Safety and Efficacy of Rituximab in Children with Steroid-Dependent or Resistant Nephrotic Syndrome

Backgroundand Aim:Rituximab is a novel therapy that can help patients with steroid-dependent or resistant nephrotic syndrome.The aim of this study was to evaluate the efficacy of rituximab in children with corticosteroid-dependent and resistant nephrotic syndrome and to determine the factors associated with its efficacy. Methods:In this study, 40 children with corticosteroid-dependent or resistant nephrotic syndrome who were treated with rituximab in Dr. Sheikh Hospital,Mashhad,between 2014 and 2018 were enrolled. Patients with a history of hematuria, severe urinary tract infection, or secondary nephrotic syndrome were excluded. Results:The mean age of patients was 11.9 ± 5.04 years, and 55% were female. The most common underlying pathology of nephrotic syndrome was focal segmental glomerulonephritis (FSGS) (42.5%) followed by membranoproliferative glomerulonephritis (MPGN) and minimal change disease (MCD). Most of the participants (62.5%) were steroid-dependent and the rest (27.5%) were steroid resistant. Only 10% of the patients showed complications following rituximab administration and 57.5% went into complete remission. A negative family history and steroid-dependent nephrotic syndrome were significantly associated with a better treatment response. Moreover, patients with steroid-resistant nephrotic syndrome were more likely to have a positive family history, while factors associated with steroid response included underlying pathology, gender, and family history. Conclusion: Rituximab can cause remission in more than half of the patients with steroid-resistant or dependent nephrotic syndrome. Moreover, the only factors that reduce response to rituximab are a history of corticosteroid resistance and a positive family history of nephrotic syndrome

Mutations in NSUN2 Cause Autosomal- Recessive Intellectual Disability

With a prevalence between 1 and 3%, hereditary forms of intellectual disability (ID) are among the most important problems in health care. Particularly, autosomal-recessive forms of the disorder have a very heterogeneous molecular basis, and genes with an increased number of disease-causing mutations are not common. Here, we report on three different mutations (two nonsense mutations, c.679C>T [p.Gln227∗] and c.1114C>T [p.Gln372∗], as well as one splicing mutation, g.6622224A>C [p.Ile179Argfs∗192]) that cause a loss of the tRNA-methyltransferase-encoding NSUN2 main transcript in homozygotes. We identified the mutations by sequencing exons and exon-intron boundaries within the genomic region where the linkage intervals of three independent consanguineous families of Iranian and Kurdish origin overlapped with the previously described MRT5 locus. In order to gain further evidence concerning the effect of a loss of NSUN2 on memory and learning, we constructed a Drosophila model by deleting the NSUN2 ortholog, CG6133, and investigated the mutants by using molecular and behavioral approaches. When the Drosophila melanogaster NSUN2 ortholog was deleted, severe short-term-memory (STM) deficits were observed; STM could be rescued by re-expression of the wild-type protein in the nervous system. The humans homozygous for NSUN2 mutations showed an overlapping phenotype consisting of moderate to severe ID and facial dysmorphism (which includes a long face, characteristic eyebrows, a long nose, and a small chin), suggesting that mutations in this gene might even induce a syndromic form of ID. Moreover, our observations from the Drosophila model point toward an evolutionarily conserved role of RNA methylation in normal cognitive development

BOD1 Is Required for Cognitive Function in Humans and <i>Drosophila</i>

Here we report a stop-mutation in the BOD1 (Biorientation Defective 1) gene, which co-segregates with intellectual disability in a large consanguineous family, where individuals that are homozygous for the mutation have no detectable BOD1 mRNA or protein. The BOD1 protein is required for proper chromosome segregation, regulating phosphorylation of PLK1 substrates by modulating Protein Phosphatase 2A (PP2A) activity during mitosis. We report that fibroblast cell lines derived from homozygous BOD1 mutation carriers show aberrant localisation of the cell cycle kinase PLK1 and its phosphatase PP2A at mitotic kinetochores. However, in contrast to the mitotic arrest observed in BOD1-siRNA treated HeLa cells, patient-derived cells progressed through mitosis with no apparent segregation defects but at an accelerated rate compared to controls. The relatively normal cell cycle progression observed in cultured cells is in line with the absence of gross structural brain abnormalities in the affected individuals. Moreover, we found that in normal adult brain tissues BOD1 expression is maintained at considerable levels, in contrast to PLK1 expression, and provide evidence for synaptic localization of Bod1 in murine neurons. These observations suggest that BOD1 plays a cell cycle-independent role in the nervous system. To address this possibility, we established two Drosophila models, where neuron-specific knockdown of BOD1 caused pronounced learning deficits and significant abnormalities in synapse morphology. Together our results reveal novel postmitotic functions of BOD1 as well as pathogenic mechanisms that strongly support a causative role of BOD1 deficiency in the aetiology of intellectual disability. Moreover, by demonstrating its requirement for cognitive function in humans and Drosophila we provide evidence for a conserved role of BOD1 in the development and maintenance of cognitive features

Identifizierung und funktionelle Charakterisierung eines Gendefekts im Kinetochor Protein BOD1, welches mit autosomal rezessiver mentaler Retardierung und Oligomenorrhö assoziiert ist

In the course of systematic clinical and molecular studies to identify intellectual disability (ID) causing defects that follow an autosomal recessive mode of inheritance (ARID), we found a single 4.3 Mbp interval on chromosome 5q with a LOD score of 4.41 by autozygosity mapping in a family with four females affected by mild to moderate ID and oligomenorrhea. By sequencing the coding regions of all 28 genes within this region we discovered a nonsense mutation in exon 2 of the BOD1 gene. This defect co-segregated with the disease and was not found in 720 Iranian and German control chromosomes. All other genes within the interval were not affected by nucleotide changes. BOD1 is expressed in a wide range of tissues, including brain and ovary. By RT-PCR, we identified two previously unknown isoforms of BOD1 in control lymphoblast and fibroblast cells and showed expression of all four transcripts in a variety of brain tissues. qRT-PCR revealed loss of all BOD1 isoforms in patient fibroblasts, including splice variants that did not contain exon 2. For all transcripts except one, this seems to be due to nonsense mediated decay, as defect of this mRNA could be abrogated by cycloheximide treatment of the cells. Absence of BOD1 protein in cells of the patients was confirmed by Western blotting experiments. BOD1 is required for proper chromosome segregation and correction of synthelic chromosomes during mitosis (Porter et al. 2007). Fibroblasts from two different patients showed several abnormalities in cell division (chromosomal bi-orientation, mitotic index, mitotic timings, increased levels of Plk1 activity, etc.) which are all in line with the findings in the BOD1 depleted HeLa cells (Porter et al. 2007; Porter et al. unpublished) and may also provide an explanation for the oligomenorrhea observed in this family. In patient fibroblasts, confocal indirect immunoflorescence imaging revealed nuclear structural defects. Subsequent overexpression experiments using BOD1 cDNA in HaCat cells were performed to further investigate the cell biology of this protein in non- dividing cells and provided preliminary evidence for an involvement of BOD1 in nuclear and chromatin organization. This indicated a putative role in the regulation of gene expression and whole genome expression profiling in patient lymphoblast cells showed deregulation of target genes that are critical for human cognition. Moreover, in patient cells the formation of primary cilia was found to be defective. Cilia defects have been observed previously in several other disorders involving ID. Finally, overexpression experiments in murine primary neuronal cells showed co-localization of GFP-tagged BOD1 with presynaptic proteins, suggesting a putative function of BOD1 in neuronal synapses, which could be an explanation for the ID observed in our patients. In summary, our results provide evidence indicating that BOD1 plays critical roles in cell cycle progression, the formation of primary cilia, chromatin organization and the regulation of transcription. Furthermore our observations suggest that in humans, this protein is required for normal brain function, which may be related to the role of BOD1 in the regulation of PLK1 during brain development. However, further in depth functional investigations are needed to shed more light on the precise role of this protein during brain development and in fully differentiated neuronal tissues.Im Zuge unserer klinischen und molekularen Studien zur Identifizierung der genetischen Ursachen autosomal-rezessiver geistiger Behinderung, untersuchten wir eine iranische Familie mit vier Patientinnen, welche einen milden bis mittelschweren Grad geistiger Behinderung sowie Oligomenorrhoe aufweisen. Mittels Autozygosity Mapping wurde ein 4,3 Mbp Intervall auf Chromosom 5 identifiziert, welches 28 Gene beinhaltet. Die kodierenden Bereiche dieser Gene wurden sequenziert und als einzige Nukleotidänderung wurde eine Nonsense Mutation in Exon 2 des BOD1 Gens nachgewiesen. Diese Mutation co-seggregiert mit der Krankheit und wurde nicht in 720 iranischen und deutschen Kontroll- Chromosomen gefunden. BOD1 wird in einer Vielzahl von Geweben exprimiert, einschließlich des Gehirns sowie der Eierstöcke. Durch RT-PCR wurden zwei bislang unbekannte Isoformen BOD1s entdeckt, die ebenfalls im Gehirn exprimiert werden. qRT-PCR zeigte den Verlust aller Isoformen in Fibroblasten der Patientinnen. Für alle Isoformen bis auf eine ist hierfür vermutlich nonsense mediated decay verantwortlich, da in dieser mRNA der Defekt durch die Behandlung mit Cycloheximid aufgehoben wurde. Die Abwesenheit von BOD1 in den Zellen der Patientinnen wurde auch mittels Western Blot nachgewiesen. BOD1 wird für die korrekte Chromosomentrennung und die Korrektur der synthelischen Chromosomen während der Meiose benötigt (Porter et al. 2007). In Übereinstimmung mit bereits beschriebenen Anomalien, welche in HeLa Zellen ohne BOD1 auftreten (Porter et al. 2007; Porter et al. unveröffentlicht), wiesen Fibroblasten der Patientinnen mehrere Abnormitäten während der Zellteilung auf (chromosomale Biorientierung, mitotischer Index, zeitliche Koordinierung der Mitose, erhöhte Plk1 Aktivität, etc.), welche eine Erklärung für die Oligomenorrhoe der Patientinnen bieten. Die Untersuchung von Interphase Fibroblasten der Patientinnen mittels konfokaler indirekter Immunfloureszenz ergab, dass strukturelle Defekte des Zellkerns vorliegen. Überexpression von BOD1 in sich nicht teilenden HaCat Zellen zeigte eine Beteiligung von BOD1 an der Zellkern- und Chromatinorganisation, was eine putative Rolle BOD1s bei der Regulierung der Genexpression nahe legt. Whole Genome Expression Profiling in Lymphoblasten der Patientinnen zeigte eine Deregulation von Zielgenen, die entscheidend für die humane Kognition sind. Darüber hinaus ist die Formation der primären Zilien in den Zellen der Patientinnen fehlerhaft. Schäden an Zilien wurden in einer Vielzahl von Krankheiten die mit geistiger Behinderung einhergehen beobachtet. Letztendlich zeigten Überexpressionsstudien in murinen primären neuronalen Zellen Co- Lokalisation von GFP getaggten BOD1 mit Page: 168 präsynaptischen Proteinen, was auf eine putative Funktion von BOD1 in neuronalen Synapsen hinweist, deren Beeinträchtigung zu der in den Patientinnen beobachteten geistigen Behinderung führen könnten. Unsere Ergebnisse zeigen die kritische Beteiligung BOD1s am Zellzyklus, an der Formation primärer Zilien, der Chromatinorganisation sowie der Regulierung der Transkription. Des Weiteren weisen unsere Beobachtungen darauf hin, dass BOD1 für die normale Gehirnfunktion des Menschen notwendig ist, was im Zusammenhang mit der Rolle BOD1 als Regulator von PLK1 während der Gehirnentwicklung im Zusammenhang stehen kann. Weiterführende funktionelle Studien sind nötig um die genaue Funktion BOD1s während der Gehirnentwicklung und besonders im differenzierten neuronalen Gewebe aufzuklären

Epileptic Encephalopathies: New Genes and New Pathways

Epileptic encephalopathies represent a group of devastating epileptic disorders that occur early in life and are often characterized by pharmaco-resistant epilepsy, persistent severe electroencephalographic abnormalities, and cognitive dysfunction or decline. Next generation sequencing technologies have increased the speed of gene discovery tremendously. Whereas ion channel genes were long considered to be the only significant group of genes implicated in the genetic epilepsies, a growing number of non-ion-channel genes are now being identified. As a subgroup of the genetically mediated epilepsies, epileptic encephalopathies are complex and heterogeneous disorders, making diagnosis and treatment decisions difficult. Recent exome sequencing data suggest that mutations causing epileptic encephalopathies are often sporadic, typically resulting from de novo dominant mutations in a single autosomal gene, although inherited autosomal recessive and X-linked forms also exist. In this review we provide a summary of the key features of several early- and mid-childhood onset epileptic encephalopathies including Ohtahara syndrome, Dravet syndrome, Infantile spasms and Lennox Gastaut syndrome. We review the recent next generation sequencing findings that may impact treatment choices. We also describe the use of conventional and newer anti-epileptic and hormonal medications in the various syndromes based on their genetic profile. At a biological level, developments in cellular reprogramming and genome editing represent a new direction in modeling these pediatric epilepsies and could be used in the development of novel and repurposed therapies

The level of urinary endothelin in patients with urinary reflux

Background: In different tissues, the endothelin is produced by vascular endothelium. They are potent vasoconstrictor peptides. There is a little information about the role of endothelin in reflux nephropathy. Objectives: The aim of this study is to evaluate urinary levels of endothelin in patients with vesicoureteral reflux (VUR). Patients and Methods: It was a cross-sectional study that conducted on 81 children who received voiding cystourethrogram (VCUG). Based on VCUG reports, patients were divided into two groups; with reflux (40 persons) and without reflux (41 persons). We got a urine sample from patients with mid-stream or urine bag method. The endothelin level was assessed with ELISA immunoassay. Data was analyzed using SPSS 16. Results: Based on VCUG reports, 40 patients (49.4%) had urinary reflux, of them 20 cases suffered from unilateral urinary reflux and others from bilateral. Of 40 patients with reflux, 23 cases (57.5% of reflux group) had kidney scar and seven individuals (17.5%) had abnormal kidney sonography. Of patients with urinary reflux, 13 cases (32.5%) had grade1 urinary reflux, 8 cases (20%) grade 2, and 5 cases (12.5%) grade 3 and finally 14 cases (35%) grade 4. The UET-1 levels were significantly higher in VUR patients compared to the control group (P < 0.001). Comparison of mean endothelin levels between two groups was done using Mann-Whitney U test and was statistically significance (P < 0.001). We used Kruskal-Wallis for comparison of endothelin levels in different grades of reflux (P < 0.001). Conclusions: Urine endothelin-1 level can be considered as an alternative to VCUG for screening vesicourethral reflux

Clinical Effects of Methylphenidate Compared to Oxybutynin on Management of Giggle Incontinence

Background and Aim: Giggle incontinence, also known as “enuresis risoria”, is characterized by unexpected, involuntary, and complete bladder voiding in response to laughter. The cause is unknown; however, there are different assumptions based on several case studies. This research discusses the effectiveness of methylphenidate for giggle incontinence in children.Methods: Fifteen girls who met the giggle incontinence criteria were randomly divided to two groups: group A (n=8 girls) and group B (n=7 girls). The participants in group A took Oxybutynin chloride and the patients in group B received methylphenidate for one month. The response of the two groups to drugs was assessed.Results: Group A included 8 girls (mean age: 7.7 years) and group B comprised 7 girls (mean age: 8.4 years). Only one patient in group A showed complete response to Oxybutynin chloride. No wetting was reported by six patients in group B.Conclusion: Giggle incontinence is a rare form of incontinence. The pathophysiology is unfortunately unknown yet. Methylphenidate may be suggested for symptomatic relief compared to Oxybutynin chloride until the etiology of the disease is more clearly defined.Keywords: Giggle incontinence; Giggle micturition; Laughter incontinence; Enuresis