HCN4 and Sinus bradycardia: Different from the mutation of the HCN4 protein p.Gly482Arg discovered by Wacker-Gussmann et al [12], this study found that this patient had objective clinical evidence of sinus bradycardia and multivalued pulmonary valves, with a mutation of p. Cys679Tyr carrying the HCN4 protein (Figure 6).