@article {545, title = {A homozygous missense variant in VWA2, encoding an interactor of the Fraser-complex, in a patient with vesicoureteral reflux.}, journal = {PLoS One}, volume = {13}, year = {2018}, month = {2018}, pages = {e0191224}, abstract = {

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.

}, keywords = {Amino Acid Sequence, Amino Acid Substitution, Animals, Animals, Newborn, Biomarkers, Tumor, Child, Consanguinity, Conserved Sequence, Exons, Extracellular Matrix Proteins, Fraser Syndrome, Gene Expression Regulation, Developmental, Homozygote, Humans, Male, Mice, Models, Animal, Models, Molecular, Mutation, Missense, Pedigree, Sequence Homology, Amino Acid, Urogenital Abnormalities, Urogenital System, Vesico-Ureteral Reflux}, issn = {1932-6203}, doi = {10.1371/journal.pone.0191224}, author = {van der Ven, Amelie T and Kobbe, Birgit and Kohl, Stefan and Shril, Shirlee and Pogoda, Hans-Martin and Imhof, Thomas and Ityel, Hadas and Vivante, Asaf and Chen, Jing and Hwang, Daw-Yang and Connaughton, Dervla M and Mann, Nina and Widmeier, Eugen and Taglienti, Mary and Schmidt, Johanna Magdalena and Nakayama, Makiko and Senguttuvan, Prabha and Kumar, Selvin and Tasic, Velibor and Kehinde, Elijah O and Mane, Shrikant M and Lifton, Richard P and Soliman, Neveen and Lu, Weining and Bauer, Stuart B and Hammerschmidt, Matthias and Wagener, Raimund and Hildebrandt, Friedhelm} } @article {350, title = {Genetic Drivers of Kidney Defects in the DiGeorge Syndrome.}, journal = {N Engl J Med}, volume = {376}, year = {2017}, month = {2017 02 23}, pages = {742-754}, abstract = {

BACKGROUND: The DiGeorge syndrome, the most common of the microdeletion syndromes, affects multiple organs, including the heart, the nervous system, and the kidney. It is caused by deletions on chromosome 22q11.2; the genetic driver of the kidney defects is unknown.

METHODS: We conducted a genomewide search for structural variants in two cohorts: 2080 patients with congenital kidney and urinary tract anomalies and 22,094 controls. We performed exome and targeted resequencing in samples obtained from 586 additional patients with congenital kidney anomalies. We also carried out functional studies using zebrafish and mice.

RESULTS: We identified heterozygous deletions of 22q11.2 in 1.1\% of the patients with congenital kidney anomalies and in 0.01\% of population controls (odds ratio, 81.5; P=4.5{\texttimes}10). We localized the main drivers of renal disease in the DiGeorge syndrome to a 370-kb region containing nine genes. In zebrafish embryos, an induced loss of function in snap29, aifm3, and crkl resulted in renal defects; the loss of crkl alone was sufficient to induce defects. Five of 586 patients with congenital urinary anomalies had newly identified, heterozygous protein-altering variants, including a premature termination codon, in CRKL. The inactivation of Crkl in the mouse model induced developmental defects similar to those observed in patients with congenital urinary anomalies.

CONCLUSIONS: We identified a recurrent 370-kb deletion at the 22q11.2 locus as a driver of kidney defects in the DiGeorge syndrome and in sporadic congenital kidney and urinary tract anomalies. Of the nine genes at this locus, SNAP29, AIFM3, and CRKL appear to be critical to the phenotype, with haploinsufficiency of CRKL emerging as the main genetic driver. (Funded by the National Institutes of Health and others.).

}, keywords = {Adaptor Proteins, Signal Transducing, Adolescent, Animals, Child, Chromosome Deletion, Chromosomes, Human, Pair 22, DiGeorge Syndrome, Exome, Female, Haploinsufficiency, Heterozygote, Humans, Infant, Infant, Newborn, Kidney, Male, Mice, Models, Animal, Nuclear Proteins, Sequence Analysis, DNA, Urinary Tract, Young Adult, Zebrafish}, issn = {1533-4406}, doi = {10.1056/NEJMoa1609009}, author = {Lopez-Rivera, Esther and Liu, Yangfan P and Verbitsky, Miguel and Anderson, Blair R and Capone, Valentina P and Otto, Edgar A and Yan, Zhonghai and Mitrotti, Adele and Martino, Jeremiah and Steers, Nicholas J and Fasel, David A and Vukojevic, Katarina and Deng, Rong and Racedo, Silvia E and Liu, Qingxue and Werth, Max and Westland, Rik and Vivante, Asaf and Makar, Gabriel S and Bodria, Monica and Sampson, Matthew G and Gillies, Christopher E and Vega-Warner, Virginia and Maiorana, Mariarosa and Petrey, Donald S and Honig, Barry and Lozanovski, Vladimir J and Salomon, R{\'e}mi and Heidet, Laurence and Carpentier, Wassila and Gaillard, Dominique and Carrea, Alba and Gesualdo, Loreto and Cusi, Daniele and Izzi, Claudia and Scolari, Francesco and van Wijk, Joanna A E and Arapovic, Adela and Saraga-Babic, Mirna and Saraga, Marijan and Kunac, Nenad and Samii, Ali and McDonald-McGinn, Donna M and Crowley, Terrence B and Zackai, Elaine H and Drozdz, Dorota and Miklaszewska, Monika and Tkaczyk, Marcin and Sikora, Przemyslaw and Szczepanska, Maria and Mizerska-Wasiak, Malgorzata and Krzemien, Grazyna and Szmigielska, Agnieszka and Zaniew, Marcin and Darlow, John M and Puri, Prem and Barton, David and Casolari, Emilio and Furth, Susan L and Warady, Bradley A and Gucev, Zoran and Hakonarson, Hakon and Flogelova, Hana and Tasic, Velibor and Latos-Bielenska, Anna and Materna-Kiryluk, Anna and Allegri, Landino and Wong, Craig S and Drummond, Iain A and D{\textquoteright}Agati, Vivette and Imamoto, Akira and Barasch, Jonathan M and Hildebrandt, Friedhelm and Kiryluk, Krzysztof and Lifton, Richard P and Morrow, Bernice E and Jeanpierre, Cecile and Papaioannou, Virginia E and Ghiggeri, Gian Marco and Gharavi, Ali G and Katsanis, Nicholas and Sanna-Cherchi, Simone} }