BACKGROUND: Familial dilated cardiomyopathy is a highly heterogeneous genetic 
disease. Thus, identification of disease-causing mutations is a challenging and 
time-consuming task. Genotype-phenotype associations may alleviate 
identification of the underlying mutation.
OBJECTIVE: The purpose of this study was to investigate cardiac phenotypes 
within a family harboring a familial dilated cardiomyopathy-related mutation in 
the gene encoding phospholamban.
METHODS: Complete genetic and clinical analyses were performed in a family with 
familial dilated cardiomyopathy due to the PLN-R14Del mutation. Family relatives 
were studied by ECG, Holter ECG, echocardiography, ECG body surface potential 
mapping, and cardiac magnetic resonance imaging.
RESULTS: A candidate gene approach resulted in identification of a heterozygous 
deletion of arginine 14 in the gene encoding phospholamban (PLN-R14Del) 
segregating with dilated cardiomyopathy in the family pedigree. Mutation 
carriers suffered from familial dilated cardiomyopathy associated with cardiac 
death between the ages of 26 and 50 years. Interestingly, all adult mutation 
carriers revealed strikingly attenuated R amplitudes on standard ECG, regardless 
of the absence or presence of echocardiographic abnormalities. 
Gadolinium-enhanced cardiac magnetic resonance imaging showed late enhancement 
in PLN-R14Del carriers with preserved ejection fraction. Late enhancement was 
regionally related to areas of most pronounced R-amplitude attenuation as 
assessed by body surface potential mapping.
CONCLUSION: Attenuated R amplitudes were identified as an early ECG phenotype in 
a family with familial dilated cardiomyopathy due to the PLN-R14Del mutation. 
All adults harboring PLN-R14Del had attenuated R waves irrespective of 
echocardiographic abnormalities. The study findings suggest a mutation-related 
remodeling process preceding ventricular dysfunction.