@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 {19, title = {Whole-exome sequencing in the molecular diagnosis of individuals with congenital anomalies of the kidney and urinary tract and identification of a new causative gene.}, journal = {Genet Med}, volume = {19}, year = {2017}, month = {2017 Apr}, pages = {412-420}, abstract = {

PURPOSE: To investigate the utility of whole-exome sequencing (WES) to define a molecular diagnosis for patients clinically diagnosed with congenital anomalies of kidney and urinary tract (CAKUT).

METHODS: WES was performed in 62 families with CAKUT. WES data were analyzed for single-nucleotide variants (SNVs) in 35 known CAKUT genes, putatively deleterious sequence changes in new candidate genes, and potentially disease-associated copy-number variants (CNVs).

RESULTS: In approximately 5\% of families, pathogenic SNVs were identified in PAX2, HNF1B, and EYA1. Observed phenotypes in these families expand the current understanding about the role of these genes in CAKUT. Four pathogenic CNVs were also identified using two CNV detection tools. In addition, we found one deleterious de novo SNV in FOXP1 among the 62 families with CAKUT. The clinical database of the Baylor Miraca Genetics laboratory was queried and seven additional unrelated individuals with novel de novo SNVs in FOXP1 were identified. Six of these eight individuals with FOXP1 SNVs have syndromic urinary tract defects, implicating this gene in urinary tract development.

CONCLUSION: We conclude that WES can be used to identify molecular etiology (SNVs, CNVs) in a subset of individuals with CAKUT. WES can also help identify novel CAKUT genes.Genet Med 19 4, 412-420.

}, keywords = {Adolescent, Child, Child, Preschool, DNA Copy Number Variations, Exome Sequencing, Female, Forkhead Transcription Factors, Genetic Predisposition to Disease, Hepatocyte Nuclear Factor 1-beta, Humans, Infant, Intracellular Signaling Peptides and Proteins, Male, Nuclear Proteins, PAX2 Transcription Factor, Pedigree, Polymorphism, Single Nucleotide, Protein Tyrosine Phosphatases, Repressor Proteins, Urogenital Abnormalities, Vesico-Ureteral Reflux, Young Adult}, issn = {1530-0366}, doi = {10.1038/gim.2016.131}, author = {Bekheirnia, Mir Reza and Bekheirnia, Nasim and Bainbridge, Matthew N and Gu, Shen and Coban Akdemir, Zeynep Hande and Gambin, Tomek and Janzen, Nicolette K and Jhangiani, Shalini N and Muzny, Donna M and Michael, Mini and Brewer, Eileen D and Elenberg, Ewa and Kale, Arundhati S and Riley, Alyssa A and Swartz, Sarah J and Scott, Daryl A and Yang, Yaping and Srivaths, Poyyapakkam R and Wenderfer, Scott E and Bodurtha, Joann and Applegate, Carolyn D and Velinov, Milen and Myers, Angela and Borovik, Lior and Craigen, William J and Hanchard, Neil A and Rosenfeld, Jill A and Lewis, Richard Alan and Gonzales, Edmond T and Gibbs, Richard A and Belmont, John W and Roth, David R and Eng, Christine and Braun, Michael C and Lupski, James R and Lamb, Dolores J} }