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Mutations in the NPHS2 gene, which encodes the podocyte slit diaphragm protein podocin, cause autosomal recessive steroid-resistant nephrotic syndrome (Online Mendelian Inheritance in Man [OMIM] #600995). Basic research and clinical studies have provided important insights about genotype-phenotype correlations. This knowledge allows personalized genetic (risk) counseling and should lead to changes in the advice given to patients. A patient who carries the R229Q variant (which has a high allele frequency of 3.7% in the European population) in combination with a pathogenic variant in exon 7 or 8 is at high risk for developing nephrotic syndrome that may not manifest before adulthood, whereas a patient with 2 pathogenic variants will develop congenital or childhood-onset nephrotic syndrome. In contrast, a patient who carries the R229Q variant in combination with a pathogenic variant in exons 1 to 6 is unlikely to develop nephrotic syndrome. In this article, we review the emerging knowledge about the NPHS2 gene and translate these findings from the bench to practical advice for the clinical bedside., (Copyright © 2018 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Background: The development of complement inhibitors has greatly improved the outcome of patients with atypical hemolytic uremic syndrome (aHUS), making kidney transplantation a more feasible option. Although prophylactic eculizumab therapy may prevent recurrent disease after transplantation, its necessity for all transplant recipients is debated., Study Design: A case series., Setting & Participants: Patients with aHUS who underwent living donor kidney transplantation after 2011 at 2 university centers, prospectively followed up with a protocol of eculizumab therapy limited to only recipients with documented posttransplantation recurrent thrombotic microangiopathy. In addition, the protocol emphasized lower target level tacrolimus and aggressive treatment of high blood pressure., Outcomes: Recurrence of aHUS, kidney function, acute kidney injury., Results: We describe 12 female and 5 male patients with a mean age of 47 years. 5 patients had lost a previous transplant due to aHUS recurrence. 16 patients carried a pathogenic or likely pathogenic variant in genes encoding complement factor H, C3, or membrane cofactor protein, giving a high risk for aHUS recurrence. Median follow-up after transplantation was 25 (range, 7-68) months. One patient had aHUS recurrence 68 days after transplantation, which was successfully treated with eculizumab. 3 patients were treated for rejection and 2 patients developed BK nephropathy. At the end of follow-up, median serum creatinine concentration was 106 (range, 67-175) μmol/L and proteinuria was negligible., Limitations: Small series and short duration of follow-up., Conclusions: Living donor kidney transplantation in aHUS without prophylactic eculizumab treatment appears feasible., (Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)