Homozygous SCN5A mutation in Brugada syndrome with monomorphic ventricular tachycardia and structural heart abnormalities

Aims To describe a patient showing monomorphic ventricuiar tachycardia, ECG aspect of Brugada syndrome, and structural heart abnormalities due to a homozygous missense mutation in SCN5A.Methods and results Thirteen subjects (six mates, seven females, mean age 46 +/- 22 years) belonging to the same family underwent physical examination, basal biochemical marker detection, 12-Lead ECG, Hotter ECG, signat-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 asymptornatic. 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 ventricutar arrhythmias and right structural abnormalities.