Fig. 1

The molecular and clinical findings for family I (a) Pedigree of the family I; Case 1 (II-1) who is carrying homozygous c.728G > A (p.Arg243His) mutation in the KCNQ1 gene, heterozygous c.1346 T > G (p.Ile449Arg) alteration in RYR2 gene and heterozygous c.809G > A (p.Cys270Tyr) alteration in NKX2–5 gene and the carrier status of the other family members were shown in the fig. (N: Normal, +: Mutant allele, −: Normal allele) (b) DNA sequencing image for KCNQ1 mutation (c) DNA sequencing image for RYR2 variant (d) DNA sequencing image for NKX2–5 variant (e) Predicted secondary structures and 3D modelling of wild type and mutant RYR2 protein (left) and NKX2–5 protein (right) (H: Helix, E: Beta Sheet, C: Loop). For 3-state secondary structure, It is predicted that the secondary structure of RYR2 mutant type is altered when compared to wild type and the secondary structure of NKX2–5 mutant type is not altered when compared to wild type (f) Predicted secondary structures of wild type and mutant RYR2 protein (left) and NKX2–5 protein (right). The altered residues of RYR2 (p.Ile449Arg) and NKX2–5 (p.Cys270Tyr) are shown with red arrows. It is predicted that the secondary structure of RYR2 mutant type is altered when compared to wild type (shown with orange arrow) and the secondary structure of NKX2–5 mutant type is not altered when compared to wild type