Genetic screening revealed heterozygous variant c.635G>A (p.Arg218Gln) in the KCNJ2 gene, a known cause of Andersen-Tawil syndrome, and additional rare variant p.Thr983Ile in the KCNH2 gene. This evidence concerns the gene KCNH2 and Cardiodysrhythmic potassium-sensitive periodic paralysis.