A Novel Gain-of-Function CACNA1C Variant (Gly856Asp) Associated With QT Prolongation and Sudden Death

The investigation of sudden death is challenging, but of utmost importance to guide screening in potentially at-risk relatives. We present a case of a 14-year-old boy of Central Asian ancestry with palpitations and recent sudden death of his sister. Autopsy revealed ischemic injury of uncertain etiology. Family evaluation revealed mild QT prolongation in relatives cosegregating with a novel CACNA1C variant (Gly856Asp). Functional in vitro analyses show slower inactivation kinetics (gain of function) as shown in the long QT syndrome type 8. The case highlights the importance of a holistic approach to the investigation of sudden death and screening of at-risk relatives.