title: Evidence-based diagnosis of familial non-X-linked dilated cardiomyopathy. Prevalence, inheritance and characteristics.
abstract: OBJECTIVE
  To assess the prevalence of familial non-X-linked dilated cardiomyopathy, to diagnose early asymptomatic cases evaluate inheritance and characterize clinical phenotypes.
  
  
  RESULTS
  We screened 472 relatives of 104 consecutive patients diagnosed with dilated cardiomyopathy; males with X-linked dilated cardiomyopathy were excluded based on systematic immunohistochemical and molecular analysis. Relatives underwent clinical examination, electrocardiography, echocardiography and serum creatine-phosphokinase determination. Twenty-six index patients (25%) had familial disease: four youths (< or = 20 years) had rapidly progressive outcome and underwent emergency transplantation. In a sib-pair, the onset was with atrioventricular block. Inheritance was autosomal dominant in 15, undetermined in seven (four sib-pairs); mitochondrial DNA pathological mutations were found in four. The screening identified 23 newly diagnosed relatives in the familial group. Transplantation (P = 0.04) and atrial fibrillation (P = 0.04) were more frequent, and left bundle branch block (P = 0.04) less frequent in index patients with familial than in those with non-familial disease. Several non-affected relatives had instrumental abnormalities potentially useful as pre-clinical markers: their prevalence was similar in both groups.
  
  
  CONCLUSIONS
  The prevalence of familial, non X-linked dilated cardiomyopathy was 25%. The immediate benefits of screening family members of index patients was early diagnosis in unaware symptomless affected relatives.
authors.affiliation: Cardiology, IRCCS San Matteo Hospital, Pavia, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Gavazzi
authors.forename: A
authors.initials: A
authors.lastname: Repetto
authors.forename: L
authors.initials: L
authors.lastname: Scelsi
authors.forename: C
authors.initials: C
authors.lastname: Inserra
authors.forename: M L
authors.initials: ML
authors.lastname: Laudisa
authors.forename: C
authors.initials: C
authors.lastname: Campana
authors.forename: C
authors.initials: C
authors.lastname: Specchia
authors.forename: B
authors.initials: B
authors.lastname: Dal Bello
authors.forename: M
authors.initials: M
authors.lastname: Diegoli
authors.forename: L
authors.initials: L
authors.lastname: Tavazzi
authors.forename: E
authors.initials: E
authors.lastname: Arbustini
mesh_terms: D000328:Adult; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D004452:Echocardiography; D004562:Electrocardiography / Q000379:methods; D019317:Evidence-Based Medicine; D005260:Female; D005799:Genes, Dominant; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D010375:Pedigree; D015995:Prevalence; D011446:Prospective Studies; D014960:X Chromosome