Publications by authors named "Makiko Nakayama"

43 Publications

Recessive Mutations in as a Candidate of Monogenic Nephrotic Syndrome.

Kidney Int Rep 2021 Feb 10;6(2):472-483. Epub 2020 Nov 10.

Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Introduction: Most of the approximately 60 genes that if mutated cause steroid-resistant nephrotic syndrome (SRNS) are highly expressed in the glomerular podocyte, rendering SRNS a "podocytopathy."

Methods: We performed whole-exome sequencing (WES) in 1200 nephrotic syndrome (NS) patients.

Results: We discovered homozygous truncating and homozygous missense mutation in (synaptopodin-2) (p.Lys1124∗ and p.Ala1134Thr) in 2 patients with childhood-onset NS. We found SYNPO2 expression in both podocytes and mesangial cells; however, notably, immunofluorescence staining of adult human and rat kidney cryosections indicated that SYNPO2 is localized mainly in mesangial cells. Subcellular localization studies reveal that in these cells SYNPO2 partially co-localizes with α-actinin and filamin A-containing F-actin filaments. Upon transfection in mesangial cells or podocytes, EGFP-SYNPO2 co-localized with α-actinin-4, which gene is mutated in autosomal dominant SRNS in humans. SYNPO2 overexpression increases mesangial cell migration rate (MMR), whereas shRNA knockdown reduces MMR. Decreased MMR was rescued by transfection of wild-type mouse cDNA but only partially by cDNA representing mutations from the NS patients. The increased mesangial cell migration rate (MMR) by SYNPO2 overexpression was inhibited by ARP complex inhibitor CK666. shRNA knockdown in podocytes decreased active Rac1, which was rescued by transfection of wild-type cDNA but not by cDNA representing any of the 2 mutant variants.

Conclusion: We show that SYNPO2 variants may lead to Rac1-ARP3 dysregulation, and may play a role in the pathogenesis of nephrotic syndrome.
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http://dx.doi.org/10.1016/j.ekir.2020.10.040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7879128PMC
February 2021

Generation of Monogenic Candidate Genes for Human Nephrotic Syndrome Using 3 Independent Approaches.

Kidney Int Rep 2021 Feb 3;6(2):460-471. Epub 2020 Dec 3.

Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Introduction: Steroid-resistant nephrotic syndrome (SRNS) is the second most common cause of chronic kidney disease during childhood. Identification of 63 monogenic human genes has delineated 12 distinct pathogenic pathways.

Methods: Here, we generated 2 independent sets of nephrotic syndrome (NS) candidate genes to augment the discovery of additional monogenic causes based on whole-exome sequencing (WES) data from 1382 families with NS.

Results: We first identified 63 known monogenic causes of NS in mice from public databases and scientific publications, and 12 of these genes overlapped with the 63 known human monogenic SRNS genes. Second, we used a set of 64 genes that are regulated by the transcription factor Wilms tumor 1 (WT1), which causes SRNS if mutated. Thirteen of these WT1-regulated genes overlapped with human or murine NS genes. Finally, we overlapped these lists of murine and WT1 candidate genes with our list of 120 candidate genes generated from WES in 1382 NS families, to identify novel candidate genes for monogenic human SRNS. Using this approach, we identified 7 overlapping genes, of which 3 genes were shared by all datasets, including . We show that loss-of-function of leads to decreased CDC42 activity and reduced podocyte migration rate, both of which are rescued by overexpression of wild-type complementary DNA (cDNA), but not by cDNA representing the patient mutation.

Conclusion: Thus, we identified 3 novel candidate genes for human SRNS using 3 independent, nonoverlapping hypotheses, and generated functional evidence for as a novel potential monogenic cause of NS.
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http://dx.doi.org/10.1016/j.ekir.2020.11.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7879125PMC
February 2021

Mutations in Are a Novel Cause of Galloway-Mowat Syndrome.

J Am Soc Nephrol 2021 Mar 16;32(3):580-596. Epub 2021 Feb 16.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts

Background: Galloway-Mowat syndrome (GAMOS) is characterized by neurodevelopmental defects and a progressive nephropathy, which typically manifests as steroid-resistant nephrotic syndrome. The prognosis of GAMOS is poor, and the majority of children progress to renal failure. The discovery of monogenic causes of GAMOS has uncovered molecular pathways involved in the pathogenesis of disease.

Methods: Homozygosity mapping, whole-exome sequencing, and linkage analysis were used to identify mutations in four families with a GAMOS-like phenotype, and high-throughput PCR technology was applied to 91 individuals with GAMOS and 816 individuals with isolated nephrotic syndrome. and studies determined the functional significance of the mutations identified.

Results: Three biallelic variants of the transcriptional regulator were detected in six families with proteinuric kidney disease. Four families with a variant in the protein's zinc-finger (ZNF) domain have additional GAMOS-like features, including brain anomalies, cardiac defects, and skeletal defects. All variants destabilize the PRDM15 protein, and the ZNF variant additionally interferes with transcriptional activation. Morpholino oligonucleotide-mediated knockdown of Prdm15 in embryos disrupted pronephric development. Human wild-type RNA rescued the disruption, but the three variants did not. Finally, CRISPR-mediated knockout of in human podocytes led to dysregulation of several renal developmental genes.

Conclusions: Variants in can cause either isolated nephrotic syndrome or a GAMOS-type syndrome on an allelic basis. PRDM15 regulates multiple developmental kidney genes, and is likely to play an essential role in renal development in humans.
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http://dx.doi.org/10.1681/ASN.2020040490DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7920168PMC
March 2021

Recessive variants impair actin remodeling and cause glomerulopathy in humans and mice.

Sci Adv 2021 Jan 1;7(1). Epub 2021 Jan 1.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

Nephrotic syndrome (NS) is a leading cause of chronic kidney disease. We found recessive variants in two families with early-onset NS by exome sequencing. Overexpression of wild-type (WT) , but not cDNA constructs bearing patient variants, increased active CDC42 and promoted filopodia and podosome formation. Pharmacologic inhibition of CDC42 or its effectors, formin proteins, reduced NOS1AP-induced filopodia formation. knockdown reduced podocyte migration rate (PMR), which was rescued by overexpression of WT but not by constructs bearing patient variants. PMR in knockdown podocytes was also rescued by constitutively active or the formin Modeling a patient variant in knock-in human kidney organoids revealed malformed glomeruli with increased apoptosis. mice recapitulated the human phenotype, exhibiting proteinuria, foot process effacement, and glomerulosclerosis. These findings demonstrate that recessive variants impair CDC42/DIAPH-dependent actin remodeling, cause aberrant organoid glomerulogenesis, and lead to a glomerulopathy in humans and mice.
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http://dx.doi.org/10.1126/sciadv.abe1386DOI Listing
January 2021

DAAM2 Variants Cause Nephrotic Syndrome via Actin Dysregulation.

Am J Hum Genet 2020 12 23;107(6):1113-1128. Epub 2020 Nov 23.

Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Electronic address:

The discovery of >60 monogenic causes of nephrotic syndrome (NS) has revealed a central role for the actin regulators RhoA/Rac1/Cdc42 and their effectors, including the formin INF2. By whole-exome sequencing (WES), we here discovered bi-allelic variants in the formin DAAM2 in four unrelated families with steroid-resistant NS. We show that DAAM2 localizes to the cytoplasm in podocytes and in kidney sections. Further, the variants impair DAAM2-dependent actin remodeling processes: wild-type DAAM2 cDNA, but not cDNA representing missense variants found in individuals with NS, rescued reduced podocyte migration rate (PMR) and restored reduced filopodia formation in shRNA-induced DAAM2-knockdown podocytes. Filopodia restoration was also induced by the formin-activating molecule IMM-01. DAAM2 also co-localizes and co-immunoprecipitates with INF2, which is intriguing since variants in both formins cause NS. Using in vitro bulk and TIRF microscopy assays, we find that DAAM2 variants alter actin assembly activities of the formin. In a Xenopus daam2-CRISPR knockout model, we demonstrate actin dysregulation in vivo and glomerular maldevelopment that is rescued by WT-DAAM2 mRNA. We conclude that DAAM2 variants are a likely cause of monogenic human SRNS due to actin dysregulation in podocytes. Further, we provide evidence that DAAM2-associated SRNS may be amenable to treatment using actin regulating compounds.
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http://dx.doi.org/10.1016/j.ajhg.2020.11.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820625PMC
December 2020

Long-term efficacy of early infliximab-induced remission for refractory uveoretinitis associated with Behçet's disease.

Br J Ophthalmol 2020 Sep 24. Epub 2020 Sep 24.

Department of Ophthalmology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan

Background: To evaluate long-term efficacy of infliximab (IFX) in refractory uveoretinitis associated with Behçet's disease (BD) depending on uveoretinitis duration.

Methods: Records of 16 patients with BD (32 eyes) followed for >5 years after starting IFX, were retrospectively reviewed. Long-term efficacy was compared between patients with short duration (≤18 months, n=7) versus long duration (>18 months, n=9) of their uveoretinitis prior to starting IFX.

Results: The median follow-up after starting IFX was 132 months (76-146 months). Mean frequency of attacks and the 1-year Behçet's Disease Ocular Attack Score 24 decreased significantly over 10 years. Overall, the percentage of eyes with a best-corrected visual acuity (BCVA) ≥1.0 increased from 47% at baseline to 59% at 5 years; the percentage of eyes with a BCVA ≤0.1 was 19% at both baseline and 5 years. The frequency of ocular attacks decreased similarly in both short duration and long duration groups; however, the percentage of eyes with a BCVA ≥1.0 at 5 years was 100% in the short duration group versus 28% in the long duration group. IFX was discontinued in four patients with an excellent response to IFX therapy; all were young male patients in the short duration group with good BCVA bilaterally, and none had inflammatory recurrences over a median follow-up of 56 months off IFX.

Conclusion: Initiation of IFX therapy in patients with BD within 18 months of their uveoretinitis onset was more effective in maintaining good BCVA than after 18 months.
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http://dx.doi.org/10.1136/bjophthalmol-2020-316892DOI Listing
September 2020

Mutations of the Transcriptional Corepressor ZMYM2 Cause Syndromic Urinary Tract Malformations.

Authors:
Dervla M Connaughton Rufeng Dai Danielle J Owen Jonathan Marquez Nina Mann Adda L Graham-Paquin Makiko Nakayama Etienne Coyaud Estelle M N Laurent Jonathan R St-Germain Lot Snijders Blok Arianna Vino Verena Klämbt Konstantin Deutsch Chen-Han Wilfred Wu Caroline M Kolvenbach Franziska Kause Isabel Ottlewski Ronen Schneider Thomas M Kitzler Amar J Majmundar Florian Buerger Ana C Onuchic-Whitford Mao Youying Amy Kolb Daanya Salmanullah Evan Chen Amelie T van der Ven Jia Rao Hadas Ityel Steve Seltzsam Johanna M Rieke Jing Chen Asaf Vivante Daw-Yang Hwang Stefan Kohl Gabriel C Dworschak Tobias Hermle Mariëlle Alders Tobias Bartolomaeus Stuart B Bauer Michelle A Baum Eva H Brilstra Thomas D Challman Jacob Zyskind Carrie E Costin Katrina M Dipple Floor A Duijkers Marcia Ferguson David R Fitzpatrick Roger Fick Ian A Glass Peter J Hulick Antonie D Kline Ilona Krey Selvin Kumar Weining Lu Elysa J Marco Ingrid M Wentzensen Heather C Mefford Konrad Platzer Inna S Povolotskaya Juliann M Savatt Natalia V Shcherbakova Prabha Senguttuvan Audrey E Squire Deborah R Stein Isabelle Thiffault Victoria Y Voinova Michael J G Somers Michael A Ferguson Avram Z Traum Ghaleb H Daouk Ankana Daga Nancy M Rodig Paulien A Terhal Ellen van Binsbergen Loai A Eid Velibor Tasic Hila Milo Rasouly Tze Y Lim Dina F Ahram Ali G Gharavi Heiko M Reutter Heidi L Rehm Daniel G MacArthur Monkol Lek Kristen M Laricchia Richard P Lifton Hong Xu Shrikant M Mane Simone Sanna-Cherchi Andrew D Sharrocks Brian Raught Simon E Fisher Maxime Bouchard Mustafa K Khokha Shirlee Shril Friedhelm Hildebrandt

Am J Hum Genet 2020 10 4;107(4):727-742. Epub 2020 Sep 4.

Department of Pediatrics, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA. Electronic address:

Congenital anomalies of the kidney and urinary tract (CAKUT) constitute one of the most frequent birth defects and represent the most common cause of chronic kidney disease in the first three decades of life. Despite the discovery of dozens of monogenic causes of CAKUT, most pathogenic pathways remain elusive. We performed whole-exome sequencing (WES) in 551 individuals with CAKUT and identified a heterozygous de novo stop-gain variant in ZMYM2 in two different families with CAKUT. Through collaboration, we identified in total 14 different heterozygous loss-of-function mutations in ZMYM2 in 15 unrelated families. Most mutations occurred de novo, indicating possible interference with reproductive function. Human disease features are replicated in X. tropicalis larvae with morpholino knockdowns, in which expression of truncated ZMYM2 proteins, based on individual mutations, failed to rescue renal and craniofacial defects. Moreover, heterozygous Zmym2-deficient mice recapitulated features of CAKUT with high penetrance. The ZMYM2 protein is a component of a transcriptional corepressor complex recently linked to the silencing of developmentally regulated endogenous retrovirus elements. Using protein-protein interaction assays, we show that ZMYM2 interacts with additional epigenetic silencing complexes, as well as confirming that it binds to FOXP1, a transcription factor that has also been linked to CAKUT. In summary, our findings establish that loss-of-function mutations of ZMYM2, and potentially that of other proteins in its interactome, as causes of human CAKUT, offering new routes for studying the pathogenesis of the disorder.
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http://dx.doi.org/10.1016/j.ajhg.2020.08.013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536580PMC
October 2020

Phenotype expansion of heterozygous FOXC1 pathogenic variants toward involvement of congenital anomalies of the kidneys and urinary tract (CAKUT).

Genet Med 2020 10 1;22(10):1673-1681. Epub 2020 Jun 1.

Department of Pediatrics, Boston Children's Hospital/Harvard Medical School, Boston, MA, USA.

Purpose: Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in childhood and adolescence. We aim to identify novel monogenic causes of CAKUT.

Methods: Exome sequencing was performed in 550 CAKUT-affected families.

Results: We discovered seven FOXC1 heterozygous likely pathogenic variants within eight CAKUT families. These variants are either never reported, or present in <5 alleles in the gnomAD database with ~141,456 controls. FOXC1 is a causal gene for Axenfeld-Rieger syndrome type 3 and anterior segment dysgenesis 3. Pathogenic variants in FOXC1 have not been detected in patients with CAKUT yet. Interestingly, mouse models for Foxc1 show severe CAKUT phenotypes with incomplete penetrance and variable expressivity. The FOXC1 variants are enriched in the CAKUT cohort compared with the control. Genotype-phenotype correlations showed that Axenfeld-Rieger syndrome or anterior segment dysgenesis can be caused by both truncating and missense pathogenic variants, and the missense variants are located at the forkhead domain. In contrast, for CAKUT, there is no truncating pathogenic variant, and all variants except one are located outside the forkhead domain.

Conclusion: We thereby expanded the phenotype of FOXC1 pathogenic variants toward involvement of CAKUT, which can potentially be explained by allelism.
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http://dx.doi.org/10.1038/s41436-020-0844-zDOI Listing
October 2020

Effect of In Vivo Expansion of Regulatory T Cells with IL-2/anti-IL-2 Antibody Complex Plus Rapamycin on Experimental Autoimmune Uveoretinitis.

Ocul Immunol Inflamm 2020 May 27:1-10. Epub 2020 May 27.

Department of Ophthalmology, Kyorin University School of Medicine, Mitaka, Tokyo, Japan.

: To determine the effect of injection of IL-2/anti-IL-2 antibody (IL-2 complex) together with rapamycin on the development of experimental autoimmune uveoretinitis (EAU).: C57BL/6J mice were immunized with human interphotoreceptor retinoid-binding protein peptide. The immunized mice were injected intraperitoneally with PBS, IL-2 complex, rapamycin, or IL-2 complex/rapamycin on days 1, 2, 3, and 4 (induction phase) or days 10, 11, 12, and 13 (effector phase) after immunization.: Expansion of CD4Foxp3 regulatory T cells in draining lymph nodes was observed in IL-2 complex and IL-2 complex/rapamycin-treated mice. Although injection of IL-2 complex alone was not capable of decreasing the clinical score of EAU, injection of IL-2 complex/rapamycin significantly delayed the onset of EAU. In contrast, the treatment with IL-2 complex alone or IL-2 complex/rapamycin during effector phase failed to suppress EAU.: These findings suggest the potential limitations of IL-2 complex or IL-2 complex/rapamycin during EAU.
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http://dx.doi.org/10.1080/09273948.2020.1757119DOI Listing
May 2020

Two-Year Outcomes of Treat-and-Extend Intravitreal Aflibercept for Exudative Age-Related Macular Degeneration: A Prospective Study.

Ophthalmol Retina 2020 Aug 19;4(8):767-776. Epub 2020 Mar 19.

Department of Ophthalmology, Tokyo Women's Medical University, Tokyo, Japan.

Purpose: To report the 2-year outcomes of intravitreal aflibercept injections (IAIs) in Japanese patients with neovascular age-related macular degeneration (AMD) using a 1-month adjusted treat-and-extend (TAE) regimen.

Design: Multicenter, prospective, nonrandomized, interventional study.

Participants: Ninety-seven eyes of 97 patients with treatment-naive AMD were studied at 3 tertiary ophthalmological institutions.

Methods: The patients were treated with 3 consecutive monthly IAIs followed by the TAE regimen with a 1-month adjustment for a maximum of 3 months. Our TAE regimen allowed us to shorten and extend the treatment intervals even after a 3-month or 1-month treatment interval, or both, were reached. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), and subfoveal choroidal thickness (SCT) were analyzed.

Main Outcome Measures: The mean changes in the BCVA, CRT, and SCT from the baseline to 2 years after initiating the treatment were determined. In addition, the number of injections also was determined.

Results: The mean BCVA significantly improved from 0.27 logarithm of the minimum angle of resolution (logMAR) units to 0.14 logMAR at 2 years (P < 0.01). The mean CRT decreased significantly from 307±132 μm to 202±76 μm at 2 years (P < 0.01). The mean SCT decreased significantly from 247±106 μm to 203±96 μm at 2 years (P < 0.01). Seventy eyes (72.2%) showed a dry macula at 2 years. The treatment interval at 2 years was 1 month in 20 eyes (20.6%), 2 months in 18 eyes (18.6%), and 3 months in 59 eyes (60.8%). In 49 (50.5%) eyes with a 3-month treatment interval immediately after the loading phase, no fluid was seen in 25 eyes (51.0%) for the duration of this study. The rest had switched to a more frequent scheme. The mean number of injections during the 2-year period was 13.0±3.9.

Conclusions: Intravitreal aflibercept injections with a 1-month adjusted TAE regimen significantly improved the BCVA and CRT with a reduced number of injections at 2 years. The treatment interval was adjusted to extend to 3 months in 60% and to shorten to 1 month in 20% of the eyes at 2 years.
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http://dx.doi.org/10.1016/j.oret.2020.03.010DOI Listing
August 2020

ADCK4 Deficiency Destabilizes the Coenzyme Q Complex, Which Is Rescued by 2,4-Dihydroxybenzoic Acid Treatment.

J Am Soc Nephrol 2020 06 7;31(6):1191-1211. Epub 2020 May 7.

Departments of Pharmacology, Yonsei University College of Medicine, Seoul, Korea

Background: Mutations in (aarF domain containing kinase 4) generally manifest as steroid-resistant nephrotic syndrome and induce coenzyme Q (CoQ) deficiency. However, the molecular mechanisms underlying steroid-resistant nephrotic syndrome resulting from mutations are not well understood, largely because the function of ADCK4 remains unknown.

Methods: To elucidate the ADCK4's function in podocytes, we generated a podocyte-specific, -knockout mouse model and a human podocyte cell line featuring knockout of . These knockout mice and podocytes were then treated with 2,4-dihydroxybenzoic acid (2,4-diHB), a CoQ precursor analogue, or with a vehicle only. We also performed proteomic mass spectrometry analysis to further elucidate ADCK4's function.

Results: Absence of in mouse podocytes caused FSGS and albuminuria, recapitulating features of nephrotic syndrome caused by mutations. studies revealed that ADCK4-knockout podocytes had significantly reduced CoQ concentration, respiratory chain activity, and mitochondrial potential, and subsequently displayed an increase in the number of dysmorphic mitochondria. However, treatment of 3-month-old knockout mice or ADCK4-knockout cells with 2,4-diHB prevented the development of renal dysfunction and reversed mitochondrial dysfunction in podocytes. Moreover, ADCK4 interacted with mitochondrial proteins such as COQ5, as well as cytoplasmic proteins such as myosin and heat shock proteins. Thus, ADCK4 knockout decreased the COQ complex level, but overexpression of ADCK4 in ADCK4-knockout podocytes transfected with wild-type ADCK4 rescued the COQ5 level.

Conclusions: Our study shows that ADCK4 is required for CoQ biosynthesis and mitochondrial function in podocytes, and suggests that ADCK4 in podocytes stabilizes proteins in complex Q in podocytes. Our study also suggests a potential treatment strategy for nephrotic syndrome resulting from mutations.
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http://dx.doi.org/10.1681/ASN.2019070756DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269352PMC
June 2020

CAKUT and Autonomic Dysfunction Caused by Acetylcholine Receptor Mutations.

Am J Hum Genet 2019 12 7;105(6):1286-1293. Epub 2019 Nov 7.

Department of Pediatrics, Boston Children's Hospital, Boston, MA 02115, USA. Electronic address:

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in the first three decades of life, and in utero obstruction to urine flow is a frequent cause of secondary upper urinary tract malformations. Here, using whole-exome sequencing, we identified three different biallelic mutations in CHRNA3, which encodes the α3 subunit of the nicotinic acetylcholine receptor, in five affected individuals from three unrelated families with functional lower urinary tract obstruction and secondary CAKUT. Four individuals from two families have additional dysautonomic features, including impaired pupillary light reflexes. Functional studies in vitro demonstrated that the mutant nicotinic acetylcholine receptors were unable to generate current following stimulation with acetylcholine. Moreover, the truncating mutations p.Thr337Asnfs81 and p.Ser340 led to impaired plasma membrane localization of CHRNA3. Although the importance of acetylcholine signaling in normal bladder function has been recognized, we demonstrate for the first time that mutations in CHRNA3 can cause bladder dysfunction, urinary tract malformations, and dysautonomia. These data point to a pathophysiologic sequence by which monogenic mutations in genes that regulate bladder innervation may secondarily cause CAKUT.
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http://dx.doi.org/10.1016/j.ajhg.2019.10.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6904809PMC
December 2019

Design of 2'--methyl RNA and DNA double-stranded oligonucleotides: naturally-occurring nucleotide components with strong RNA interference gene expression inhibitory activity.

Nucleosides Nucleotides Nucleic Acids 2020 11;39(1-3):292-309. Epub 2019 Sep 11.

R&D and Biologics Divisions, Daiichi Sankyo Co. Ltd, Shinagawa, Tokyo, Japan.

Double-stranded RNAs consisting of 21-nucleotide passenger and guide strands, known as small interfering RNAs (siRNAs), can be used for the identification of gene functions and the regulation of genes involved in disease for therapeutics. The difficulty with unmodified siRNAs lies in the chemical synthesis of RNA, its degradation by RNase, the immune response derived from natural RNA, and the off-target effects mediated by the passenger strand. In this study, asymmetrical 18 base-paired double-strand oligonucleotides comprised of alternately combined DNAs and 2'--methyl RNAs, denoted as MED-siRNA, were evaluated. These modified oligonucleotides showed high RNase resistance, a reduced immune response, a highly efficient cleavage of target mRNA with binding to Argonaute 2 (Ago2) RNA interference, and the subsequent reduction of target protein expression. These findings suggest the possibility of alternatives to unmodified siRNAs with potential use in therapeutics.
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http://dx.doi.org/10.1080/15257770.2019.1663384DOI Listing
September 2020

Mutations in KIRREL1, a slit diaphragm component, cause steroid-resistant nephrotic syndrome.

Kidney Int 2019 10 10;96(4):883-889. Epub 2019 Jul 10.

Department of Medicine, Nephrology Division, Medical University of South Carolina, Charleston, South Carolina, USA. Electronic address:

Steroid-resistant nephrotic syndrome is a frequent cause of chronic kidney disease almost inevitably progressing to end-stage renal disease. More than 58 monogenic causes of SRNS have been discovered and majority of known steroid-resistant nephrotic syndrome causing genes are predominantly expressed in glomerular podocytes, placing them at the center of disease pathogenesis. Herein, we describe two unrelated families with steroid-resistant nephrotic syndrome with homozygous mutations in the KIRREL1 gene. One mutation showed high frequency in the European population (minor allele frequency 0.0011) and this patient achieved complete remission following treatment, but later progressed to chronic kidney disease. We found that mutant KIRREL1 proteins failed to localize to the podocyte cell membrane, indicating defective trafficking and impaired podocytes function. Thus, the KIRREL1 gene product has an important role in modulating the integrity of the slit diaphragm and maintaining glomerular filtration function.
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http://dx.doi.org/10.1016/j.kint.2019.06.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6756928PMC
October 2019

COL4A1 mutations as a potential novel cause of autosomal dominant CAKUT in humans.

Hum Genet 2019 Oct 22;138(10):1105-1115. Epub 2019 Jun 22.

Department of Medicine, Boston Children's Hospital, Enders 561, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA.

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. 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). 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). 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.
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http://dx.doi.org/10.1007/s00439-019-02042-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6745245PMC
October 2019

Clinical Features, Treatment, and Visual Outcomes of Japanese Patients with Posterior Scleritis.

Ocul Immunol Inflamm 2020 26;28(2):209-216. Epub 2019 Feb 26.

Department of Ophthalmology, Kyorin University School of Medicine, Tokyo, Japan.

: The purpose of this study is to describe clinical features and visual outcomes of Japanese patients with posterior scleritis.: Clinical records of 10 patients (13 eyes) presenting between 2006 and 2016 were retrospectively reviewed.: The mean age was 50.1 ± 20.8 years; 50% were women, and three patients had bilateral disease. Associated anterior scleritis (11 eyes, 85%) and serous retinal detachment (8 eyes, 62%) were common at presentation. Treatment consisted of corticosteroids (all patients) and immunosuppressive agents (seven patients). The mean subfoveal choroidal thickness was significantly reduced over follow-up [611 μm at baseline, 298 μm ( < 0.01) at 1 month, and 238 μm ( < 0.01) at 1 year]. Recurrent inflammation was observed in six patients. A best-corrected visual acuity of 0.8 or better was achieved in all 13 eyes at 3 years and 71% of eyes at 5 years.: Although 60% of patients with posterior scleritis had recurrence, visual outcomes were favorable.
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http://dx.doi.org/10.1080/09273948.2019.1574838DOI Listing
January 2021

Monogenic causes of chronic kidney disease in adults.

Kidney Int 2019 04 14;95(4):914-928. Epub 2019 Feb 14.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address:

Approximately 500 monogenic causes of chronic kidney disease (CKD) have been identified, mainly in pediatric populations. The frequency of monogenic causes among adults with CKD has been less extensively studied. To determine the likelihood of detecting monogenic causes of CKD in adults presenting to nephrology services in Ireland, we conducted whole exome sequencing (WES) in a multi-centre cohort of 114 families including 138 affected individuals with CKD. Affected adults were recruited from 78 families with a positive family history, 16 families with extra-renal features, and 20 families with neither a family history nor extra-renal features. We detected a pathogenic mutation in a known CKD gene in 42 of 114 families (37%). A monogenic cause was identified in 36% of affected families with a positive family history of CKD, 69% of those with extra-renal features, and only 15% of those without a family history or extra-renal features. There was no difference in the rate of genetic diagnosis in individuals with childhood versus adult onset CKD. Among the 42 families in whom a monogenic cause was identified, WES confirmed the clinical diagnosis in 17 (40%), corrected the clinical diagnosis in 9 (22%), and established a diagnosis for the first time in 16 families referred with CKD of unknown etiology (38%). In this multi-centre study of adults with CKD, a molecular genetic diagnosis was established in over one-third of families. In the evolving era of precision medicine, WES may be an important tool to identify the cause of CKD in adults.
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http://dx.doi.org/10.1016/j.kint.2018.10.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6431580PMC
April 2019

Treatment with 2,4-Dihydroxybenzoic Acid Prevents FSGS Progression and Renal Fibrosis in Podocyte-Specific Knockout Mice.

J Am Soc Nephrol 2019 Feb 8. Epub 2019 Feb 8.

Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;

Background: Although studies have identified >55 genes as causing steroid-resistant nephrotic syndrome (SRNS) and localized its pathogenesis to glomerular podocytes, the disease mechanisms of SRNS remain largely enigmatic. We recently reported that individuals with mutations in COQ6, a coenzyme Q (also called CoQ, CoQ, or ubiquinone) biosynthesis pathway enzyme, develop SRNS with sensorineural deafness, and demonstrated the beneficial effect of CoQ for maintenace of kidney function.

Methods: To study function in podocytes, we generated a podocyte-specific knockout mouse ( ) model and a transient siRNA-based knockdown in a human podocyte cell line. Mice were monitored for development of proteinuria and assessed for development of glomerular sclerosis. Using a podocyte migration assay, we compared motility in knockdown podocytes and control podocytes. We also randomly assigned 5-month-old mice and controls to receive no treatment or 2,4-dihydroxybenzoic acid (2,4-diHB), an analog of a CoQ precursor molecule that is classified as a food additive by health authorities in Europe and the United States.

Results: Abrogation of in mouse podocytes caused FSGS and proteinuria (>46-fold increases in albuminuria). studies revealed an impaired podocyte migration rate in knockdown human podocytes. Treating mice or cells with 2,4-diHB prevented renal dysfunction and reversed podocyte migration rate impairment. Survival of mice given 2,4diHB was comparable to that of control mice and significantly higher than that of untreated mice, half of which died by 10 months of age.

Conclusions: These findings reveal a potential novel treatment strategy for those cases of human nephrotic syndrome that are caused by a primary dysfunction in the CoQ biosynthesis pathway.
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http://dx.doi.org/10.1681/ASN.2018060625DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6405149PMC
February 2019

Whole-Exome Sequencing Enables a Precision Medicine Approach for Kidney Transplant Recipients.

J Am Soc Nephrol 2019 02 17;30(2):201-215. Epub 2019 Jan 17.

Division of Nephrology,

Background: Whole-exome sequencing (WES) finds a CKD-related mutation in approximately 20% of patients presenting with CKD before 25 years of age. Although provision of a molecular diagnosis could have important implications for clinical management, evidence is lacking on the diagnostic yield and clinical utility of WES for pediatric renal transplant recipients.

Methods: To determine the diagnostic yield of WES in pediatric kidney transplant recipients, we recruited 104 patients who had received a transplant at Boston Children's Hospital from 2007 through 2017, performed WES, and analyzed results for likely deleterious variants in approximately 400 genes known to cause CKD.

Results: By WES, we identified a genetic cause of CKD in 34 out of 104 (32.7%) transplant recipients. The likelihood of detecting a molecular genetic diagnosis was highest for patients with urinary stone disease (three out of three individuals), followed by renal cystic ciliopathies (seven out of nine individuals), steroid-resistant nephrotic syndrome (nine out of 21 individuals), congenital anomalies of the kidney and urinary tract (ten out of 55 individuals), and chronic glomerulonephritis (one out of seven individuals). WES also yielded a molecular diagnosis for four out of nine individuals with ESRD of unknown etiology. The WES-related molecular genetic diagnosis had implications for clinical care for five patients.

Conclusions: Nearly one third of pediatric renal transplant recipients had a genetic cause of their kidney disease identified by WES. Knowledge of this genetic information can help guide management of both transplant patients and potential living related donors.
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http://dx.doi.org/10.1681/ASN.2018060575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6362619PMC
February 2019

Panel sequencing distinguishes monogenic forms of nephritis from nephrosis in children.

Nephrol Dial Transplant 2019 03;34(3):474-485

Department of Medicine, Division of Nephrology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

Background: Alport syndrome (AS) and atypical hemolytic-uremic syndrome (aHUS) are rare forms of chronic kidney disease (CKD) that can lead to a severe decline of renal function. Steroid-resistant nephrotic syndrome (SRNS) is more common than AS and aHUS and causes 10% of childhood-onset CKD. In recent years, multiple monogenic causes of AS, aHUS and SRNS have been identified, but their relative prevalence has yet to be studied together in a typical pediatric cohort of children with proteinuria and hematuria. We hypothesized that identification of causative mutations by whole exome sequencing (WES) in known monogenic nephritis and nephrosis genes would allow distinguishing nephritis from nephrosis in a typical pediatric group of patients with both proteinuria and hematuria at any level.

Methods: We therefore conducted an exon sequencing (WES) analysis for 11 AS, aHUS and thrombotic thrombocytopenic purpura-causing genes in an international cohort of 371 patients from 362 families presenting with both proteinuria and hematuria before age 25 years. In parallel, we conducted either WES or high-throughput exon sequencing for 23 SRNS-causing genes in all patients.

Results: We detected pathogenic mutations in 18 of the 34 genes analyzed, leading to a molecular diagnosis in 14.1% of families (51 of 362). Disease-causing mutations were detected in 3 AS-causing genes (4.7%), 3 aHUS-causing genes (1.4%) and 12 NS-causing genes (8.0%). We observed a much higher mutation detection rate for monogenic forms of CKD in consanguineous families (35.7% versus 10.1%).

Conclusions: We present the first estimate of relative frequency of inherited AS, aHUS and NS in a typical pediatric cohort with proteinuria and hematuria. Important therapeutic and preventative measures may result from mutational analysis in individuals with proteinuria and hematuria.
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http://dx.doi.org/10.1093/ndt/gfy050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6399484PMC
March 2019

Whole-Exome Sequencing Identifies Causative Mutations in Families with Congenital Anomalies of the Kidney and Urinary Tract.

J Am Soc Nephrol 2018 09 24;29(9):2348-2361. Epub 2018 Aug 24.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;

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.
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http://dx.doi.org/10.1681/ASN.2017121265DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6115658PMC
September 2018

Mutations in WDR4 as a new cause of Galloway-Mowat syndrome.

Am J Med Genet A 2018 11 6;176(11):2460-2465. Epub 2018 Aug 6.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.

Galloway-Mowat syndrome (GAMOS) is a phenotypically heterogeneous disorder characterized by neurodevelopmental defects combined with renal-glomerular disease, manifesting with proteinuria. To identify additional monogenic disease causes, we here performed whole exome sequencing (WES), linkage analysis, and homozygosity mapping in three affected siblings of an Indian family with GAMOS. Applying established criteria for variant filtering, we identify a novel homozygous splice site mutation in the gene WDR4 as the likely disease-causing mutation in this family. In line with previous reports, we observe growth deficiency, microcephaly, developmental delay, and intellectual disability as phenotypic features resulting from WDR4 mutations. However, the newly identified allele additionally gives rise to proteinuria and nephrotic syndrome, a phenotype that was never reported in patients with WDR4 mutations. Our data thus expand the phenotypic spectrum of WDR4 mutations by demonstrating that, depending on the specific mutated allele, a renal phenotype may be present. This finding suggests that GAMOS may occupy a phenotypic spectrum with other microcephalic diseases. Furthermore, WDR4 is an additional example of a gene that encodes a tRNA modifying enzyme and gives rise to GAMOS, if mutated. Our findings thereby support the recent observation that, like neurons, podocytes of the renal glomerulus are particularly vulnerable to cellular defects resulting from altered tRNA modifications.
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http://dx.doi.org/10.1002/ajmg.a.40489DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6289609PMC
November 2018

and Mutations Implicate RAB5 Regulation in Nephrotic Syndrome.

J Am Soc Nephrol 2018 08 29;29(8):2123-2138. Epub 2018 Jun 29.

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;

Background: Steroid-resistant nephrotic syndrome (SRNS) is a frequent cause of CKD. The discovery of monogenic causes of SRNS has revealed specific pathogenetic pathways, but these monogenic causes do not explain all cases of SRNS.

Methods: To identify novel monogenic causes of SRNS, we screened 665 patients by whole-exome sequencing. We then evaluated the functional significance of two genes and the mutations therein that we discovered through this sequencing and conducted complementary studies in podocyte-like nephrocytes.

Results: We identified conserved, homozygous missense mutations of in two families with early-onset NS and a homozygous missense mutation of in two siblings with SRNS. GAPVD1 and ANKFY1 interact with the endosomal regulator RAB5. Coimmunoprecipitation assays indicated interaction between GAPVD1 and ANKFY1 proteins, which also colocalized when expressed in HEK293T cells. Silencing either protein diminished the podocyte migration rate. Compared with wild-type GAPVD1 and ANKFY1, the mutated proteins produced upon ectopic expression of or bearing the patient-derived mutations exhibited altered binding affinity for active RAB5 and reduced ability to rescue the knockout-induced defect in podocyte migration. Coimmunoprecipitation assays further demonstrated a physical interaction between nephrin and GAPVD1, and immunofluorescence revealed partial colocalization of these proteins in rat glomeruli. The patient-derived mutations reduced nephrin-GAPVD1 binding affinity. In , silencing impaired endocytosis and caused mistrafficking of the nephrin ortholog.

Conclusions: Mutations in and probably in are novel monogenic causes of NS. The discovery of these genes implicates RAB5 regulation in the pathogenesis of human NS.
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http://dx.doi.org/10.1681/ASN.2017121312DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6065084PMC
August 2018

Clinical features and visual outcomes of 111 patients with new-onset acute Vogt-Koyanagi-Harada disease treated with pulse intravenous corticosteroids.

Br J Ophthalmol 2019 02 17;103(2):274-278. Epub 2018 Apr 17.

Department of Ophthalmology, Kyorin University School of Medicine, Tokyo, Japan

Purpose: To describe the clinical features, treatment and visual outcomes of Japanese patients with new-onset acute Vogt-Koyanagi-Harada (VKH) disease.

Methods: Clinical records of 111 patients who presented between 1999 and 2015 to the Ocular Inflammation Service of the Kyorin Eye Center, Tokyo, were reviewed.

Results: Of the 111 patients (68 women, 43 men), 16 had complete, 90 had incomplete and 5 had probable VKH disease. The median follow-up period was 36 months (4-175 months). The mean age at presentation was 41 years (19-74 years). Serous retinal detachment (202 eyes) and optic disc hyperaemia (89 eyes) were observed at presentation. Of the patients tested, 45/48 (93.8%) were human leucocyte antigen-DR4 positive and 63/77 (81.8%) had cerebrospinal fluid pleocytosis. Initial corticosteroid treatment consisted of pulse intravenous therapy in all patients. Sunset glow fundus was observed in 49.5% of eyes, and anterior and/or posterior segment recurrence of inflammation was observed in 25 patients (22.5%). Treatment was transitioned to cyclosporine in 17 patients (15.3%) for steroid sparing (6 patients) or recurrent inflammation (11 patients), with good subsequent control. Ocular complications were observed in 47 of 222 eyes (21.2%) (mostly cataract), and systemic complications were observed in 8.1% of patients (mostly hypertension and diabetes mellitus). Ninety-three percent of eyes (167 of 178 eyes) had a visual acuity of ≥1.0 at 1 year after presentation.

Conclusions: An aggressive corticosteroid treatment strategy in a large number of patients with new-onset acute VKH disease, with transitioning to cyclosporine in selected cases, resulted in excellent visual outcomes and low rates of recurrence.
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http://dx.doi.org/10.1136/bjophthalmol-2017-311691DOI Listing
February 2019

Genetic variants in the LAMA5 gene in pediatric nephrotic syndrome.

Nephrol Dial Transplant 2019 03;34(3):485-493

Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

Background: Nephrotic syndrome (NS), a chronic kidney disease, is characterized by significant loss of protein in the urine causing hypoalbuminemia and edema. In general, ∼15% of childhood-onset cases do not respond to steroid therapy and are classified as steroid-resistant NS (SRNS). In ∼30% of cases with SRNS, a causative mutation can be detected in one of 44 monogenic SRNS genes. The gene LAMA5 encodes laminin-α5, an essential component of the glomerular basement membrane. Mice with a hypomorphic mutation in the orthologous gene Lama5 develop proteinuria and hematuria.

Methods: To identify additional monogenic causes of NS, we performed whole exome sequencing in 300 families with pediatric NS. In consanguineous families we applied homozygosity mapping to identify genomic candidate loci for the underlying recessive mutation.

Results: In three families, in whom mutations in known NS genes were excluded, but in whom a recessive, monogenic cause of NS was strongly suspected based on pedigree information, we identified homozygous variants of unknown significance (VUS) in the gene LAMA5. While all affected individuals had nonsyndromic NS with an early onset of disease, their clinical outcome and response to immunosuppressive therapy differed notably.

Conclusion: We here identify recessive VUS in the gene LAMA5 in patients with partially treatment-responsive NS. More data will be needed to determine the impact of these VUS in disease management. However, familial occurrence of disease, data from genetic mapping and a mouse model that recapitulates the NS phenotypes suggest that these genetic variants may be inherited factors that contribute to the development of NS in pediatric patients.
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http://dx.doi.org/10.1093/ndt/gfy028DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6399483PMC
March 2019

A homozygous missense variant in VWA2, encoding an interactor of the Fraser-complex, in a patient with vesicoureteral reflux.

PLoS One 2018 19;13(1):e0191224. Epub 2018 Jan 19.

Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States of America.

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause (40-50%) of chronic kidney disease (CKD) in children. About 40 monogenic causes of CAKUT have so far been discovered. To date less than 20% of CAKUT cases can be explained by mutations in these 40 genes. To identify additional monogenic causes of CAKUT, we performed whole exome sequencing (WES) and homozygosity mapping (HM) in a patient with CAKUT from Indian origin and consanguineous descent. We identified a homozygous missense mutation (c.1336C>T, p.Arg446Cys) in the gene Von Willebrand factor A domain containing 2 (VWA2). With immunohistochemistry studies on kidneys of newborn (P1) mice, we show that Vwa2 and Fraser extracellular matrix complex subunit 1 (Fras1) co-localize in the nephrogenic zone of the renal cortex. We identified a pronounced expression of Vwa2 in the basement membrane of the ureteric bud (UB) and derivatives of the metanephric mesenchyme (MM). By applying in vitro assays, we demonstrate that the Arg446Cys mutation decreases translocation of monomeric VWA2 protein and increases translocation of aggregated VWA2 protein into the extracellular space. This is potentially due to the additional, unpaired cysteine residue in the mutated protein that is used for intermolecular disulfide bond formation. VWA2 is a known, direct interactor of FRAS1 of the Fraser-Complex (FC). FC-encoding genes and interacting proteins have previously been implicated in the pathogenesis of syndromic and/or isolated CAKUT phenotypes in humans. VWA2 therefore constitutes a very strong candidate in the search for novel CAKUT-causing genes. Our results from in vitro experiments indicate a dose-dependent neomorphic effect of the Arg446Cys homozygous mutation in VWA2.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0191224PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5774751PMC
February 2018

Whole Exome Sequencing of Patients with Steroid-Resistant Nephrotic Syndrome.

Clin J Am Soc Nephrol 2018 01 10;13(1):53-62. Epub 2017 Nov 10.

Due to the number of contributing authors, the affiliations are provided in the Supplemental Material.

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 <25 years of age. Exome data were evaluated for 33 known monogenic steroid-resistant nephrotic syndrome genes.

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. , , , and 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.
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http://dx.doi.org/10.2215/CJN.04120417DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5753307PMC
January 2018

One-Year Outcomes of a Treat-and-Extend Regimen of Aflibercept for Exudative Age-Related Macular Degeneration.

Ophthalmologica 2017 4;237(3):139-144. Epub 2017 Mar 4.

Department of Ophthalmology, Kyorin University Hospital, Kyorin University School of Medicine, Tokyo, Japan.

Purpose: The aim of this study was to investigate the 1-year outcomes of treat-and-extend aflibercept for exudative age-related macular degeneration (AMD) in Japan.

Procedures: Clinical records of 67 patients (67 eyes) were reviewed. Monthly aflibercept was administered until resolution of exudation and maximal reduction of pigment epithelial detachment. Injection intervals were extended by 2-week units up to 12 weeks if no exudation was observed and shortened for recurrence.

Results: Mean best-corrected visual acuity (logarithm of the minimum angle of resolution) improved from 0.29 to 0.14 at 12 months (p < 0.0001). Mean central retinal thickness decreased from 430 μm to 236 μm at 12 months (p < 0.0001). Fifty-nine eyes (88.0%) achieved a dry macula with a mean of 8.3 injections by study end. The injection interval was extended to 10 weeks in 44.8% and to 12 weeks in 17.9% of eyes.

Conclusions: At 1 year, good outcomes were obtained using treat-and-extend aflibercept for exudative AMD in Japan.
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http://dx.doi.org/10.1159/000458538DOI Listing
September 2017

Efficacy of Infliximab for Early Remission Induction in Refractory Uveoretinitis Associated with Behçet Disease: A 2-year Follow-up Study.

Ocul Immunol Inflamm 2017 Feb 21;25(1):46-51. Epub 2016 Oct 21.

a Department of Ophthalmology , Kyorin University School of Medicine , Tokyo , Japan.

Purpose: To compare the efficacy of infliximab (IFX) on refractory uveoretinitis between Behçet disease (BD) patients with short duration (≤18 months, n = 6) versus long duration (>18 months, n = 7) of their ocular disease.

Methods: Records of 13 BD patients treated with IFX for 24 months were retrospectively reviewed.

Results: Frequency of ocular attacks decreased with IFX treatment in both groups, with no significant difference. Retinal and disc vascular leakage scores also decreased in both groups, however was significantly lower in the short-duration group. Percentage of eyes with a best-corrected visual acuity (BCVA) of 1.0 or better at year 2 was 100% in the short-duration and 21% in the long-duration group.

Conclusions: Induction of early remission using IFX appeared to be more effective in reducing background vascular leakage and in maintaining good visual acuity in BD patients.
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http://dx.doi.org/10.1080/09273948.2016.1239746DOI Listing
February 2017