Of particular note, we previously showed that genetic ablation of Girk4 prevents SND and associated arrhythmias in mice expressing dominant negative HCN4 channels with silenced channel conductance45, suggesting that inhibition of IKACh could be an effective strategy also in severe forms of primary SND due to HCN4 loss-of-function. The gene discussed is KCNJ5; the disease is cardiac arrhythmia.