KCNJ2 and cardiac arrhythmia: The loss-of-function mutation of potassium voltage-gated channel subfamily J member 2 (KCNJ2), the encoding gene of Kir2.1, could lead to Andersen–Tawil syndrome accompanied by periodic paralysis, cardiac arrhythmia, and dysmorphic features (Seebohm et al., 2012).