Fig. 2

Pedigree of the affected family and genetic testing of SCN5A gene revealing c.5174C>T, p.P1725L variant. a Topographic schema of sodium channel type 5 α-subunit. The mutation site p.P1725L is located in the pore region of domain 4 (figure was cited from Selga et al. [10]). b Sanger’s method shows three individuals had heterogeneous c.5174C>T (CCG > CTG), p.P1725L variant, which was previously reported in a patient with long QT syndrome. c The arrow indicates the proband, and the solid left upper quarter indicates members with P1725L variant, the solid right upper quarter indicates members with VF, and the solid left lower quarter indicates members with SSS. Oblique lines indicate dead persons.