KCNJ2 and Familial short QT syndrome: In the KCNJ2 gene, a total of four rare missense variants were identified in cases with definite SQTS, one in relation with isolated SQTS (p.Asp172Asn) (Du et al. 2021), two in patients with SQTS concomitant to other entities such as AF (p.Glu299Val and p.Met301Lys) (Deo et al. 2013; Hasegawa et al. 2014), or ASD (p.Lys346Thr) (Ambrosini et al. 2014).