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