title: Autosomal dominant dilated cardiomyopathy with atrioventricular block: a lamin A/C defect-related disease.
abstract: OBJECTIVE
  We investigated the prevalence of lamin A/C (LMNA) gene defects in familial and sporadic dilated cardiomyopathies (DCM) associated with atrioventricular block (AVB) or increased serum creatine-phosphokinase (sCPK), and the corresponding changes in myocardial and protein expression.
  
  
  BACKGROUND
  It has been reported that familial DCM, associated with conduction disturbances or variable myopathies, is causally linked to LMNA gene defects.
  
  
  METHODS
  The LMNA gene and myocardial ultrastructural and immunochemical changes were analyzed in 73 cases of DCM (49 pure, 15 with AVB [seven familial, eight sporadic], 9 with increased sCPK), four cases of familial AVB and 19 non-DCM heart diseases. The normal controls included eight heart donor biopsies for tissue studies and 107 subjects for LMNA gene studies.
  
  
  RESULTS
  Five novel LMNA mutations (K97E, E111X, R190W, E317K, four base pair insertion at 1,713 cDNA) were identified in five cases of familial autosomal dominant DCM with AVB (5/15: 33%). The LMNA expression of the myocyte nuclei was reduced or absent. Western blot protein analyses of three hearts with different mutations showed an additional 30-kDa band, suggesting a degrading effect of mutated on wild-type protein. Focal disruptions, bleb formation and nuclear pore clustering were documented by electron microscopy of the myocyte nuclear membranes. None of these changes and no mutations were found in the nine patients with DCM and increased sCPK or in the disease and normal controls.
  
  
  CONCLUSIONS
  The LMNA gene mutations account for 33% of the DCMs with AVB, all familial autosomal dominant. Increased sCPK in patients with DCM without AVB is not a useful predictor of LMNA mutation.
authors.affiliation: Molecular Diagnostic Division, IRCCS Policlinico San Matteo, Pavia, Italy. e.arbustini@smatteo.pv.it
authors.forename: Eloisa
authors.initials: E
authors.lastname: Arbustini
authors.forename: Andrea
authors.initials: A
authors.lastname: Pilotto
authors.forename: Alessandra
authors.initials: A
authors.lastname: Repetto
authors.forename: Maurizia
authors.initials: M
authors.lastname: Grasso
authors.forename: Andrea
authors.initials: A
authors.lastname: Negri
authors.forename: Marta
authors.initials: M
authors.lastname: Diegoli
authors.forename: Carlo
authors.initials: C
authors.lastname: Campana
authors.forename: Laura
authors.initials: L
authors.lastname: Scelsi
authors.forename: Elisa
authors.initials: E
authors.lastname: Baldini
authors.forename: Antonello
authors.initials: A
authors.lastname: Gavazzi
authors.forename: Luigi
authors.initials: L
authors.lastname: Tavazzi
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000150:complications* / Q000235:genetics*; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D003402:Creatine Kinase / Q000097:blood / Q000235:genetics; D005192:Family Health; D005260:Female; D005500:Follow-Up Studies; D005799:Genes, Dominant / Q000235:genetics*; D006327:Heart Block / Q000097:blood / Q000150:complications* / Q000235:genetics*; D006801:Humans; D034904:Lamin Type A; D034882:Lamins; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D009206:Myocardium / Q000166:cytology / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D011110:Polymorphism, Genetic / Q000235:genetics; D011237:Predictive Value of Tests; D015995:Prevalence
chemical_list: D034904:Lamin Type A; D034882:Lamins; D009687:Nuclear Proteins; D003402:Creatine Kinase