The fourth gene is SLC4A3, and we identified five rare missense variants associated with a definite SQTS (p.Arg370His, p.Arg600Cys, p.Arg621Trp, p.Glu852Asp and p.Arg952His) (Christiansen et al. 2023; Thorsen et al. 2017). Here, SLC4A3 is linked to Familial short QT syndrome.