title: FLNCGene Splice Mutations Cause Dilated Cardiomyopathy.
abstract: OBJECTIVE
  To identify novel dilated cardiomyopathy (DCM) causing genes, and to elucidate the pathological mechanism leading to DCM by utilizing zebrafish as a model organism.
  
  
  BACKGROUND
  DCM, a major cause of heart failure, is frequently familial and caused by a genetic defect. However, only 50% of DCM cases can be attributed to a known DCM gene variant, motivating the ongoing search for novel disease genes.
  
  
  METHODS
  We performed whole exome sequencing (WES) in two multigenerational Italian families and one US family with arrhythmogenic DCM without skeletal muscle defects, in whom prior genetic testing had been unrevealing. Pathogenic variants were sought by a combination of bioinformatic filtering and cosegregation testing among affected individuals within the families. We performed function assays and generated a zebrafish morpholino knockdown model.
  
  
  RESULTS
  A novel filamin C gene splicing variant (FLNCc.7251+1 G>A) was identified by WES in all affected family members in the two Italian families. A separate novel splicing mutation (FLNCc.5669-1delG) was identified in the US family. Western blot analysis of cardiac heart tissue from an affected individual showed decreasedFLNCprotein, supporting a haploinsufficiency model of pathogenesis. To further analyze this model, a morpholino knockdown of the ortholog filamin Cb in zebrafish was created which resulted in abnormal cardiac function and ultrastructure.
  
  
  CONCLUSIONS
  Using WES, we identified two novelFLNCsplicing variants as the likely cause of DCM in three families. We provided protein expression andin vivozebrafish data supporting haploinsufficiency as the pathogenic mechanism leading to DCM.
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Rene L
authors.initials: RL
authors.lastname: Begay
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Charles A
authors.initials: CA
authors.lastname: Tharp
authors.affiliation: Center for Cardiovascular Research and Department of Biology, Colorado State University, Fort Collins, CO.
authors.forename: August
authors.initials: A
authors.lastname: Martin
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Sharon L
authors.initials: SL
authors.lastname: Graw
authors.affiliation: Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Sinagra
authors.affiliation: Department of Cardiothoracic Science, University Hospital S. Maria della Misericordia, Udine, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Miani
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Mary E
authors.initials: ME
authors.lastname: Sweet
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Dobromir B
authors.initials: DB
authors.lastname: Slavov
authors.affiliation: Center for Cardiovascular Research and Department of Biology, Colorado State University, Fort Collins, CO; Cardiovascular and Biofluid Mechanics Laboratory, Colorado State University, Fort Collins, CO.
authors.forename: Neil
authors.initials: N
authors.lastname: Stafford
authors.affiliation: Center for Cardiovascular Research and Department of Biology, Colorado State University, Fort Collins, CO.
authors.forename: Molly J
authors.initials: MJ
authors.lastname: Zeller
authors.affiliation: Center for Cardiovascular Research and Department of Biology, Colorado State University, Fort Collins, CO.
authors.forename: Rasha
authors.initials: R
authors.lastname: Alnefaie
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Teisha J
authors.initials: TJ
authors.lastname: Rowland
authors.affiliation: Cardiovascular Department, Ospedali Riuniti and University of Trieste, Trieste, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Brun
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, CO.
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Jones
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, CO.
authors.forename: Katherine
authors.initials: K
authors.lastname: Gowan
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Luisa
authors.initials: L
authors.lastname: Mestroni
authors.affiliation: Center for Cardiovascular Research and Department of Biology, Colorado State University, Fort Collins, CO.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Garrity
authors.affiliation: Cardiovascular Institute and Adult Medical Genetics Program, University of Colorado Denver, Aurora, CO.
authors.forename: Matthew R G
authors.initials: MR
authors.lastname: Taylor
keywords: cardiovascular genetics; dilated cardiomyopathy; filamin C; heart failure; zebrafish