A rare association with suffered cardiac arrest, long qt interval, and syndactyly: Timothy syndrome (LQT-8)

Abstract

Timothy syndrome (TS), also referred to as syndactylyassociated long QT syndrome (LQTS) or LQT8, is a multi-system disorder characterized by developmental defects causing dysmorphic facial features, congenital heart abnormalities, neurocognitive impairment, and webbing of the toes and fingers (syndactyly) (1). TS is caused by mutations of the CACNA1C gene, which encodes L-type calcium channel Ca (V) 1.2. Two types of TS have been defined according to the mutation sites: G406R in exon 8A (TS1) and G402S/G406R in exon 8 (TS2). These gain-offunction mutations result in an impaired open-state and voltagedependent inactivation of the L-type calcium channel, ultimately 672 Case Reports Anatol J Cardiol 2015; 15: 671-4 leading to a markedly prolonged myocardial action potential (delayed ventricular repolarization) (1-4).