AIMS: To describe a patient showing monomorphic ventricular tachycardia, ECG 
aspect of Brugada syndrome, and structural heart abnormalities due to a 
homozygous missense mutation in SCN5A.
METHODS AND RESULTS: Thirteen subjects (six males, seven females, mean age 46 
+/- 22 years) belonging to the same family underwent physical examination, basal 
biochemical marker detection, 12-lead ECG, Holter ECG, signal-averaged ECG, 
echocardiogram and genetic analysis. The proband underwent a stress test 
together with left and right ventricular angiography and electrophysiological 
study. Three subjects (the proband, his mother, and one brother) showed on ECG 
an ST-segment elevation in the right precordial leads with coved type aspect. 
Moreover, the proband presented a sustained monomorphic ventricular tachycardia 
(left bundle branch block aspect with superior axis), whereas all other family 
members were asymptomatic. Imaging techniques documented right ventricular 
structural abnormalities only in the proband. Mutation screening in SCN5A gene 
was performed in the proband and in available family members. The proband 
carries a novel SCN5A mutation, R814Q, in homozygous, whereas the parents and 
four siblings were heterozygous carriers of the same mutation.
CONCLUSION: This study provides the first evidence of a homozygous missense 
mutation in SCN5A associated with atypical ventricular arrhythmias and right 
structural abnormalities.