Mutations in SCN5A may also lead to overlapping phenotypes (SCN5A overlap syndromes), where clinical characteristics of LQTS, BrS, and other arrhythmia syndromes, e.g., conduction disease and sinus node dysfunction, coexist in a single family or even in a single patient (Remme et al., 2008; Giudicessi et al., 2018). Here, SCN5A is linked to overlapping connective tissue disease.