title: The role of sarcomere gene mutations in patients with idiopathic dilated cardiomyopathy.
abstract: We investigated a Danish cohort of 31 unrelated patients with idiopathic dilated cardiomyopathy (IDC), to assess the role that mutations in sarcomere protein genes play in IDC. Patients were genetically screened by capillary electrophoresis single strand conformation polymorphism and subsequently by bidirectional DNA sequencing of conformers in the coding regions of MYH7, MYBPC3, TPM1, ACTC, MYL2, MYL3, TNNT2, CSRP3 and TNNI3. Eight probands carried disease-associated genetic variants (26%). In MYH7, three novel mutations were found; in MYBPC3, one novel variant and two known mutations were found; and in TNNT2, a known mutation was found. One proband was double heterozygous. We find evidence of phenotypic plasticity: three mutations described earlier as HCM causing were found in four cases of IDC, with no history of a hypertrophic phase. Furthermore, one pedigree presented with several cases of classic DCM as well as one case with left ventricular non-compaction. Disease-causing sarcomere gene mutations were found in about one-quarter of IDC patients, and seem to play an important role in the causation of the disease. The genetics is as complex as seen in HCM. Thus, our data suggest that a genetic work-up should include screening of the most prominent sarcomere genes even in the absence of a family history of the disease.
authors.affiliation: Department of Cardiology, Rigshospitalet, University of Copenhagen, Denmark. dvega@gmx.net
authors.forename: Daniel Vega
authors.initials: DV
authors.lastname: Møller
authors.forename: Paal Skytt
authors.initials: PS
authors.lastname: Andersen
authors.forename: Paula
authors.initials: P
authors.lastname: Hedley
authors.forename: Mads Kristian
authors.initials: MK
authors.lastname: Ersbøll
authors.forename: Henning
authors.initials: H
authors.lastname: Bundgaard
authors.forename: Johanna
authors.initials: J
authors.lastname: Moolman-Smook
authors.forename: Michael
authors.initials: M
authors.lastname: Christiansen
authors.forename: Lars
authors.initials: L
authors.lastname: Køber
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D002311:Cardiomyopathy, Dilated / Q000235:genetics*; D015331:Cohort Studies; D003718:Denmark; D004452:Echocardiography / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D018807:Polymorphism, Single-Stranded Conformational; D012518:Sarcomeres / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA