A Homozygous Variant in SRNS-1 mmc2.xlsx (14K) GUID:?8F743830-CF22-484B-8620-1EFF78031E14 Table S5. scaffold and is an essential protein in all eukaryotic cells. Here, we report on biallelic mutations in nine affected individuals who are from five unrelated families and show early-onset steroid-resistant nephrotic syndrome (SRNS). These individuals have pathologically focal segmental glomerulosclerosis, a condition that leads to end-stage renal disease with high frequency. is ubiquitously expressed, including in glomerular podocytes. Three of four mutations detected in the affected individuals hamper NUP107 binding to NUP133 (nucleoporin 133?kDa) and NUP107 incorporation into NPCs in?vitro. Zebrafish with knockdown generated by morpholino oligonucleotides displayed hypoplastic glomerulus structures Oxoadipic acid and abnormal podocyte foot processes, thereby mimicking the pathological changes seen in the kidneys of the SRNS individuals with mutations. Considering the unique properties of?the podocyte (highly differentiated foot-process architecture and slit membrane and the inability to regenerate), we propose a podocyte-injury model as the pathomechanism for SRNS due to biallelic mutations. Introduction Nephrotic syndrome (NS) is usually a renal disease caused by disruption of the glomerular filtration barrier, which results in massive proteinuria, hypoalbuminemia, and dyslipidemia. Idiopathic NS occurs in 16/100,000 children.1 Most children with idiopathic NS respond well to steroids, but 10%C20% of affected children are categorized as having steroid-resistant NS (SRNS).2C6 SRNS is a clinically and genetically heterogeneous renal disorder that might have an immunological, structural, or functional etiology.2,5,7C9 Higher rates of genetic delineation are expected in early-onset SRNS.7 Clinical differences in SRNS have been suggested to depend on its age of onset.7 Current medical management and prognosis in NS Oxoadipic acid are based largely around the histological diagnosis. Effective SRNS treatments are not well established, and renal transplantation is usually eventually required. Importantly, 63%C73% of those with childhood-onset SRNS show pathologically focal segmental glomerulosclerosis (FSGS),which carries a great risk of progression to end-stage renal disease (ESRD).1,6,8,10 To date, at least 27 genes are associated with SRNS, thereby expanding our knowledge of the pathomechanisms involved in SRNS and podocyte development and function.11 Although SRNS is the leading cause of ESRD in children worldwide, approximately 70% of those with childhood-onset SRNS are genetically uncharacterized.7,11 We describe here an additional genetic cause of early-onset SRNS and Oxoadipic acid propose its possible pathomechanism. Material Oxoadipic acid and Methods Human Subjects A total of 18 families (10 with affected siblings and 8 with a single affected individual) who lack any known genetic causes of SRNS (in 27 known genes) were recruited to this study. They presented with non-syndromic early-onset SRNS with onset ages between 1 and 11 years. The clinical aspects of 7 of the 18 families have been described previously.12 Affected individuals were resistant to standard steroid therapy but were partially responsive to immunosuppressive drugs. At least ten affected individuals in eight families underwent renal transplants and have had no recurrence of SRNS to date. All samples were collected after written informed consent was obtained. The study protocol was approved by the institutional review boards of Yokohama City University School of Medicine, Kansai Medical University, RIKEN, Tokyo Womens Hospital, and Kobe University. DNA Extraction Peripheral-blood leukocytes or saliva from affected individuals and their families was collected. Genomic DNA was extracted with a QIAamp DNA Blood Max Kit (QIAGEN) or Oragene DNA (DNA Genoteck) according to the instructions of each manufacturer. Whole-Exome Sequencing and Informatics Analyses Whole-exome CTSB sequencing (WES) was performed on affected individuals (one individual from each family) and their parents when the samples were available, as reported previously.13 In brief, 3-g samples of genomic DNA were sheared with the Covaris S2 system (Covaris); genome partitioning was performed with SureSelect Human All Exon V5 (Agilent Technology) according to the manufacturers instructions. Prepared samples were run on a HiSeq 2000 instrument (Illumina) with 101-bp paired-end reads and 7-bp index reads. The sequence reads were mapped to the human reference sequence (GRCh37) by Novoalign 3.00. Next, PCR.