A Novel Frameshift Mutation, KCNH2 [p.Asp896ArgfsX79], Leading to Malignant Ventricular Arrhythmia, Identified After Treatment of Gastrointestinal Bleeding

A novel frameshift mutation in the KCNH2 gene for long QT syndrome type 2 (LQTS2) was identified after torsades des pointes ventricular tachycardia in a 49-year-old patient managed with octreotide and nadolol for an acute variceal bleed. In spite of removal of offending medications, and correction of underlying electrolyte abnormalities, the patient’s QT interval remained prolonged—at 521 ms—raising the suspicion of an underlying channelopathy. Genetic studies confirmed heterozygosity for a novel frameshift mutation for the KCNH2 gene, D896Rfs X79. We explore the pathogenicity and clinical impact of this variant mutation.