narrowing, but all had end-stage renal failure under 13 years of age and retinal dystrophy when examined for ocular dysfunction. This is consistent with the severe cystic phenotype of Ift140 conditional knockout mice, and the higher level of Ift140 expression in kidney and retina compared with the skeleton at E15.5 in the mouse. IFT140 is therefore a major cause of cono-renal syndromes (JATD and MSS). The present study strengthens the rationale for IFT140 screening in skeletal ciliopathy spectrum patients that have kidney disease and/or retinal dystrophy.

Renal tubular acidosis (RTA) is common in adults with primary Sjogren syndrome (pSS) but to date this condition has only been identified in 12 pediatric cases of pSS. Here we present the case of a 13-year-old, otherwise asymptomatic girl in whom the search for the etiology of incidentally found nephrocalcinosis led to diagnosis of distal RTA and nephrogenic diabetes insipidus secondary to SS-associated tubulointerstitial nephritis. Immunosupressive treatment and alkali/electrolyte supplementation resulted in stable renal function over the 6-year follow-up. A review of the literature focuses on two aspects of pSS: (1) the difficulties in diagnosing pSS in childhood and (2) clinical-pathological features, treatment and outcome of renal tubulointerstitial disease in childhood pSS. SS should be considered in older children, particularly females with otherwise unexplained RTA. A careful search for other renal dysfunctions is necessary, and renal biopsy may be of value in assessing the extent of renal damage and the need for immunomodulatory therapy.

Cystinuria is an autosomal recessive disorder caused by defective transport of cystine and dibasic amino acids in the proximal renal tubules and small intestine. So far, more than 128 mutations in SLC3A1 gene, and 93 in SLC7A9 gene have been described as a cause of cystinuria. We present a molecular characterization of the cystinuria in 47 unrelated south-east European families. The molecular methodology included direct sequencing, single strand conformational polymorphism, and restriction fragment length polymorphism. A total of 93 (94.9 %) out of 98 unrelated cystinuric chromosomes have been characterized. Mutations in SLC3A1 gene account for 64.3 % and in SLC7A9 gene for 30.6 % of the cystinuric chromosomes. Ten different mutations in SLC3A1 gene were found, and two of them were novel (C242R and L573X), while in SLC7A9 gene seven mutations were found, of which three were novel (G73R, V375I and c. 1048_1051delACTC). The most common mutations in this study were T216M (24.5 %), M467T (16.3 %) and R365L (11.2 %) in SLC3A1 and G105R (21.4 %) in SLC7A9 gene. A population specificity of cystinuria mutations was observed; T216M mutation was the only mutation present among Gypsies, G105R was the most common mutation among Albanians and Macedonians, and R365L among Serbs. The results of this study allowed introduction of rapid, simple and cost-effective genetic diagnosis of cystinuria that enables an early preventive care of affected patients and a prenatal diagnosis in affected families.

Steroid-resistant nephrotic syndrome (SRNS) causes 15% of chronic kidney disease (CKD). Here we show that recessive mutations in FAT1 cause a distinct renal disease entity in four families with a combination of SRNS, tubular ectasia, haematuria and facultative neurological involvement. Loss of FAT1 results in decreased cell adhesion and migration in fibroblasts and podocytes and the decreased migration is partially reversed by a RAC1/CDC42 activator. Podocyte-specific deletion of Fat1 in mice induces abnormal glomerular filtration barrier development, leading to podocyte foot process effacement. Knockdown of Fat1 in renal tubular cells reduces migration, decreases active RAC1 and CDC42, and induces defects in lumen formation. Knockdown of fat1 in zebrafish causes pronephric cysts, which is partially rescued by RAC1/CDC42 activators, confirming a role of the two small GTPases in the pathogenesis. These findings provide new insights into the pathogenesis of SRNS and tubulopathy, linking FAT1 and RAC1/CDC42 to podocyte and tubular cell function., Steroid-sensitive nephrotic syndrome (SRNS) can cause CKD and necessitate kidney transplant. Here the authors identify FAT1 mutations by homozygosity mapping and whole-exome sequencing in families with SRNS and provide functional mouse and zebrafish evidence that FAT1 is required for normal glomerular and tubular function and that FAT1 mutations can cause SRNS.

Nucleoporins are essential components of the nuclear pore complex (NPC). Only a few diseases have been attributed to NPC dysfunction. Steroid-resistant nephrotic syndrome (SRNS), a frequent cause of chronic kidney disease, is caused by dysfunction of glomerular podocytes. Here we identify in eight families with SRNS mutations in NUP93, its interaction partner NUP205 or XPO5 (encoding exportin 5) as hitherto unrecognized monogenic causes of SRNS. NUP93 mutations caused disrupted NPC assembly. NUP93 knockdown reduced the presence of NUP205 in the NPC, and, reciprocally, a NUP205 alteration abrogated NUP93 interaction. We demonstrate that NUP93 and exportin 5 interact with the signaling protein SMAD4 and that NUP93 mutations abrogated interaction with SMAD4. Notably, NUP93 mutations interfered with BMP7-induced SMAD transcriptional reporter activity. We hereby demonstrate that mutations of NUP genes cause a distinct renal disease and identify aberrant SMAD signaling as a new disease mechanism of SRNS, opening a potential new avenue for treatment.

Introduction. Chronic kidney disease (CKD) is a significant cause of morbidity and mortality in paediatric population. Objective. The aim of the study was analysis of aetiology, staging and associated complications of CKD at the time of diagnosis. Methods. Data of 97 patients (56 boys) of average age 7.8±5.8 years, referred for the first time to the Institute for Mother and Child Healthcare „Dr Vukan Cupic”, Belgrade in the period 1998- 2009, due to CKD, stage 2-5, were analysed. In each patient illness history was obtained, and physical examination, laboratory, X-ray and other investigations were performed according to the indications. CKD was classified according to the glomerular filtration rate into four grades: 2 - mild (60-90 ml/min/1.73 m2); 3 - moderate (30-60 ml/min/1.73 m2); 4 - advanced (15-30 ml/ min/1.73 m2); and 5 - terminal (

Background. The epidemiological information from welldefined populations regarding childhood chronic kidney disease (CKD), particularly those concerning non-terminal stages, are scanty. The epidemiology of CKD in children is often based on renal replacement therapy (RRT) data, which means that a considerable number of children in earlier stages of CKD are missed as they will reach end-stage renal disease (ESRD) in adulthood. Here, we report the basic epidemiological data on childhood CKD in Serbia, gathered over the 10-year period of activity of the Serbian Pediatric Registry of Chronic Kidney Disease. Methods. Since 2000–09, data on incidence, prevalence, aetiology, treatment modalities and outcome of children aged 0–18 years, with CKD Stages 2–4 and CKD Stage 5, were collected by reporting index cases from paediatric centres. Results. Three hundred and thirty-six children were registered (211 boys, 125 girls, male/female ratio 1.7). The median age at registration was 9.0 years [interquartile range (IQR) 3–13]. Median follow-up was 4.0 years (IQR, 1–9). The median glomerular filtration rate (GFR) at the time of the registration was 39.6 mL/min/1.73m 2 (IQR, 13.8–65.4). Median annual incidence of CKD 2–5 stages was 14.3 per million age-related population (p.m.a.r.p.), while those of CKD 2–4 or CKD 5 were 9.1 and 5.7 p.m.a.r.p., respectively. The median prevalence of CKD 2–5 was 96.1 p.m.a.r.p., 52.8 p.m.a.r.p. in CKD 2–4 and 62.2 p.m.a.r.p. in CKD 5. The main causes of CKD were congenital anomalies of kidney and urinary tract and hereditary nephropathies. Kidney survival was the worst in children with glomerular diseases and in those with advanced CKD. Haemodialysis was the most common first modality of RRT. Mortality rate was 4.5%, mainly due to cardiovascular and infectious complications. Conclusions. Epidemiology of paediatric CKD in Serbia is similar to that reported from developed European countries. The knowledge of the epidemiology of earlier stages of CKD is essential for both institution of renoprotective therapy and planning of RRT, a fact of paramount importance in countries with limited resources.

Introduction. Infantile nephropathic cystinosis (INC) is a metabolic disorder due to impaired carrier-mediated transport of cystine out of cellular lysosomes. Objective. To examine the prevalence and clinical characteristics of INC in paediatric patients with end- stage renal disease (ESRD) in Serbia and give a recent statement of the disease. Methods. ESRD database of the Centre for Paediatric Renal Replacement Therapy (RRT) in Serbia was used to identify all patients with INC who started RRT before age of 19 years during the period January 1980 - December 2008; their records concerning clinical characteristics, therapy and outcome were evaluated. Results. Only three of 298 paediatric patients with ESRD had INC. The first signs of the illness were recognised during infancy. Fancony syndrome was diagnosed in the second year, but the diagnosis of cystinosis was delayed at mean 6 years. ESRD occurred in the first decade of life. All patients under- went cadaver kidney transplantation. At the end of the study period all patients were alive. A 31-year-old female patient was on maintenance chemodialysis due to graft failure after functioning for 11 years. She was growth retarded, single, unemployed, with severe signs of renal dystrophy. Two male patients (14.3 and 14.7 years old) had normal graft function, normal education, and good quality of life, although they were also severe growth retarded. Conclusion. The prevalence of infantile nephropathic cystinosis is low in Serbia. The diagnosis of cystinosis was delayed in all patients, although they exhibited the typical course of the disease.

Assessment of the first febrile urinary tract infection (UTI) in children has been the subject of debate for many years. Diagnosis of acute pyelonephritis (APN) is usually based on clinical and biological data. The clinical usefulness of early Tc-99m DMSA scintigraphy remains controversial, although it may influence the type and duration of treatment. The aim of this study was to assess the role of initial cortical scintigraphy in the detection of early renal parenchymal damage in children highly suspected of having APN and to compare the scintigraphic findings with selected clinical/laboratory parameters and ultrasonography.A prospective study was conducted in 34 infants and young children (18 boys, 16 girls), aged 1.5-36 months (mean 9.8 ± 8.7 months), hospitalized with a first episode of clinically suspected APN. Within the first 5 days after admission, Tc-99m DMSA renal scintigraphy, ultrasonography (US), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC) and urine analyses were performed.DMSA scintigraphy showed changes consistent with APN in 27/34 (79%) patients, with a mean age of 10.9 months, including 12 males (44%) and 15 (56%) females. Out of 9 febrile children with negative urine culture and supportive evidence of UTI, scintigraphy showed parenchymal involvement in 8 children (24% in the whole group, 30% in scintigraphically documented APN). There were no statistically significant correlations between the frequency or size of the initial scintigraphic abnormalities and age, sex, body temperature, CRP levels or ESR. A CRP level of54 mg/L and a WBC of13,300/mm³ had sensitivities of 56 and 59% and specificities of 86 and 71%, respectively. US showed changes consistent with APN in 7/34 (21%) in the whole group and in 7/27 (26%) patients with positive cortical scan (p0.05).Initial DMSA renal scintigraphy is a sensitive method for the early diagnosis of APN in young children and is useful in the assessment of the severity of kidney injury even in patients with negative urine culture. Clinical, biological and ultrasound parameters do not identify children with renal damage. Normal DMSA study, excluding parenchymal involvement and late sequelae, could minimize the use of scintigraphy in the follow-up and reduce the redundancy of cystography.

Schimke immunoosseous dysplasia (SIOD) is an autosomal recessive multisystem disorder characterized by prominent spondyloepiphyseal dysplasia, T cell deficiency, and focal segmental glomerulosclerosis. Biallelic mutations in swi/snf-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1 (SMARCAL1) are the only identified cause of SIOD, but approximately half of patients referred for molecular studies do not have detectable mutations in SMARCAL1. We hypothesized that skeletal features distinguish between those with or without SMARCAL1 mutations. Therefore, we analyzed the skeletal radiographs of 22 patients with and 11 without detectable SMARCAL1 mutations. We found that patients with SMARCAL1 mutations have a spondyloepiphyseal dysplasia (SED) essentially limited to the spine, pelvis, capital femoral epiphyses, and possibly the sella turcica, whereas the hands and other long bones are basically normal. Additionally, we found that several of the adolescent and young adult patients developed osteoporosis and coxarthrosis. Of the 11 patients without detectable SMARCAL1 mutations, seven had a SED indistinguishable from patients with SMARCAL1 mutations. We conclude therefore that SED is a feature of patients with SMARCAL1 mutations and that skeletal features do not distinguish who of those with SED have SMARCAL1 mutations. Electronic supplementary material The online version of this article (doi:10.1007/s00431-009-1115-9) contains supplementary material, which is available to authorized users.

Type 1 diabetes mellitus (T1DM) commonly occurs in childhood or adolescence, although the rising prevalence of type 2 diabetes mellitus (T2DM) in these age groups is now being seen worldwide. Diabetic nephropathy (DN) develops in 15-20% of subjects with T1DM and in similar or higher percentage of T2DM patients, causing increased morbidity and premature mortality. Although overt DN or kidney failure caused by either type of diabetes are very uncommon during childhood or adolescence, diabetic kidney disease in susceptible patients almost certainly begins soon after disease onset and may accelerate during adolescence, leading to microalbuminuria or incipient DN. Therefore, all diabetics warrant ongoing assessment of kidney function and screening for the earliest manifestations of renal injury. Pediatric health care professionals ought to understand about risk factors, strategy for prevention, method for screening, and treatment of early DN. This review considers each form of diabetes separately, including natural history, risk factors for development, screening for early manifestations, and strategy recommended for prevention and treatment of DN in children and adolescents.

INTRODUCTION. Two types of hereditary nephritis, nonprogressive and progressive, clinically present as asymptomatic haematuria, sometimes combined with proteinuria. At the onset, in both types, light microscopic changes are minimal, immunofluorescence findings are negative, and diagnosis can be made only upon electron microscopic findings that are considered to be specific. OBJECTIVE. The aim of this study was to determine the significance of Goodpasture antigen detection in diagnosis of progressive and nonprogressive hereditary nephritis in its early phase. METHOD. Analysis of renal biopsy specimens was done in patients with hereditary nephritis that were followed from 1990 to 2005. Progression of renal disease was examined in 14 patients with Alport’s syndrome, 10 patients with thin basement membrane disease, and 6 patients with unclassified hereditary nephritis diagnosed. For all these cases, indirect immunofluorescence study with serum from a patient with high titer of Goodpasture autoantibodies that recognize the antigenic determinants in human glomerular and tubular basement membrane was performed. RESULTS. In 11 out of 14 cases diagnosed as Alport’s syndrome, there was negative staining with Goodpasture serum, and in 3 additional cases with Alport’s syndrome, expression of Goodpasture antigen in glomerular basement membrane and thin basement membrane was highly reduced. In all 10 patients with thin basement membrane disease, immunofluorescence showed intensive, bright linear staining with Goodpasture serum along glomerular and tubular basement membrane. In 2 out of 6 patients with unclassified hereditary nephritis, Goodpasture antigen expression was very strong, in one patient it was very reduced, and in 3 patients it was negative. CONCLUSION. The results of our study show that Goodpasture antigen detection plays a very important role in differential diagnosis of progressive and nonpregressive hereditary nephritis, particularly in early phases of the disease.

Podocytes, the visceral glomerular epithelial cells, are the postmythotic cells that line the outer aspects of the glomerular basement membrane. A number of advances have been made in recent years, linked to the discovery of singlegene defects in hereditary glomerular disease, which highlight the role of these cells in preventing proteinuria. Despite the rarity of hereditary proteinuric syndromes, genetic, biochemical, and structural studies of these diseases have made important contributions to our knowledge of how the normal glomerular filter works and the mechanism of proteinuria. The course of these diseases can vary; some patients present with severe proteinuria and congenital nephrotic syndrome, whereas others have only moderate proteinuria and focal segmental glomerulosclerosis. Regardless of its cause, the disease often progresses to end-stage renal disease. There can be overlap between the diseases: mutations in the same gene can lead to different renal phenotypes. It is important to know that some hereditary podocytopathies respond to therapy, whereas majority does not. For this reason, genetic testing, which is available for some hereditary podocytopathies should be performed whenever possible. This review summarizes recent progress in the eludication of genetic causes of disease and discusses their implication for the understanding of the pathogenic mechanisms which can lead to disruption of the glomerular filtration barrier.

INTRODUCTION. Congenital nephrotic syndrome is usually presented with heavy proteinuria, hypoproteinaemia, oedema and hyperlipidaemia in a child from its birth until the age of 3 months. Aetiology of the disease is mutation in the relevant gene or it develops secondary to various infections. The most common form of congenital nephrotic syndrome is caused by mutation in gene for nephrin, the most important protein of the slit diaphragm. CASE OUTLINE. We present the patient with the clinical and laboratory signs of nephrotic syndrome expressed in the first day of life. Despite the adequate and regular substitution, antiproteinuric and antithrombotic therapy, complications occurred and the patient deceased. Genetic analysis revealed homozygous mutation in gene for nephrin (614del8ins2TT). Three years later, in the patient’s mother who was in the 12th week of pregnancy at that time, biopsy of chorionic villi was performed and the foetal genetic material showed heterozygosity for the same recessive mutation which meant that the foetus had the status of a carrier. To the best of our knowledge, this is the first family in Serbia in which prenatal molecular - genetic testing for the congenital nephrotic syndrome was accomplished. CONCLUSION. We wish to stress the importance of molecular diagnosis in patients with congenital nephrotic syndrome in order to perform early prenatal diagnosis in future pregnancies.

INTRODUCTION. Dent disease is X-linked recessive proximal tubulopathy, due to mutations in the CLCN5 gene. It is characterized by low molecular weight proteinuria, hypercalciuria, nephrocalcinosis and progressive renal failure. CASE OUTLINE. A seven-year-old boy was referred after endocrinological examination where abdominal ultrasound showed nephrocalcinosis. There were anamnestic data neither of oedema, macrohaematuria, nor polyuria or hypertension. There were also no data of chronic renal failure in the family. We determined: proteinuria (1.8 g/day), elevated urinary excretion of Beta 2 microglobulin, microscopic haematuria, hypercalciuria (8-10 mg/kg/day), nephrocalcinosis, decreased tubular reabsorption phosphate (65%). Values of growth hormone, parathormone on thyroid hormone were normal. Except hypercalciuria, which was registered in the patient?s mother, all other analyses performed in family members were betwen reference values. Diagnosis was finalized by mutation analysis, which showed S244L substitution on CNCL5. Mutation carrier was mother with normal phenotype. CONCLUSION. Dent disease is rare X-linked nephrocalcinosis. Definitive diagnosis of this proximal tubulopathy which leads to progressive renal damage is not possible without evidence of gene mutation in renal chlorine channel.

Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive disorder caused by mutations in SMARCAL1. A frequent complication is arteriosclerosis associated with reduced elastin expression; however, the mechanism underlying the reduced elastin expression remains unknown.Expression of transcriptional regulators of elastin (ELN) and microRNA (miRNA) regulators of ELN messenger RNA (mRNA), ELN promoter methylation, and ELN mRNA poly(A) tail length were assessed by quantitative RT-PCR, bisulfite Sanger sequencing, and the Poly(A) Tail Length Assay Kit, respectively, in unaffected developing human aortae and in an SIOD aorta.Comparing unaffected fetal and adult aortae, ELN precursor mRNA (pre-mRNA) levels remained nearly constant, whereas mRNA levels declined by ~10(2)-fold. This corresponded with a reduction in poly(A) tail length but not with changes in the other parameters. In contrast, compared to the unaffected fetal aortae, the SIOD aorta had 18-fold less ELN pre-mRNA and 10(4)-fold less mRNA. This corresponded with increased expression of miRNA regulators and shorter ELN mRNA poly(A) tail lengths but not with altered expression of ELN transcriptional regulators or ELN promoter methylation.Posttranscriptional mechanisms account for the reduction in ELN mRNA levels in unaffected aortae, whereas transcriptional and posttranscriptional mechanisms reduce elastin expression in SIOD aorta and predispose to arteriosclerosis.

IgA nephropathy is glomerular disease caracterized by the presence morphologic changes as wella as the prognosis is in correlation with of IgA dominant or codominant imunoglobuline deposits in glomer-the amount of proteinuria. The prognosis is better in children. ular mesangium which can be demostrated by immunofluorescence. Clinical manifestations of IgA nephropathy in the majority of cases is hematuria which can be macro or mikroskopic, isolated or combined with proteinuria, which can be of nephrotic range. The prognosis o the disease is better if presented with haematuria. Intensity of????.

The authors present the case of a girl with Frasier syndrome that was diagnosed at the age of 4 years. At 3.5 years, she was diagnosed a steroid-resistant nephrotic syndrome associated with focal segmental glomerulosclerosis. The girl presented with female phenotype and male genotype (46XY) as well with gonadal dysgenesis. Genetic analysis confirmed the +2T>C mutation in the intron 9 of the WT1 gene. She developed end-stage renal disease at 14 years, culminating in renal transplantation. The liver biopsy revealed a post-transplantation lymph-proliferative disease.

Introduction. Infants with cystic fibrosis may fail to thrive despite recommended caloric intake because of electrolyte disurbances caused by salt depletion resulting in hypochloremic metabolic alkalosis or pseudo-Bartter's syndrome. In most patients reported symptoms began in infancy, but it may be an initial presentation of disease in a previously healthy adolescent. Case report. A 15-year-old boy was admitted for evaluation of recurrent episodes of malaise associated with dehydration and acute renal insufficiency. Laboratory analysis showed hypochloremic metabolic alkalosis with hyponatremia and hypokalemia. On admission the boy was obese, with body weight of 95.5 kg (> P97), height 174 cm (> P75), and body mass index of 31.2 kg/m2 (> P95). Physical examination was inconclusive. Blood pressure holter monitoring proved significant systolic hypertension. Routine urinalysis, protein and electrolyte levels in urine were normal. Plasma renin and aldosteron were normal. Sweat chloride concentration was 63 mmol/L. Genetic testing confirmed the diagnosis of cystic fibrosis. Conclusion. To our knowledge, this is the first reported case of atypical presentation of cystic fibrosis in an adolescent presented with pseudo-Bartter's syndrome and signs of obesity and hypertension. We suggest that every patient with hypochloremic metabolic alkalosis should be evaluated for cystic fibrosis.

Schimke immuno-osseous dysplasia (SIOD, MIM 242900) is an autosomal-recessive pleiotropic disorder with the diagnostic features of spondyloepiphyseal dysplasia, renal dysfunction and T-cell immunodeficiency. Using genome-wide linkage mapping and a positional candidate approach, we determined that mutations in SMARCAL1 (SWI/SNF2-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), are responsible for SIOD. Through analysis of data from persons with SIOD in 26 unrelated families, we observed that affected individuals from 13 of 23 families with severe disease had two alleles with nonsense, frameshift or splicing mutations, whereas affected individuals from 3 of 3 families with milder disease had a missense mutation on each allele. These observations indicate that some missense mutations allow retention of partial SMARCAL1 function and thus cause milder disease.

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated with steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented also hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementemia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient haematological improvement occurred. Relapse subsequently occurred that was manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease but haematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, two years after the onset of MDS. Patient 2, who had refractory anemia with clonal monosomy 19, manifested bowel disease, hepatospleno- megaly, anaemia and non-organic specific autoantibodies. Prednisone led to both clinical and haematological remission. Haematologic disease relapsed 12 months later, when nephrotic-range proteinuria, haematuria and mild azotaemia were also found. Corticosteroid treatment led to long-lasting renal and haematologic remission, maintained by a small dosage of prednisone. In both patients renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with either acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis and AL amyloidosis, were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS; (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.

WT1 mutations cause a wide spectrum of renal and extrarenal manifestations. Here we evaluated disease prevalence, phenotype spectrum, and genotype–phenotype correlations of 61 patients with WT1 -related steroid-resistant nephrotic syndrome relative to 700 WT1 -negative patients, all with steroid-resistant nephrotic syndrome. WT1 patients more frequently presented with chronic kidney disease and hypertension at diagnosis and exhibited more rapid disease progression. Focal segmental glomerulosclerosis was equally prevalent in both cohorts, but diffuse mesangial sclerosis was largely specific for WT1 disease and was present in 34% of cases. Sex reversal and/or urogenital abnormalities (52%), Wilms tumor (38%), and gonadoblastoma (5%) were almost exclusive to WT1 disease. Missense substitutions affecting DNA-binding residues were associated with diffuse mesangial sclerosis (74%), early steroid-resistant nephrotic syndrome onset, and rapid progression to ESRD. Truncating mutations conferred the highest Wilms tumor risk (78%) but typically late-onset steroid-resistant nephrotic syndrome. Intronic (KTS) mutations were most likely to present as isolated steroid-resistant nephrotic syndrome (37%) with a median onset at an age of 4.5 years, focal segmental glomerulosclerosis on biopsy, and slow progression (median ESRD age 13.6 years). Thus, there is a wide range of expressivity, solid genotype–phenotype associations, and a high risk and significance of extrarenal complications in WT1 -associated nephropathy. We suggest that all children with steroid-resistant nephrotic syndrome undergo WT1 gene screening.

Several reports have documented various forms of glomerular diseases in adults with myelodysplastic syndromes (MDS), but similar reports in children are lacking. We describe two children with MDS-associated steroid-responsive nephrotic syndrome (NS). Patient 1, who had MDS with myelofibrosis, presented with hepatosplenomegaly, pancytopenia, chronic hepatitis, moderate proteinuria, hypocomplementemia and elevated ANA titer. During initial prednisone treatment proteinuria markedly diminished and partial but transient hematological improvement occurred. Relapse subsequently occurred that manifested by overt NS and pancytopenia. High doses of prednisolone led to remission of the renal disease, but hematological remission did not occur. Persisting pancytopenia and repeated infections terminated in sepsis, 2 years after the onset of the MDS. Patient 2, who had refractory anemia with clonal monosomy 19, presented with bowel disease, hepatosplenomegaly, anemia and non-organ-specific autoantibodies. Prednisone led to both clinical and hematological remission. The hematologic disease relapsed 12 months later, when nephrotic-range proteinuria, hematuria and mild azotemia were also found. Corticosteroid treatment led to long-lasting renal and hematologic remission, maintained by a small dosage of prednisone. In both patients, renal biopsy findings were consistent with those seen in idiopathic NS. A Medline search disclosed 16 cases of glomerulopathy in the course of MDS in adult patients. Clinical features included NS, usually accompanied by renal insufficiency with acute, chronic, or rapidly progressive glomerulonephritis. On biopsy, membranous nephropathy, crescentic or mesangial proliferative glomerulonephritis, and AL amyloidosis were found. We conclude: (1) that glomerular disease may be present and should be searched for in patients with MDS and (2) that MDS can be added to the list of rare conditions associated with corticosteroid-responsive NS in children.

A high prevalence of chronic kidney disease among children with focal segmental glomerulosclerosis (FSGS) leads to a permanent quest for good predictors of kidney dysfunction. Thus, we carried out a retrospective cohort study in order to examine known clinical and morphological predictors of adverse outcome, as well as to investigate glomerular nestin expression as a potential new early predictor of kidney dysfunction in children with FSGS. Relationships between nestin expression and clinical and morphological findings were also investigated. Among 649 renal biopsy samples, obtained from two children’s hospitals, FSGS was diagnosed in 60 children. Thirty-eight patients, who met the criteria for this study, were followed up for 9.0 ± 5.2 years. Using Kaplan–Meier and Cox’s regression analysis, potential clinical and morphological predictors were applied in two models of prediction: after disease onset and after the biopsy. The present study revealed the following significant predictors of kidney dysfunction: patients’ ages at disease onset, as well as age at biopsy, resistance to corticosteroid treatment, serum creatinine level, urine protein/creatinine ratio, vascular involvement, tubular atrophy, interstitial fibrosis, and decreased glomerular nestin expression. The most important finding of our study is that nestin can be used as a potential new early morphological predictor of kidney dysfunction in childhood onset of FSGS, since nestin has been obviously decreased in both sclerotic and normal glomeruli seen by light microscopy.

Schimke immuno-osseous dysplasia (SIOD) is a rare autosomal recessive spondylo-epiphyseal dysplasia. The characteristic features of SIOD include 1) short stature with hyperpigmented macules and an unusual facies, 2) proteinuria with progressive renal failure, 3) lymphopenia with recurrent infections, and 4) cerebral ischaemia. Although 25 patients have been reported with this disorder, the clinical course and phenotype of SIOD are not well characterized. This report summarizes the clinical findings, course and treatment of reported patients and includes 14 additional patients with SIOD. We emphasize the high incidence of cerebral ischaemia and ocular abnormalities, define the high incidence of thyroid dysfunction and blood cytopenia, and confirm the absence of effective and durable medical therapies.Schimke immuno-osseous dysplasia is a multi-system autosomal recessive disorder with variable expression that affects the skeletal, renal, immune, vascular, and haematopoietic systems. Medical therapy is limited especially for more severely affected individuals.

A 23-year old male patient had eight distinct episodes of hemolytic uremic syndrome (HUS) between 8.5 and 15 years of age, five of them accompanied by hypocomplementemia. In the further course, severe hypertension, renal insufficiency as well as protein-losing enteropathy due to intestinal lymphangiectasia developed, whilst hypocomplementemia persisted. The association of recurrent HUS with hypocomplementemia and intestinal lymphangiectasia may represent a new association within a subgroup of the atypical HUS.

WOS: 000321044400026, PubMed ID: 23515051, Genetic screening paradigms for congenital and infantile nephrotic syndrome are well established; however, screening in adolescents has received only minor attention. To help rectify this, we analyzed an unselected adolescent cohort of the international PodoNet registry to develop a rational screening approach based on 227 patients with nonsyndromic steroid-resistant nephrotic syndrome aged 10-20 years. Of these, 21% had a positive family history. Autosomal dominant cases were screened for WT1, TRPC6, ACTN4, and INF2 mutations. All other patients had the NPHS2 gene screened, and WT1 was tested in sporadic cases. In addition, 40 sporadic cases had the entire coding region of INF2 tested. Of the autosomal recessive and the sporadic cases, 13 and 6%, respectively, were found to have podocin-associated nephrotic syndrome, and 56% of them were compound heterozygous for the nonneutral p.R229Q polymorphism. Four percent of the sporadic and 10% of the autosomal dominant cases had a mutation in WT1. Pathogenic INF2 mutations were found in 20% of the dominant but none of the sporadic cases. In a large cohort of adolescents including both familial and sporadic disease, NPHS2 mutations explained about 7% and WT1 4% of cases, whereas INF2 proved relevant only in autosomal dominant familial disease. Thus, screening of the entire coding sequence of NPHS2 and exons 8-9 of WT1 appears to be the most rational and cost-effective screening approach in sporadic juvenile steroid-resistant nephrotic syndrome., E-Rare (PodoNet project); EUEuropean Union (EU) [305608]; Polish Ministry of Science and EducationMinistry of Science and Higher Education, Poland [N402631840]; German Research FoundationGerman Research Foundation (DFG) [Scha 477/11-1]; Chilean FondecytComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [11090045]; DAAD scholarshipDeutscher Akademischer Austausch Dienst (DAAD); Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [108S417]; Hacettepe UniversityHacettepe University [06A101008], This work was financed by E-Rare (PodoNet project), the EU 7th Framework Programme (EURenOmics, grant 305608), the Polish Ministry of Science and Education grant N402631840, the German Research Foundation (Scha 477/11-1), and Chilean Fondecyt grant 11090045 (to MA). BSL was granted a DAAD scholarship. FO was supported by the Scientific and Technological Research Council of Turkey (grant 108S417) and by the Hacettepe University Infrastructure Project (grant 06A101008). We are grateful to Dr S Zietkiewicz from the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology at the University of Gdansk, Poland, for help with the in silico analyses.

Granulomatosis with polyangiitis (GPA), also known as Wegener's granulomatosis, is a rare disease in childhood. Of 39 GPA patients that we diagnosed during a 20-year period, only 3 (7.7%) were younger than 18 years. We report the course of GPA in three girls whose disease started at the ages of 16, 11, and 6 years. All had cutaneous manifestations: the first had necrotizing vasculitis, the second had palpable purpura, and the third had right upper-eyelid edema and infiltration and proptosis caused by extraocular pseudotumor, initially histologically misdiagnosed as orbital immunoglobulin G4 (IgG4)-related disease. Unlike with skin vasculitis and glomerulonephritis, upper-airway and orbital inflammation were resistant to immunosuppressive therapy. Our report emphasizes that children presenting with cutaneous vasculitis, chronic eyelid swelling, sinusitis, or hoarseness should be tested for antineutrophil cytoplasmic antibodies. We emphasize that the upper-eyelid edema and infiltration, with histologic characteristics of orbital IgG4-related disease, may be the initial presentation of localized GPA in children, a feature that, until now, has been described only in adults.

Background Arteriosclerosis and emphysema develop in individuals with Schimke immuno-osseous dysplasia (SIOD), a multisystem disorder caused by biallelic mutations in SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1). However, the mechanism by which the vascular and pulmonary disease arises in SIOD remains unknown. Methods We reviewed the records of 65 patients with SMARCAL1 mutations. Molecular and immunohistochemical analyses were conducted on autopsy tissue from 4 SIOD patients. Results Thirty-two of 63 patients had signs of arteriosclerosis and 3 of 51 had signs of emphysema. The arteriosclerosis was characterized by intimal and medial hyperplasia, smooth muscle cell hyperplasia and fragmented and disorganized elastin fibers, and the pulmonary disease was characterized by panlobular enlargement of air spaces. Consistent with a cell autonomous disorder, SMARCAL1 was expressed in arterial and lung tissue, and both the aorta and lung of SIOD patients had reduced expression of elastin and alterations in the expression of regulators of elastin gene expression. Conclusions This first comprehensive study of the vascular and pulmonary complications of SIOD shows that these commonly cause morbidity and mortality and might arise from impaired elastogenesis. Additionally, the effect of SMARCAL1 deficiency on elastin expression provides a model for understanding other features of SIOD.

Described for the first time in 1971, Schimke immuno-osseous dysplasia (SIOD) is an autosomal-recessive multisystem disorder that is caused by bi-allelic mutations of SMARCAL1, which encodes a DNA annealing helicase. To define better the dental anomalies of SIOD, we reviewed the records from SIOD patients with identified bi-allelic SMARCAL1 mutations, and we found that 66.0% had microdontia, hypodontia, or malformed deciduous and permanent molars. Immunohistochemical analyses showed expression of SMARCAL1 in all developing teeth, raising the possibility that the malformations are cell-autonomous consequences of SMARCAL1 deficiency. We also found that stimulation of cultured skin fibroblasts from SIOD patients with the tooth morphogens WNT3A, BMP4, and TGFβ1 identified altered transcriptional responses, raising the hypothesis that the dental malformations arise in part from altered responses to developmental morphogens. To the best of our knowledge, this is the first systematic study of the dental anomalies associated with SIOD. © 2012, International & American Associations for Dental Research. All rights reserved.

The association of a spondyloepiphyseal dysplasia and disproportionate short stature with focal glomerular sclerosis is reported in two girls. Renal disease manifested by proteinuria at the age of 2.5 and 11 years, leading to treatment-resistant nephrotic syndrome over 15 and 45 months, respectively. One patient went into end-stage renal failure shortly after nephrotic syndrome developed, the other died from sepsis. The association of spondyloepiphyseal dysplasia and focal glomerular sclerosis with nephrotic syndrome may represent a distinct disease entity.