RYR2 and ataxia telangiectasia: Seven RyR2 mutations are additionally associated with atrial arrhythmic disorders that include atrial tachycardia (AT), fibrillation (AF), and standstill as well as sinus node dysfunction (SND) (Laitinen et al., 2001; Bhuiyan et al., 2007; Sumitomo et al., 2007; Beery et al., 2009; Marjamaa et al., 2009; Kazemian et al., 2011).