Board Thread:General Discussion/@comment-24.157.36.219-20130614155339/@comment-24267938-20130614192319

Blood is passed down so Martin septim has dragon blood, that much we know... Dovahkiin also has dragonblood according to Paarthurnax, And accoridng to the greybeards the Dovahkiin also has a dragon soul...

Now on to the actual question... No, the dragonborn is not related to the septims therefore he/she does not haveany calim to the throne.. yet the chances of becoming the next emperor might be high... (Join Imperial Legion, kill titus be an Imperial(Race) + you're dragonborn most people would want you as the emperor :p)