title: A novel missense mutation of Wilms' Tumor 1 causes autosomal dominant FSGS.
abstract: FSGS is a clinical disorder characterized by focal scarring of the glomerular capillary tuft, podocyte injury, and nephrotic syndrome. Although idiopathic forms of FSGS predominate, recent insights into the molecular and genetic causes of FSGS have enhanced our understanding of disease pathogenesis. Here, we report a novel missense mutation of the transcriptional regulator Wilms' Tumor 1 (WT1) as the cause of nonsyndromic, autosomal dominant FSGS in two Northern European kindreds from the United States. We performed sequential genome-wide linkage analysis and whole-exome sequencing to evaluate participants from family DUK6524. Subsequently, whole-exome sequencing and direct sequencing were performed on proband DNA from family DUK6975. We identified multiple suggestive loci on chromosomes 6, 11, and 13 in family DUK6524 and identified a segregating missense mutation (R458Q) in WT1 isoform D as the cause of FSGS in this family. The identical mutation was found in family DUK6975. The R458Q mutation was not found in 1600 control chromosomes and was predicted as damaging by in silico simulation. We depleted wt1a in zebrafish embryos and observed glomerular injury and filtration defects, both of which were rescued with wild-type but not mutant human WT1D mRNA. Finally, we explored the subcellular mechanism of the mutation in vitro. WT1(R458Q) overexpression significantly downregulated nephrin and synaptopodin expression, promoted apoptosis in HEK293 cells and impaired focal contact formation in podocytes. Taken together, these data suggest that the WT1(R458Q) mutation alters the regulation of podocyte homeostasis and causes nonsyndromic FSGS.
authors.affiliation: Division of Nephrology, Departments of Medicine, Duke Molecular Physiology Institute.
authors.forename: Gentzon
authors.initials: G
authors.lastname: Hall
authors.affiliation: Division of Nephrology, Duke Molecular Physiology Institute, Pediatrics.
authors.forename: Rasheed A
authors.initials: RA
authors.lastname: Gbadegesin
authors.affiliation: Department of Transplant, Urology and Nephrology, Beaumont Hospital, Dublin, Ireland.
authors.forename: Peter
authors.initials: P
authors.lastname: Lavin
authors.affiliation: Duke Molecular Physiology Institute.
authors.forename: Guanghong
authors.initials: G
authors.lastname: Wu
authors.affiliation: Cell Biology, Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina;
authors.forename: Yangfan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Cell Biology, Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina;
authors.forename: Edwin C
authors.initials: EC
authors.lastname: Oh
authors.affiliation: Division of Nephrology.
authors.forename: Liming
authors.initials: L
authors.lastname: Wang
authors.affiliation: Division of Nephrology, Departments of Medicine.
authors.forename: Robert F
authors.initials: RF
authors.lastname: Spurney
authors.affiliation: Division of Nephrology, Departments of Medicine.
authors.forename: Jason
authors.initials: J
authors.lastname: Eckel
authors.affiliation: Duke Molecular Physiology Institute.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lindsey
authors.affiliation: Duke Molecular Physiology Institute.
authors.forename: Alison
authors.initials: A
authors.lastname: Homstad
authors.affiliation: Division of Nephrology, Departments of Medicine, Duke Molecular Physiology Institute.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Malone
authors.affiliation: Division of Nephrology, Departments of Medicine, Duke Molecular Physiology Institute.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Phelan
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine in St. Louis, St. Louis, Missouri; and.
authors.forename: Andrey
authors.initials: A
authors.lastname: Shaw
authors.affiliation: Pathology, and.
authors.forename: David N
authors.initials: DN
authors.lastname: Howell
authors.affiliation: Department of Transplant, Urology and Nephrology, Beaumont Hospital, Dublin, Ireland.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Conlon
authors.affiliation: Departments of Medicine, Cell Biology, Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina;
authors.forename: Nicholas
authors.initials: N
authors.lastname: Katsanis
authors.affiliation: Division of Nephrology, Departments of Medicine, Duke Molecular Physiology Institute, michelle.winn@duke.edu.
authors.forename: Michelle P
authors.initials: MP
authors.lastname: Winn
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D002465:Cell Movement; D002470:Cell Survival; D059472:Exome; D005260:Female; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D008040:Genetic Linkage; D005923:Glomerulosclerosis, Focal Segmental / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D020125:Mutation, Missense; D009401:Nephrosis / Q000209:etiology / Q000378:metabolism; D050199:Podocytes / Q000502:physiology; D017422:Sequence Analysis, DNA; D025721:WT1 Proteins / Q000172:deficiency / Q000235:genetics*; D055815:Young Adult; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000172:deficiency
chemical_list: D008840:Microfilament Proteins; C503967:SYNPO protein, human; D025721:WT1 Proteins; C583751:WT1 protein, human; C000594123:Wt1a protein, zebrafish; D029961:Zebrafish Proteins
keywords: FSGS; genetic renal disease; podocyte