A recent study of 326 RyR2 mutations including control (non-pathogenic) and CPVT-associated groups found that many of the mutations were located in four CPVT hot spot regions: 10.7% in region I (residues 77–466); 14.7% in region II (2246–2534); 21.5% in region III (3778–4201) and 21.2% in region IV (4497–4949), while 31.9% were situated outside hotspot regions (Olubando et al., 2020). The gene discussed is RYR2; the disease is catecholaminergic polymorphic ventricular tachycardia.