Ankyrin-B Syndrome: A Case of Sinus Node Dysfunction, Atrial Fibrillation and Prolonged QT in a Young Adult

Ankyrin-B protein is involved in regulating expression and localisation of cardiac ion channels and transporters. Mutations of the ANK2 gene in the rare condition Ankyrin-B syndrome result in loss of function of the ankyrin-B protein which in turn leads to abnormal regulation of intracellular sodium and calcium and a predisposition to cardiac arrhythmia including torsades de pointes. We describe a rare case of this condition characterised by sinus node dysfunction, atrial fibrillation and prolonged QT syndrome in a young patient with a family history of sudden death. The management of Ankyrin-B syndrome may include avoidance of QT prolonging medications, insertion of a permanent pacemaker for sinus node dysfunction, or a cardioverter defibrillator for those at high-risk of sudden death from torsades de pointes.