SCN5A and overlapping connective tissue disease: The aforementioned SCN5A overlap mutation 1795insD is prevalent in the north of the Netherlands (Fig. 1), in the eastern part the SCN5A mutation c.2582-2583delTT is highly prevalent (associated with conduction abnormalities and occasionally Brugada syndrome, Fig. 1) and in the south the SCN5A mutation c.Phe1617del, also associated with an overlap syndrome, is highly prevalent [12].