We confirmed the drastic reduction of function for p. Arg82Trp mutated Kir2.1 channel and described the new loss of function p. Pro186Gln variant in KCNJ2. These two cases add further evidence that patients with KCNJ2 pathogenic variants can present with cardiac arrhythmias that can phenocopy CPVT. The gene discussed is KCNJ2; the disease is cardiac rhythm disease.