Genetic mutation in Egyptian children with steroid-resistant nephrotic syndrome

Mutational analysis of phospholipase C epsilon 1 gene in Egyptian children with steroid-resistant nephrotic syndrome

Background

Steroid-resistant nephrotic syndrome (SRNS) is characterized by unresponsiveness of nephrotic range proteinuria to standard steroid therapy, and is the main cause of childhood renal failure. The identification of more than 53 monogenic causes of SRNS has led researchers to focus on the genetic mutations related to the molecular mechanisms of the disease. Mutations in the PLCE1 gene, which encodes phospholipase C epsilon 1 (PLCε1), have been described in patients with early-onset SRNS characterized by progressive renal failure. In this study we screened for PLCE1 mutations in Egyptian children with SRNS. This is a descriptive case series study aiming to screen for PLCE1 gene mutations by direct sequencing of five exons—9, 12, 15, 19, 27—in 20 Egyptian children with SRNS who entered the Nephrology Unit, Faculty of Medicine, Ain-Shams University from November 2015 to December 2017. The variants detected were submitted to in silico analysis.

Results

We screened for mutations in five selected exons of PLCE1 gene. We identified seven variants in the five selected exons with homozygous and heterozygous inheritance pattern, two are intronic variants, two are silent variants, and three are missense variants. We identified four novel variants two are silent with no clinical significance and two are missense with uncertain clinical significance and pathogenic in-silico predictions; one p.Arg1230His in exon 12, the other is p.Glu1393Lys in exon 15.

Conclusions

We identified four novel mutations, findings which added to the registered SNP spectrum of the PLCE1 gene. These results widen the spectrum of PLCE1 gene mutations and support the importance of genetic testing in different populations of SRNS patients, therefore, to assess the vulnerability of Egyptian children to SRNS candidate genes, further studies needed on a larger number of cases which undoubtedly provide new insights into the pathogenic mechanisms of SRNS and might help in control of the patient. Additionally, the use of computational scoring and modeling tools may assist in the evaluation of the way in which the SNPs affect protein functionality.

Disease-Associated Systemic Complications in Childhood Nephrotic Syndrome: A Systematic Review

INTRODUCTION

Nephrotic syndrome (NS) is one of the most common childhood kidney diseases. During the active phase, the disease pathogenesis affects various biological functions linked to loss of proteins negatively, which can result in systemic complications. Complications of childhood NS are divided into two categories: disease-associated complications and drug-associated complications. However, complications in pediatric patients with NS, especially disease-associated complications are still limited. Although reported in the literature, information is not comprehensive and needs to be updated. This study aimed to systematically assess systemic complications in children with NS, especially disease-associated complications, to better understand how they impact outcomes.

METHODS

We conducted a systematic search of several databases: BioMed Central Pediatrics, PubMed, Google Scholar, the National Library of Medicine, Cochrane Library, CINAHL/EBSCO, British Medical Journal, Science Direct, Scopus, and Elsevier's ClinicalKey. We followed the PRISMA guidelines to plan, conduct, and report this review. We used the Joanna Briggs Institute's critical appraisal tools for assuring the quality of the journal articles that were chosen.

RESULTS

Eleven articles concerning complications in childhood NS were analyzed. Systemic disease-associated complications in covered were cardiovascular complications, infections, thyroid-hormone complication, kidney complications, and oral health complications.

CONCLUSION

NS is marked by heavy proteinuria, hypoalbuminemia, edema, and hyperlipidemia, which can result in systemic disease-associated complications. Cardiovascular complications, infections, thyroid-hormone complications, kidney complications, and oral health complications are the main systemic complications in childhood NS. It is essential that health-care providers prevent these complications for proper maintenance of patients' health.

Mir-142-5p as an indicator of autoimmune processes in childhood idiopathic nephrotic syndrome and as a part of MicroRNAs expression panels for its diagnosis and prediction of response to steroid treatment

BACKGROUND

Nephrotic syndrome (NS) is the most frequent glomerular disease among children. Renal biopsy is the most precise procedure for diagnosing and following childhood NS; however, it is an invasive procedure with potential complications. As a result, early non-invasive diagnostic and prognostic indicators and new treatment targets are urgently needed for this disease.

PURPOSE

To assess the miR-142-5p expression in peripheral blood as an indicator of the autoimmune processes in children with NS and the role of differential microRNAs (miR) expression and expression panels in diagnosing and predicting the response to steroid treatment in children with NS.

METHODS

Eighty (80) children with NS and 100 subjects matched for age and gender used as controls constitute the study sample in this case-control study. MiR-142-5p, miR-191, miR-181-5p, miR-30a-5p and miR-50a-5p expression are measured in all enrolled children by real-time PCR. We assessed the sensitivity and accuracy of different MicroRNAs panels.

RESULTS

miR-142-5p, miR-191, miR-181-5p, miR-30a-5p and miR-150a-5p expressions were significantly increased in the children with NS than controls. There was a significant difference in the five mRNAs differential expressions between steroid-resistant and steroid-sensitive children with NS. Of the selected five microRNAs, miR-142a-5p was the best to allow very good discrimination of the children with NS and predict steroid resistance (AUC = 0.965 and 1.00, respectively), suggesting the possible autoimmunity processes' role in the pathogenesis of NS and the resistance to steroids. The (miR-142a-5p with miR-181a-5p and miR-30a-5p) was the best expression panel to diagnose new NS cases and predict steroid resistance.

CONCLUSIONS

microRNAs expressions, either differential or as a panel, are important for early diagnosing childhood NS and may provide a non-invasive clue for the response to steroid treatment in these patients. The (miR-142a-5p, miR-181-5p, and miR-30a-5p) panel was the best one to cover both the diagnosis of the new cases and prediction of response to steroid treatment. Autoimmunity has an important role in NS pathogenesis and resistance to steroid treatment.