SQTS is characterized either by a QTc ≤ 340 ms or a QTc ≤ 360 ms with at least another suggestive feature among the following: a pathogenic mutation (usually a gain-of-function mutation of potassium channels genes like KCNQ1, KCNH2, KCNJ2), a family history of SQTS or juvenile SCD, or survival from cardiac arrest in the absence of structural heart disease [1,6]. The gene discussed is KCNA3; the disease is Familial short QT syndrome.