The diagnosis of LQT1 was performed by DNA sequence identifying an allelic missense mutation C1322T (Figure 1B), Among mammalian homologs, the species of the amino acid corresponding to P441 of human KCNQ1 subunit are conserved, but not conserved in the KCNQ family (KCNQ2-5) (Figures 1C,D and Supplementary Figure 1). This evidence concerns the gene KCNQ1 and long QT syndrome 1.