Furthermore, mutations in the KCNJ2 gene (encoding inward-rectifier potassium channel Kir2.1), which have been linked to Andersen-Tawil syndrome (ATS), could also result in a PP phenotype, although typically accompanied by ventricular arrhythmias and dysmorphism (10). The gene discussed is KCNJ2; the disease is Andersen-Tawil syndrome.