Limberg et al. reported two KCNJ2 mutations (p.Asn318Cys, p. Trp322Cys) associated with an isolated cardiac phenotype and the authors proposed that the mild reduction of native Kir2.1 currents due to the mutations may lead to ATS with an isolated cardiac phenotype (Limberg et al., 2013). Here, KCNJ2 is linked to Andersen-Tawil syndrome.