[Warbreaker] Divine Breath and the Royal Locks.

We now know for sure that the Royal family of Idris has part of a Divine Breath in them, something that was passed down from a Returned ancestor. The question then is: Do they actually have a part of a Divine Breath or are the Royal Locks written in their sipiritual DNA? Either that Returned ancestor passed a part of his breath to the next generation or those kids had their sDNA altered and inherited that (similar to what we see in Scaldrial with the first generation of allomancers and their descendants. What do you guys think it is?