@article {587, title = {Genetic variants in the LAMA5 gene in pediatric nephrotic syndrome.}, journal = {Nephrol Dial Transplant}, volume = {34}, year = {2019}, month = {2019 03 01}, pages = {485-493}, abstract = {

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.

}, issn = {1460-2385}, doi = {10.1093/ndt/gfy028}, author = {Braun, Daniela A and Warejko, Jillian K and Ashraf, Shazia and Tan, Weizhen and Daga, Ankana and Schneider, Ronen and Hermle, Tobias and Jobst-Schwan, Tilman and Widmeier, Eugen and Majmundar, Amar J and Nakayama, Makiko and Schapiro, David and Rao, Jia and Schmidt, Johanna Magdalena and Hoogstraten, Charlotte A and Hugo, Hannah and Bakkaloglu, Sevcan A and Kari, Jameela A and El Desoky, Sherif and Daouk, Ghaleb and Mane, Shrikant and Lifton, Richard P and Shril, Shirlee and Hildebrandt, Friedhelm} } @article {513, title = {Mutations in multiple components of the nuclear pore complex cause nephrotic syndrome.}, journal = {J Clin Invest}, volume = {128}, year = {2018}, month = {2018 Oct 01}, pages = {4313-4328}, abstract = {

Steroid-resistant nephrotic syndrome (SRNS) almost invariably progresses to end-stage renal disease. Although more than 50 monogenic causes of SRNS have been described, a large proportion of SRNS remains unexplained. Recently, it was discovered that mutations of NUP93 and NUP205, encoding 2 proteins of the inner ring subunit of the nuclear pore complex (NPC), cause SRNS. Here, we describe mutations in genes encoding 4 components of the outer rings of the NPC, namely NUP107, NUP85, NUP133, and NUP160, in 13 families with SRNS. Using coimmunoprecipitation experiments, we showed that certain pathogenic alleles weakened the interaction between neighboring NPC subunits. We demonstrated that morpholino knockdown of nup107, nup85, or nup133 in Xenopus disrupted glomerulogenesis. Re-expression of WT mRNA, but not of mRNA reflecting mutations from SRNS patients, mitigated this phenotype. We furthermore found that CRISPR/Cas9 knockout of NUP107, NUP85, or NUP133 in podocytes activated Cdc42, an important effector of SRNS pathogenesis. CRISPR/Cas9 knockout of nup107 or nup85 in zebrafish caused developmental anomalies and early lethality. In contrast, an in-frame mutation of nup107 did not affect survival, thus mimicking the allelic effects seen in humans. In conclusion, we discovered here that mutations in 4 genes encoding components of the outer ring subunits of the NPC cause SRNS and thereby provide further evidence that specific hypomorphic mutations in these essential genes cause a distinct, organ-specific phenotype.

}, issn = {1558-8238}, doi = {10.1172/JCI98688}, author = {Braun, Daniela A and Lovric, Svjetlana and Schapiro, David and Schneider, Ronen and Marquez, Jonathan and Asif, Maria and Hussain, Muhammad Sajid and Daga, Ankana and Widmeier, Eugen and Rao, Jia and Ashraf, Shazia and Tan, Weizhen and Lusk, C Patrick and Kolb, Amy and Jobst-Schwan, Tilman and Schmidt, Johanna Magdalena and Hoogstraten, Charlotte A and Eddy, Kaitlyn and Kitzler, Thomas M and Shril, Shirlee and Moawia, Abubakar and Schrage, Kathrin and Khayyat, Arwa Ishaq A and Lawson, Jennifer A and Gee, Heon Yung and Warejko, Jillian K and Hermle, Tobias and Majmundar, Amar J and Hugo, Hannah and Budde, Birgit and Motameny, Susanne and Altm{\"u}ller, Janine and Noegel, Angelika Anna and Fathy, Hanan M and Gale, Daniel P and Waseem, Syeda Seema and Khan, Ayaz and Kerecuk, Larissa and Hashmi, Seema and Mohebbi, Nilufar and Ettenger, Robert and Serdaroglu, Erkin and Alhasan, Khalid A and Hashem, Mais and Goncalves, Sara and Ariceta, Gema and Ubetagoyena, Mercedes and Antonin, Wolfram and Baig, Shahid Mahmood and Alkuraya, Fowzan S and Shen, Qian and Xu, Hong and Antignac, Corinne and Lifton, Richard P and Mane, Shrikant and N{\"u}rnberg, Peter and Khokha, Mustafa K and Hildebrandt, Friedhelm} } @article {611, title = {Mutations in WDR4 as a new cause of Galloway-Mowat syndrome.}, journal = {Am J Med Genet A}, volume = {176}, year = {2018}, month = {2018 Nov}, pages = {2460-2465}, abstract = {

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.

}, issn = {1552-4833}, doi = {10.1002/ajmg.a.40489}, author = {Braun, Daniela A and Shril, Shirlee and Sinha, Aditi and Schneider, Ronen and Tan, Weizhen and Ashraf, Shazia and Hermle, Tobias and Jobst-Schwan, Tilman and Widmeier, Eugen and Majmundar, Amar J and Daga, Ankana and Warejko, Jillian K and Nakayama, Makiko and Schapiro, David and Chen, Jing and Airik, Merlin and Rao, Jia and Schmidt, Johanna Magdalena and Hoogstraten, Charlotte A and Hugo, Hannah and Meena, Jitendra and Lek, Monkol and Laricchia, Kristen M and Bagga, Arvind and Hildebrandt, Friedhelm} } @article {634, title = {Mutations in KEOPS-complex genes cause nephrotic syndrome with primary microcephaly.}, journal = {Nat Genet}, volume = {49}, year = {2017}, month = {2017 Oct}, pages = {1529-1538}, abstract = {

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

}, keywords = {Animals, Apoptosis, Carrier Proteins, Cell Movement, CRISPR-Cas Systems, Cytoskeleton, DNA Repair, Endoplasmic Reticulum Stress, Gene Knockout Techniques, Hernia, Hiatal, Humans, Intracellular Signaling Peptides and Proteins, Metalloendopeptidases, Mice, Microcephaly, Models, Molecular, Multiprotein Complexes, Mutation, Nephrosis, Nephrotic Syndrome, Podocytes, Protein Conformation, Protein-Serine-Threonine Kinases, RNA Processing, Post-Transcriptional, RNA, Transfer, Telomere Homeostasis, Zebrafish, Zebrafish Proteins}, issn = {1546-1718}, doi = {10.1038/ng.3933}, author = {Braun, Daniela A and Rao, Jia and Mollet, Geraldine and Schapiro, David and Daugeron, Marie-Claire and Tan, Weizhen and Gribouval, Olivier and Boyer, Olivia and Revy, Patrick and Jobst-Schwan, Tilman and Schmidt, Johanna Magdalena and Lawson, Jennifer A and Schanze, Denny and Ashraf, Shazia and Ullmann, Jeremy F P and Hoogstraten, Charlotte A and Boddaert, Nathalie and Collinet, Bruno and Martin, Ga{\"e}lle and Liger, Dominique and Lovric, Svjetlana and Furlano, Monica and Guerrera, I Chiara and Sanchez-Ferras, Oraly and Hu, Jennifer F and Boschat, Anne-Claire and Sanquer, Sylvia and Menten, Bj{\"o}rn and Vergult, Sarah and De Rocker, Nina and Airik, Merlin and Hermle, Tobias and Shril, Shirlee and Widmeier, Eugen and Gee, Heon Yung and Choi, Won-Il and Sadowski, Carolin E and Pabst, Werner L and Warejko, Jillian K and Daga, Ankana and Basta, Tamara and Matejas, Verena and Scharmann, Karin and Kienast, Sandra D and Behnam, Babak and Beeson, Brendan and Begtrup, Amber and Bruce, Malcolm and Ch{\textquoteright}ng, Gaik-Siew and Lin, Shuan-Pei and Chang, Jui-Hsing and Chen, Chao-Huei and Cho, Megan T and Gaffney, Patrick M and Gipson, Patrick E and Hsu, Chyong-Hsin and Kari, Jameela A and Ke, Yu-Yuan and Kiraly-Borri, Cathy and Lai, Wai-Ming and Lemyre, Emmanuelle and Littlejohn, Rebecca Okashah and Masri, Amira and Moghtaderi, Mastaneh and Nakamura, Kazuyuki and Ozaltin, Fatih and Praet, Marleen and Prasad, Chitra and Prytula, Agnieszka and Roeder, Elizabeth R and Rump, Patrick and Schnur, Rhonda E and Shiihara, Takashi and Sinha, Manish D and Soliman, Neveen A and Soulami, Kenza and Sweetser, David A and Tsai, Wen-Hui and Tsai, Jeng-Daw and Topaloglu, Rezan and Vester, Udo and Viskochil, David H and Vatanavicharn, Nithiwat and Waxler, Jessica L and Wierenga, Klaas J and Wolf, Matthias T F and Wong, Sik-Nin and Leidel, Sebastian A and Truglio, Gessica and Dedon, Peter C and Poduri, Annapurna and Mane, Shrikant and Lifton, Richard P and Bouchard, Maxime and Kannu, Peter and Chitayat, David and Magen, Daniella and Callewaert, Bert and van Tilbeurgh, Herman and Zenker, Martin and Antignac, Corinne and Hildebrandt, Friedhelm} }