Journal of Rare Cardiovascular Diseases

Long QT syndrome (LQTS) may be a cause of foetal bradyarrhythmia and an important cause of death in children with arrhythmia. We present the case of a patient of Kadazan Iban descent with LQTS. He was detected prenatally to have foetal 2:1 atrioventricular (AV) block and tetralogy of Fallot. His postnatal electrocardiogram revealed a functional 2:1 AV block with QTc interval of 690 ms. Dysmorphism and cutaneous syndactyly of both hands and feet pointed to a diagnosis of classical Timothy syndrome (TS) type 1. This diagnosis was confirmed molecularly with a heterozygous mutation c.1216G>A. p. (Gly406Arg) at exon 8A in the CACNA1C gene. To the best of our knowledge, this is the first reported case of TS in a Kadazan Iban child. JRCD 2019; 4 (2): 42-46.

rare disease; bradyarrhythmia; long QT syndrome; tetralogy of Fallot; syndactyly; electrocardiography; echocardiography

Crotti L, Celano G, Dagradi F,et al. Congenital long QT syndrome. Orphanet J Rare Dis 2008; 3: 18.

Splawski I, Timothy KW, Sharpe L, et al. Ca (V)1.2 calcium channel dysfunction causes a multisystem disorder including arrhythmia and autism. Cell 2004; 119: 19–31.

Splawski I, Timothy KW, Decher N, et al. Severe arrhythmia disorder caused by cardiac L‐type calcium channel mutations. Proc Natl Acad Sci USA 2005; 102: 8089 – 8096.

Walsh MA, Turner C, Timothy KW, et al. A multicenter study of patients with Timothy syndrome. Europace 2018; 20: 377–385.

An HS, Choi EY, Kwon BS, et al. Sudden cardiac arrest during anesthesia in a 30‐month‐old boy with syndactyly: a case of genetically proven Timothy syndrome. J Korean Med Sci 2013; 28: 788–791.

Gillis J, Burashnikov E, Antzelevitch C, et al. Long QT, syndactyly, joint contractures, stroke, and novel CACNA1C mutation: expanding the spectrum of Timothy syndrome. Am J Med Genet A 2012; 158A: 182–187.

Etheridge SP, Bowles NE, Arrington CB, et al. Somatic mosaicism contributes to phenotypic variation in Timothy syndrome. Am J Med Genet A 2011; 155A: 2578–2583.

Krause U, Gravenhurst V, Kriebel T, et al. A rare association of long QT syndrome and syndactyly: Timothy Syndrome (LQTS 8). Clin Res Cardiol 2011; 100: 1123 – 1127.

Schwartz PJ, Priori SG, Cerrone M, et al. Left cardiac sympathetic denervation in the management of high‐risk patients affected by the long‐QT syndrome. Circulation 2004; 109: 1826–1833.

Horigome H, Nagashima M, Sumitomo N, et al. Clinical characteristics and genetic background of congenital long‐QT syndrome diagnosed in fetal, neonatal, and infantile life: a nationwide questionnaire survey in Japan. Circ Arrhythm Electrophysiol 2010; 3(1):10–17.