Fig. 3  Results of DNA sequencing analysis of SCN5A gene, showing nucleotide and amino acid changes. DNA sequencing results of SCN5A exon 2 (A, B), exon 12 (C), exon 17 (D), exon 20 (E), and exon 28 (F). C48G-F16L (A), A1673G-H558R (C), G3048A-T1016T (D), and G3578A-R1193Q (E) are all heterozygous nucleotide changes. G87A-A29A (B) and T5457C-D1819D (F) are heterozygous or homozygous changes that are causing the synonymous nucleotide change.