Evidence-based diagnosis of familial non-X-linked dilated cardiomyopathy. Prevalence, inheritance and characteristics.
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.
Gavazzi
A
A
Cardiology, IRCCS San Matteo Hospital, Pavia, Italy.
Repetto
A
A
Scelsi
L
L
Inserra
C
C
Laudisa
M L
ML
Campana
C
C
Specchia
C
C
Dal Bello
B
B
Diegoli
M
M
Tavazzi
L
L
Arbustini
E
E
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