Board Thread:Naruto Discussions/@comment-30881771-20170720154837/@comment-5085906-20170722154958

Actually, there is a possibility that they aren't related at all. Unlike with Mikoto, the Nara Clan don't have a KG to pass on through generations. Their defining jutsu is a Hiden, so there wouldn't be any need for in-breeding since they have nothing important to preserve.