The Gibbs free energy (ΔG) changes were significantly less favourable for LQTS‐associated variant D95V (−7.4 ± 0.1 kcal/mol) and D131H (−7.0 ± 0.1 kcal/mol), when compared with CaM‐WT (−7.7 ± 0.1 kcal/mol). The gene discussed is CALM2; the disease is familial long QT syndrome.