This ECG feature is found in patients with low K+ or in genetic conditions with loss of Kir2.1 function, such as Andersen-Tawil Syndrome (Tristani-Firouzi et al., 2002), thus, suggesting that LQT9 associated CAV3 mutations could possibly affect the function of Kir2.1. Here, KCNJ2 is linked to Andersen-Tawil syndrome.