Abstract
Andersen-Tawil syndrome (ATS) is caused by mutations in KCNJ2 (Kir2.1). It remains unclear whether dilated cardiomyopathy (DCM) is a primary feature
of ATS. We studied a proband with typical physical features of ATS plus DCM and moderate
to severe left ventricular dysfunction (left ventricular ejection fraction = 30.5%).
Genetic screening revealed a novel mutation in Kir2.1 (c.665T>C, p.L222S). Functional
studies showed that this mutation reduced ionic currents in a dominant-negative manner.
Suppression of ventricular arrhythmias with bisoprolol led to normalization of left
ventricular size and function. We conclude that DCM is likely a secondary phenotype
in ATS and is caused by high ventricular arrhythmia burden.
Résumé
Le syndrome d’Andersen-Tawil (SAT) est causé par des mutations du gène KCNJ2. On ignore toujours si la cardiomyopathie dilatée constitue une des principales caractéristiques
du SAT. Nous avons donc étudié le cas d’un proposant qui présentait des caractéristiques
physiques typiques du SAT, une cardiomyopathie dilatée ainsi qu’une dysfonction ventriculaire
gauche modérée à grave (fraction d’éjection ventriculaire gauche de 30,5 %). Le dépistage
génétique a révélé une nouvelle mutation du gène KCNJ2 (c.665T>C, p.L222S). Les études fonctionnelles ont indiqué que cette mutation réduisait
les courants ioniques de manière négative dominante. La suppression de l’arythmie
ventriculaire à l’aide de bisoprolol a permis de normaliser la taille et la fonction
du ventricule gauche. Nous avons conclu que la cardiomyopathie dilatée est vraisemblablement
un phénotype secondaire dans le SAT, associé à l’important fardeau physiologique causé
par l’arythmie ventriculaire.
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References
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Article info
Publication history
Published online: July 27, 2016
Accepted:
July 19,
2016
Received:
May 24,
2016
Footnotes
See page 1576.e18 for disclosure information.
Identification
Copyright
© 2016 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.
