The infero-apical left ventricular aneurysm and long QT syndrome caused by mutation delKKP 1504-1506 in SCN5A gene

Long QT syndrome (LQTS) is considered a primary cardiac ion channelopathy. Several studies have shown that myocardial functional alterations may occur in patients with LQTS type 3 (LQT3). However, it is currently unclear whether there is a specific relationship between phenotype and genotype. The aim of this study is to provide additional information on the phenotype and genotype of LQT3 caused by a novel delKKP 1504-1506 mutation in a Chinese family.

The family came to our attention because of a sustained corrected QT interval (QTc) prolongation in a 14-year-old girl who had experienced a loss of consciousness with Mobitz type II atrioventricular block one year earlier. Three family members carrying the delKKP 1504-1506 mutation demonstrated a combination of infero-apical left ventricular aneurysms and prolonged QTc, and two members showed J-waves in the right precordial lead V2.

This case suggests that the delKKP 1504-1506 mutation in SCN5A may not only lead to impaired impulse propagation in the conduction system and a prolonged QTc, but may also be associated with infero-apical ventricular aneurysms and J-wave syndromes, possibly corresponding to regional myocardial fibrosis.