Arrhythmogenic right ventricular cardiomyopathy in two pairs of monozygotic twins.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inheritant disease with an autosomal dominant mode of transmission with incomplete penetrance and variable expression. Linkage analysis in affected families succeeds in identifying 9 loci determining 9 subtypes of the disease. Genotype phenotype correlation is unclear and the influence of various environmental factors is discussed.


OBJECTIVE
Genotype phenotype correlation in 2 pairs of monozygotic twins with ARVC and the role of environmental factors are analyzed.


METHODS
Among 40 pts with ARVC and their 195 relatives there were 2 pairs of monozygotic twins: brothers, age 47 y; and sisters, age 48 y. History, ECG, Holter monitoring, 2D and Doppler Echo, and MRI were analyzed.


RESULTS
Twin brothers: ARVC was diagnosed in the proband after the episode of VT with LBBB morphology (enlarged right ventricle, focal hypokinesia of apex, MR evidence of adipose tissue in RV wall). Identical morphology of RV was seen in asymptomatic twin brother. The patient presenting arrhythmia has been rowing for 4 years. Twin sisters: diagnosis was done during family screening. Both were asymptomatic. RV morphology typical for ARVC was found discrete in one of them (bulges adipose tissue in the RV apex); the latter showed changes suggesting RV abnormality (mild segmental dilatation of infundibulum, adipose tissue in a free wall of the RV). No differences in previous viral infections and sports involvement were observed.


CONCLUSIONS
1. Clinical picture of ARVC in monozygotic twins is not identical. 2. Strenuous effort may be a factor triggering the arrhythmia in pts with ARVC.
Wlodarska
Elzbiet K
EK
Department of Congenital Heart Diseases, I Department of Coronary Arteries Disease, Institute of Cardiology, Alpejska 42, 04-628 Warsaw, Poland. wlodarsk@ikard.waw.pl
Konka
Marek
M
Zaleska
Teresa
T
Ploski
Rafal
R
Cedro
Krzysztof
K
Pucilowska
Bogna
B
Bekiesinska-Figatowska
Monika
M
Rydlewska-Sadowska
Wanda
W
Ruzyllo
Witold
W
Hoffman
Piotr
P
D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D017023:Coronary Angiography; D004200:Diseases in Twins; D015150:Echocardiography, Doppler; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D010375:Pedigree; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014430:Twins, Monozygotic; D015646:Ventriculography, First-Pass